View source for Medicine:Autism spectrum

{{Short description|Neurodevelopmental disorder}}
{{cs1 config|name-list-style=vanc}}{{Pp-semi-indef|small=yes}}
{{Infobox medical condition
| name          = Autism spectrum disorder
| synonyms      = {{plainlist|
* Autism spectrum condition (ASC), autism
* Formerly: Kanner syndrome/autistic disorder/childhood autism, [[Medicine:Asperger syndrome|Asperger syndrome]] (AS), [[Medicine:Childhood disintegrative disorder|childhood disintegrative disorder]] (CDD), [[Medicine:Pervasive developmental disorder not otherwise specified|pervasive developmental disorder not otherwise specified]] (PDD-NOS)
}}
| image         = Autism-stacking-cans 2nd edit.jpg
| alt           = Infant stacking cans
| caption       = Repetitively stacking or lining up objects is a common trait associated with autism.
| image2        =
| alt2          =
| caption2      =
| field         = [[Biology:Psychiatry|Psychiatry]], [[Social:Clinical psychology|clinical psychology]], [[Medicine:Pediatrics|pediatrics]], occupational medicine
| symptoms      = Difficulties in [[Social:Social relation|social interaction]], verbal and nonverbal communication, and the presence of repetitive behavior or restricted interests
| complications = [[Social:Social isolation|Social isolation]], educational and employment problems,<ref name="EPS-2022">{{cite journal |vauthors=Bonati M, Cartabia M, Clavenna A |title=Still too much delay in recognition of autism spectrum disorder |journal=Epidemiology and Psychiatric Sciences |volume=31 |issue=e1 |pages=e1 |date=January 2022 |pmid=35012703 |pmc=8786613 |doi=10.1017/S2045796021000822 |s2cid=245851335 |oclc=727338545 |publisher={{wipe|Cambridge University Press}} |lccn=2011243374 |doi-access=free}}</ref> [[Medicine:Anxiety disorder|anxiety]],<ref name="EPS-2022"/> [[Medicine:Stress|stress]],<ref name="EPS-2022"/> [[Social:Bullying|bullying]], depression,<ref name="EPS-2022"/><ref>{{cite journal |pmc=6512853 |year=2019 |last1=Pezzimenti |first1=F. |last2=Han |first2=G. T. |last3=Vasa |first3=R. A. |last4=Gotham |first4=K. |title=Depression in Youth with Autism Spectrum Disorder |journal=Child and Adolescent Psychiatric Clinics of North America |volume=28 |issue=3 |pages=397–409 |doi=10.1016/j.chc.2019.02.009 |pmid=31076116}}</ref> [[Medicine:Self-harm|self-harm]]
| onset         = Early childhood
| onset_always  = y <!-- forces display of heading "Onset" instead of "Usual onset" -->
| duration      = Lifelong
| causes        = [[Biology:Multifactorial disease|Multifactorial]], with many uncertain factors
| risks         = [[Medicine:Family history|Family history]], certain [[Medicine:Genetic disorder|genetic conditions]], having older parents, certain prescribed drugs, [[Biology:Prenatal development#Factors influencing development|perinatal]] and neonatal health issues
| diagnosis     = Based on combination of clinical observation of behavior and development and comprehensive diagnostic testing completed by a team of qualified professionals (including psychiatrists, clinical psychologists, neuropsychologists, pediatricians, and speech-language pathologists). For adults, the use of a patient's written and oral history of autistic traits becomes more important
| differential  = [[Medicine:Intellectual disability|Intellectual disability]], [[Medicine:Anxiety|anxiety]], [[Medicine:Bipolar disorder|bipolar disorder]], [[Medicine:Depression (mood)|depression]], [[Medicine:Rett syndrome|Rett syndrome]], [[Medicine:Attention deficit hyperactivity disorder|attention deficit hyperactivity disorder]], [[Medicine:Schizoid personality disorder|schizoid personality disorder]], [[Medicine:Selective mutism|selective mutism]], [[Medicine:Schizophrenia|schizophrenia]], [[Medicine:Obsessive–compulsive disorder|obsessive–compulsive disorder]], [[Medicine:Social anxiety disorder|social anxiety disorder]], [[Medicine:Late talker|Einstein syndrome]], [[Medicine:Post-traumatic stress disorder|PTSD]],<ref>{{cite web |url=https://www.spectrumnews.org/features/deep-dive/intersection-autism-trauma/#:~:text=And%20people%20with%20more%20autistic,in%20other%20forms%20of%20PTSD |title=At the intersection of autism and trauma |website=Spectrum News |date=26 September 2018 |access-date=17 November 2022 |archive-date=17 November 2022 |archive-url=https://web.archive.org/web/20221117204028/https://www.spectrumnews.org/features/deep-dive/intersection-autism-trauma/#:~:text=And%20people%20with%20more%20autistic,in%20other%20forms%20of%20PTSD |url-status=live}}</ref> learning disorders (mainly [[Medicine:Speech disorder|speech disorder]]s)
| management    = [[Philosophy:Applied behavior analysis|Applied behavior analysis]], [[Medicine:Cognitive behavioral therapy|cognitive behavioral therapy]], [[Medicine:Occupational therapy|occupational therapy]], psychotropic medication,<ref>{{cite web |url=https://www.spectrumnews.org/features/deep-dive/autisms-drug-problem/ |title=Autism's drug problem |website=Spectrum News |date=19 April 2017 |access-date=11 November 2022 |archive-date=11 November 2022 |archive-url=https://web.archive.org/web/20221111232934/https://www.spectrumnews.org/features/deep-dive/autisms-drug-problem/ |url-status=live}}</ref> [[Social:Speech–language pathology|speech–language pathology]]
| frequency     = *1 in 100 children (1%) worldwide<ref name="Autism">{{cite journal |last1=Zeidan |first1=Jinan |last2=Fombonne |first2=Eric |last3=Scorah |first3=Julie |last4=Ibrahim |first4=Alaa |last5=Durkin |first5=Maureen S. |last6=Saxena |first6=Shekhar |last7=Yusuf |first7=Afiqah |last8=Shih |first8=Andy |last9=Elsabbagh |first9=Mayada |date=2022-05-15 |title=Global prevalence of autism: A systematic review update |journal=Autism Research |volume=15 |issue=5 |pages=778–790 |doi=10.1002/aur.2696 |issn=1939-3806 |pmc=9310578 |pmid=35238171}}</ref>
}}
'''Autism''', formally called '''autism spectrum disorder''' ('''ASD''') or '''autism spectrum condition''' ('''ASC'''),<ref>{{cite web |url=https://www.england.nhs.uk/coronavirus/documents/covid-19-guide-autism-spectrum-condition-asc/ |title=COVID-19 guide – Autism Spectrum Condition (ASC) |author= |date=7 June 2020 |website=NHS England |publisher=National Health Service, United Kingdom |access-date=12 June 2023 |quote=ASC is a 'spectrum condition' meaning that, while all people with autism share certain difficulties, their condition affects them in different ways. |archive-date=12 June 2023 |archive-url=https://web.archive.org/web/20230612162411/https://www.england.nhs.uk/coronavirus/documents/covid-19-guide-autism-spectrum-condition-asc/ |url-status=live}}</ref> is a [[Medicine:Neurodevelopmental disorder|neurodevelopmental disorder]] marked by impaired social [[Medicine:Communication disorder|communication]] and restricted and repetitive patterns of behavior. Other common signs include difficulty with [[Social:Interpersonal relationship|social interaction]], verbal and nonverbal communication, along with [[Medicine:Perseveration|perseverative interests]], [[Biology:Stereotypy|stereotypic body movements]], rigid routines, and [[Philosophy:Sensory processing sensitivity|hyper- or hyporeactivity to sensory input]]. Autism is clinically regarded as a ''spectrum disorder'', meaning that it can manifest very differently in each person. For example, some are [[Medicine:Nonverbal autism|nonspeaking]], while others have proficient [[Social:Spoken language|spoken language]]. Because of this, there is wide variation in the support needs of people across the autism spectrum.

<!-- Causes and prevalence -->There are many theories about [[Social:Causes of autism|what causes autism]]; it is [[Medicine:Heritability of autism|highly heritable and mainly genetic]], but many genes are involved, and environmental factors may also be relevant.<ref>{{cite journal |vauthors=Mandy W, Lai MC |title=Annual Research Review: The role of the environment in the developmental psychopathology of autism spectrum condition |journal=Journal of Child Psychology and Psychiatry, and Allied Disciplines |issn=0021-9630 |eissn=1469-7610 |oclc=01307942 |volume=57 |issue=3 |pages=271–292 |date=March 2016 |pmid=26782158 |doi=10.1111/jcpp.12501 |doi-access=free}}</ref> The syndrome frequently co-occurs with other conditions, including [[Medicine:Attention deficit hyperactivity disorder|attention deficit hyperactivity disorder]], [[Medicine:Epilepsy|epilepsy]], and [[Medicine:Intellectual disability|intellectual disability]]. Disagreements persist about what should be included as part of the diagnosis, whether there are meaningful subtypes of autism,<ref name="The Diagnosis of Autism: From Kanne">{{cite journal |vauthors=Rosen NE, Lord C, Volkmar FR |date=December 2021 |title=The Diagnosis of Autism: From Kanner to DSM-III to DSM-5 and Beyond |journal=Journal of Autism and Developmental Disorders |volume=51 |issue=12 |pages=4253–4270 |doi=10.1007/s10803-021-04904-1 |pmc=8531066 |pmid=33624215}}</ref> and the significance of autism-associated traits in the wider population.<ref>{{cite book |vauthors=Losh M, Adolphs R, Piven J |title=Autism Spectrum Disorders |chapter=The Broad Autism Phenotype |year=2011 |pages=457–476 |publisher=[[Organization:Oxford University Press|Oxford University Press]] |isbn=978-0-19-996521-2 |language=en-US |doi=10.1093/med/9780195371826.003.0031}}</ref><ref>{{cite journal |vauthors=Chapman R, Veit W |title=Correction to: The essence of autism: fact or artefact? |journal=Molecular Psychiatry |volume=26 |issue=11 |page=7069 |date=November 2021 |pmid=34697454 |doi=10.1038/s41380-021-01057-6 |s2cid=239771302 |doi-access=free}}</ref> The combination of broader criteria, increased awareness, and potentially increasing actual prevalence, has led to a trend of steadily increasing ''estimates'' of [[Medicine:Epidemiology of autism|autism prevalence]],<ref>{{cite journal |vauthors=Wazana A, Bresnahan M, Kline J |title=The autism epidemic: fact or artifact? |language=English |journal=Journal of the American Academy of Child and Adolescent Psychiatry |volume=46 |issue=6 |pages=721–730 |date=June 2007 |pmid=17513984 |doi=10.1097/chi.0b013e31804a7f3b}}</ref> perpetuating the disproven myth that it is [[Unsolved:Vaccines and autism|caused by vaccines]].<ref name=":9">{{cite journal |vauthors=DeStefano F, Shimabukuro TT |title=The MMR Vaccine and Autism |journal=Annual Review of Virology |volume=6 |issue=1 |pages=585–600 |date=September 2019 |pmid=30986133 |pmc=6768751 |doi=10.1146/annurev-virology-092818-015515}}</ref> 

<!-- The neurodiversity perspective -->[[Biology:Psychiatry|Psychiatry]] has traditionally classified autism as a [[Medicine:Mental disorder|mental disorder]], but the autism rights movement and an increasing number of researchers see autism as part of [[Biology:Neurodiversity|neurodiversity]], the natural diversity in human thinking and experience, with strengths, differences, and weaknesses.<ref name="Pellicano">{{cite journal |vauthors=Pellicano E, den Houting J |date=April 2022 |title=Annual Research Review: Shifting from 'normal science' to neurodiversity in autism science |journal=Journal of Child Psychology and Psychiatry, and Allied Disciplines |volume=63 |issue=4 |pages=381–396 |doi=10.1111/jcpp.13534 |issn=0021-9630 |eissn=1469-7610 |oclc=01307942 |pmc=9298391 |pmid=34730840 |s2cid=241118562}}</ref> From this point of view, autistic people often still have a [[Social:Disability|disability]], but need to be accommodated rather than cured.<ref>{{cite web |title=Welcome to the Autistic Community |url=https://autismacceptance.com/ |access-date=2023-02-21 |publisher=Autistic Self Advocacy Network |language=en-US |archive-date=21 February 2023 |archive-url=https://web.archive.org/web/20230221025253/https://autismacceptance.com/ |url-status=live}}</ref><ref>{{cite web |date=6 June 2019 |title=Clearing Up Some Misconceptions about Neurodiversity |url=https://blogs.scientificamerican.com/observations/clearing-up-some-misconceptions-about-neurodiversity/ |archive-url=https://web.archive.org/web/20190629190546/https://blogs.scientificamerican.com/observations/clearing-up-some-misconceptions-about-neurodiversity/ |archive-date=29 June 2019 |access-date=17 March 2022 |website=Scientific American Blog Network |publisher=Nature America, Inc. |language=en |vauthors=Bailin A}}</ref> This perspective has led to significant controversy among those who are autistic and advocates, practitioners, and charities.<ref>{{cite book |vauthors=Robison JE |date=2020 |title=Autistic Community and the Neurodiversity Movement: Stories from the Frontline |publisher=Springer |isbn=978-981-13-8437-0 |veditors=Kapp SK |place=Singapore |pages=221–232 |chapter=My Time with Autism Speaks |doi=10.1007/978-981-13-8437-0_16 |doi-access=free |s2cid=210496353}}</ref><ref>{{cite journal |last=Opar |first=Alisa |date=2019-04-24 |title=In search of truce in the autism wars |url=https://www.spectrumnews.org/features/deep-dive/search-truce-autism-wars |journal=Spectrum |publisher=Simons Foundation |doi=10.53053/VRKL4748 |s2cid=249140855 |access-date=9 July 2022 |archive-date=8 July 2022 |archive-url=https://web.archive.org/web/20220708195918/https://www.spectrumnews.org/features/deep-dive/search-truce-autism-wars/ |url-status=live |doi-access=free}}</ref> As of 2023, consensus is growing among researchers of various empirical and theoretical positions that the established ASD criteria are ineffective to describe autism as a unitary biological entity, and that alternative research approaches should be encouraged.<ref name="Waterhouse2023" />

<!-- Therapies and pharmacological interventions -->There is no cure for autism. Although [[Medicine:Autism therapies|early intervention services]] based on [[Philosophy:Applied behavior analysis|applied behavior analysis]] (ABA) can help children gain self-care, social, and language skills,<ref name="Smith"/><ref name="Cochrane" /><ref name=AutismResearch2023Study/><ref name=psychiatric_investigation>{{cite journal |last1=Yu |first1=Qian |last2=Li |first2=Enyao |last3=Li |first3=Liguo |last4=Liang |first4=Weiyi |date=May 2020 |title=Efficacy of Interventions Based on Applied Behavior Analysis for Autism Spectrum Disorder: A Meta-Analysis |journal=Psychiatry Investigation |language=en |volume=17 |issue=5 |pages=432–443 |doi=10.30773/pi.2019.0229 |pmid=32375461 |pmc=7265021}}</ref> independent living is unlikely in more severe forms of the condition. Speech and [[Medicine:Occupational therapy|occupational therapy]], as well as implementing alternative modes of communication, are effective [[Chemistry:Adjuvant therapy|adjunctive therapies]], but some in the autism rights movement consider ABA therapy unethical and unhelpful.<ref>{{cite journal |vauthors=Kirkham P |date=2017-04-01 |title='The line between intervention and abuse' – autism and applied behaviour analysis |journal=History of the Human Sciences |language=en |volume=30 |issue=2 |pages=107–126 |doi=10.1177/0952695117702571 |issn=0952-6951 |s2cid=152017417}}</ref> Pharmacological treatments also may be useful; the [[Chemistry:Atypical antipsychotic|atypical antipsychotic]]s [[Chemistry:Risperidone|risperidone]] and [[Chemistry:Aripiprazole|aripiprazole]] are empirically validated for alleviating co-morbid irritability.<ref>{{cite web |title=Medication Treatment for Autism |url=https://www.nichd.nih.gov/health/topics/autism/conditioninfo/treatments/medication-treatment |access-date=2023-02-21 |website=www.nichd.nih.gov/ |date=19 April 2021 |language=en |archive-date=7 February 2023 |archive-url=https://web.archive.org/web/20230207142659/https://www.nichd.nih.gov/health/topics/autism/conditioninfo/treatments/medication-treatment |url-status=live}}</ref>

== Classification ==
=== Spectrum model ===
Before the DSM-5 (2013) and [[Medicine:ICD-11|ICD-11]] (2022) diagnostic manuals were adopted, what is now called ASD was found under the diagnostic category [[Medicine:Pervasive developmental disorder|pervasive developmental disorder]]. The previous system relied on a set of closely related and overlapping diagnoses such as [[Medicine:Asperger syndrome|Asperger syndrome]] and [[Medicine:Classic autism|Kanner syndrome]]. This created unclear boundaries between the terms, so for the DSM-5 and ICD-11, a spectrum approach was taken. The new system is also more restrictive, meaning fewer people now qualify for diagnosis.<ref>{{cite web |url=https://www.parents.com/health/autism/what-happened-to-aspergers/ |title=Why Asperger's Syndrome is no longer listed in the DSM |website=parents.com |access-date=26 December 2022 |archive-date=26 December 2022 |archive-url=https://web.archive.org/web/20221226202800/https://www.parents.com/health/autism/what-happened-to-aspergers}}</ref>

The DSM-5 and ICD-11 use different categorization tools to define this spectrum. DSM-5 uses a "level" system, which ranks how in need of support the patient is,<ref>{{cite web |url=https://www.cdc.gov/ncbddd/autism/hcp-dsm.html |title=Diagnostic Criteria &#124; Autism Spectrum Disorder (ASD) &#124; NCBDDD &#124; CDC |date=2 November 2022 |access-date=21 February 2021 |archive-date=16 August 2019 |archive-url=https://web.archive.org/web/20190816080840/https://www.cdc.gov/ncbddd/autism/hcp-dsm.html |url-status=live}}</ref> while the ICD-11 system has two axes, intellectual impairment and language impairment,<ref>{{cite web |url=https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/437815624 |title=ICD-11 for Mortality and Morbidity Statistics |access-date=6 April 2022 |archive-date=1 August 2018 |archive-url=https://archive.today/20180801205234/https://icd.who.int/browse11/l-m/en%23/http://id.who.int/icd/entity/294762853#/http://id.who.int/icd/entity/437815624 |url-status=live}}</ref> as these are seen as the most crucial factors.

Autism is currently defined as a highly variable [[Medicine:Neurodevelopmental disorder|neurodevelopmental disorder]]<ref name="Geschwind">{{cite journal |vauthors=Geschwind DH |title=Autism: many genes, common pathways? |journal=Cell |volume=135 |issue=3 |pages=391–395 |date=October 2008 |pmid=18984147 |pmc=2756410 |doi=10.1016/j.cell.2008.10.016}}</ref> that is generally thought to cover a broad and deep spectrum, manifesting very differently from one person to another. Some have high support needs, may be [[Medicine:Nonverbal autism|non-speaking]], and experience developmental delays; this is more likely with other co-existing diagnoses. Others have relatively low support needs; they may have more typical speech-language and intellectual skills but atypical social/conversation skills, narrowly focused interests, and wordy, pedantic communication.<ref>{{cite journal |vauthors=Happé F |year=1999 |title=Understanding assets and deficits in autism: why success is more interesting than failure |url=http://www.thepsychologist.org.uk/archive/archive_home.cfm/volumeID_12-editionID_46-ArticleID_133-getfile_getPDF/thepsychologist/psy_11_99_p540-547_happe.pdf |journal=Psychologist |volume=12 |issue=11 |pages=540–547 |archive-url=https://web.archive.org/web/20120517162434/http://www.thepsychologist.org.uk/archive/archive_home.cfm/volumeID_12-editionID_46-ArticleID_133-getfile_getPDF/thepsychologist/psy_11_99_p540-547_happe.pdf |archive-date=17 May 2012}}</ref> They may still require significant support in some areas of their lives. The spectrum model should not be understood as a continuum running from mild to severe, but instead means that autism can present very differently in each person.<ref>{{cite journal |vauthors=Wing L |title=The autistic spectrum |language=English |journal=The Lancet |volume=350 |issue=9093 |pages=1761–1766 |date=December 1997 |pmid=9413479 |doi=10.1016/S0140-6736(97)09218-0 |s2cid=7165992}}</ref> How a person presents can depend on context, and may vary over time.<ref>{{cite web |title=Diagnostic criteria – a guide for all audiences |url=https://www.autism.org.uk/advice-and-guidance/topics/diagnosis/diagnostic-criteria/all-audiences |access-date=2022-12-01 |website=National Autistic Society |language=en |archive-date=21 September 2023 |archive-url=https://web.archive.org/web/20230921010739/https://www.autism.org.uk/advice-and-guidance/topics/diagnosis/diagnostic-criteria/all-audiences |url-status=live}}</ref>

While the DSM and ICD greatly influence each other, there are also differences. For example, [[Medicine:Rett syndrome|Rett syndrome]] was included in ASD in the DSM-5, but in the ICD-11 it was excluded and placed in the chapter on Developmental Anomalies. The ICD and the DSM change over time, and there has been collaborative work toward a convergence of the two since 1980 (when DSM-III was published and ICD-9 was current), including more rigorous biological assessment—in place of historical experience—and a simplification of the classification system.<ref name="Pickett & Anderson" /><ref name="APA">{{cite news |date=2009 |title=ICD vs. DSM |volume=40 |page=63 |newspaper=APA Monitor |publisher=[[Organization:American Psychological Association|American Psychological Association]] |number=9 |url=https://www.apa.org/monitor/2009/10/icd-dsm |access-date=22 October 2021 |archive-date=29 December 2022 |archive-url=https://web.archive.org/web/20221229093045/https://www.apa.org/monitor/2009/10/icd-dsm |url-status=live}}</ref><ref name="Mezzich">{{cite journal |vauthors=Mezzich JE |date=2002 |title=International surveys on the use of ICD-10 and related diagnostic systems |journal=Psychopathology |volume=35 |issue=2–3 |pages=72–75 |doi=10.1159/000065122 |pmid=12145487 |s2cid=35857872}}</ref><ref name="Goldberg">{{cite journal |vauthors=Goldberg D |date=January 2010 |title=The classification of mental disorder: a simpler system for DSM–V and ICD–11 |journal=Advances in Psychiatric Treatment |volume=16 |pages=14–19 |doi=10.1192/apt.bp.109.007120 |doi-access=free |number=1}}</ref>

As of 2023, empirical and theoretical research is leading to a growing consensus among researchers that the established ASD criteria are ineffective to describe autism as a unitary biological entity, and that alternative research approaches must be encouraged, such as going back to autism prototypes, exploring new causal models of autism, or developing transdiagnostic [[Biology:Endophenotype|endophenotype]]s.<ref name="Waterhouse2023">{{cite journal |last1=Waterhouse |first1=Lynn |last2=Mottron |first2=Laurent |title=Editorial: Is autism a biological entity? |journal=Frontiers in Psychiatry |volume=14 |date=2 May 2023 |doi=10.3389/fpsyt.2023.1180981 |pmid=37200904 |pmc=10185896 |doi-access=free}}</ref> Proposed alternatives to the current disorder-focused spectrum model deconstruct autism into at least two separate phenomena: (1) a non-pathological spectrum of behavioral traits in the population,<ref name=Sarovic2021>{{cite journal |last1=Sarovic |first1=Darko |date=16 November 2021 |title=A Unifying Theory for Autism: The Pathogenetic Triad as a Theoretical Framework |journal=Frontiers in Psychiatry |volume=12 |doi=10.3389/fpsyt.2021.767075 |pmid=34867553 |pmc=8637925 |doi-access=free}}</ref><ref name=Chawner2022>{{cite journal |last1=Chawner |first1=Samuel |date=2 September 2022 |title=Autism: A model of neurodevelopmental diversity informed by genomics |journal=Frontiers in Psychiatry |volume=13 |doi=10.3389/fpsyt.2022.981691 |pmid=36117659 |pmc=9479184 |doi-access=free}}</ref> and (2) the neuropathological burden of rare genetic mutations and environmental risk factors potentially leading to neurodevelopmental and psychological disorders,<ref name=Sarovic2021 /><ref name=Chawner2022 /> (3) governed by an individual's cognitive ability to compensate.<ref name=Sarovic2021 />

=== ICD ===
The [[Organization:World Health Organization|World Health Organization]]'s [[International Classification of Diseases]] (11th Revision), [[Medicine:ICD-11|ICD-11]], was released in June 2018 and came into full effect as of January 2022.<ref name="WHO 2021">{{cite web |url=https://www.who.int/news/item/18-06-2018-who-releases-new-international-classification-of-diseases-(icd-11) |title=WHO releases new International Classification of Diseases (ICD 11) |website=World Health Organisation |type=Press Release |access-date=29 October 2021 |archive-date=25 December 2021 |archive-url=https://web.archive.org/web/20211225230744/https://www.who.int/news/item/18-06-2018-who-releases-new-international-classification-of-diseases-(icd-11) |url-status=live}}</ref><ref name="Pickett & Anderson">{{cite report |vauthors=Pickett D, Anderson RN |title=Status on ICD-11: The WHO Launch |url=https://ncvhs.hhs.gov/wp-content/uploads/2018/08/ICD-11_WHO-v_7-17-2018.pdf |date=18 July 2018 |publisher=CDC/NCHS |access-date=22 October 2021 |archive-date=15 March 2023 |archive-url=https://web.archive.org/web/20230315022814/https://ncvhs.hhs.gov/wp-content/uploads/2018/08/ICD-11_WHO-v_7-17-2018.pdf |url-status=live}}</ref> It describes ASD as follows:{{sfn|ICD-11}}

{{Blockquote|text=Autism spectrum disorder is characterised by persistent deficits in the ability to initiate and to sustain reciprocal social interaction and social communication, and by a range of restricted, repetitive, and inflexible patterns of behaviour, interests or activities that are clearly atypical or excessive for the individual's age and sociocultural context. The onset of the disorder occurs during the developmental period, typically in early childhood, but symptoms may not become fully manifest until later, when social demands exceed limited capacities. Deficits are sufficiently severe to cause impairment in personal, family, social, educational, occupational or other important areas of functioning and are usually a pervasive feature of the individual's functioning observable in all settings, although they may vary according to social, educational, or other context. Individuals along the spectrum exhibit a full range of intellectual functioning and language abilities.|title=ICD-11|source=chapter 6, section A02}}

ICD-11 was produced by professionals from 55 countries out of the 90 involved and is the most widely used reference worldwide.

=== DSM ===
The American Psychiatric Association's ''Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision'' (DSM-5-TR), released in 2022, is the current version of the DSM. It is the predominant mental health diagnostic system used in the United States and Canada, and is often used in Anglophone countries.

Its fifth edition, DSM-5, released in May 2013, was the first to define ASD as a single diagnosis,<ref>{{cite Q|Q3064664}}<!-- Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition--></ref> which is still the case in the DSM-5-TR.{{sfn|DSM-5-TR}} ASD encompasses previous diagnoses, including the four traditional diagnoses of autism—classic Kanner syndrome, [[Medicine:Asperger syndrome|Asperger syndrome]], [[Medicine:Childhood disintegrative disorder|childhood disintegrative disorder]], and [[Medicine:Pervasive developmental disorder not otherwise specified|pervasive developmental disorder not otherwise specified (PDD-NOS)]]—and the range of diagnoses that included the word "autism".{{sfn|DSM-5-TR|loc="Autism spectrum disorder encompasses disorders previously referred to as early infantile autism, childhood autism, Kanner's autism, [[Medicine:High-functioning autism|high-functioning autism]], atypical autism, pervasive developmental disorder not otherwise specified, childhood disintegrative disorder, and Asperger's disorder"}} Rather than distinguishing among these diagnoses, the DSM-5 and DSM-5-TR adopt a dimensional approach with one diagnostic category for disorders that fall under the autism spectrum umbrella. Within that category, the DSM-5 and the DSM include a framework that differentiates each person by dimensions of symptom severity, as well as by associated features (i.e., the presence of other disorders or factors that likely contribute to the symptoms, other neurodevelopmental or mental disorders, intellectual disability, or language impairment).{{sfn|DSM-5-TR}} The symptom domains are (a) social communication and (b) restricted, repetitive behaviors, and there is the option of specifying a separate severity—the negative effect of the symptoms on the person—for each domain, rather than just overall severity.{{sfn|DSM-5-TR|loc="It may be helpful to note level of support needed for each of the two core psychopathological domains in Table 2 (e.g., 'requiring very substantial support for deficits in social communication and requiring substantial support for restricted, repetitive behaviors')"}} Before the DSM-5, the DSM separated social deficits and communication deficits into two domains.<ref>{{cite journal |vauthors=Kulage KM, Smaldone AM, Cohn EG |title=How will DSM-5 affect autism diagnosis? A systematic literature review and meta-analysis |journal=Journal of Autism and Developmental Disorders |volume=44 |issue=8 |pages=1918–1932 |date=August 2014 |pmid=24531932 |doi=10.1007/s10803-014-2065-2 |s2cid=18865395}}</ref> Further, the DSM-5 changed to an onset age in the early developmental period<!-- "early developmental period" is the specific wording from the DSM -->, with a note that symptoms may manifest later when social demands exceed capabilities, rather than the previous, more restricted three years of age.<ref name="IACC">{{cite web |title=DSM-5 Diagnostic Criteria |url=https://iacc.hhs.gov/about-iacc/subcommittees/resources/dsm5-diagnostic-criteria.shtml#autism-spectrum-disorder |publisher=U.S. Department of Health & Human Services Interagency Autism Coordinating Committee |access-date=17 May 2017 |archive-date=11 February 2017 |archive-url=https://web.archive.org/web/20170211004905/https://iacc.hhs.gov/about-iacc/subcommittees/resources/dsm5-diagnostic-criteria.shtml#autism-spectrum-disorder |url-status=live}}</ref> These changes remain in the DSM-5-TR.{{sfn|DSM-5-TR}}

== Common characteristics<span class="anchor" id="Features and characteristics"></span> ==
=== Pre-diagnosis ===
For many autistic people, characteristics first appear during infancy or childhood and follow a steady course without [[Medicine:Remission|remission]] (different developmental timelines are described in more detail below).<ref name="ICD-10-F84.0">{{cite web |year=2007 |title=F84. Pervasive developmental disorders |url=http://apps.who.int/classifications/apps/icd/icd10online/?gf80.htm+f84 |archive-url=https://web.archive.org/web/20130421042448/http://apps.who.int/classifications/apps/icd/icd10online/?gf80.htm%20f84 |archive-date=21 April 2013 |access-date=10 October 2009 |website=ICD-10: International Statistical Classification of Diseases and Related Health Problems: Tenth Revision |publisher=World Health Organization}}</ref> Autistic people may be severely impaired in some respects but average, or even superior, in others.<ref>{{cite book |vauthors=Loukusa S |title=Handbook of Pragmatic Language Disorders |veditors=Cummings L |date=2021 |publisher=Springer |location=Cham, Switzerland |isbn=978-3-030-74984-2 |pages=45–78 |doi=10.1007/978-3-030-74985-9_3 |chapter=Autism Spectrum Disorder |s2cid=239160368 |oclc=1269056169}}</ref><ref>{{cite book |title=Biopsychology |vauthors=Pinel JP |publisher=Pearson |year=2011 |isbn=978-0-205-03099-6 |edition=8th |location=Boston, Massachusetts |page=235 |oclc=1085798897}}</ref><ref>{{cite book |title=Autism Spectrum Disorders |date=2018 |publisher=American Psychiatric Association |chapter=Cognitive Assessment |doi=10.1176/appi.books.9781615371921 |isbn=978-1-61537-192-1 |veditors=Hollander E, Hagerman R, Fein D}}</ref>

Clinicians consider assessment for ASD when a patient shows:
* regular difficulties in social interaction or communication
* restricted or repetitive behaviors (often called "[[Medicine:Stimming|stimming]]")
* resistance to changes or restricted interests

These features are typically assessed with the following, when appropriate:
* problems in obtaining or sustaining employment or education
* difficulties in initiating or sustaining social relationships
* connections with mental health or learning disability services
* a history of neurodevelopmental conditions (including learning disabilities and [[Medicine:Attention deficit hyperactivity disorder|ADHD]]) or mental health conditions.<ref name="NICE adult 2021">{{citation |title=Autism spectrum disorder in adults: diagnosis and management |date=14 June 2021 |url=https://www.nice.org.uk/guidance/cg142 |publisher=NICE |id=CG142 |access-date=24 October 2021 |archive-date=2 September 2023 |archive-url=https://web.archive.org/web/20230902193040/https://www.nice.org.uk/guidance/cg142 |url-status=live}}</ref><ref name="Canada Health ASD 2018">{{cite web |url=https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/about-autism-spectrum-disorder-asd.html |title=About autism spectrum disorder (ASD) |website=Government of Canada |language=en |date=18 January 2016 |access-date=4 November 2021 |archive-date=26 March 2023 |archive-url=https://web.archive.org/web/20230326225043/https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/about-autism-spectrum-disorder-asd.html |url-status=live}}</ref>

There are many signs associated with autism; the presentation varies widely:<ref name="Canada Health ASD 2018 signs">{{cite web |url=https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/signs-symptoms-autism-spectrum-disorder-asd.html |title=What are the signs and symptoms of ASD? |website=Government of Canada |language=en |date=18 January 2016 |access-date=4 November 2021 |archive-date=1 June 2023 |archive-url=https://web.archive.org/web/20230601202634/https://www.canada.ca/en/public-health/services/diseases/autism-spectrum-disorder-asd/signs-symptoms-autism-spectrum-disorder-asd.html |url-status=live}}</ref><ref name="CDC Autism 2020">{{cite web |author=National Center on Birth Defects and Developmental Disabilities |date=25 March 2020 |title=What is Autism Spectrum Disorder? |url=https://www.cdc.gov/ncbddd/autism/facts.html |access-date=24 October 2021 |website=Centers for Disease Control and Prevention |archive-date=21 September 2023 |archive-url=https://web.archive.org/web/20230921231100/https://www.cdc.gov/ncbddd/autism/facts.html |url-status=live}}</ref>

:{| class="wikitable" style="width:55em;border:solid 1px #999999; margin:0 0 1em 1em;"
|-
!Common signs for autism spectrum disorder
|-
|
* avoidance of eye-contact
* little or no babbling as an infant
* not showing interest in indicated objects
* [[Medicine:Language disorder#Autism spectrum disorder|delayed language skills]] (e.g. having a smaller vocabulary than peers or difficulty expressing themselves in words)
* reduced interest in other children or caretakers, possibly with more interest in objects
* difficulty playing reciprocal games (e.g. peek-a-boo)
* hyper- or hypo-sensitivity to or unusual response to the smell, texture, sound, taste, or appearance of things
* resistance to changes in routine
* repetitive, limited, or otherwise unusual usage of toys (e.g. lining up toys)
* repetition of words or phrases ([[Medicine:Echolalia|echolalia]])
* repetitive motions or movements, including [[Medicine:Stimming|stimming]]
* [[Medicine:Self-harm#Mental disorder|self-harming]]
|}

=== Broader autism phenotype ===
The broader autism [[Biology:Phenotype|phenotype]] (BAP) describes people who may not have ASD but do have autistic [[Biology:Phenotypic trait|traits]], such as avoiding eye contact and [[Medicine:Stimming|stimming]].<ref>{{cite journal |vauthors=Piven J, Palmer P, Jacobi D, Childress D, Arndt S |date=February 1997 |title=Broader autism phenotype: evidence from a family history study of multiple-incidence autism families |journal=The American Journal of Psychiatry |volume=154 |issue=2 |pages=185–190 |doi=10.1176/ajp.154.2.185 |pmid=9016266 |doi-access=free}}</ref>

=== Social and communication skills ===
According to the medical model, autistic people experience social communications impairments. Until 2013, deficits in social function and communication were considered two separate symptom domains.<ref>{{cite journal |vauthors=Frye RE |title=Social Skills Deficits in Autism Spectrum Disorder: Potential Biological Origins and Progress in Developing Therapeutic Agents |journal=CNS Drugs |volume=32 |issue=8 |pages=713–734 |date=August 2018 |pmid=30105528 |doi=10.1007/s40263-018-0556-y |pmc=6105175}}</ref> The current social communication domain criteria for autism diagnosis require people to have deficits across three social skills: social-emotional reciprocity, nonverbal communication, and developing and sustaining relationships.{{sfn|DSM-5-TR}}

A deficit-based view predicts that autistic–autistic interaction would be less effective than autistic–non-autistic interactions or even non-functional.<ref name=Crompton2020 /> But recent research has found that autistic–autistic interactions are as effective in information transfer as interactions between non-autistics are, and that communication breaks down only between autistics and non-autistics.<ref name=Crompton2020>{{cite journal |last=Crompton |first=Catherine J |date=May 20, 2020 |title=Autistic peer-to-peer information transfer is highly effective |journal=Autism |language=en |volume=24 |issue=7 |pages=1704–1712 |doi=10.1177/1362361320919286 |pmid=32431157 |pmc=7545656}}</ref><ref name=Heasman2018>{{cite journal |last1=Heasman |first1=Brett |last2=Alex |first2=Gillespie |title=Neurodivergent intersubjectivity: Distinctive features of how autistic people create shared understanding |url=https://eprints.lse.ac.uk/90098/1/Heasman_Neurodivergent-intersubjectivity_Published.pdf |journal=Autism |date=2019 |language=en |volume=23 |issue=4 |pages=910–921 |doi=10.1177/1362361318785172 |pmid=30073872 |pmc=6512057}}</ref> Also contrary to social cognitive deficit interpretations, recent research recorded similar social cognitive performances in autistic and non-autistic adults, with both of them rating autistic individuals less favorably than non-autistic individuals; however, autistic individuals showed more interest in engaging with autistic people than non-autistic people did, and learning of a person's ASD diagnosis did not influence their interest level.<ref>{{cite journal |first1=Kilee M. |last1=DeBrabander |first2=Kerrianne E. |last2=Morrison |first3=Desiree R. |last3=Jones |first4=Daniel J. |last4=Faso |first5=Mike |last5=Chmielewski |first6=Noah J. |last6=Sasson |date=13 December 2019 |title=Do First Impressions of Autistic Adults Differ Between Autistic and Nonautistic Observers? |journal=Autism in Adulthood |language=en |volume=1 |issue=4 |pages=250–257 |doi=10.1089/aut.2019.0018 |pmid=36601322 |pmc=8992824}}</ref>

Thus, there has been a recent shift to acknowledge that autistic people may simply respond and behave differently than people without ASD.<ref>{{cite web |date=31 March 2022 |title=Basics About Autism Spectrum Disorder (ASD) |url=https://www.cdc.gov/ncbddd/autism/facts.html |access-date=15 September 2022 |website=Centers for Disease Control and Prevention |language=en-us |archive-date=21 September 2023 |archive-url=https://web.archive.org/web/20230921231100/https://www.cdc.gov/ncbddd/autism/facts.html |url-status=live}}</ref> So far, research has identified two unconventional features by which autistic people create shared understanding ([[Philosophy:Intersubjectivity|intersubjectivity]]): "a generous assumption of common ground that, when understood, led to rapid rapport, and, when not understood, resulted in potentially disruptive utterances; and a low demand for coordination that ameliorated many challenges associated with disruptive turns."<ref name=Heasman2018 /> Autistic interests, and thus conversational topics, seem to be largely driven by an intense interest in specific topics ([[Philosophy:Monotropism|monotropism]]).<ref>{{cite journal |first1=Rachel |last1=Grove |first2=Rosa A |last2=Hoekstra |first3=Marlies |last3=Wierda |first4=Sander |last4=Begeer |date=May 20, 2020 |title=Special interests and subjective wellbeing in autistic adults |url=https://pubmed.ncbi.nlm.nih.gov/29427546/ |journal=Autism Research |language=en |volume=11 |issue=5 |pages=766–775 |doi=10.1002/aur.1931 |pmid=29427546 |hdl=1871.1/d5c70844-3d23-4e71-8c5d-82533196b003 |s2cid=205456773 |hdl-access=free}}</ref><ref>{{cite journal |first1=Dinah |last1=Murray |first2=Mike |last2=Lesser |first3=Wendy |last3=Lawson |date=May 2005 |title=Attention, monotropism and the diagnostic criteria for autism |journal=Autism Research |language=en |volume=9 |issue=2 |pages=139–156 |doi=10.1177/1362361305051398 |pmid=15857859 |s2cid=6476917 |doi-access=free}}</ref>

<!-- EMPATHY -->Historically, autistic children were said to be delayed in developing a [[Philosophy:Theory of mind|theory of mind]], and the [[Biology:Empathizing–systemizing theory|empathizing–systemizing theory]] has argued that while autistic people have compassion (affective empathy) for others with similar presentation of symptoms, they have limited, though not necessarily absent, [[Philosophy:Social cognition|cognitive empathy]].<ref name="Baron-Cohen, S. 2005">{{cite journal |last1=Baron-Cohen |first1=Simon |last2=Knickmeyer |first2=Rebecca C. |last3=Belmonte |first3=Matthew K. |title=Sex differences in the brain: implications for explaining autism |journal=Science |volume=310 |issue=5749 |pages=819–823 |doi = 10.1126/science.1115455 |pmid=16272115 |date=4 November 2005 |bibcode=2005Sci...310..819B |s2cid=44330420 |url=http://docs.autismresearchcentre.com/papers/2005_BC_etal_Science.pdf |access-date=10 September 2023 |archive-date=17 May 2017 |archive-url=https://web.archive.org/web/20170517064851/http://docs.autismresearchcentre.com/papers/2005_BC_etal_Science.pdf |url-status=live}}</ref> This may present as social naïvety,<ref>{{cite book |vauthors=Klin A, Volkmar FR, Sparrow SS |date=2000 |chapter=Introduction |veditors=Klin A, Volkmar FR, Sparrow SS |title=Asperger syndrome |location=New York |publisher=Guilford Press |pages=1–24 |isbn=1-57230-534-7}}</ref> lower than average intuitive perception of the utility or meaning of body language, social reciprocity,<ref>{{cite journal |last=Gernsbacher |first=Morton Ann |date=2017-08-06 |title=Editorial Perspective: The use of person-first language in scholarly writing may accentuate stigma |journal=Journal of Child Psychology and Psychiatry |language=en |volume=58 |issue=7 |pages=859–861 |doi=10.1111/jcpp.12706 |pmc=5545113 |pmid=28621486}}</ref> and/or social expectations, including the [[Social:Habitus (sociology)|habitus]], [[Social:Social cue|social cue]]s, and/or some aspects of sarcasm,<ref name=":1">{{cite web |title=DSM-5 Full Text Online |url=http://repository.poltekkes-kaltim.ac.id/657/1/Diagnostic%20and%20statistical%20manual%20of%20mental%20disorders%20_%20DSM-5%20(%20PDFDrive.com%20).pdf |url-status=bot: unknown |access-date=10 January 2022 |website=Archive.Today |archive-url=https://web.archive.org/web/20220111010541/https://archive.today/aS0dU |archive-date=11 January 2022}}</ref> which to some degree may also be due to comorbid [[Medicine:Alexithymia|alexithymia]].<ref>{{cite book |vauthors=Hogeveen J, Grafman J |title=Disorders of Emotion in Neurologic Disease |chapter=Alexithymia |series=Handbook of Clinical Neurology |volume=183 |pages=47–62 |date=2021 |pmid=34389125 |pmc=8456171 |doi=10.1016/b978-0-12-822290-4.00004-9 |publisher=[[Company:Elsevier|Elsevier]] |isbn=978-0-12-822290-4}}</ref> But recent research has increasingly questioned these findings, as the "[[Philosophy:Double empathy problem|double empathy problem]]" theory (2012) argues that there is a lack of mutual understanding and empathy between both neurotypical persons and autistic individuals.<ref>{{cite journal |last=Milton |first=Damian E. M. |date=October 2012 |title=On the ontological status of autism: the 'double empathy problem' |url=http://www.tandfonline.com/doi/abs/10.1080/09687599.2012.710008 |journal=Disability & Society |language=en |volume=27 |issue=6 |pages=883–887 |doi=10.1080/09687599.2012.710008 |issn=0968-7599 |s2cid=54047060}}</ref><ref>{{cite journal |last1=Milton |first1=Damian |last2=Gurbuz |first2=Emine |last3=López |first3=Beatriz |date=November 2022 |title=The 'double empathy problem': Ten years on |url=http://journals.sagepub.com/doi/10.1177/13623613221129123 |journal=Autism |language=en |volume=26 |issue=8 |pages=1901–1903 |doi=10.1177/13623613221129123 |pmid=36263746 |s2cid=253020669 |issn=1362-3613 |access-date=25 February 2023 |archive-date=25 February 2023 |archive-url=https://web.archive.org/web/20230225135833/https://journals.sagepub.com/doi/10.1177/13623613221129123 |url-status=live}}</ref><ref>{{cite journal |title=Double Empathy: Why Autistic People Are Often Misunderstood |year=2021 |language=en |doi=10.3389/frym.2021.554875|doi-access=free |last1=Crompton |first1=Catherine J. |last2=Debrabander |first2=Kilee |last3=Heasman |first3=Brett |last4=Milton |first4=Damian |last5=Sasson |first5=Noah J. |journal=Frontiers for Young Minds |volume=9|hdl=20.500.11820/94ee032a-6103-470a-bc06-08337dd6b512 |hdl-access=free }}</ref><ref>{{cite journal |last1=Sasson |first1=Noah J. |last2=Faso |first2=Daniel J. |last3=Nugent |first3=Jack |last4=Lovell |first4=Sarah |last5=Kennedy |first5=Daniel P. |last6=Grossman |first6=Ruth B. |date=2017-02-01 |title=Neurotypical Peers are Less Willing to Interact with Those with Autism based on Thin Slice Judgments |journal=Scientific Reports |language=en |volume=7 |issue=1 |page=40700 |bibcode=2017NatSR...740700S |doi=10.1038/srep40700 |issn=2045-2322 |pmc=5286449 |pmid=28145411}}</ref><ref>{{cite journal |vauthors=Hamilton AF |title=Goals, intentions and mental states: challenges for theories of autism |journal=Journal of Child Psychology and Psychiatry |volume=50 |issue=8 |pages=881–92 |year=2009 |pmid=19508497 |doi=10.1111/j.1469-7610.2009.02098.x |citeseerx=10.1.1.621.6275}}</ref> 

As communication is bidirectional,<ref name=Mitchell2021 /> research on communication difficulties has since also begun to study non-autistic behavior, with researcher Catherine Crompton writing in 2020 that non-autistic people "struggle to identify autistic mental states, identify autistic facial expressions, overestimate autistic egocentricity, and are less willing to socially interact with autistic people. Thus, although non-autistic people are generally characterised as socially skilled, these skills may not be functional, or effectively applied, when interacting with autistic people."<ref name=Crompton2020 /> Any previously observed communication deficits of autistic people may thus have been constructed through a neurotypical bias in autism research, which has come to be scrutinized for "dehumanization, objectification, and stigmatization".<ref>{{cite journal |last1=Bothan |first1=Monique |last2=Cage |first2=Eilidh |date=24 November 2022 |title="Autism research is in crisis": A mixed method study of researcher's constructions of autistic people and autism research |journal=Frontiers in Psychology |language=en |volume=13 |doi=10.3389/fpsyg.2022.1050897 |pmid=36506950 |pmc=9730396 |doi-access=free}}</ref> Recent research has proposed that autistics' lack of readability and a neurotypical lack of effort to interpret atypical signals may cause a negative interaction loop, increasingly driving both groups apart into two distinct groups with different social interaction styles.<ref name=Mitchell2021>{{cite journal |first1=Peter |last1=Mitchell |first2=Elizabeth |last2=Sheppard |first3=Sarah |last3=Cassidy |date=4 January 2021 |title=Autism and the double empathy problem: Implications for development and mental health |journal=British Journal of Developmental Psychology |volume=39 |issue=1 |pages=1–18, vi |doi=10.1111/bjdp.12350 |pmid=33393101 |s2cid=230489027 |doi-access=free}}</ref>

<!-- VERBAL COMMUNICATION. Not a distinct DSM-5 or DSM-5-TR criteria, but still common, and they are interspersed as examples throughout the other criteria. -->Differences in verbal communication begin to be noticeable in childhood, as many autistic children develop language skills at an uneven pace. Verbal communication may be delayed or never develop ([[Medicine:Nonverbal autism|nonverbal autism]]), while reading ability may be present before school age ([[Medicine:Hyperlexia|hyperlexia]]).<ref name=Bal2018 /><ref name="NIH2017Com" /> Reduced [[Social:Joint attention|joint attention]] seem to distinguish autistic from neurotypical infants.<ref name="John2007">{{cite journal |vauthors=Johnson CP, Myers SM |date=November 2007 |title=Identification and evaluation of children with autism spectrum disorders |url=http://pediatrics.aappublications.org/cgi/content/full/120/5/1183 |journal=Pediatrics |volume=120 |issue=5 |pages=1183–1215 |doi=10.1542/peds.2007-2361 |pmid=17967920 |archive-url=https://web.archive.org/web/20090208013449/http://pediatrics.aappublications.org/cgi/content/full/120/5/1183 |archive-date=8 February 2009 |doi-access=free}}</ref> Infants may show delayed onset of [[Social:Babbling|babbling]], unusual gestures, diminished responsiveness, and vocal patterns that are not synchronized with the caregiver. In the second and third years, autistic children may have less frequent and less diverse babbling, consonants, words, and word combinations; their gestures are less often integrated with words. Autistic children are less likely to make requests or share experiences and more likely to simply repeat others' words ([[Medicine:Echolalia|echolalia]]).<ref name="Tager-Flusberg">{{cite journal |vauthors=Tager-Flusberg H, Caronna E |date=June 2007 |title=Language disorders: autism and other pervasive developmental disorders |journal=Pediatric Clinics of North America |volume=54 |issue=3 |pages=469–81, vi |doi=10.1016/j.pcl.2007.02.011 |pmid=17543905 |s2cid=13615727}}</ref> The CDC estimated in 2015 that around 40% of autistic children do not speak at all.<ref>{{cite web |url=https://www.cdc.gov/ncbddd/autism/signs.html |title=Signs & Symptoms: Autism Spectrum Disorder |date=26 February 2015 |author=National Center on Birth Defects and Developmental Disabilities |website=Centers for Disease Control and Prevention |archive-url=https://web.archive.org/web/20150310030922/https://www.cdc.gov/ncbddd/autism/signs.html |archive-date=10 March 2015}} (Also available in Spanish.)</ref> Autistic adults' verbal communication skills largely depend on when and how well speech is acquired during childhood.<ref name=Bal2018>{{cite journal |first1=Vanessa H. |last1=Bal |first2=So-Hyun |last2=Kim |first3=Megan |last3=Fok |first4=Catherine |last4=Lord |date=12 August 2018 |title=Autism Spectrum Disorder symptoms from 2 to 19: Implications for diagnosing adolescents and young adults |journal=Autism Research |language=en |volume=12 |issue=1 |pages=89–99 |doi=10.1002/aur.2004 |pmc=6600818 |pmid=30101492}}</ref>

[[File:TempleGrandin.jpg|thumb|alt=Temple Grandin|Temple Grandin in 2011]]

<!-- NONVERBAL COMMUNICATION -->Autistic people display atypical nonverbal behaviors or show differences in nonverbal communication. They may make infrequent [[Biology:Eye contact|eye contact]], even when called by name, or avoid it altogether. Autistic people often recognize fewer emotions and their meaning from others' facial expressions, and may not respond with facial expressions expected by their non-autistic peers.<ref>{{cite web |title=Autism: Overview |url=https://www.asha.org/Practice-Portal/Clinical-Topics/Autism/ |publisher=American Speech-Language-Hearing Association |access-date=17 December 2017 |archive-date=23 April 2019 |archive-url=https://web.archive.org/web/20190423134030/https://www.asha.org/Practice-Portal/Clinical-Topics/Autism/ |url-status=live}}</ref><ref name="NIH2017Com">{{cite web |date=18 August 2015 |title=Autism Spectrum Disorder: Communication Problems in Children |url=https://www.nidcd.nih.gov/health/autism-spectrum-disorder-communication-problems-children |access-date=17 December 2017 |website=NIDCD |archive-date=22 December 2017 |archive-url=https://web.archive.org/web/20171222090623/https://www.nidcd.nih.gov/health/autism-spectrum-disorder-communication-problems-children |url-status=live}}</ref> [[Biography:Temple Grandin|Temple Grandin]], an autistic woman involved in autism activism, described her inability to understand neurotypicals' [[Biology:Communication|social communication]] as leaving her feeling "like an anthropologist on Mars".<ref>{{cite news |last1=Cohen |first1=David |last2=Grandin |first2=Temple |title=Temple Grandin: 'I'm an anthropologist from Mars' |url=https://www.theguardian.com/education/2005/oct/25/highereducationprofile.academicexperts |access-date=6 July 2022 |work={{wipe|The Guardian}} |issn=0261-3077 |eissn=1756-3224 |oclc=60623878 |location=Kings Place, London |publisher=Scott Trust |date=25 October 2005 |archive-url=https://web.archive.org/web/20131109145205/https://www.theguardian.com/education/2005/oct/25/highereducationprofile.academicexperts |archive-date=9 November 2013}}</ref> Autistic people struggle to understand the social context and subtext of neurotypical conversational or printed situations, and form different conclusions about the content.<ref name="iidc.indiana.edu">{{cite web |vauthors=Vicker B |title=Social communication and language characteristics associated with high-functioning, verbal children and adults with autism spectrum disorder |url=https://www.iidc.indiana.edu/pages/Social-Communication-and-Language-Characteristics-Associated-with-High-Functioning-Verbal-Children-and-Adults-with-ASD |access-date=17 December 2017 |publisher=Indiana Resource Center for Autism |archive-date=14 December 2018 |archive-url=https://web.archive.org/web/20181214181341/https://www.iidc.indiana.edu/pages/Social-Communication-and-Language-Characteristics-Associated-with-High-Functioning-Verbal-Children-and-Adults-with-ASD |url-status=live}}</ref> Autistic people may not control the volume of their voice in different social settings.<ref name="Fusaroli 2017" /> At least half of autistic children have unusual [[Social:Prosody (linguistics)|prosody]].<ref name="Fusaroli 2017">{{cite journal |vauthors=Fusaroli R, Lambrechts A, Bang D, Bowler DM, Gaigg SB |date=March 2017 |title=Is voice a marker for Autism spectrum disorder? A systematic review and meta-analysis |url=https://pure.au.dk/ws/files/101709535/046565.full.pdf |journal=Autism Research |volume=10 |issue=3 |pages=384–407 |doi=10.1002/aur.1678 |pmid=27501063 |s2cid=13772771 |access-date=27 March 2020 |archive-date=20 March 2021 |archive-url=https://web.archive.org/web/20210320203509/https://pure.au.dk/ws/files/101709535/046565.full.pdf |url-status=live}}</ref> <!-- Tone and volume are both non-verbal forms of communication. Verbal communication refers exclusively to the words themselves, not to the way that they are expressed. See the Wikipedia articles on these topics. -->

<!-- DEVELOPING AND SUSTAINING RELATIONSHIPS -->What may look like self-involvement or indifference to non-autistic people stems from autistic differences in recognizing how other people have their own personalities, perspectives, and interests.<ref name="iidc.indiana.edu" /><ref name="Lawson 2001">{{cite book |url=https://archive.org/details/understandingwor00laws_352 |title=Understanding and Working With the Spectrum of Autism: An Insider's View |vauthors=Lawson W |publisher=Jessica Kingsley Publishers |year=2001 |isbn=978-1853029714 |location=London UK, & Philadelphia PA |pages=[https://archive.org/details/understandingwor00laws_352/page/n33 33] |url-access=limited}}</ref> Most published research focuses on the interpersonal relationship difficulties between autistic people and their non-autistic counterparts and how to solve them through teaching neurotypical social skills, but newer research has also evaluated what autistic people want from friendships, such as a sense of belonging and good mental health.<ref>{{cite journal |last1=Finke |first1=Erinn |date=16 May 2022 |title=The Kind of Friend I Think I Am: Perceptions of Autistic and Non‑autistic Young Adults |journal=Journal of Autism and Developmental Disorders |language=en |volume=53 |issue=8 |pages=3047–3064 |doi=10.1007/s10803-022-05573-4 |pmid=35570241 |s2cid=248812844 |url=https://www.researchgate.net/publication/360622541}}</ref><ref>{{cite journal |last1=O'Connor |first1=Rachel A G |first2=Neeltje |last2=van den Bedem |first3=Els M A |last3=Blijd-Hoogewys |first4=Lex |last4=Stockmann |first5=Carolien |last5=Rieffe |title=Friendship quality among autistic and non-autistic (pre-) adolescents: Protective or risk factor for mental health? |journal=Autism |date=22 January 2022 |language=en |volume=26 |issue=8 |pages=2041–2051 |doi=10.1177/13623613211073448 |pmid=35068188 |pmc=9597130}}</ref> Children with ASD are more frequently involved in bullying situations than their neurotypical peers, and predominantly experience bullying as victims rather than perpetrators or victim-perpetrators, especially after controlling for comorbid psychopathology.<ref>{{cite journal |first1=Eeske |last1=van Roekel |first2=Ron H. J. |last2=Scholte |first3=Robert |last3=Didden |date=2010 |title=Bullying Among Adolescents With Autism Spectrum Disorders: Prevalence and Perception |journal=Journal of Autism and Developmental Disorders |volume=40 |issue=1 |pages=63–73 |doi=10.1007/s10803-009-0832-2 |pmid=17543905 |s2cid=13615727 |doi-access=free|pmc=2809311 }}</ref> Prioritizing dependability and intimacy in friendships during adolescence, coupled with lowered friendship quantity and quality, often lead to increased loneliness in autistic people.<ref>{{cite journal |last1=O'Connor |first1=Rachel A G |first2=Neeltje |last2=van den Bedem |first3=Els M A |last3=Blijd-Hoogewys |first4=Lex |last4=Stockmann |first5=Carolien |last5=Rieffe |title=Sex differences in friendships and loneliness in autistic and non-autistic children across development |journal=Molecular Autism |date=November 2022 |language=en |volume=4 |issue=9 |page=9 |doi=10.1186/s13229-023-00542-9 |pmid=36829214 |pmc=9960478 |doi-access=free}}</ref> As they progress through life, autistic people observe and form a model of social patterns, and develop coping mechanisms, referred to as "[[Medicine:Autistic masking|masking]]",<ref>{{cite journal |last1=Pearson |first1=Amy |last2=Rose |first2=Kieran |date=2021-03-01 |title=A Conceptual Analysis of Autistic Masking: Understanding the Narrative of Stigma and the Illusion of Choice |journal=Autism in Adulthood |volume=3 |issue=1 |pages=52–60 |doi=10.1089/aut.2020.0043 |issn=2573-9581 |pmc=8992880 |pmid=36601266}}</ref><ref>{{cite journal |last1=Petrolini |first1=Valentina |last2=Rodríguez-Armendariz |first2=Ekaine |last3=Vicente |first3=Agustín |date=2023 |title=Autistic camouflaging across the spectrum |journal=New Ideas in Psychology |language=en |volume=68 |page=100992 |doi=10.1016/j.newideapsych.2022.100992 |hdl=10810/59712 |s2cid=253316582 |doi-access=free|hdl-access=free }}</ref> which has recently been found to come with psychological costs and a highly increased risk of suicidality.<ref name=Mitchell2021 />

=== Restricted and repetitive behaviors ===
[[File:Autistic-sweetiepie-boy-with-ducksinarow.jpg|alt=Sleeping boy beside a dozen or so toys arranged in a line|thumb|A young autistic boy who has arranged his toys in a row]]
ASD includes a wide variety of characteristics. Some of these include behavioral characteristics which widely range from slow development of social and learning skills to difficulties creating connections with other people. Autistic people may experience these challenges with forming connections due to anxiety or depression, which they are more likely to experience, and as a result isolate themselves.<ref>{{cite web |title=Engaging people on the autism spectrum |date=7 October 2013 |publisher=Autism Spectrum Australia |url=https://www.autismspectrum.org.au/about-aspect/diversity-inclusion/engaging-people-on-the-autism-spectrum |archive-url=https://web.archive.org/web/20200319233547/https://www.autismspectrum.org.au/about-aspect/diversity-inclusion/engaging-people-on-the-autism-spectrum |archive-date=19 March 2020 <!-- the page now redirects to one called "Working in partnership with autistic people" -->}}</ref>{{medical citation needed|date=April 2022}}

Other behavioral characteristics include abnormal responses to sensations (such as sights, sounds, touch, taste and smell) and problems keeping a consistent speech rhythm. The latter problem influences social skills, leading to potential problems in understanding for interlocutors. Autistic people's behavioral characteristics typically influence development, language, and social competence. Their behavioral characteristics can be observed as perceptual disturbances, disturbances of development rate, relating, speech and language, and motility.<ref>{{cite book |vauthors=Hinerman PS |title=Teaching Autistic Children to Communicate |date=1983 |publisher=Aspens System Corporation |location=Rockville, Maryland |isbn=978-0-89443-884-4 |page=180}}</ref>

The second core symptom of autism spectrum is a pattern of restricted and repetitive behaviors, activities, and interests. In order to be diagnosed with ASD under the DSM-5-TR, a person must have at least two of the following behaviors:{{sfn|DSM-5-TR}}<ref name="Lord 2018">{{cite journal |vauthors=Lord C, Elsabbagh M, Baird G, Veenstra-Vanderweele J |date=August 2018 |title=Autism spectrum disorder |journal=The Lancet |volume=392 |issue=10146 |pages=508–520 |doi=10.1016/S0140-6736(18)31129-2 |pmc=7398158 |pmid=30078460 |s2cid=51922565}}</ref>
* [[File:James arranging brads.jpg|thumb|An older autistic boy arranging brads on a cork coaster.]] [[Medicine:Stimming|'''Repetitive behaviors''']] – Repetitive behaviors such as rocking, hand flapping, finger flicking, head banging, or repeating phrases or sounds.<ref name="UpToDate Clinical Features">{{cite web |url=https://www.uptodate.com/contents/autism-spectrum-disorder-clinical-features |title=Autism spectrum disorder: Clinical features |vauthors=Augustyn M |website=UpToDate |access-date=22 March 2020 |archive-date=7 November 2022 |archive-url=https://web.archive.org/web/20221107065340/https://www.uptodate.com/contents/autism-spectrum-disorder-clinical-features |url-status=live}}</ref> These behaviors may occur constantly or only when the person gets stressed, anxious or upset. These behaviors are also known as stimming.
* '''Resistance to change''' – A strict adherence to routines such as eating certain foods in a specific order or taking the same path to school every day.<ref name="UpToDate Clinical Features" /> The person may become distressed if there is a change or disruption to their routine.
* '''Restricted interests''' – An excessive interest in a particular activity, topic, or hobby, and devoting all their attention to it. For example, young children might completely focus on things that spin and ignore everything else. Older children might try to learn everything about a single topic, such as the weather or sports, and [[Medicine:Perseveration|perseverate]] or talk about it constantly.<ref name="UpToDate Clinical Features" />
* '''Sensory reactivity''' – An unusual reaction to certain sensory inputs, such as negative reaction to specific sounds or textures, fascination with lights or movements, or apparent indifference to pain or heat.{{sfn|DSM-5-TR|loc="Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement)"}}
Autistic people can display many forms of repetitive or restricted behavior, which the Repetitive Behavior Scale-Revised (RBS-R) categorizes as follows.<ref name="Lam-Aman">{{cite journal |vauthors=Lam KS, Aman MG |date=May 2007 |title=The Repetitive Behavior Scale-Revised: independent validation in individuals with autism spectrum disorders |journal=Journal of Autism and Developmental Disorders |volume=37 |issue=5 |pages=855–866 |doi=10.1007/s10803-006-0213-z |pmid=17048092 |s2cid=41034513}}</ref>
* [[Biology:Stereotypy|Stereotyped behaviors]]: Repetitive movements, such as hand flapping, head rolling, or body rocking.
* [[Medicine:Compulsive behavior|Compulsive behavior]]s: Time-consuming behaviors intended to reduce anxiety, that a person feels compelled to perform repeatedly or according to rigid rules, such as placing objects in a specific order, checking things, or handwashing.
* Sameness: Resistance to change; for example, insisting that the furniture not be moved or refusing to be interrupted.
* Ritualistic behavior: Unvarying pattern of daily activities, such as an unchanging menu or a dressing ritual. This is closely associated with sameness and an independent validation has suggested combining the two factors.<ref name="Lam-Aman" />
* Restricted interests: Interests or fixations that are abnormal in theme or intensity of focus, such as preoccupation with a single television program, toy, or game.
* [[Medicine:Self-harm|Self-injury]]: Behaviors such as eye-poking, [[Medicine:Excoriation disorder|skin-picking]], hand-biting and head-banging.<ref name="John2007" />

==== Self-injury ====
Self-injurious behaviors (SIB) are relatively common in autistic people, and can include head-banging, self-cutting, self-biting, and hair-pulling.<ref name="Mins2014">{{cite journal |vauthors=Minshawi NF, Hurwitz S, Fodstad JC, Biebl S, Morriss DH, McDougle CJ |title=The association between self-injurious behaviors and autism spectrum disorders |journal=Psychology Research and Behavior Management |volume=7 |pages=125–36 |date=April 2014 |pmid=24748827 |pmc=3990505 |doi=10.2147/PRBM.S44635 |doi-access=free}}</ref> Some of these can result in serious injury or death.<ref name="Mins2014" /> Following are theories about the cause of self-injurious behavior in children with developmental delay, including autistic children:<ref name="Oliver2015">{{cite journal |vauthors=Oliver C, Richards C |title=Practitioner Review: Self-injurious behaviour in children with developmental delay |journal=Journal of Child Psychology and Psychiatry |volume=56 |issue=10 |pages=1042–54 |date=October 2015 |pmid=25916173 |doi=10.1111/jcpp.12425 |s2cid=206034400 |url=http://pure-oai.bham.ac.uk/ws/files/26880648/Oliver_Richards_2015_Self_injurious_behaviour_children_dev._delay_JCPP.pdf |type=Review |access-date=25 August 2020 |archive-date=12 August 2023 |archive-url=https://web.archive.org/web/20230812175509/http://pure-oai.bham.ac.uk/ws/files/26880648/Oliver_Richards_2015_Self_injurious_behaviour_children_dev._delay_JCPP.pdf |url-status=live}}</ref>
* Frequency and/or continuation of self-injurious behavior can be influenced by environmental factors (e.g. reward in return for halting self-injurious behavior). This theory does not apply to younger children with autism. There is some evidence that frequency of self-injurious behavior can be reduced by removing or modifying environmental factors that reinforce the behavior.<ref name="Oliver2015" />{{rp|10–12|}}
* Higher rates of self-injury are also noted in socially isolated people with autism. Studies have shown that socialization skills are related factors to self-injurious behavior for people with autism.<ref>{{cite journal |vauthors=Flowers J, Lantz J, Hamlin T, Simeonsson RJ |title=Associated Factors of Self-injury Among Adolescents with Autism Spectrum Disorder in a Community and Residential Treatment Setting |journal=Journal of Autism and Developmental Disorders |volume=50 |issue=8 |pages=2987–3004 |date=August 2020 |pmid=32056114 |doi=10.1007/s10803-020-04389-4 |s2cid=211111895}}</ref>
* Self-injury could be a response to modulate [[Biology:Nociception|pain perception]] when chronic pain or other health problems that cause pain are present.<ref name="Oliver2015" />{{rp|12-13|q=In the last decade a number of studies has emerged which indicate that pain might directly cause self-injury ... Self-injury could moderate the perception of pain caused by ongoing health problem}}
* An abnormal [[Biology:Basal ganglia|basal ganglia]] connectivity may predispose to self-injurious behavior.<ref name="Oliver2015" />{{rp|13|q=In a recent review, Muehlmann and Lewis (2012) concluded that alterations in cortical basal ganglia circuitry underlie both self-injurious and stereotypic/compulsive behaviours.}}
The suicide rate for verbal autistics is nine times that of the general population.<ref name="auto">{{cite news |url=https://www.theguardian.com/society/2023/jul/31/autism-could-be-seen-as-part-of-personality-for-some-diagnosed-experts-say |title=Autism could be seen as part of personality for some diagnosed, experts say |first=Amelia |last=Hill |date=31 July 2023 |newspaper={{wipe|The Guardian}} |access-date=1 August 2023 |archive-date=1 August 2023 |archive-url=https://web.archive.org/web/20230801022836/https://www.theguardian.com/society/2023/jul/31/autism-could-be-seen-as-part-of-personality-for-some-diagnosed-experts-say |url-status=live}}</ref>

=== Other features ===
Autistic people may have symptoms that do not contribute to the official diagnosis, but that can affect the person or the family.<ref name="Filipek">{{cite journal |display-authors=6 |vauthors=Filipek PA, Accardo PJ, Baranek GT, Cook EH, Dawson G, Gordon B, Gravel JS, Johnson CP, Kallen RJ, Levy SE, Minshew NJ, Ozonoff S, Prizant BM, Rapin I, Rogers SJ, Stone WL, Teplin S, Tuchman RF, Volkmar FR |date=December 1999 |title=The screening and diagnosis of autistic spectrum disorders |journal=Journal of Autism and Developmental Disorders |volume=29 |issue=6 |pages=439–484 |doi=10.1023/A:1021943802493 |pmid=10638459 |s2cid=145113684}} This paper represents a consensus of representatives from nine professional and four parent organizations in the US.</ref>
* Some people with ASD show unusual or notable abilities, ranging from [[Philosophy:Splinter skill|splinter skill]]s (such as the memorization of trivia) to rare talents in mathematics, music, or artistic reproduction, which in exceptional cases are considered a part of the [[Medicine:Savant syndrome|savant syndrome]].<ref>{{cite journal |vauthors=Treffert DA |date=May 2009 |title=The savant syndrome: an extraordinary condition. A synopsis: past, present, future |journal=Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences |volume=364 |issue=1522 |pages=1351–1357 |doi=10.1098/rstb.2008.0326 |pmc=2677584 |pmid=19528017}}</ref><ref name="Yu & Han 2018">{{cite journal |vauthors=Zhang Y, Han VZ |date=April 2018 |title=[Neurobiological mechanisms of autistic savant and acquired savant] |trans-title=Neurobiological mechanisms of autistic savant and acquired savant |journal=Sheng Li Xue Bao |language=zh |volume=70 |issue=2 |pages=201–210 |pmid=29691585}}</ref><ref name="Molecular Autism 2018">{{cite journal |vauthors=Hughes JE, Ward J, Gruffydd E, Baron-Cohen S, Smith P, Allison C, Simner J |date=October 2018 |title=Savant syndrome has a distinct psychological profile in autism |journal=Molecular Autism |volume=9 |page=53 |doi=10.1186/s13229-018-0237-1 |pmc=6186137 |pmid=30344992 |doi-access=free}}</ref> One study describes how some people with ASD show superior skills in perception and attention relative to the general population.<ref>{{cite journal |vauthors=Plaisted Grant K, Davis G |date=May 2009 |title=Perception and apperception in autism: rejecting the inverse assumption |journal=[[Organization:Philosophical Transactions of the Royal Society B|Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences]] |volume=364 |issue=1522 |pages=1393–1398 |doi=10.1098/rstb.2009.0001 |pmc=2677593 |pmid=19528022}}</ref> [[Biology:Sensory nervous system|Sensory]] abnormalities are found in over 90% of autistic people, and are considered core features by some.<ref name="Geschwind-2009">{{cite journal |vauthors=Geschwind DH |year=2009 |title=Advances in autism |journal=Annual Review of Medicine |volume=60 |pages=367–380 |doi=10.1146/annurev.med.60.053107.121225 |pmc=3645857 |pmid=19630577}}</ref>
* More generally, autistic people tend to show a "spiky skills profile", with strong abilities in some areas contrasting with much weaker abilities in others.<ref>{{cite journal |vauthors=Happé F, Frith U |date=August 1996 |title=The neuropsychology of autism |journal=Brain |publisher=[[Organization:Oxford University Press|Oxford University Press]] |volume=119 |issue=4 |pages=1377–1400 |doi=10.1093/brain/119.4.1377 |pmid=8813299 |doi-access=free}}</ref>
* Differences between the previously recognized disorders under the autism spectrum are greater for under-responsivity (for example, walking into things) than for over-responsivity (for example, distress from loud noises) or for sensation seeking (for example, rhythmic movements).<ref>{{cite journal |vauthors=Ben-Sasson A, Hen L, Fluss R, Cermak SA, Engel-Yeger B, Gal E |date=January 2009 |title=A meta-analysis of sensory modulation symptoms in individuals with autism spectrum disorders |journal=Journal of Autism and Developmental Disorders |volume=39 |issue=1 |pages=1–11 |doi=10.1007/s10803-008-0593-3 |pmid=18512135 |s2cid=5208889}}</ref> An estimated 60–80% of autistic people have motor signs that include [[Medicine:Hypotonia|poor muscle tone]], [[Engineering:Apraxia|poor motor planning]], and [[Medicine:Toe walking|toe walking]];<ref name="Geschwind-2009" /><ref name="Gargot2022">{{cite journal |vauthors=Gargot T, Archambault D, Chetouani M, Cohen D, Johal W, Anzalone SM |date=10 January 2022 |title=Automatic Assessment of Motor Impairments in Autism Spectrum Disorders: A Systematic Review |journal=Cognitive Computation |volume=14 |issue=2 |pages=624–659 |doi=10.1007/s12559-021-09940-8 |issn=1866-9964 |s2cid=248326222 |url=https://hal.archives-ouvertes.fr/hal-03520967/file/review_article__for_Cognitive_computations__with_proper_model_.pdf |access-date=14 July 2022 |archive-date=15 December 2022 |archive-url=https://web.archive.org/web/20221215184813/https://hal.archives-ouvertes.fr/hal-03520967/file/review_article__for_Cognitive_computations__with_proper_model_.pdf |url-status=live}}</ref> deficits in motor coordination are pervasive across ASD and are greater in autism proper.<ref>{{cite journal |vauthors=Fournier KA, Hass CJ, Naik SK, Lodha N, Cauraugh JH |date=October 2010 |title=Motor coordination in autism spectrum disorders: a synthesis and meta-analysis |journal=Journal of Autism and Developmental Disorders |volume=40 |issue=10 |pages=1227–1240 |doi=10.1007/s10803-010-0981-3 |pmid=20195737 |s2cid=3469612}}</ref><ref>{{cite journal |last1=Wang |first1=Leah A. L. |last2=Petrulla |first2=Victoria |last3=Zampella |first3=Casey J. |last4=Waller |first4=Rebecca |last5=Schultz |first5=Robert T. |date=2022 |title=Gross motor impairment and its relation to social skills in autism spectrum disorder: A systematic review and two meta-analyses. |journal=Psychological Bulletin |language=en |volume=148 |issue=3–4 |pages=273–300 |doi=10.1037/bul0000358 |issn=1939-1455 |pmc=9894569 |pmid=35511567}}</ref>
* [[Social:Pathological demand avoidance|Pathological demand avoidance]] can occur. People with this set of autistic symptoms are more likely to refuse to do what is asked or expected of them, even to activities they enjoy.
* Unusual or atypical eating behavior occurs in about three-quarters of children with ASD, to the extent that it was formerly a diagnostic indicator.<ref name="Filipek" /> Selectivity is the most common problem, although eating rituals and food refusal also occur.<ref name="Dominick">{{cite journal |vauthors=Dominick KC, Davis NO, Lainhart J, Tager-Flusberg H, Folstein S |year=2007 |title=Atypical behaviors in children with autism and children with a history of language impairment |journal=Research in Developmental Disabilities |publisher=[[Company:Elsevier|Elsevier]] |eissn=1873-3379 |issn=0891-4222 |volume=28 |issue=2 |pages=145–162 |doi=10.1016/j.ridd.2006.02.003 |pmid=16581226}}</ref>

== Possible causes ==
{{Main|Social:Causes of autism}}
Exactly what causes autism remains unknown.<ref>{{cite book |title=Handbook of autism and pervasive developmental disorder: assessment, diagnosis, and treatment |publisher=[[Company:Springer Nature|Springer Nature]] |editor1-first=Johnny L. |editor1-last=Matson |editor2-first=Peter |editor2-last=Sturmey |series=Autism and Child Psychopathology Series |year=2022 |isbn=978-3-030-88538-0 |location=Cham |page=18 |language=en |doi=10.1007/978-3-030-88538-0 |s2cid=251520573 |oclc=1341298051 |quote=To date no one genetic feature or environmental cause has proven etiological in explaining most cases autism or has been able to account for rising rates of autism.}}</ref><ref>{{cite book |last1=Sauer |first1=Ann Katrin |title=Autism spectrum disorders |last2=Stanton |first2=Janelle E. |last3=Hans |first3=Sakshi |last4=Grabrucker |first4=Andreas M. |publisher=Exon Publications |others=Andreas M. Grabrucker |isbn=978-0-6450017-8-5 |editor-last=Grabrucker |editor-first=Andreas M. |location=Brisbane, Australia |publication-place=Brisbane |publication-date=August 20, 2021 |language=en |chapter=Autism Spectrum Disorders: Etiology and Pathology |year=2021 |pages=1–16 |doi=10.36255/exonpublications.autismspectrumdisorders.2021.etiology |oclc=1280592589 |pmid=34495611 |quote=The cause of ASD is unknown, but several genetic and non-genetic risk factors have been characterized that, alone or in combination, are implicated in the development of ASD. |doi-access=free}}</ref><ref>{{cite journal |last1=Kałużna-Czaplińska |first1=Joanna |last2=Żurawicz |first2=Ewa |last3=Jóźwik-Pruska |first3=Jagoda |title=Focus on the Social Aspect of Autism |journal=Journal of Autism and Developmental Disorders |year=2018 |language=en |publisher=[[Company:Springer Nature|Springer Nature]] |publication-date=November 29, 2017 |volume=48 |issue=5 |pages=1861–1867 |doi=10.1007/s10803-017-3407-7 |issn=1573-3432 |pmc=5889772 |pmid=29188587 |quote=Despite extensive ASD research lasting more than 60 years, its causes are still unknown.}}</ref><ref>{{cite journal |last1=Medavarapu |first1=Srinivas |last2=Marella |first2=Lakshmi Lavanya |last3=Sangem |first3=Aneela |last4=Kairam |first4=Ram |title=Where is the Evidence? A Narrative Literature Review of the Treatment Modalities for Autism Spectrum Disorders |journal=Cureus |year=2019 |volume=11 |issue=1 |pages=e3901 |language=en |publisher=[[Company:Springer Nature|Springer Nature]] |publication-date=January 16, 2019 |doi=10.7759/cureus.3901 |issn=2168-8184 |pmc=6424545 |pmid=30911457 |quote=It is important to realize that the etiology of autism is unknown and at present, there is no cure, although there are interventions that may be effective in alleviating some symptoms and improving skills that may help autistic persons lead more productive lives. |doi-access=free}}</ref> It was long mostly presumed that there is a common cause at the genetic, cognitive, and neural levels for the social and non-social components of ASD's symptoms, described as a triad in the classic autism criteria.<ref name="Fractionable">{{cite journal |vauthors=Happé F, Ronald A |date=December 2008 |title=The 'fractionable autism triad': a review of evidence from behavioural, genetic, cognitive and neural research |journal=Neuropsychology Review |volume=18 |issue=4 |pages=287–304 |doi=10.1007/s11065-008-9076-8 |pmid=18956240 |s2cid=13928876}}</ref> But it is increasingly suspected that autism is instead a complex disorder whose core aspects have distinct causes that often cooccur.<ref name="Fractionable" /><ref name="HappeTime">{{cite journal |vauthors=Happé F, Ronald A, Plomin R |date=October 2006 |title=Time to give up on a single explanation for autism |journal=Nature Neuroscience |volume=9 |issue=10 |pages=1218–1220 |doi=10.1038/nn1770 |pmid=17001340 |doi-access=free}}</ref> It is unlikely that ASD has a single cause;<ref name="HappeTime" /> many risk factors identified in the research literature may contribute to ASD. These include genetics, prenatal and perinatal factors (meaning factors during pregnancy or very early infancy), [[Biology:Neuroanatomy|neuroanatomical]] abnormalities, and environmental factors. It is possible to identify general factors, but much more difficult to pinpoint specific ones. Given the current state of knowledge, prediction can only be of a global nature and so requires the use of general markers.<ref name="Tager-Flusberg 2010">{{cite journal |vauthors=Tager-Flusberg H |title=The origins of social impairments in autism spectrum disorder: studies of infants at risk |journal=Neural Networks |volume=23 |issue=8–9 |pages=1072–6 |year=2010 |pmid=20800990 |pmc=2956843 |doi=10.1016/j.neunet.2010.07.008}}</ref>

=== Biological subgroups ===
Research into causes has been hampered by the inability to identify biologically meaningful subgroups within the autistic population<ref>{{cite journal |vauthors=Altevogt BM, Hanson SL, Leshner AI |date=June 2008 |title=Autism and the environment: challenges and opportunities for research |url=http://pediatrics.aappublications.org/cgi/content/full/121/6/1225 |journal=Pediatrics |volume=121 |issue=6 |pages=1225–1229 |doi=10.1542/peds.2007-3000 |pmid=18519493 |archive-url=https://web.archive.org/web/20100115140620/http://pediatrics.aappublications.org/cgi/content/full/121/6/1225 |archive-date=15 January 2010 |s2cid=24595814}}</ref> and by the traditional boundaries between the disciplines of [[Biology:Psychiatry|psychiatry]], [[Social:Psychology|psychology]], [[Biology:Neurology|neurology]] and [[Medicine:Pediatrics|pediatrics]].<ref>{{cite journal |vauthors=Reiss AL |date=January 2009 |title=Childhood developmental disorders: an academic and clinical convergence point for psychiatry, neurology, psychology and pediatrics |journal=Journal of Child Psychology and Psychiatry, and Allied Disciplines |issn=0021-9630 |eissn=1469-7610 |oclc=01307942 |volume=50 |issue=1–2 |pages=87–98 |doi=10.1111/j.1469-7610.2008.02046.x |pmc=5756732 |pmid=19220592}}</ref> Newer technologies such as [[Physics:Functional magnetic resonance imaging|fMRI]] and diffusion tensor imaging can help identify biologically relevant [[Biology:Phenotype|phenotype]]s (observable traits) that can be viewed on [[Biology:Neuroimaging|brain scans]], to help further [[Biology:Neurogenetics|neurogenetic]] studies of autism;<ref>{{cite journal |vauthors=Piggot J, Shirinyan D, Shemmassian S, Vazirian S, Alarcón M |date=November 2009 |title=Neural systems approaches to the neurogenetics of autism spectrum disorders |journal=Neuroscience |volume=164 |issue=1 |pages=247–256 |doi=10.1016/j.neuroscience.2009.05.054 |pmid=19482063 |s2cid=207246176}}</ref> one example is lowered activity in the [[Biology:Fusiform face area|fusiform face area]] of the brain, which is associated with impaired perception of people versus objects.<ref name="Levy 2009">{{cite journal |vauthors=Levy SE, Mandell DS, Schultz RT |date=November 2009 |title=Autism |journal=The Lancet |volume=374 |issue=9701 |pages=1627–1638 |doi=10.1016/S0140-6736(09)61376-3 |pmc=2863325 |pmid=19819542}}{{Erratum|https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(11)61666-8/fulltext|doi=10.1016/S0140-6736(11)61666-8|checked=yes}}</ref> It has been proposed to classify autism using genetics as well as behavior.<ref>{{cite journal |vauthors=Stephan DA |date=January 2008 |title=Unraveling autism |journal=American Journal of Human Genetics |volume=82 |issue=1 |pages=7–9 |doi=10.1016/j.ajhg.2007.12.003 |pmc=2253980 |pmid=18179879}}</ref>

==== Syndromic autism and non-syndromic autism ====
{{Main|Medicine:Syndromic autism}}
Autism spectrum disorder (ASD) can be classified into two categories: "syndromic autism" and "non-syndromic autism."

Syndromic autism refers to cases where ASD is one of the characteristics associated with a broader medical condition or [[Medicine:Syndrome|syndrome]], representing about 25% of ASD cases. The causes of syndromic autism are often known, and monogenic disorders account for approximately 5% of these cases.

Non-syndromic autism, also known as classic or idiopathic autism, represents the majority of cases, and its cause is typically polygenic and unknown.

=== Genetics ===
{{Main|Medicine:Heritability of autism}}
[[File:Autism susceptibility genes effect on brain structure.png|alt=|thumb|upright=1.6|Hundreds of different genes are implicated in susceptibility to developing autism,<ref name="brown2018">{{cite journal |vauthors=Brown EA, Lautz JD, Davis TR, Gniffke EP, VanSchoiack AA, Neier SC, Tashbook N, Nicolini C, Fahnestock M, Schrum AG, Smith SE |display-authors=6 |title=Clustering the autisms using glutamate synapse protein interaction networks from cortical and hippocampal tissue of seven mouse models |journal=Molecular Autism |volume=9 |issue=48 |page=48 |date=2018 |pmid=30237867 |pmc=6139139 |doi=10.1186/s13229-018-0229-1 |doi-access=free}}</ref> most of which alter the brain structure in a similar way.]]
Autism has a strong genetic basis, although the [[Medicine:Heritability of autism|genetics of autism]] are complex and it is unclear whether ASD is explained more by rare [[Biology:Mutation|mutation]]s with major effects, or by rare multi-gene interactions of common genetic variants.<ref name="Abrahams">{{cite journal |vauthors=Abrahams BS, Geschwind DH |date=May 2008 |title=Advances in autism genetics: on the threshold of a new neurobiology |journal=Nature Reviews. Genetics |volume=9 |issue=5 |pages=341–355 |doi=10.1038/nrg2346 |pmc=2756414 |pmid=18414403}}</ref><ref>{{cite journal |vauthors=Buxbaum JD |year=2009 |title=Multiple rare variants in the etiology of autism spectrum disorders |journal=Dialogues in Clinical Neuroscience |volume=11 |issue=1 |pages=35–43 |doi=10.31887/DCNS.2009.11.1/jdbuxbaum |pmc=3181906 |pmid=19432386}}</ref> Complexity arises due to interactions among multiple genes, the environment, and [[Biology:Epigenetics|epigenetic]] factors which do not change [[Biology:DNA|DNA]] sequencing but are heritable and influence [[Biology:Gene expression|gene expression]].<ref name="Rapin">{{cite journal |vauthors=Rapin I, Tuchman RF |date=October 2008 |title=Autism: definition, neurobiology, screening, diagnosis |journal=Pediatric Clinics of North America |volume=55 |issue=5 |pages=1129–46, viii |doi=10.1016/j.pcl.2008.07.005 |pmid=18929056}}</ref> Many genes have been associated with autism through sequencing the genomes of affected people and their parents.<ref name="SandersHe2015">{{cite journal |display-authors=6 |vauthors=Sanders SJ, He X, Willsey AJ, Ercan-Sencicek AG, Samocha KE, Cicek AE, Murtha MT, Bal VH, Bishop SL, Dong S, Goldberg AP, Jinlu C, Keaney JF, Klei L, Mandell JD, Moreno-De-Luca D, Poultney CS, Robinson EB, Smith L, Solli-Nowlan T, Su MY, Teran NA, Walker MF, Werling DM, Beaudet AL, Cantor RM, Fombonne E, Geschwind DH, Grice DE, Lord C, Lowe JK, Mane SM, Martin DM, Morrow EM, Talkowski ME, Sutcliffe JS, Walsh CA, Yu TW, Ledbetter DH, Martin CL, Cook EH, Buxbaum JD, Daly MJ, Devlin B, Roeder K, State MW |date=September 2015 |title=Insights into Autism Spectrum Disorder Genomic Architecture and Biology from 71 Risk Loci |journal=Neuron |volume=87 |issue=6 |pages=1215–1233 |doi=10.1016/j.neuron.2015.09.016 |pmc=4624267 |pmid=26402605 |author45-link=Kathryn Roeder}}</ref> But most of the mutations that increase autism risk have not been identified. Typically, autism cannot be traced to a [[Biology:Mendelian inheritance|Mendelian]] (single-gene) mutation or to a single [[Biology:Chromosome abnormality|chromosome abnormality]], and none of the genetic syndromes associated with ASD have been shown to selectively cause ASD.<ref name="Abrahams" /> Numerous genes have been found, with only small effects attributable to any particular gene.<ref name="Abrahams" /> Most loci individually explain less than 1% of cases of autism.<ref>{{cite journal |vauthors=Persico AM, Napolioni V |date=August 2013 |title=Autism genetics |journal=Behavioural Brain Research |volume=251 |pages=95–112 |doi=10.1016/j.bbr.2013.06.012 |pmid=23769996 |s2cid=15721666}}</ref> {{as of|2018}}, it appeared that between 74% and 93% of ASD risk is heritable.<ref name="Lord 2018" /> After an older child is diagnosed with ASD, 7% to 20% of subsequent children are likely to be as well.<ref name="Lord 2018" /> If parents have one autistic child, they have a 2% to 8% chance of having a second child who is autistic. If the autistic child is an identical twin, the other will be affected 36% to 95% of the time. A fraternal twin is affected up to 31% of the time.{{medical citation needed|date=April 2022}} The large number of autistic people with unaffected family members may result from spontaneous [[Biology:Structural variation|structural variation]], such as [[Biology:Deletion (genetics)|deletions]], [[Biology:Gene duplication|duplications]] or [[Biology:Chromosomal inversion|inversions]] in genetic material during [[Biology:Meiosis|meiosis]].<ref>{{cite journal |vauthors=Cook EH, Scherer SW |date=October 2008 |title=Copy-number variations associated with neuropsychiatric conditions |journal=Nature |volume=455 |issue=7215 |pages=919–923 |bibcode=2008Natur.455..919C |doi=10.1038/nature07458 |pmid=18923514 |s2cid=4377899}}</ref><ref>{{cite journal |display-authors=6 |vauthors=Brandler WM, Antaki D, Gujral M, Noor A, Rosanio G, Chapman TR, Barrera DJ, Lin GN, Malhotra D, Watts AC, Wong LC, Estabillo JA, Gadomski TE, Hong O, Fajardo KV, Bhandari A, Owen R, Baughn M, Yuan J, Solomon T, Moyzis AG, Maile MS, Sanders SJ, Reiner GE, Vaux KK, Strom CM, Zhang K, Muotri AR, Akshoomoff N, Leal SM, Pierce K, Courchesne E, Iakoucheva LM, Corsello C, Sebat J |date=April 2016 |title=Frequency and Complexity of De Novo Structural Mutation in Autism |journal=American Journal of Human Genetics |volume=98 |issue=4 |pages=667–679 |doi=10.1016/j.ajhg.2016.02.018 |pmc=4833290 |pmid=27018473}}</ref> Hence, a substantial fraction of autism cases may be traceable to genetic causes that are highly heritable but not inherited: that is, the mutation that causes the autism is not present in the parental genome.<ref name="Beaudet2">{{cite journal |vauthors=Beaudet AL |date=May 2007 |title=Autism: highly heritable but not inherited |journal=Nature Medicine |volume=13 |issue=5 |pages=534–536 |doi=10.1038/nm0507-534 |pmid=17479094 |s2cid=11673879}}</ref>{{Verify source|date=May 2022|reason=Need confirmation on whether the source is actually discussing ASD, or if its only about classic autism.}}

{{as of|2018}}, understanding of genetic risk factors had shifted from a focus on a few [[Biology:Allele|allele]]s to an understanding that genetic involvement in ASD is probably diffuse, depending on a large number of variants, some of which are common and have a small effect, and some of which are rare and have a large effect. The most common gene disrupted with large effect rare variants appeared to be CHD8, but less than 0.5% of autistic people have such a mutation. The gene CHD8 encodes the protein chromodomain helicase DNA binding protein 8, which is a [[Biology:Chromatin|chromatin]] regulator enzyme that is essential during fetal development, CHD8 is an ATP dependent enzyme.<ref name="Nishiyama 172–182">{{cite journal |vauthors=Nishiyama M, Oshikawa K, Tsukada Y, Nakagawa T, Iemura S, Natsume T, Fan Y, Kikuchi A, Skoultchi AI, Nakayama KI |display-authors=6 |title=CHD8 suppresses p53-mediated apoptosis through histone H1 recruitment during early embryogenesis |journal=[[Biology:Nature Cell Biology|Nature Cell Biology]] |volume=11 |issue=2 |pages=172–182 |date=February 2009 |pmid=19151705 |pmc=3132516 |doi=10.1038/ncb1831 }}</ref><ref name="Ronan 347–359">{{cite journal |vauthors=Ronan JL, Wu W, Crabtree GR |title=From neural development to cognition: unexpected roles for chromatin |journal=Nature Reviews Genetics |volume=14 |issue=5 |pages=347–359 |date=May 2013 |pmid=23568486 |pmc=4010428 |doi=10.1038/nrg3413 }}</ref><ref name="Thompson 3894–3904">{{cite journal |vauthors=Thompson BA, Tremblay V, Lin G, Bochar DA |title=CHD8 is an ATP-dependent chromatin remodeling factor that regulates beta-catenin target genes |journal=[[Biology:Molecular and Cellular Biology|Molecular and Cellular Biology]] |volume=28 |issue=12 |pages=3894–3904 |date=June 2008 |pmid=18378692 |pmc=2423111 |doi=10.1128/mcb.00322-08 }}</ref> The protein contains an Snf2 helicase domain that is responsible for the hydrolysis of ATP to ADP.<ref name="Thompson 3894–3904" /> CHD8 encodes for a DNA helicase that function as a transcription repressor by remodeling chromatin structure by altering the position of nucleosomes. CHD8 negatively regulates Wnt signaling. Wnt signaling is important in the vertebrate early development and morphogenesis. It is believed that CHD8 also recruits the linker histone H1 and causes the repression of β-catenin and p53 target genes.<ref name="Nishiyama 172–182" /> The importance of CHD8 can be observed in studies where CHD8-knockout mice died after 5.5 embryonic days because of widespread p53 induced apoptosis. Some studies have determined the role of CHD8 in autism spectrum disorder (ASD). CHD8 expression significantly increases during human mid-fetal development.<ref name="Nishiyama 172–182" /> The chromatin remodeling activity and its interaction with transcriptional regulators have shown to play an important role in ASD [[Philosophy:Etiology|aetiology]].<ref name="Ronan 347–359" /> The developing mammalian brain has a conserved CHD8 target regions that are associated with ASD risk genes.<ref>{{cite journal |vauthors=Sugathan A, Biagioli M, Golzio C, Erdin S, Blumenthal I, Manavalan P, Ragavendran A, Brand H, Lucente D, Miles J, Sheridan SD, Stortchevoi A, Kellis M, Haggarty SJ, Katsanis N, Gusella JF, Talkowski ME |display-authors=6 |title=CHD8 regulates neurodevelopmental pathways associated with autism spectrum disorder in neural progenitors |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=111 |issue=42 |pages=E4468–E4477 |date=October 2014 |pmid=25294932 |pmc=4210312 |doi=10.1073/pnas.1405266111 |doi-access=free |bibcode=2014PNAS..111E4468S}}</ref> The knockdown of CHD8 in human neural stem cells results in dysregulation of ASD risk genes that are targeted by CHD8.<ref>{{cite journal |vauthors=Cotney J, Muhle RA, Sanders SJ, Liu L, Willsey AJ, Niu W, Liu W, Klei L, Lei J, Yin J, Reilly SK, Tebbenkamp AT, Bichsel C, Pletikos M, Sestan N, Roeder K, State MW, Devlin B, Noonan JP |display-authors=6 |title=The autism-associated chromatin modifier CHD8 regulates other autism risk genes during human neurodevelopment |journal=Nature Communications |volume=6 |issue=1 |page=6404 |date=March 2015 |pmid=25752243 |pmc=4355952 |doi=10.1038/ncomms7404 |bibcode=2015NatCo...6.6404C}}</ref> Recently CD8 has been associated to the regulation of long non-coding RNAs (lncRNAs),<ref>{{cite journal |vauthors=Wilkinson B, Grepo N, Thompson BL, Kim J, Wang K, Evgrafov OV, Lu W, Knowles JA, Campbell DB |display-authors=6 |title=The autism-associated gene chromodomain helicase DNA-binding protein 8 (CHD8) regulates noncoding RNAs and autism-related genes |journal=Translational Psychiatry |volume=5 |issue=5 |pages=e568 |date=May 2015 |pmid=25989142 |pmc=4471293 |doi=10.1038/tp.2015.62 }}</ref> and the regulation of X chromosome inactivation (XCI) initiation, via regulation of Xist long non-coding RNA,{{Ambiguous|date=June 2022}} the master regulator of XCI,{{Ambiguous|date=June 2022}} though competitive binding to Xist regulatory regions.<ref>{{cite journal |vauthors=Cerase A, Young AN, Ruiz NB, Buness A, Sant GM, Arnold M, Di Giacomo M, Ascolani M, Kumar M, Hierholzer A, Trigiante G, Marzi SJ, Avner P |display-authors=6 |title=Chd8 regulates X chromosome inactivation in mouse through fine-tuning control of Xist expression |journal=[[Biology:Communications Biology|Communications Biology]] |volume=4 |issue=1 |page=485 |date=April 2021 |pmid=33859315 |pmc=8050208 |doi=10.1038/s42003-021-01945-1 }}</ref>

Some ASD is associated with clearly genetic conditions, like [[Medicine:Fragile X syndrome|fragile X syndrome]], but only around 2% of autistic people have fragile X.<ref name="Lord 2018" /> Hypotheses from [[Philosophy:Evolutionary psychiatry|evolutionary psychiatry]] suggest that these genes persist because they are linked to human inventiveness, intelligence or systemising.<ref>{{cite journal |vauthors=Crespi BJ |title=Autism As a Disorder of High Intelligence |journal=Frontiers in Neuroscience |volume=10 |page=300 |date=30 June 2016 |pmid=27445671 |pmc=4927579 |doi=10.3389/fnins.2016.00300 |doi-access=free}}</ref><ref>{{cite book |vauthors=Baron-Cohen S |title=The pattern seekers: how autism drives human invention |date=10 November 2020 |publisher=Basic Books |isbn=978-1-5416-4713-8|oclc=1204602315}}</ref>

Current research suggests that genes that increase susceptibility to ASD are ones that control [[Biology:Protein biosynthesis|protein synthesis]] in [[Biology:Neuron|neuronal cells]] in response to cell needs, activity and adhesion of neuronal cells, [[Biology:Synapse|synapse]] formation and remodeling, and excitatory to inhibitory [[Biology:Neurotransmitter|neurotransmitter]] balance. Therefore, although up to 1,000 different genes are thought to increase the risk of ASD, all of them eventually affect normal neural development and connectivity between different functional areas of the brain in a similar manner that is characteristic of an ASD brain. Some of these genes are known to modulate production of the [[Chemistry:Gamma-Aminobutyric acid|GABA]] neurotransmitter, the nervous system's main inhibitory neurotransmitter. These GABA-related genes are under-expressed in an ASD brain. On the other hand, genes controlling expression of glial and immune cells in the brain, e.g. [[Biology:Astrocyte|astrocyte]]s and [[Biology:Microglia|microglia]], respectively, are over-expressed, which correlates with increased number of glial and immune cells found in postmortem ASD brains. Some genes under investigation in ASD pathophysiology are those that affect the [[Biology:MTOR|mTOR]] signaling pathway, which supports cell growth and survival.<ref name="Chen2015">{{cite journal |vauthors=Chen JA, Peñagarikano O, Belgard TG, Swarup V, Geschwind DH |title=The emerging picture of autism spectrum disorder: genetics and pathology |journal=Annual Review of Pathology: Mechanisms of Disease |volume=10 |pages=111–44 |date=2015 |pmid=25621659 |doi=10.1146/annurev-pathol-012414-040405 |type=Review |doi-access=free}}</ref>

All these genetic variants contribute to the development of the autism spectrum, but it cannot be guaranteed that they are determinants for the development.<ref>{{cite journal |vauthors=Werling DM, Brand H, An JY, Stone MR, Zhu L, Glessner JT, Collins RL, Dong S, Layer RM, Markenscoff-Papadimitriou E, Farrell A, Schwartz GB, Wang HZ, Currall BB, Zhao X, Dea J, Duhn C, Erdman CA, Gilson MC, Yadav R, Handsaker RE, Kashin S, Klei L, Mandell JD, Nowakowski TJ, Liu Y, Pochareddy S, Smith L, Walker MF, Waterman MJ, He X, Kriegstein AR, Rubenstein JL, Sestan N, McCarroll SA, Neale BM, Coon H, Willsey AJ, Buxbaum JD, Daly MJ, State MW, Quinlan AR, Marth GT, Roeder K, Devlin B, Talkowski ME, Sanders SJ |display-authors=6 |title=An analytical framework for whole-genome sequence association studies and its implications for autism spectrum disorder |journal=Nature Genetics |volume=50 |issue=5 |pages=727–736 |date=April 2018 |pmid=29700473 |pmc=5961723 |doi=10.1038/s41588-018-0107-y}}</ref>

ASD may be under-diagnosed in women and girls due to an assumption that it is primarily a male condition,<ref>{{cite web |date=14 September 2018 |title=Thousands of autistic girls and women 'going undiagnosed' due to gender bias |url=https://www.theguardian.com/society/2018/sep/14/thousands-of-autistic-girls-and-women-going-undiagnosed-due-to-gender-bias |work={{wipe|The Guardian}} |vauthors=Devlin H |access-date=15 May 2022 |archive-date=9 August 2020 |archive-url=https://web.archive.org/web/20200809115012/https://www.theguardian.com/society/2018/sep/14/thousands-of-autistic-girls-and-women-going-undiagnosed-due-to-gender-bias |url-status=live}}</ref> but genetic phenomena such as [[Biology:Genomic imprinting|imprinting]] and [[Biology:Sex linkage|X linkage]] have the ability to raise the frequency and severity of conditions in males, and theories have been put forward for a genetic reason why males are diagnosed more often, such as the [[Philosophy:Imprinted brain hypothesis|imprinted brain hypothesis]] and the [[Biology:Empathising–systemising theory|extreme male brain theory]].<ref>{{cite journal |vauthors=Crespi B, Badcock C |date=June 2008 |title=Psychosis and autism as diametrical disorders of the social brain |journal=The Behavioral and Brain Sciences |volume=31 |issue=3 |pages=241–61; discussion 261–320 |doi=10.1017/S0140525X08004214 |pmid=18578904 |url=http://eprints.lse.ac.uk/21571/1/Psychosis%20and%20autism%20as%20diametrical%20disorders%20of%20the%20social%20brain%20%28LSERO%29.pdf |access-date=10 June 2022 |archive-date=12 April 2020 |archive-url=https://web.archive.org/web/20200412200311/http://eprints.lse.ac.uk/21571/1/Psychosis%20and%20autism%20as%20diametrical%20disorders%20of%20the%20social%20brain%20%28LSERO%29.pdf |url-status=live}}</ref><ref>{{cite journal |vauthors=Crespi B, Stead P, Elliot M |date=January 2010 |title=Evolution in health and medicine Sackler colloquium: Comparative genomics of autism and schizophrenia |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=107 |issue=Suppl 1 |pages=1736–1741 |bibcode=2010PNAS..107.1736C |doi=10.1073/pnas.0906080106 |pmc=2868282 |pmid=19955444 |doi-access=free}}</ref><ref>{{cite journal |vauthors=Baron-Cohen S, Knickmeyer RC, Belmonte MK |date=November 2005 |title=Sex differences in the brain: implications for explaining autism |url=http://irep.ntu.ac.uk/id/eprint/2710/1/219535_PubSub1971_Belmonte.pdf |journal=Science |volume=310 |issue=5749 |pages=819–823 |bibcode=2005Sci...310..819B |doi=10.1126/science.1115455 |pmid=16272115 |s2cid=44330420 |access-date=15 May 2022 |archive-date=19 July 2018 |archive-url=https://web.archive.org/web/20180719150047/http://irep.ntu.ac.uk/id/eprint/2710/1/219535_PubSub1971_Belmonte.pdf |url-status=live}}</ref>

=== Early life ===
Several prenatal and perinatal complications have been reported as possible risk factors for autism. These risk factors include maternal [[Medicine:Gestational diabetes|gestational diabetes]], maternal and paternal age over 30, bleeding during pregnancy after the first trimester, use of certain prescription medication (e.g. [[Biology:Valproate|valproate]]) during pregnancy, and meconium in the [[Biology:Amniotic fluid|amniotic fluid]]. Research is not conclusive on the relation of these factors to autism, but each of them has been identified more frequently in children with autism compared to their siblings who do not have autism and other typically developing youth.<ref name="Garder, Spiegelman, Buka">{{cite journal |vauthors=Gardener H, Spiegelman D, Buka SL |title=Perinatal and neonatal risk factors for autism: a comprehensive meta-analysis |journal=Pediatrics |volume=128 |issue=2 |pages=344–55 |date=August 2011 |pmid=21746727 |pmc=3387855 |doi=10.1542/peds.2010-1036}}</ref> While it is unclear if any single factors during the prenatal phase affect the risk of autism,<ref name="Gardener 2009">{{cite journal |vauthors=Gardener H, Spiegelman D, Buka SL |title=Prenatal risk factors for autism: comprehensive meta-analysis |journal=The British Journal of Psychiatry |volume=195 |issue=1 |pages=7–14 |date=July 2009 |pmid=19567888 |pmc=3712619 |doi=10.1192/bjp.bp.108.051672}}</ref> complications during pregnancy may be a risk.<ref name="Gardener 2009" />

There are also studies being done to test whether certain types of regressive autism have an [[Medicine:Autoimmunity|autoimmune]] basis.<ref name="Stefanatos">{{cite journal |vauthors=Stefanatos GA |date=December 2008 |title=Regression in autistic spectrum disorders |journal=Neuropsychology Review |volume=18 |issue=4 |pages=305–319 |doi=10.1007/s11065-008-9073-y |pmid=18956241 |s2cid=34658024}}</ref><!-- This statement needs to be synced to the causes article, or removed here. -->

Maternal nutrition and inflammation during preconception and pregnancy influences fetal neurodevelopment. [[Medicine:Intrauterine growth restriction|Intrauterine growth restriction]] is associated with ASD, in both term and preterm infants.<ref name="VohrPoggiDavis2017">{{cite journal |vauthors=Vohr BR, Poggi Davis E, Wanke CA, Krebs NF |date=April 2017 |title=Neurodevelopment: The Impact of Nutrition and Inflammation During Preconception and Pregnancy in Low-Resource Settings |journal=Pediatrics |type=Review |volume=139 |issue=Suppl 1 |pages=S38–S49 |doi=10.1542/peds.2016-2828F |pmid=28562247 |doi-access=free |s2cid=28637473}}</ref> Maternal inflammatory and [[Medicine:Autoimmune disease|autoimmune disease]]s may damage fetal tissues, aggravating a genetic problem or damaging the nervous system.<ref name="SamsamAhangari2014">{{cite journal |vauthors=Samsam M, Ahangari R, Naser SA |date=August 2014 |title=Pathophysiology of autism spectrum disorders: revisiting gastrointestinal involvement and immune imbalance |journal=World Journal of Gastroenterology |type=Review |volume=20 |issue=29 |pages=9942–9951 |doi=10.3748/wjg.v20.i29.9942 |pmc=4123375 |pmid=25110424 |doi-access=free}}</ref>

Exposure to air pollution during child pregnancy, especially [[Chemistry:Heavy metals|heavy metals]] and particulates, may increase the risk of autism.<ref>{{cite journal |vauthors=Lyall K, Schmidt RJ, Hertz-Picciotto I |date=April 2014 |title=Maternal lifestyle and environmental risk factors for autism spectrum disorders |journal=International Journal of Epidemiology |volume=43 |issue=2 |pages=443–464 |doi=10.1093/ije/dyt282 |pmc=3997376 |pmid=24518932 |doi-access=free}}</ref><ref>{{cite journal |display-authors=6 |vauthors=Lam J, Sutton P, Kalkbrenner A, Windham G, Halladay A, Koustas E, Lawler C, Davidson L, Daniels N, Newschaffer C, Woodruff T |year=2016 |title=A Systematic Review and Meta-Analysis of Multiple Airborne Pollutants and Autism Spectrum Disorder |journal=PLOS ONE |volume=11 |issue=9 |pages=e0161851 |bibcode=2016PLoSO..1161851L |doi=10.1371/journal.pone.0161851 |pmc=5031428 |pmid=27653281 |doi-access=free}}</ref> Environmental factors that have been claimed without evidence to contribute to or exacerbate autism include certain foods, [[Medicine:Infection|infectious diseases]], [[Physics:Solvent|solvent]]s, [[Chemistry:Polychlorinated biphenyl|PCBs]], [[Chemistry:Phthalate|phthalate]]s and [[Chemistry:Phenols|phenols]] used in plastic products, [[Biology:Pesticide|pesticide]]s, [[Chemistry:Brominated flame retardant|brominated flame retardant]]s, [[Chemistry:Ethanol|alcohol]], smoking, [[Medicine:Prohibition of drugs|illicit drugs]], [[Biology:Vaccine|vaccine]]s,<ref name="Newschaffer 2007">{{cite journal |display-authors=6 |vauthors=Newschaffer CJ, Croen LA, Daniels J, Giarelli E, Grether JK, Levy SE, Mandell DS, Miller LA, Pinto-Martin J, Reaven J, Reynolds AM, Rice CE, Schendel D, Windham GC |year=2007 |title=The epidemiology of autism spectrum disorders |journal=Annual Review of Public Health |volume=28 |pages=235–58 |doi=10.1146/annurev.publhealth.28.021406.144007 |pmid=17367287 |doi-access=free}}</ref> and [[Medicine:Prenatal stress|prenatal stress]]. Some, such as the MMR vaccine, have been completely disproven.<ref>{{cite journal |vauthors=Kinney DK, Munir KM, Crowley DJ, Miller AM |date=October 2008 |title=Prenatal stress and risk for autism |journal=Neuroscience and Biobehavioral Reviews |volume=32 |issue=8 |pages=1519–1532 |doi=10.1016/j.neubiorev.2008.06.004 |pmc=2632594 |pmid=18598714}}</ref><ref>{{cite journal |vauthors=Hussain A, Ali S, Ahmed M, Hussain S |date=July 2018 |title=The Anti-vaccination Movement: A Regression in Modern Medicine |journal=Cureus |volume=10 |issue=7 |pages=e2919 |doi=10.7759/cureus.2919 |doi-access=free |pmc=6122668 |pmid=30186724}}</ref><ref name="AFP20172">{{cite journal |vauthors=Spencer JP, Trondsen Pawlowski RH, Thomas S |date=June 2017 |title=Vaccine Adverse Events: Separating Myth from Reality |journal=American Family Physician |volume=95 |issue=12 |pages=786–794 |pmid=28671426}}</ref><ref>{{cite journal |vauthors=Di Pietrantonj C, Rivetti A, Marchione P, Debalini MG, Demicheli V |date=November 2021 |title=Vaccines for measles, mumps, rubella, and varicella in children |journal=[[Cochrane Library#The Cochrane Database of Systematic Reviews|The Cochrane Database of Systematic Reviews]] |volume=2021 |issue=11 |pages=CD004407 |doi=10.1002/14651858.CD004407.pub5 |pmc=8607336 |pmid=34806766}}</ref>

==== Disproven vaccine hypothesis ====
{{Main|Unsolved:Vaccines and autism|Social:MMR vaccine and autism}}

Parents may first become aware of ASD symptoms in their child around the time of a routine vaccination. This has led to unsupported and disproven theories blaming vaccine "overload", the [[Unsolved:Thiomersal and vaccines|vaccine preservative thiomersal]], or the [[Social:MMR vaccine and autism|MMR vaccine]] for causing autism spectrum disorder.<ref name="GerberOffit2009">{{cite journal |vauthors=Gerber JS, Offit PA |date=February 2009 |title=Vaccines and autism: a tale of shifting hypotheses |journal=Clinical Infectious Diseases |volume=48 |issue=4 |pages=456–461 |doi=10.1086/596476 |pmc=2908388 |pmid=19128068}}</ref> In 1998, British physician and academic [[Biography:Andrew Wakefield|Andrew Wakefield]] led a fraudulent, litigation-funded study that suggested that the [[Medicine:MMR vaccine|MMR vaccine]] may cause autism.<ref>{{cite news|url=https://www.thetimes.co.uk/article/mmr-doctor-andrew-wakefield-fixed-data-on-autism-mgj82qsk50g|title=MMR doctor Andrew Wakefield fixed data on autism|vauthors=Deer B|date=8 February 2009|newspaper=The Sunday Times|access-date=19 January 2019|archive-date=20 March 2017|archive-url=https://web.archive.org/web/20170320003216/http://www.thesundaytimes.co.uk/sto/public/news/article148992.ece|url-status=live}}</ref><ref>{{cite news|url=https://www.theguardian.com/society/2010/feb/02/lancet-retracts-mmr-paper|title=Lancet retracts 'utterly false' MMR paper|vauthors=Boseley S|date=2 February 2010|newspaper=The Guardian|access-date=19 January 2019|archive-date=17 January 2021|archive-url=https://web.archive.org/web/20210117232206/https://www.theguardian.com/society/2010/feb/02/lancet-retracts-mmr-paper|url-status=live}}</ref><ref>{{cite book |chapter=Influenza Vaccine |chapter-url=https://nap.nationalacademies.org/read/13164/chapter/8 |title=Adverse Effects of Vaccines: Evidence and Causality |url=https://www.nap.edu/read/13164/ |doi=10.17226/13164 |pmid=24624471 |isbn=978-0-309-21435-3 |others=Committee to Review Adverse Effects of Vaccines, Board on Population Health and Public Health Practice |veditors=Stratton K, Ford A, Rusch E, Clayton EW |location=Washington, D.C. |publisher=Institute of Medicine/National Academies Press |date=August 2011 |access-date=19 January 2019 |archive-date=27 August 2021 |archive-url=https://web.archive.org/web/20210827234139/https://www.nap.edu/read/13164/chapter/1 |url-status=live}}</ref><ref>{{cite journal |vauthors=Flaherty DK |title=The vaccine-autism connection: a public health crisis caused by unethical medical practices and fraudulent science |journal=The Annals of Pharmacotherapy |volume=45 |issue=10 |pages=1302–1304 |date=October 2011 |pmid=21917556 |doi=10.1345/aph.1Q318 |s2cid=39479569}}</ref><ref name="Godlee2011">{{cite journal |vauthors=Godlee F, Smith J, Marcovitch H |date=January 2011 |title=Wakefield's article linking MMR vaccine and autism was fraudulent |journal=British Medical Journal |volume=342 |pages=c7452 |doi=10.1136/bmj.c7452 |pmid=21209060 |s2cid=43640126}}<!-- This ref supports that it was litigation-funded. The others might also, but not sure. --></ref>

Two versions of the vaccine causation hypothesis were that autism results from brain damage caused by either the MMR vaccine itself, or by [[Chemistry:Thiomersal|mercury]] used as a vaccine preservative.<ref name="Tan and Parkin 2008">{{cite journal |vauthors=Tan M, Parkin JE |title=Route of decomposition of thiomersal (thimerosal) |journal=International Journal of Pharmaceutics |volume=208 |issue=1–2 |pages=23–34 |date=November 2000 |pmid=11064208 |doi=10.1016/S0378-5173(00)00514-7}}</ref> No convincing scientific evidence supports these claims.<ref name=":9" /> They are biologically implausible,<ref name="GerberOffit2009" /> and further evidence continues to refute them, including the observation that the rate of autism continues to climb despite elimination of thimerosal from most routine vaccines given to children from birth to 6 years of age.<ref>{{cite web |title=Understanding Vaccines, Mercury and Thimerosal |url=https://www.fda.gov/media/83535/download |website=[[Organization:Food and Drug Administration|Food and Drug Administration]] |access-date=6 July 2023 |archive-date=6 May 2023 |archive-url=https://web.archive.org/web/20230506050839/https://www.fda.gov/media/83535/download |url-status=live}}</ref><ref>{{cite journal |last=Dona |first=Asif |date=2006 |title=Immunizations and Autism: A Review of the Literature |url=https://www.cambridge.org/core/services/aop-cambridge-core/content/view/16B999364BFFD9F0DA3B09F25C1DE28C/S031716710000528Xa.pdf/immunizations-and-autism-a-review-of-the-literature.pdf |journal=Canadian Journal of Neurological Sciences |volume=33 |issue=4 |pages=341–346 |doi=10.1017/S031716710000528X |pmid=17168158 |s2cid=4670282 |access-date=6 July 2023 |archive-date=7 July 2023 |archive-url=https://web.archive.org/web/20230707171814/https://www.cambridge.org/core/services/aop-cambridge-core/content/view/16B999364BFFD9F0DA3B09F25C1DE28C/S031716710000528Xa.pdf/immunizations-and-autism-a-review-of-the-literature.pdf |url-status=live}}</ref><ref>{{cite web |title=Thimerosal questions and answers |url=https://www.fda.gov/vaccines-blood-biologics/vaccines/thimerosal-vaccines-questions-and-answers |website=US FDA |date=18 February 2021 |access-date=6 July 2023 |archive-date=18 April 2023 |archive-url=https://web.archive.org/web/20230418195953/https://www.fda.gov/vaccines-blood-biologics/vaccines/thimerosal-vaccines-questions-and-answers |url-status=live}}</ref><ref name="Waterhouse 2008">{{cite journal |vauthors=Waterhouse L |title=Autism overflows: increasing prevalence and proliferating theories |journal=Neuropsychology Review |volume=18 |issue=4 |pages=273–286 |date=December 2008 |pmid=19015994 |doi=10.1007/s11065-008-9074-x |s2cid=8863638}}</ref><ref>{{cite web |title=87% of Flu Vaccine Doses have Reduced or "no" (only trace amounts of) Thimerosal |url=https://www.cdc.gov/flu/prevent/vaxsupply.htm |website=Centers for Disease Control and Prevention |date=16 September 2022 |access-date=6 July 2023 |archive-date=7 July 2023 |archive-url=https://web.archive.org/web/20230707162416/https://www.cdc.gov/flu/prevent/vaxsupply.htm |url-status=live}}</ref>

A 2014 meta-analysis examined ten major studies on autism and vaccines involving 1.25 million children worldwide; it concluded that neither the vaccine preservative thimerosal ([[Chemistry:Mercury (element)|mercury]]), nor the MMR vaccine, which has never contained thimerosal,<ref>{{cite web |title=Frequently Asked Questions about Thimerosal |url=https://www.cdc.gov/vaccinesafety/concerns/thimerosal/faqs.html |access-date=21 February 2017 |publisher=Centers for Disease Control and Prevention |archive-date=7 May 2019 |archive-url=https://web.archive.org/web/20190507032946/https://www.cdc.gov/vaccinesafety/concerns/thimerosal/faqs.html |url-status=live}}</ref> lead to the development of ASDs.<ref name="Taylor 2014">{{cite journal |vauthors=Taylor LE, Swerdfeger AL, Eslick GD |title=Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies |journal=Vaccine |volume=32 |issue=29 |pages=3623–3629 |date=June 2014 |pmid=24814559 |doi=10.1016/j.vaccine.2014.04.085}}</ref> Despite this, misplaced parental concern has led to lower rates of childhood immunizations, [[Social:MMR vaccine and autism#Disease outbreaks|outbreaks of previously controlled childhood diseases]] in some countries, and the preventable deaths of several children.<ref name="vaccines">Vaccines and autism:
* {{cite journal |vauthors=Doja A, Roberts W |date=November 2006 |title=Immunizations and autism: a review of the literature |journal=The Canadian Journal of Neurological Sciences. Le Journal Canadien des Sciences Neurologiques |volume=33 |issue=4 |pages=341–346 |doi=10.1017/s031716710000528x |pmid=17168158 |doi-access=free}}
* {{cite journal |vauthors=Gerber JS, Offit PA |date=February 2009 |title=Vaccines and autism: a tale of shifting hypotheses |journal=Clinical Infectious Diseases |volume=48 |issue=4 |pages=456–461 |doi=10.1086/596476 |pmc=2908388 |pmid=19128068}}
* {{cite journal |vauthors=Gross L |date=May 2009 |title=A broken trust: lessons from the vaccine--autism wars |journal=[[Biology:PLOS Biology|PLOS Biology]] |volume=7 |issue=5 |pages=e1000114 |doi=10.1371/journal.pbio.1000114 |pmc=2682483 |pmid=19478850 |doi-access=free}}
* {{cite journal |vauthors=Paul R |date=June 2009 |title=Parents ask: Am I risking autism if I vaccinate my children? |journal=Journal of Autism and Developmental Disorders |volume=39 |issue=6 |pages=962–963 |doi=10.1007/s10803-009-0739-y |pmid=19363650 |s2cid=34467853}}
* {{cite journal |vauthors=Poland GA, Jacobson RM |date=January 2011 |title=The age-old struggle against the antivaccinationists |journal=The New England Journal of Medicine |volume=364 |issue=2 |pages=97–99 |doi=10.1056/NEJMp1010594 |pmid=21226573 |doi-access=free}}</ref><ref name="dublin">{{cite journal |vauthors=McBrien J, Murphy J, Gill D, Cronin M, O'Donovan C, Cafferkey MT |date=July 2003 |title=Measles outbreak in Dublin, 2000 |journal=The Pediatric Infectious Disease Journal |volume=22 |issue=7 |pages=580–584 |doi=10.1097/00006454-200307000-00002 |pmid=12867830}}</ref>

=== Etiological hypotheses ===
Several hypotheses have been presented that try to explain how and why autism develops by integrating known causes (genetic and environmental effects) and findings (neurobiological and somatic). Some are more comprehensive, such as the Pathogenetic Triad, which proposes and operationalizes three core features (an autistic personality, cognitive compensation, neuropathological burden) that interact to cause autism,<ref name="Sarovic">{{cite journal |vauthors=Sarovic D |date=November 2021 |title=A Unifying Theory for Autism: The Pathogenetic Triad as a Theoretical Framework |journal=Frontiers in Psychiatry |type=Review |volume=12 |page=767075 |doi=10.3389/fpsyt.2021.767075 |pmc=8637925 |pmid=34867553 |s2cid=244119594 |doi-access=free}}</ref> and the Intense World Theory, which explains autism through a hyper-active neurobiology that leads to an increased perception, attention, memory, and emotionality.<ref name="Markram">{{cite journal |vauthors=Markram K, Markram H |date=21 December 2010 |title=The intense world theory - a unifying theory of the neurobiology of autism |journal=Frontiers in Human Neuroscience |type=Review |volume=4 |issue= |page=224 |doi=10.3389/fnhum.2010.00224 |pmc=3010743 |pmid=21191475 |quote=The proposed neuropathology is hyper-functioning of local neural microcircuits, best characterized by hyper-reactivity and hyper-plasticity. Such hyper-functional microcircuits are speculated to become autonomous and memory trapped leading to the core cognitive consequences of hyper-perception, hyper-attention, hyper-memory and hyper-emotionality. The theory is centered on the neocortex and the amygdala, but could potentially be applied to all brain regions. (...) This may lead to obsessively detailed information processing of fragments of the world and an involuntarily and systematic decoupling of the autist from what becomes a painfully intense world. |doi-access=free}}</ref> There are also simpler hypotheses that explain only individual parts of the neurobiology or phenotype of autism, such as [[Social:Mind-blindness|mind-blindness]] (a decreased ability for [[Philosophy:Theory of mind|theory of mind]]), the [[Medicine:Weak central coherence theory|weak central coherence theory]], or the extreme male brain and [[Biology:Empathising–systemising theory|empathising–systemising theory]].

=== Evolutionary hypotheses ===

Research exploring the [[Biology:Evolution|evolution]]ary benefits of autism and associated genes has suggested that autistic people may have played a "unique role in technological spheres and understanding of natural systems" in the course of human development.<ref>{{cite web |vauthors=Spikins P |title=How our autistic ancestors played an important role in human evolution |url=https://theconversation.com/how-our-autistic-ancestors-played-an-important-role-in-human-evolution-73477 |website=The Conversation |language=en |date=27 March 2017 |access-date=28 June 2022 |archive-date=28 June 2022 |archive-url=https://web.archive.org/web/20220628105438/https://theconversation.com/how-our-autistic-ancestors-played-an-important-role-in-human-evolution-73477 |url-status=live}}</ref><ref>{{cite book |vauthors=Spikins P |veditors=Fitzgerald M |title=Recent Advances in Autism Spectrum Disorders |volume=II |date=6 March 2013 |language=en |chapter=The Stone Age Origins of Autism}}</ref> It has been suggested that it may have arisen as "a slight trade off for other traits that are seen as highly advantageous", providing "advantages in tool making and mechanical thinking", with speculation that the condition may "reveal itself to be the result of a balanced polymorphism, like sickle cell anemia, that is advantageous in a certain mixture of genes and disadvantageous in specific combinations".<ref>{{cite journal |vauthors=Lomelin DE |title=An Examination of Autism Spectrum Disorders in Relation to Human Evolution and Life History Theory |journal=Nebraska Anthropologist |date=2010 |volume=57 |url=https://digitalcommons.unl.edu/nebanthro/57/ |access-date=28 June 2022 |archive-date=9 May 2022 |archive-url=https://web.archive.org/web/20220509140740/https://digitalcommons.unl.edu/nebanthro/57/ |url-status=live}}</ref>

In 2011, a paper in ''Evolutionary Psychology'' proposed that autistic traits, including increased abilities for spatial intelligence, concentration and memory, could have been [[Biology:Natural selection|naturally selected]] to enable self-sufficient foraging in a more (although not completely) solitary environment, referred to as the "Solitary Forager Hypothesis".<ref>{{cite journal |vauthors=Reser JE |title=Conceptualizing the autism spectrum in terms of natural selection and behavioral ecology: the solitary forager hypothesis |journal=Evolutionary Psychology |volume=9 |issue=2 |pages=207–238 |date=May 2011 |pmid=22947969 |doi=10.1177/147470491100900209 |s2cid =25378900 |doi-access=free}}</ref><ref>{{cite news |title=Autism may have had advantages in humans' hunter-gatherer past, researcher believes |url=https://www.sciencedaily.com/releases/2011/06/110603122849.htm |website=ScienceDaily |agency=[[Organization:University of Southern California|University of Southern California]] |language=en |date=3 June 2011 |access-date=28 June 2022 |archive-date=28 June 2022 |archive-url=https://web.archive.org/web/20220628105438/https://www.sciencedaily.com/releases/2011/06/110603122849.htm |url-status=live}}</ref><ref>{{cite web |vauthors=Rudacille D |title=Lonely hunters |url=https://www.spectrumnews.org/opinion/lonely-hunters/ |website=Spectrum News |date=8 July 2011 |access-date=28 June 2022 |archive-date=16 August 2022 |archive-url=https://web.archive.org/web/20220816004226/https://www.spectrumnews.org/opinion/lonely-hunters/ |url-status=live}}</ref> A 2016 paper examines Asperger syndrome as "an alternative prosocial adaptive strategy" which may have developed as a result of the emergence of "collaborative morality" in the context of small-scale [[Biology:Hunter-gatherer|hunter-gathering]], i.e. where "a positive social reputation for making a contribution to group wellbeing and survival" becomes more important than complex social understanding.<ref>{{cite journal |vauthors=Spikins P, Wright B, Hodgson D |title=Are there alternative adaptive strategies to human pro-sociality? The role of collaborative morality in the emergence of personality variation and autistic traits |journal=Time and Mind |date=1 October 2016 |volume=9 |issue=4 |pages=289–313 |doi=10.1080/1751696X.2016.1244949 |s2cid=151820168 |issn=1751-696X |doi-access=free}}</ref>

Conversely, some multidisciplinary research suggests that [[Biology:Recent human evolution|recent human evolution]] may be a driving force in the rise of a number of medical conditions in recent human populations, including autism. Studies in [[Medicine:Evolutionary medicine|evolutionary medicine]] indicate that as biological evolution becomes outpaced by cultural evolution, disorders linked to bodily dysfunction increase in prevalence due to a lack of contact with pathogens and negative environmental conditions that once widely affected ancestral populations. Because natural selection primarily favors reproduction over health and longevity, the lack of this impetus to adapt to certain harmful circumstances creates a tendency for genes in descendant populations to over-express themselves, which may cause a wide array of maladies, ranging from [[Medicine:Mental disorder|mental disorder]]s to [[Medicine:Autoimmune disease|autoimmune disease]]s.<ref>{{cite news |last=[[Organization:Harvard University|Harvard University]] |date=11 January 2020 |title=Ongoing human evolution could explain recent rise in certain disorders |work=ScienceDaily |url=https://www.sciencedaily.com/releases/2010/01/100111102538.htm |access-date=24 May 2020 |archive-date=6 February 2017 |archive-url=https://web.archive.org/web/20170206012836/https://www.sciencedaily.com/releases/2010/01/100111102538.htm |url-status=live}}</ref>

== Pathophysiology ==
{{Main|Biology:Mechanism of autism|Biology:Pathophysiology of autism}}

== Diagnosis ==
{{Main|Biology:Diagnosis of autism}}

== Conditions correlated or comorbid to autism ==
{{Main|Medicine:Conditions comorbid to autism spectrum disorders}}
Autism is correlated or comorbid with several personality traits/disorders.<ref name="Levy 2009" /> [[Medicine:Comorbidity|Comorbidity]] may increase with age and may worsen the course of youth with ASDs and make intervention and treatment more difficult. Distinguishing between ASDs and other diagnoses can be challenging because the traits of ASDs often overlap with symptoms of other disorders, and the characteristics of ASDs make traditional diagnostic procedures difficult.<ref name="Helverschou 2011">{{cite book |title=International handbook of autism and pervasive developmental disorders |vauthors=Helverschou SB, Bakken TL, Martinsen H |publisher=Springer |year=2011 |isbn=978-1-4419-8064-9 |veditors=Matson JL, Sturmey P |location=New York |pages=53–74 |chapter=Psychiatric Disorders in People with Autism Spectrum Disorders: Phenomenology and Recognition |oclc=746203105}}<!--|access-date=12 June 2013 --></ref><ref name="Underwood 2010">{{cite journal |vauthors=Underwood L, McCarthy J, Tsakanikos E |date=September 2010 |title=Mental health of adults with autism spectrum disorders and intellectual disability |journal=Current Opinion in Psychiatry |volume=23 |issue=5 |pages=421–6 |doi=10.1097/YCO.0b013e32833cfc18 |pmid=20613532 |s2cid=13735841}}</ref>

=== Correlations ===
Research [[Medicine:Autism and LGBT identities|indicates that autistic people]] are significantly more likely to be [[Social:LGBT community|LGBT]] than the general population.<ref name="Graham Holmes-2022" /> There is tentative evidence that [[Medicine:Gender dysphoria|gender dysphoria]] occurs more frequently in autistic people.<ref>{{cite journal |vauthors=Van Der Miesen AI, Hurley H, De Vries AL |year=2016 |title=Gender dysphoria and autism spectrum disorder: A narrative review |journal=International Review of Psychiatry |volume=28 |issue=1 |pages=70–80 |doi=10.3109/09540261.2015.1111199 |pmid=26753812 |s2cid=20918937 |doi-access=free}}</ref><ref>{{cite journal |vauthors=Glidden D, Bouman WP, Jones BA, Arcelus J |date=January 2016 |title=Gender Dysphoria and Autism Spectrum Disorder: A Systematic Review of the Literature |url=https://figshare.com/articles/journal_contribution/9620366 |journal=Sexual Medicine Reviews |volume=4 |issue=1 |pages=3–14 |doi=10.1016/j.sxmr.2015.10.003 |pmid=27872002 |s2cid=3454600 |access-date=19 June 2023 |archive-date=3 November 2023 |archive-url=https://web.archive.org/web/20231103124238/https://figshare.com/articles/journal_contribution/Gender_dysphoria_and_autism_spectrum_disorder_a_systematic_review_of_the_literature/9620366 |url-status=live}}</ref> A 2021 anonymized online survey of 16- to 90-year-olds revealed that autistic males are more likely to identify as bisexual than their non-autistic peers, while autistic females are more likely to identify as homosexual than non-autistic females do.<ref>{{cite journal |vauthors=Weir E, Allison C, Baron-Cohen S |date=November 2021 |title=The sexual health, orientation, and activity of autistic adolescents and adults |journal=Autism Research |volume=14 |issue=11 |pages=2342–2354 |doi=10.17863/CAM.74771 |pmid=34536071}}</ref>

People on the autism spectrum are significantly more likely to be [[Philosophy:Nontheism|non-theistic]] than members of the general population.<ref name=":42" />

=== Comorbidities ===
* The most common medical condition occurring in people with ASDs is seizure disorder or [[Medicine:Epilepsy|epilepsy]], which occurs in 11–39% of autistic people.<ref name="Ballaban-Gill & Tuchman">{{cite journal |vauthors=Ballaban-Gil K, Tuchman R |year=2000 |title=Epilepsy and epileptiform EEG: association with autism and language disorders |journal=Developmental Disabilities Research Reviews |volume=6 |issue=4 |pages=300–8 |doi=10.1002/1098-2779(2000)6:4<300::AID-MRDD9>3.0.CO;2-R |pmid=11107195 |doi-access=free}}</ref> The risk varies with age, cognitive level, and type of [[Medicine:Language disorder|language disorder]].<ref>{{cite journal |vauthors=Spence SJ, Schneider MT |date=June 2009 |title=The role of epilepsy and epileptiform EEGs in autism spectrum disorders |journal=Pediatric Research |volume=65 |issue=6 |pages=599–606 |doi=10.1203/PDR.0b013e31819e7168 |pmc=2692092 |pmid=19454962}}</ref>
* [[Medicine:Tuberous sclerosis|Tuberous sclerosis]], an [[Biology:Dominance (genetics)|autosomal dominant]] genetic condition in which non-malignant tumors grow in the brain and on other vital organs, is present in 1–4% of people with ASDs.<ref name="Wiznitzer">{{cite journal |vauthors=Wiznitzer M |date=September 2004 |title=Autism and tuberous sclerosis |journal=Journal of Child Neurology |volume=19 |issue=9 |pages=675–9 |doi=10.1177/08830738040190090701 |pmid=15563013 |s2cid=38157900}}</ref>
* [[Medicine:Intellectual disability|Intellectual disabilities]] are some of the most common comorbid disorders with ASDs. As diagnosis is increasingly being given to people with higher functioning autism, there is a tendency for the proportion with comorbid intellectual disability to decrease over time. In a 2019 study, it was estimated that approximately 30-40% of people diagnosed with ASD also have intellectual disability.<ref>{{cite journal |last1=Sala |first1=G. |last2=Hooley |first2=M. |last3=Attwood |first3=T. |date=2019 |title=Autism and Intellectual Disability: A Systematic Review of Sexuality and Relationship Education |journal=Sexuality and Disability |volume=37 |issue=3 |pages=353–382 |doi=10.1007/s11195-019-09577-4 |s2cid=255011485}}</ref> Recent research has suggested that autistic people with intellectual disability tend to have rarer, more harmful, genetic mutations than those found in people solely diagnosed with autism.<ref>{{cite journal |last1=Jensen |first1=M. |last2=Smolen |first2=C. |last3=Girirajan |first3=S. |date=2020 |title=Gene discoveries in autism are biased towards comorbidity with intellectual disability |journal=Journal of Medical Genetics |volume=57 |issue=9 |pages=647–652 |doi=10.1136/jmedgenet-2019-106476 |pmc=7483239 |pmid=32152248}}</ref> A number of genetic syndromes causing intellectual disability may also be comorbid with ASD, including [[Medicine:Fragile X syndrome|fragile X]], [[Medicine:Down syndrome|Down]], [[Medicine:Prader–Willi syndrome|Prader-Willi]], [[Medicine:Angelman syndrome|Angelman]], [[Unsolved:Williams syndrome|Williams syndrome]],<ref>{{cite journal |vauthors=Zafeiriou DI, Ververi A, Vargiami E |date=June 2007 |title=Childhood autism and associated comorbidities |journal=Brain & Development |volume=29 |issue=5 |pages=257–272 |doi=10.1016/j.braindev.2006.09.003 |pmid=17084999 |s2cid=16386209}}</ref> [[Medicine:Branched-chain keto acid dehydrogenase kinase deficiency|branched-chain keto acid dehydrogenase kinase deficiency]],<ref>{{cite web |last=Schenkman |first=Lauren |date=2023-02-21 |title=Dietary changes ease traits in rare autism-linked condition |url=https://www.spectrumnews.org/news/dietary-changes-ease-traits-in-rare-autism-linked-condition/ |access-date=2023-02-23 |website=Spectrum |language=en-US |archive-date=25 March 2023 |archive-url=https://web.archive.org/web/20230325004116/https://www.spectrumnews.org/news/dietary-changes-ease-traits-in-rare-autism-linked-condition/ |url-status=live}}</ref><ref>{{cite journal |vauthors=Tangeraas T, Constante JR, Backe PH, Oyarzábal A, Neugebauer J, Weinhold N, Boemer F, Debray FG, Ozturk-Hism B, Evren G, Tuba EF, Ummuhan O, Footitt E, Davison J, Martinez C, Bueno C, Machado I, Rodríguez-Pombo P, Al-Sannaa N, De Los Santos M, López JM, Ozturkmen-Akay H, Karaca M, Tekin M, Pajares S, Ormazabal A, Stoway SD, Artuch R, Dixon M, Mørkrid L, García-Cazorla A |date=2023-02-02 |title=BCKDK deficiency: a treatable neurodevelopmental disease amenable to newborn screening |journal=Brain |volume=146 |issue=7 |pages=3003–3013 |doi=10.1093/brain/awad010 |pmid=36729635}}</ref> and [[Medicine:SYNGAP1-related intellectual disability|SYNGAP1-related intellectual disability]].<ref>{{cite journal |display-authors=6 |vauthors=Satterstrom FK, Kosmicki JA, Wang J, Breen MS, De Rubeis S, An JY, Peng M, Collins R, Grove J, Klei L, Stevens C, Reichert J, Mulhern MS, Artomov M, Gerges S, Sheppard B, Xu X, Bhaduri A, Norman U, Brand H, Schwartz G, Nguyen R, Guerrero EE, Dias C, Betancur C, Cook EH, Gallagher L, Gill M, Sutcliffe JS, Thurm A, Zwick ME, Børglum AD, State MW, Cicek AE, Talkowski ME, Cutler DJ, Devlin B, Sanders SJ, Roeder K, Daly MJ, Buxbaum JD |date=February 2020 |title=Large-Scale Exome Sequencing Study Implicates Both Developmental and Functional Changes in the Neurobiology of Autism |journal=Cell |volume=180 |issue=3 |pages=568–584.e23 |doi=10.1016/j.cell.2019.12.036 |pmc=7250485 |pmid=31981491}}</ref><ref>{{cite journal |vauthors=Holder Jr JL, Hamdan FF, Michaud JL |date=2019 |title=SYNGAP1-Related Intellectual Disability |url=https://www.ncbi.nlm.nih.gov/books/NBK537721/ |journal=Gene Reviews |type=Review |pmid=30789692 |access-date=25 July 2020 |archive-date=2 April 2021 |archive-url=https://web.archive.org/web/20210402192137/https://www.ncbi.nlm.nih.gov/books/NBK537721/ |url-status=live}}</ref>
* [[Medicine:Learning disability|Learning disabilities]] are also highly comorbid in people with an ASD. Approximately 25–75% of people with an ASD also have some degree of a learning disability.<ref name="Obrien & Pearson">{{cite journal |vauthors=O'Brien G, Pearson J |date=June 2004 |title=Autism and learning disability |journal=Autism |volume=8 |issue=2 |pages=125–40 |doi=10.1177/1362361304042718 |pmid=15165430 |s2cid=17372893}}</ref>
* Various [[Medicine:Anxiety disorder|anxiety disorder]]s tend to co-occur with ASDs, with overall comorbidity rates of 7–84%.<ref name="Mash & Barkley">{{cite book |url=https://archive.org/details/childpsychopatho00mash_735 |title=Child Psychopathology |vauthors=Mash EJ, Barkley RA |publisher=The Guilford Press |year=2003 |isbn=978-1-57230-609-7 |location=New York |pages=[https://archive.org/details/childpsychopatho00mash_735/page/n421 409]–454 |url-access=limited}}</ref> They are common among children with ASD; there are no firm data, but studies have reported prevalences ranging from 11% to 84%. Many anxiety disorders have symptoms that are better explained by ASD itself, or are hard to distinguish from ASD's symptoms.<ref>{{cite journal |vauthors=White SW, Oswald D, Ollendick T, Scahill L |date=April 2009 |title=Anxiety in children and adolescents with autism spectrum disorders |journal=Clinical Psychology Review |volume=29 |issue=3 |pages=216–229 |doi=10.1016/j.cpr.2009.01.003 |pmc=2692135 |pmid=19223098}}</ref>
* Rates of comorbid [[Medicine:Depression (mood)|depression]] in people with an ASD range from 4–58%.<ref name="Lainhart">{{cite journal |vauthors=Lainhart J |year=1999 |title=Psychiatric problems in individuals with autism, their parents and siblings |journal=International Review of Psychiatry |volume=11 |issue=4 |pages=278–298 |doi=10.1080/09540269974177}}</ref>
* The relationship between ASD and [[Medicine:Schizophrenia|schizophrenia]] remains a controversial subject under continued investigation, and recent [[Meta-analysis|meta-analyses]] have examined genetic, environmental, infectious, and immune risk factors that may be shared between the two conditions.<ref>{{cite journal |vauthors=Chisholm K, Lin A, Abu-Akel A, Wood SJ |date=August 2015 |title=The association between autism and schizophrenia spectrum disorders: A review of eight alternate models of co-occurrence |url=http://pure-oai.bham.ac.uk/ws/files/22611324/Chisholm_et_al_Association_between_autism_and_schizophrenia_2015_Post_Print.pdf |journal=Neuroscience and Biobehavioral Reviews |volume=55 |pages=173–83 |doi=10.1016/j.neubiorev.2015.04.012 |pmid=25956249 |s2cid=21450062 |access-date=20 August 2019 |archive-date=8 June 2020 |archive-url=https://web.archive.org/web/20200608221602/http://pure-oai.bham.ac.uk/ws/files/22611324/Chisholm_et_al_Association_between_autism_and_schizophrenia_2015_Post_Print.pdf |url-status=live}}</ref><ref>{{cite journal |vauthors=Hamlyn J, Duhig M, McGrath J, Scott J |date=May 2013 |title=Modifiable risk factors for schizophrenia and autism—shared risk factors impacting on brain development |journal=Neurobiology of Disease |volume=53 |pages=3–9 |doi=10.1016/j.nbd.2012.10.023 |pmid=23123588 |s2cid=207067275}}</ref><ref>{{cite journal |vauthors=Crespi BJ, Thiselton DL |date=October 2011 |title=Comparative immunogenetics of autism and schizophrenia |journal=Genes, Brain and Behavior |volume=10 |issue=7 |pages=689–701 |doi=10.1111/j.1601-183X.2011.00710.x |pmid=21649858 |s2cid=851655 |doi-access=free}}</ref> [[Biology:Oxidative stress|Oxidative stress]], [[Biology:DNA damage (naturally occurring)|DNA damage]] and [[Biology:DNA|DNA]] repair have been postulated to play a role in the aetiopathology of both ASD and schizophrenia.<ref>{{cite journal |vauthors=Markkanen E, Meyer U, Dianov GL |date=June 2016 |title=DNA Damage and Repair in Schizophrenia and Autism: Implications for Cancer Comorbidity and Beyond |journal=[[Physics:International Journal of Molecular Sciences|International Journal of Molecular Sciences]] |volume=17 |issue=6 |page=856 |doi=10.3390/ijms17060856 |pmc=4926390 |pmid=27258260 |doi-access=free}}</ref>
* Deficits in ASD are often linked to behavior problems, such as difficulties following directions, being cooperative, and doing things on other people's terms.<ref name="Tsakanikos 2007">{{cite journal |vauthors=Tsakanikos E, Costello H, Holt G, Sturmey P, Bouras N |date=July 2007 |title=Behaviour management problems as predictors of psychotropic medication and use of psychiatric services in adults with autism |url=http://cogprints.org/6268/2/JADD_2007.pdf |journal=Journal of Autism and Developmental Disorders |volume=37 |issue=6 |pages=1080–5 |doi=10.1007/s10803-006-0248-1 |pmid=17053989 |s2cid=14272598 |access-date=23 March 2012 |archive-date=19 May 2012 |archive-url=https://web.archive.org/web/20120519000144/http://cogprints.org/6268/2/JADD_2007.pdf |url-status=live}}</ref> Symptoms similar to those of [[Medicine:Attention deficit hyperactivity disorder|attention deficit hyperactivity disorder]] (ADHD) can be part of an ASD diagnosis.<ref name="Rommelse et al.">{{cite journal |vauthors=Rommelse NN, Franke B, Geurts HM, Hartman CA, Buitelaar JK |date=March 2010 |title=Shared heritability of attention-deficit/hyperactivity disorder and autism spectrum disorder |journal=European Child & Adolescent Psychiatry |volume=19 |issue=3 |pages=281–95 |doi=10.1007/s00787-010-0092-x |pmc=2839489 |pmid=20148275}}</ref>
* [[Medicine:Sensory processing disorder|Sensory processing disorder]] is also comorbid with ASD, with comorbidity rates of 42–88%.<ref name="Baranek 2002">{{cite journal |vauthors=Baranek GT |date=October 2002 |title=Efficacy of sensory and motor interventions for children with autism |journal=Journal of Autism and Developmental Disorders |volume=32 |issue=5 |pages=397–422 |doi=10.1023/A:1020541906063 |pmid=12463517 |s2cid=16449130}}</ref>
* Starting in adolescence, some people with Asperger syndrome (26% in one sample)<ref name=":17">{{cite journal |vauthors=Lugnegård T, Hallerbäck MU, Gillberg C |date=May 2012 |title=Personality disorders and autism spectrum disorders: what are the connections? |journal=[[Medicine:Comprehensive Psychiatry|Comprehensive Psychiatry]] |volume=53 |issue=4 |pages=333–40 |doi=10.1016/j.comppsych.2011.05.014 |pmid=21821235}}</ref> fall under the criteria for the similar condition [[Medicine:Schizoid personality disorder|schizoid personality disorder]], which is characterized by a [[Social:Asociality|lack of interest in social relationships]], a tendency towards a solitary or sheltered lifestyle, secretiveness, emotional coldness, detachment and [[Philosophy:Apathy|apathy]].<ref name=":17" /><ref name=":16">{{cite journal |vauthors=Tantam D |date=December 1988 |title=Lifelong eccentricity and social isolation. II: Asperger's syndrome or schizoid personality disorder? |journal=The British Journal of Psychiatry |volume=153 |pages=783–91 |doi=10.1192/bjp.153.6.783 |pmid=3256377 |s2cid=39433805}}</ref><ref name=":5">{{cite book |title=Integrated Treatment for Co-Occurring Disorders: Personality Disorders and Addiction |vauthors=Ekleberry SC |publisher=[[Company:Routledge|Routledge]] |year=2008 |isbn=978-0-7890-3693-3 |pages=31–32 |chapter=Cluster A - Schizoid Personality Disorder and Substance Use Disorders |chapter-url=https://books.google.com/books?id=O5HY1xcfjEcC&pg=PA31}}</ref> Asperger syndrome was traditionally called "schizoid disorder of childhood."
* [[Medicine:Genetic disorder|Genetic disorder]]s - about 10–15% of autism cases have an identifiable Mendelian (single-gene) condition, [[Biology:Chromosome abnormality|chromosome abnormality]], or other genetic syndromes.<ref>{{cite journal |vauthors=Folstein SE, Rosen-Sheidley B |date=December 2001 |title=Genetics of autism: complex aetiology for a heterogeneous disorder |journal=Nature Reviews Genetics |volume=2 |issue=12 |pages=943–955 |doi=10.1038/35103559 |pmid=11733747 |s2cid=9331084}}</ref>
* Several [[Biology:Inborn errors of metabolism|metabolic defects]], such as [[Medicine:Phenylketonuria|phenylketonuria]], are associated with autistic symptoms.<ref name="Manzi">{{cite journal |vauthors=Manzi B, Loizzo AL, Giana G, Curatolo P |date=March 2008 |title=Autism and metabolic diseases |journal=Journal of Child Neurology |volume=23 |issue=3 |pages=307–314 |doi=10.1177/0883073807308698 |pmid=18079313 |s2cid=30809774}}</ref>{{Verify source|date=May 2022|reason=Needs confirmation that it is referring to ASD rather than to classic autism.}}
* Gastrointestinal problems are one of the most commonly [[Medicine:Conditions comorbid to autism spectrum disorders|co-occurring medical conditions]] in autistic people.<ref name="IsraelyanMargolis2018">{{cite journal |vauthors=Israelyan N, Margolis KG |date=June 2018 |title=Serotonin as a link between the gut-brain-microbiome axis in autism spectrum disorders |journal=Pharmacological Research |type=Review |volume=132 |pages=1–6 |doi=10.1016/j.phrs.2018.03.020 |pmc=6368356 |pmid=29614380}}</ref> These are linked to greater social impairment, irritability, language impairments, mood changes, and behavior and sleep problems.<ref name="IsraelyanMargolis2018" /><ref name="WasilewskaKlukowski2015">{{cite journal |vauthors=Wasilewska J, Klukowski M |year=2015 |title=Gastrointestinal symptoms and autism spectrum disorder: links and risks - a possible new overlap syndrome |journal=Pediatric Health, Medicine and Therapeutics |type=Review |volume=6 |pages=153–166 |doi=10.2147/PHMT.S85717 |pmc=5683266 |pmid=29388597 |doi-access=free}}</ref><ref name="RaoGershon2016">{{cite journal |vauthors=Rao M, Gershon MD |date=September 2016 |title=The bowel and beyond: the enteric nervous system in neurological disorders |journal=Nature Reviews. Gastroenterology & Hepatology |type=Review |volume=13 |issue=9 |pages=517–528 |doi=10.1038/nrgastro.2016.107 |pmc=5005185 |pmid=27435372 |quote=immune dysregulation, GI inflammation, malfunction of the ANS, genetic and metabolic activity of the microbiome, and dietary metabolites may contribute to brain dysfunction and neuroinflammation depending upon individual genetic vulnerability}}</ref> A 2015 review proposed that immune, [[Biology:Gastrointestinal tract|gastrointestinal]] inflammation, malfunction of the autonomic nervous system, [[Biology:Gut microbiota|gut flora]] alterations, and food [[Biology:Metabolite|metabolite]]s may cause brain neuroinflammation and dysfunction.<ref name="WasilewskaKlukowski2015" /> A 2016 review concludes that [[Biology:Enteric nervous system|enteric nervous system]] abnormalities might play a role in neurological disorders such as autism. Neural connections and the immune system are a pathway that may allow diseases originated in the intestine to spread to the brain.<ref name="RaoGershon2016" />
* Sleep problems affect about two-thirds of people with ASD at some point in childhood. These most commonly include symptoms of [[Medicine:Insomnia|insomnia]], such as difficulty falling asleep, frequent nocturnal awakenings, and early morning awakenings. Sleep problems are associated with difficult behaviors and family stress, and are often a focus of clinical attention over and above the primary ASD diagnosis.<ref>{{cite journal |vauthors=Richdale AL, Schreck KA |date=December 2009 |title=Sleep problems in autism spectrum disorders: prevalence, nature, & possible biopsychosocial aetiologies |journal=Sleep Medicine Reviews |volume=13 |issue=6 |pages=403–411 |doi=10.1016/j.smrv.2009.02.003 |pmid=19398354}}</ref>
* [[Medicine:Dysautonomia|Dysautonomia]] is common in ASD, affecting heart rate and blood pressure and causing symptoms such as brain fog, blurry vision, and bowel dysfunction.<ref>{{cite journal |vauthors=Al-Beltagi M|date=May 2021 |title=Autism medical comorbidities |journal=World Journal of Clinical Pediatrics |volume=10 |issue=3 |pages=15–28 |doi=10.5409/wjcp.v10.i3.15 |pmid=33972922 |pmc=8085719 |doi-access=free}}</ref> It can be diagnosed through a Tilt table test.<ref>{{cite journal |vauthors=Mustafa H, Fessel J, Barwise J, Shannon J, Raj S, Dierich A, Biaggioni I, Robertson D, Warner S |date=January 2012 |title=Dysautonomia: Perioperative Implications |journal=Anesthesiology |volume=116 |issue= 1 |pages=205–215 |doi=10.1097/ALN.0b013e31823db712 |pmid=22143168 |pmc=3296831 |s2cid=42572502}}</ref>
* The frequency of ASD is 10 times higher in [[Medicine:Mast cell activation syndrome|Mast cell activation syndrome]] patients than in the general population. This immunological condition causes cardiovascular, dermatological, gastrointestinal, neurological, and respiratory problems.<ref>{{cite journal |vauthors=Theoharides C, Angelidou A, Alysandratos K, Zhang B, Asadi S, Francis K, Taniato E, Kalegeromitros D |date=January 2022 |title=Mast cell activation and autism |journal=Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease |volume=1822 |issue= 1 |pages=34–41 |doi=10.1016/j.bbadis.2010.12.017 |pmid=21193035}}</ref>

== Management ==
{{Main|Medicine:Autism therapies}}
There is no treatment as such for autism,<ref>{{cite web |date=2 May 2019 |title=Fake and harmful autism 'treatments' |url=https://www.nhs.uk/conditions/autism/autism-and-everyday-life/fake-and-harmful-treatments/ |access-date=29 April 2022 |website=nhs.uk |language=en |archive-date=1 December 2022 |archive-url=https://web.archive.org/web/20221201180111/https://www.nhs.uk/conditions/autism/autism-and-everyday-life/fake-and-harmful-treatments/ |url-status=live}}</ref> and many sources advise that this is not an appropriate goal,<ref>{{cite web |title=Making information and the words we use accessible |url=https://www.england.nhs.uk/learning-disabilities/about/get-involved/involving-people/making-information-and-the-words-we-use-accessible/ |access-date=29 April 2022 |website=NHS England |archive-date=16 July 2023 |archive-url=https://web.archive.org/web/20230716192201/https://www.england.nhs.uk/learning-disabilities/about/get-involved/involving-people/making-information-and-the-words-we-use-accessible/ |url-status=live}}</ref><ref>{{cite web |title=How to talk about autism |url=https://www.autism.org.uk/what-we-do/help-and-support/how-to-talk-about-autism |access-date=29 April 2022 |website=autism.org.uk |language=en |archive-date=7 March 2022 |archive-url=https://web.archive.org/web/20220307130201/https://www.autism.org.uk/what-we-do/help-and-support/how-to-talk-about-autism |url-status=live}}</ref> although treatment of co-occurring conditions remains an important goal.<ref>{{cite web |title=The psychiatric management of autism in adults (CR228) |url=https://www.rcpsych.ac.uk/improving-care/campaigning-for-better-mental-health-policy/college-reports/2020-college-reports/cr228 |access-date=29 April 2022 |website=Royal College of Psychiatrists (UK) |language=en |archive-date=2 June 2023 |archive-url=https://web.archive.org/web/20230602113739/https://www.rcpsych.ac.uk/improving-care/campaigning-for-better-mental-health-policy/college-reports/2020-college-reports/cr228 |url-status=live}}</ref> There is no cure for autism as of 2023, nor can any of the known treatments significantly reduce brain mutations caused by autism, although those who require little to no support are more likely to experience a lessening of symptoms over time.<ref name="McPartland">{{cite journal |vauthors=McPartland J, Klin A |title=Asperger's syndrome |journal=Adolescent Medicine Clinics |volume=17 |issue=3 |pages=771–88; abstract xiii |date=October 2006 |pmid=17030291 |doi=10.1016/j.admecli.2006.06.010 |doi-broken-date=31 January 2024}}</ref><ref name="Woodbury-Smith">{{cite journal |vauthors=Woodbury-Smith MR, Volkmar FR |s2cid=12808995 |title=Asperger syndrome |journal=European Child & Adolescent Psychiatry |volume=18 |issue=1 |pages=2–11 |date=June 2008 |pmid=18563474 |doi=10.1007/s00787-008-0701-0 |url=http://www.ssoar.info/ssoar/handle/document/12424 |access-date=21 September 2018 |archive-date=31 March 2019 |archive-url=https://web.archive.org/web/20190331141120/https://www.ssoar.info/ssoar/handle/document/12424 |url-status=live}}</ref><ref name="Coplan">{{cite journal |vauthors=Coplan J, Jawad AF |s2cid=8440775 |title=Modeling clinical outcome of children with autistic spectrum disorders |journal=Pediatrics |volume=116 |issue=1 |pages=117–22 |date=July 2005 |pmid=15995041 |doi=10.1542/peds.2004-1118}}</ref> Several interventions can help children with autism,<ref name="HHS2017">{{cite web |title=10 Facts about Autism Spectrum Disorder (ASD) |url=https://www.acf.hhs.gov/ecd/10-facts-about-asd |access-date=6 November 2019 |website=Early Childhood Development {{!}} ACF |language=en |archive-date=6 November 2019 |archive-url=https://web.archive.org/web/20191106044902/https://www.acf.hhs.gov/ecd/10-facts-about-asd |url-status=live}}</ref> and no single treatment is best, with treatment typically tailored to the child's needs.<ref name="Myers 2007">{{cite journal |vauthors=Myers SM, Johnson CP |date=November 2007 |title=Management of children with autism spectrum disorders |journal=Pediatrics |volume=120 |issue=5 |pages=1162–1182 |doi=10.1542/peds.2007-2362 |pmid=17967921 |doi-access=free}}</ref> Studies of interventions have methodological problems that prevent definitive conclusions about [[Chemistry:Efficacy|efficacy]],<ref>{{cite journal |display-authors=6 |vauthors=Ospina MB, Krebs Seida J, Clark B, Karkhaneh M, Hartling L, Tjosvold L, Vandermeer B, Smith V |year=2008 |title=Behavioural and developmental interventions for autism spectrum disorder: a clinical systematic review |journal=PLOS ONE |volume=3 |issue=11 |pages=e3755 |bibcode=2008PLoSO...3.3755O |doi=10.1371/journal.pone.0003755 |pmc=2582449 |pmid=19015734 |doi-access=free}}</ref> but the development of evidence-based interventions has advanced.<ref name=":06">{{cite journal |vauthors=Smith T, Iadarola S |date=2 November 2015 |title=Evidence Base Update for Autism Spectrum Disorder |journal=Journal of Clinical Child and Adolescent Psychology |publisher=Taylor & Francis |issn=1537-4416 |volume=44 |issue=6 |pages=897–922 |doi=10.1080/15374416.2015.1077448 |pmid=26430947 |doi-access=free}}</ref>

The main goals of treatment are to lessen associated deficits and family distress, and to increase [[Philosophy:Quality of life|quality of life]] and functional independence. In general, higher [[Philosophy:Intelligence quotient|IQs]] are correlated with greater responsiveness to treatment and improved treatment outcomes.<ref>{{cite journal |vauthors=Eldevik S, Hastings RP, Hughes JC, Jahr E, Eikeseth S, Cross S |title=Meta-analysis of Early Intensive Behavioral Intervention for children with autism |journal=Journal of Clinical Child and Adolescent Psychology |volume=38 |issue=3 |pages=439–450 |date=May 2009 |pmid=19437303 |doi=10.1080/15374410902851739 |publisher=Taylor & Francis |s2cid=205873629 |citeseerx=10.1.1.607.9620}}</ref><ref name="Smith" /> Behavioral, psychological, education, and/or skill-building interventions may be used to assist autistic people to learn life skills necessary for living independently,<ref>{{cite journal |vauthors=Matson JL, Dempsey T, Fodstad JC |title=The effect of Autism Spectrum Disorders on adaptive independent living skills in adults with severe intellectual disability |journal=Research in Developmental Disabilities |volume=30 |issue=6 |pages=1203–1211 |date=November 2009 |pmid=19450950 |doi=10.1016/j.ridd.2009.04.001 |publisher=[[Company:Elsevier|Elsevier]] |eissn=1873-3379}}</ref> as well as other social, communication, and language skills. Therapy also aims to reduce challenging behaviors and build upon strengths.<ref>{{cite web |title=NIMH » Autism Spectrum Disorder |url=https://www.nimh.nih.gov/health/publications/autism-spectrum-disorder/index.shtml |access-date=8 April 2021 |website=National Institute of Mental Health (US) |publisher=[[Organization:National Institutes of Health|National Institutes of Health]] (US) |archive-date=23 April 2021 |archive-url=https://web.archive.org/web/20210423081752/https://www.nimh.nih.gov/health/publications/autism-spectrum-disorder/index.shtml |url-status=live}}</ref>

Intensive, sustained [[Social:Special education|special education]] programs and behavior therapy early in life may help children acquire self-care, language, and job skills.<ref name="Myers 2007" /> Although evidence-based interventions for autistic children vary in their methods, many adopt a [[Medicine:Psychoeducation|psychoeducation]]al approach to enhancing cognitive, communication, and social skills while minimizing problem behaviors. While medications have not been found to help with core symptoms, they may be used for associated symptoms, such as irritability, inattention, or repetitive behavior patterns.<ref name="Ji2015">{{cite journal |vauthors=Ji N, Findling RL |date=March 2015 |title=An update on pharmacotherapy for autism spectrum disorder in children and adolescents |journal=Current Opinion in Psychiatry |volume=28 |issue=2 |pages=91–101 |doi=10.1097/YCO.0000000000000132 |pmid=25602248 |s2cid=206141453}}</ref>

=== Non-pharmacological interventions ===
Intensive, sustained [[Social:Special education|special education]] or [[Social:Remedial education|remedial education]] programs and [[Philosophy:Behaviour therapy|behavior therapy]] early in life may help children acquire self-care, social, and job skills. Available approaches include [[Philosophy:Applied behavior analysis|applied behavior analysis]], developmental models, structured teaching, [[Social:Speech–language pathology|speech and language therapy]], [[Medicine:Cognitive behavioral therapy|cognitive behavioral therapy]],<ref name="Wang Zhao Huang Chen 2021 p.">{{cite journal |vauthors=Wang X, Zhao J, Huang S, Chen S, Zhou T, Li Q, Luo X, Hao Y |display-authors=6 |title=Cognitive Behavioral Therapy for Autism Spectrum Disorders: A Systematic Review |journal=Pediatrics  |volume=147 |issue=5 |date=May 2021 |pmid=33888566 |doi=10.1542/peds.2020-049880 |publisher=American Academy of Pediatrics (AAP) |s2cid=233370479 |doi-access=free}}</ref> [[Philosophy:Social skills|social skills]] therapy, and [[Medicine:Occupational therapy|occupational therapy]].<ref name="Myers">{{cite journal |vauthors=Myers SM, Johnson CP |title=Management of children with autism spectrum disorders |journal=Pediatrics |volume=120 |issue=5 |pages=1162–1182 |date=November 2007 |pmid=17967921 |doi=10.1542/peds.2007-2362 |url=http://pediatrics.aappublications.org/cgi/content/full/120/5/1162 |s2cid=1656920 |doi-access=free |archive-url=https://web.archive.org/web/20090612191201/http://pediatrics.aappublications.org/cgi/content/full/120/5/1162 |archive-date=12 June 2009}}</ref> Among these approaches, interventions either treat autistic features comprehensively, or focus treatment on a specific area of deficit.<ref name="Smith" /> Generally, when educating those with autism, specific tactics may be used to effectively relay information to these people. Using as much social interaction as possible is key in targeting the inhibition autistic people experience concerning person-to-person contact. Additionally, research has shown that employing semantic groupings, which involves assigning words to typical conceptual categories, can be beneficial in fostering learning.<ref>{{cite book |vauthors=Sigman M, Capps L |title=Children with Autism: A Developmental Perspective |location=Cambridge |publisher=Harvard University Press |date=2002 |pages=178–179 |isbn=978-0-674-05313-7}}</ref>

There has been increasing attention to the development of evidence-based interventions for autistic young children. Three theoretical frameworks outlined for early childhood intervention include [[Philosophy:Applied behavior analysis|applied behavior analysis]] (ABA), [[Medicine:Developmental social-pragmatic model|the developmental social-pragmatic model]] (DSP) and [[Medicine:Cognitive behavioral therapy|cognitive behavioral therapy]] (CBT).<ref name="Wang Zhao Huang Chen 2021 p." /><ref name="Smith" /> Although ABA therapy has a strong evidence base, particularly in regard to early intensive home-based therapy, ABA's effectiveness may be limited by diagnostic severity and IQ of the person affected by ASD.<ref>{{cite journal |vauthors=Rogers SJ, Vismara LA |title=Evidence-based comprehensive treatments for early autism |journal=Journal of Clinical Child and Adolescent Psychology |publisher=Taylor & Francis |issn=1537-4416 |volume=37 |issue=1 |pages=8–38 |date=January 2008 |pmid=18444052 |pmc=2943764 |doi=10.1080/15374410701817808}}</ref> The ''Journal of Clinical Child and Adolescent Psychology'' has published a paper deeming two early childhood interventions "well-established": individual comprehensive ABA, and focused teacher-implemented ABA combined with DSP.<ref name="Smith">{{cite journal |vauthors=Smith T, Iadarola S |title=Evidence Base Update for Autism Spectrum Disorder |journal=Journal of Clinical Child and Adolescent Psychology |volume=44 |issue=6 |pages=897–922 |date=2015 |pmid=26430947 |doi=10.1080/15374416.2015.1077448 |publisher=Taylor & Francis |issn=1537-4416 |doi-access=free}}</ref>

Another [[Evidence-based practice|evidence-based]] intervention that has demonstrated efficacy is a parent training model, which teaches parents how to implement various ABA and DSP techniques themselves.<ref name="Smith" /> Various DSP programs have been developed to explicitly deliver intervention systems through at-home parent implementation.

In October 2015, the American Academy of Pediatrics (AAP) proposed new evidence-based recommendations for early interventions in ASD for children under 3.<ref name="APP2015">{{cite journal |vauthors=Zwaigenbaum L, Bauman ML, Choueiri R, Kasari C, Carter A, Granpeesheh D, Mailloux Z, Smith Roley S, Wagner S, Fein D, Pierce K, Buie T, Davis PA, Newschaffer C, Robins D, Wetherby A, Stone WL, Yirmiya N, Estes A, Hansen RL, McPartland JC, Natowicz MR |display-authors=6 |title=Early Intervention for Children With Autism Spectrum Disorder Under 3 Years of Age: Recommendations for Practice and Research |journal=Pediatrics |volume=136 |issue=Supplement 1 |pages=S60-81 |date=October 2015 |pmid=26430170 |doi=10.1542/peds.2014-3667E |pmc=9923898 |doi-access=free}}</ref> These recommendations emphasize early involvement with both developmental and behavioral methods, support by and for parents and caregivers, and a focus on both the core and associated symptoms of ASD.<ref name="APP2015" /> But a [[Organization:Cochrane (organisation)|Cochrane]] review found no evidence that early intensive behavioral intervention (EIBI) is effective in reducing behavioral problems associated with autism in most autistic children, though it did improve IQ and language skills.<ref name=":4" /> The Cochrane review acknowledged that this may be due to the low quality of studies available on EIBI and therefore providers should recommend EIBI based on their clinical judgment and the family's preferences.<ref name=":4" /> No adverse effects of EIBI treatment were found.<ref name=":4">{{cite journal |vauthors=Reichow B, Hume K, Barton EE, Boyd BA |title=Early intensive behavioral intervention (EIBI) for young children with autism spectrum disorders (ASD) |journal=[[Cochrane Library#The Cochrane Database of Systematic Reviews|The Cochrane Database of Systematic Reviews]] |volume=5 |issue=10 |pages=CD009260 |date=May 2018 |pmid=29742275 |pmc=6494600 |doi=10.1002/14651858.CD009260.pub3}}</ref> A meta-analysis in that same database indicates that due to the degrees of severity in ASD, there is variable responses to differing early ABA interventions.<ref name="Cochrane" />

ASD treatment generally focuses on behavioral and educational interventions to target its two core symptoms: social communication deficits and restricted, repetitive behaviors.<ref name=":7" /> If symptoms continue after behavioral strategies have been implemented, some medications can be recommended to target specific symptoms or co-existing problems such as restricted and repetitive behaviors (RRBs), anxiety, depression, hyperactivity/inattention and sleep disturbance.<ref name=":7">{{cite web |url=https://www.uptodate.com/contents/autism-spectrum-disorder-in-children-and-adolescents-pharmacologic-interventions |title=Autism spectrum disorder in children and adolescents: Pharmacologic interventions |vauthors=Weissman L |date=March 2020 |access-date=17 March 2020 |archive-date=20 September 2022 |archive-url=https://web.archive.org/web/20220920172640/https://www.uptodate.com/contents/autism-spectrum-disorder-in-children-and-adolescents-pharmacologic-interventions |url-status=live}}</ref> [[Chemistry:Melatonin|Melatonin]], for example, can be used for sleep problems.<ref>{{cite journal |vauthors=Williams Buckley A, Hirtz D, Oskoui M, ''et al'' |title=Practice guideline: Treatment for insomnia and disrupted sleep behavior in children and adolescents with autism spectrum disorder: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology |journal=Neurology |volume=94 |issue=9 |pages=392–404 |date=March 2020 |pmid=32051244 |pmc=7238942 |doi=10.1212/WNL.0000000000009033}}</ref>

Several parent-mediated behavioral therapies target social communication deficits in children with autism, but their efficacy in treating RRBs is uncertain.<ref>{{cite journal |vauthors=Harrop C |title=Evidence-based, parent-mediated interventions for young children with autism spectrum disorder: The case of restricted and repetitive behaviors |language=en-US |journal=Autism |volume=19 |issue=6 |pages=662–72 |date=August 2015 |pmid=25186943 |doi=10.1177/1362361314545685 |s2cid=32326472}}</ref>

==== Education ====
[[File:Opening a window to the autistic brain.jpg|alt=A young child points, in front of a woman who smiles and points in the same direction.|thumb|An autistic three-year-old points to fish in an aquarium, as part of an experiment on the effect of intensive shared-attention training on language development.<ref name="Powell">{{cite journal |vauthors=Powell K |date=August 2004 |title=Opening a window to the autistic brain |journal=PLOS Biology |volume=2 |issue=8 |pages=E267 |doi=10.1371/journal.pbio.0020267 |pmc=509312 |pmid=15314667 |doi-access=free}}</ref>]]
Educational interventions often used include [[Philosophy:Applied behavior analysis|applied behavior analysis]] (ABA), developmental models, structured teaching, speech and language therapy and [[Philosophy:Social skills|social skills]] therapy.<ref name="Myers 2007" /> Among these approaches, interventions either treat autistic features comprehensively, or focalize treatment on a specific area of deficit.<ref name=":06" />

The quality of research for early intensive behavioral intervention (EIBI)—a treatment procedure incorporating over thirty hours per week of the [[Philosophy:Discrete trial training|structured type of ABA]] that is carried out with very young children—is low; more vigorous research designs with larger sample sizes are needed.<ref name=":4" /> Two theoretical frameworks outlined for early childhood intervention include [[Philosophy:Discrete trial training|structured]] and [[Medicine:Pivotal response treatment|naturalistic]] ABA interventions, and developmental social pragmatic models (DSP).<ref name=":06" /> One interventional strategy utilizes a parent training model, which teaches parents how to implement various ABA and DSP techniques, allowing for parents to disseminate interventions themselves.<ref name=":06" /> Various DSP programs have been developed to explicitly deliver intervention systems through at-home parent implementation. Despite the recent development of parent training models, these interventions have demonstrated effectiveness in numerous studies, being evaluated as a probable efficacious mode of treatment.<ref name=":06" /> [[Philosophy:Discrete trial training|Early, intensive ABA therapy]] has demonstrated effectiveness in enhancing communication and adaptive functioning in preschool children;<ref name="Myers 2007" /><ref>{{cite journal |last=Virués-Ortega |first=Javier |date=1 June 2010 |title=Applied behavior analytic intervention for autism in early childhood: Meta-analysis, meta-regression and dose–response meta-analysis of multiple outcomes |url=https://www.sciencedirect.com/science/article/pii/S0272735810000218 |journal=Clinical Psychology Review |language=en |volume=30 |issue=4 |pages=387–399 |doi=10.1016/j.cpr.2010.01.008 |pmid=20223569 |issn=0272-7358 |access-date=17 June 2023 |archive-date=3 November 2023 |archive-url=https://web.archive.org/web/20231103124300/https://www.sciencedirect.com/science/article/abs/pii/S0272735810000218 |url-status=live}}</ref> it is also well-established for improving the intellectual performance of that age group.<ref name="Myers 2007" />

In 2018, a Cochrane meta-analysis database concluded that some recent research is beginning to suggest that because of the heterology of ASD, there are two different ABA teaching approaches to acquiring [[Social:Spoken language|spoken language]]: children with more general [[Medicine:Expressive language disorder|expressive language delays]] respond sufficiently to the [[Medicine:Pivotal response treatment|naturalistic approach]], whereas children with significant [[Medicine:Mixed receptive-expressive language disorder|receptive language delays]] require [[Philosophy:Discrete trial training|discrete trial training]]—the structured and intensive form of ABA.<ref name="Cochrane">{{cite journal |vauthors=Brignell A, Chenausky KV, Song H, Zhu J, Suo C, Morgan AT |title=Communication interventions for autism spectrum disorder in minimally verbal children |journal=[[Cochrane Library#The Cochrane Database of Systematic Reviews|The Cochrane Database of Systematic Reviews]]  |volume=2018 |issue=11 |pages=CD012324 |date=November 2018 |pmid=30395694 |pmc=6516977 |doi=10.1002/14651858.CD012324.pub2}}</ref> A 2023 semi-randomized control trial study of 168 participants showed similar findings.<ref name=AutismResearch2023Study>{{cite journal|author=Kasari C, Shire S, Shih W, Landa R, Levato L, Smith T|title=Spoken language outcomes in limited language preschoolers with autism and global developmental delay: RCT of early intervention approaches|journal=Autism Research|date=June 2023|volume=16|issue=6|pages=1236–1246|doi=10.1002/aur.2932|pmc=10460274|pmid=37070270|pmc-embargo-date=June 1, 2024 }}</ref>

Similarly, a teacher-implemented intervention that utilizes a more [[Medicine:Pivotal response treatment|naturalistic form of ABA]] combined with a developmental social pragmatic approach has been found to be beneficial in improving social-communication skills in young children, although there is less evidence in its treatment of global symptoms.<ref name=":06" /> Neuropsychological reports are often poorly communicated to educators, resulting in a gap between what a report recommends and what education is provided.<ref name="Kanne 2008">{{cite journal |vauthors=Kanne SM, Randolph JK, Farmer JE |date=December 2008 |title=Diagnostic and assessment findings: a bridge to academic planning for children with autism spectrum disorders |journal=Neuropsychology Review |volume=18 |issue=4 |pages=367–384 |doi=10.1007/s11065-008-9072-z |pmid=18855144 |s2cid=21108225}}</ref> The appropriateness of including children with varying severity of autism spectrum disorders in the general education population is a subject of current debate among educators and researchers.<ref>{{cite journal |vauthors=Simpson RL, de Boer-Ott SR, Smith-Myles B |year=2003 |title=Inclusion of Learners with Autism Spectrum Disorders in General Education Settings |url=http://www.nursingcenter.com/pdf.asp?AID=520301 |journal=Topics in Language Disorders |volume=23 |issue=2 |pages=116–133 |doi=10.1097/00011363-200304000-00005 |archive-url=https://web.archive.org/web/20110714215923/http://www.nursingcenter.com/pdf.asp?AID=520301 |archive-date=14 July 2011 |s2cid=143733343}}</ref>

=== Pharmacological interventions ===
Medications may be used to treat ASD symptoms that interfere with integrating a child into home or school when behavioral treatment fails.<ref name="San2016">{{cite journal |vauthors=Sanchack KE, Thomas CA |date=December 2016 |title=Autism Spectrum Disorder: Primary Care Principles |journal=American Family Physician |volume=94 |issue=12 |pages=972–979 |pmid=28075089}}</ref> They may also be used for associated health problems, such as ADHD, [[Medicine:Anxiety disorder|anxiety]], or if the person is hurting themself or aggressive with others,<ref name="San2016" /><ref>{{cite journal |last1=Iffland |first1=Michelle |last2=Livingstone |first2=Nuala |last3=Jorgensen |first3=Mikaela |last4=Hazell |first4=Philip |last5=Gillies |first5=Donna |date=2023-10-09 |editor-last=Cochrane Developmental, Psychosocial and Learning Problems Group |title=Pharmacological intervention for irritability, aggression, and self-injury in autism spectrum disorder (ASD) |journal=[[Cochrane Library#The Cochrane Database of Systematic Reviews|The Cochrane Database of Systematic Reviews]] |language=en |volume=2023 |issue=10 |pages=CD011769 |doi=10.1002/14651858.CD011769.pub2 |pmc=10561353 |pmid=37811711 |pmc-embargo-date=October 9, 2024}}</ref> but their routine prescription for ASD's core features is not recommended.<ref name="Siafis2022">{{cite journal |vauthors=Siafis S, Çıray O, Wu H, Schneider-Thoma J, Bighelli I, Krause M, Rodolico A, Ceraso A, Deste G, Huhn M, Fraguas D, San José Cáceres A, Mavridis D, Charman T, Murphy DG, Parellada M, Arango C, Leucht S |date=2022 |title=Pharmacological and dietary-supplement treatments for autism spectrum disorder: a systematic review and network meta-analysis |journal=Molecular Autism |volume=13 |issue=1 |page=10 |doi=10.1186/s13229-022-00488-4 |pmid=35246237|pmc=8896153 |doi-access=free}}</ref> More than half of US children diagnosed with ASD are prescribed psychoactive drugs or [[Chemistry:Anticonvulsant|anticonvulsant]]s, with the most common drug classes being [[Chemistry:Antidepressant|antidepressant]]s, [[Chemistry:Stimulant|stimulant]]s, and [[Chemistry:Antipsychotic|antipsychotic]]s.<ref name="Oswald DP 2006">{{cite journal |vauthors=Oswald DP, Sonenklar NA |date=June 2007 |title=Medication use among children with autism spectrum disorders |journal=Journal of Child and Adolescent Psychopharmacology |volume=17 |issue=3 |pages=348–355 |doi=10.1089/cap.2006.17303 |pmid=17630868}}</ref><ref name="ReferenceA">{{cite journal |vauthors=Doyle CA, McDougle CJ |date=September 2012 |title=Pharmacologic treatments for the behavioral symptoms associated with autism spectrum disorders across the lifespan |journal=Dialogues in Clinical Neuroscience |volume=14 |issue=3 |pages=263–279 |doi=10.31887/DCNS.2012.14.3/cdoyle |pmc=3513681 |pmid=23226952}}</ref> The [[Chemistry:Atypical antipsychotic|atypical antipsychotic]] drugs [[Chemistry:Risperidone|risperidone]] and [[Chemistry:Aripiprazole|aripiprazole]] are FDA-approved for treating associated aggressive and self-injurious behaviors.<ref name="Ji2015" /><ref>{{cite journal |vauthors=Leskovec TJ, Rowles BM, Findling RL |year=2008 |title=Pharmacological treatment options for autism spectrum disorders in children and adolescents |journal=Harvard Review of Psychiatry |volume=16 |issue=2 |pages=97–112 |doi=10.1080/10673220802075852 |pmid=18415882 |s2cid=26112061}}</ref> But their side effects must be weighed against their potential benefits, and autistic people may respond atypically.<ref name="Ji2015" /> Side effects may include weight gain, tiredness, drooling, and aggression.<ref name="Ji2015" /> Some emerging data show positive effects of [[Chemistry:Aripiprazole|aripiprazole]] and [[Chemistry:Risperidone|risperidone]] on restricted and repetitive behaviors (i.e., [[Medicine:Stimming|stimming]]; e.g., flapping, twisting, complex whole-body movements),<ref name="Siafis2022" /> but due to the small sample size and different focus of these studies and the concerns about its side effects, antipsychotics are not recommended as primary treatment of RRBs.<ref>{{cite journal |vauthors=Ameis SH, Kassee C, Corbett-Dick P, Cole L, Dadhwal S, Lai MC, Veenstra-VanderWeele J, Correll CU |display-authors=6 |title=Systematic review and guide to management of core and psychiatric symptoms in youth with autism |journal=Acta Psychiatrica Scandinavica |volume=138 |issue=5 |pages=379–400 |date=November 2018 |pmid=29904907 |doi=10.1111/acps.12918 |s2cid=49209337}}</ref> SSRI antidepressants, such as [[Chemistry:Fluoxetine|fluoxetine]] and [[Chemistry:Fluvoxamine|fluvoxamine]], have been shown to be effective in reducing repetitive and ritualistic behaviors, while the stimulant medication [[Chemistry:Methylphenidate|methylphenidate]] is beneficial for some children with co-morbid inattentiveness or hyperactivity.<ref name="Myers 2007" /> There is scant reliable research about the effectiveness or safety of drug treatments for adolescents and adults with ASD.<ref>{{cite journal |last1=Broadstock |first1=Marita |last2=Doughty |first2=Carolyn |last3=Eggleston |first3=Matt |year=2007 |title=Systematic review of the effectiveness of pharmacological treatments for adolescents and adults with autism spectrum disorder |journal=Autism |volume=11 |issue=4 |pages=335–348 |doi=10.1177/1362361307078132 |issn=1362-3613 |pmid=17656398 |s2cid=42629626}}</ref> No known medication relieves autism's core symptoms of social and communication impairments.<ref name="Ji2015" />

=== Alternative medicine ===
A multitude of alternative therapies have been researched and implemented. Many have resulted in harm to autistic people.<ref name="Myers" /> A 2020 systematic review on adults with autism provided evidence that [[Philosophy:Mindfulness|mindfulness]]-based interventions may decrease stress, anxiety, ruminating thoughts, anger, and aggression and improve mental health.<ref>{{cite journal |display-authors=6 |vauthors=Benevides TW, Shore SM, Andresen ML, Caplan R, Cook B, Gassner DL, Erves JM, Hazlewood TM, King MC, Morgan L, Murphy LE, Purkis Y, Rankowski B, Rutledge SM, Welch SP, Wittig K |date=August 2020 |title=Interventions to address health outcomes among autistic adults: A systematic review |journal=Autism |volume=24 |issue=6 |pages=1345–1359 |doi=10.1177/1362361320913664 |pmc=7787674 |pmid=32390461 |doi-access=free}}</ref>

Although popularly used as an [[Medicine:Alternative medicine|alternative treatment]] for autistic people, {{as of|2018|lc=y}} there is no good evidence to recommend a [[Unsolved:Gluten-free, casein-free diet|gluten- and casein-free diet]] as a standard treatment.<ref name="GogouKolios2018">{{cite journal |vauthors=Gogou M, Kolios G |date=June 2018 |title=Are therapeutic diets an emerging additional choice in autism spectrum disorder management? |journal=World Journal of Pediatrics |type=Review |volume=14 |issue=3 |pages=215–223 |doi=10.1007/s12519-018-0164-4 |pmid=29846886 |quote=Current literature knowledge provides evidence that ketogenic and casein/gluten-free diet may have their own place in our reserve for the therapeutic management of specific subsets of children with autism. ... More clinical studies about the effect of gluten/caseinfree diet in these patients are available. However, available data arise from studies with small sample size and are still controversial. In general, despite encouraging data, no definite proof still exists. Under this view, the use of therapeutic diets in children with autism should be restricted to specific subgroups, such as children with autism and epilepsy or specific inborn errors of metabolism ''(ketogenic diet)'', children with known food intolerance/allergy or even children with food intolerance markers (''gluten- and casein-free diet''). Their implementation should always be guided by health care practitioners. |s2cid=44155118}}</ref><ref name="MariBausetZazpe">{{cite journal |vauthors=Marí-Bauset S, Zazpe I, Mari-Sanchis A, Llopis-González A, Morales-Suárez-Varela M |date=December 2014 |title=Evidence of the gluten-free and casein-free diet in autism spectrum disorders: a systematic review |journal=Journal of Child Neurology |volume=29 |issue=12 |pages=1718–1727 |doi=10.1177/0883073814531330 |pmid=24789114 |hdl-access=free |s2cid=19874518 |hdl=10171/37087}}</ref><ref name="Millward2008">{{cite journal |vauthors=Millward C, Ferriter M, Calver S, Connell-Jones G |date=April 2008 |title=Gluten- and casein-free diets for autistic spectrum disorder |journal=[[Cochrane Library#The Cochrane Database of Systematic Reviews|The Cochrane Database of Systematic Reviews]] |issue=2 |pages=CD003498 |doi=10.1002/14651858.CD003498.pub3 |pmc=4164915 |pmid=18425890 |quote=Knivsberg 2002 "monitoring of the compliance with diet was not carried out" ... "several reports of children 'sneaking food' from siblings or classmates" |veditors=Ferriter M}}</ref> A 2018 review concluded that it may be a therapeutic option for specific groups of children with autism, such as those with known food intolerances or [[Medicine:Food allergy|allergies]], or with food intolerance markers. The authors analyzed the prospective trials conducted to date that studied the efficacy of the gluten- and casein-free diet in children with ASD (4 in total). All of them compared gluten- and casein-free diet versus normal diet with a control group (2 double-blind randomized controlled trials, 1 double-blind crossover trial, 1 single-blind trial). In two of the studies, whose duration was 12 and 24 months, a significant improvement in ASD symptoms (efficacy rate 50%) was identified. In the other two studies, whose duration was 3 months, no significant effect was observed.<ref name="GogouKolios2018" /> The authors concluded that a longer duration of the diet may be necessary to achieve the improvement of the ASD symptoms.<ref name="GogouKolios2018" /> Other problems documented in the trials carried out include transgressions of the diet, small sample size, the heterogeneity of the participants and the possibility of a [[Medicine:Placebo|placebo]] effect.<ref name="Millward2008" /><ref name="HymanStewart2016">{{cite journal |display-authors=6 |vauthors=Hyman SL, Stewart PA, Foley J, Cain U, Peck R, Morris DD, Wang H, Smith T |date=January 2016 |title=The Gluten-Free/Casein-Free Diet: A Double-Blind Challenge Trial in Children with Autism |journal=Journal of Autism and Developmental Disorders |volume=46 |issue=1 |pages=205–220 |doi=10.1007/s10803-015-2564-9 |pmid=26343026 |quote=20 natural challenges when parents reported that children by mistake consumed foods containing gluten or casein. |s2cid=12884691}}</ref><ref name="Siafis2020">{{cite journal |vauthors=Siafis S, Çıray O, Schneider-Thoma J, Bighelli I, Krause M, Rodolico A, Ceraso A, Deste G, Huhn M, Fraguas D, Mavridis D, Charman T, Murphy DG, Parellada M, Arango C, Leucht S |date=2020 |title=Placebo response in pharmacological and dietary supplement trials of autism spectrum disorder (ASD): systematic review and meta-regression analysis |journal=Molecular Autism |volume=11 |issue=1 |page=66 |doi=10.1186/s13229-020-00372-z |pmid=32847616 |pmc=7448339 |doi-access=free}}</ref> In the subset of people who have gluten sensitivity there is limited evidence that suggests that a gluten-free diet may improve some autistic behaviors.<ref name="Buie">{{cite journal |vauthors=Buie T |date=May 2013 |title=The relationship of autism and gluten |journal=Clinical Therapeutics |type=Review |volume=35 |issue=5 |pages=578–583 |doi=10.1016/j.clinthera.2013.04.011 |pmid=23688532 |quote=At this time, the studies attempting to treat symptoms of autism with diet have not been sufficient to support the general institution of a gluten-free or other diet for all children with autism. There may be a subgroup of patients who might benefit from a gluten-free diet, but the symptom or testing profile of these candidates remains unclear. |doi-access=free}}</ref><ref name="VoltaCaio">{{cite journal |vauthors=Volta U, Caio G, De Giorgio R, Henriksen C, Skodje G, Lundin KE |date=June 2015 |title=Non-celiac gluten sensitivity: a work-in-progress entity in the spectrum of wheat-related disorders |journal=Best Practice & Research. Clinical Gastroenterology |volume=29 |issue=3 |pages=477–491 |doi=10.1016/j.bpg.2015.04.006 |pmid=26060112 |quote=autism spectrum disorders (ASD) have been hypothesized to be associated with NCGS [47,48]. Notably, a gluten- and casein-free diet might have a positive effect in improving hyperactivity and mental confusion in some patients with ASD. This very exciting association between NCGS and ASD deserves further study before conclusions can be firmly drawn}}</ref><ref name="SanMauroGaricano">{{cite journal |vauthors=San Mauro Martín I, Garicano Vilar E, Collado Yurrutia L, Ciudad Cabañas MJ |date=December 2014 |title=[Is gluten the great etiopathogenic agent of disease in the XXI century?] |trans-title=Is gluten the great etiopathogenic agent of disease in the XXI century? |journal=Nutricion Hospitalaria |language=es |volume=30 |issue=6 |pages=1203–1210 |doi=10.3305/nh.2014.30.6.7866 |pmid=25433099}}</ref>

The preference that autistic children have for unconventional foods can lead to reduction in bone cortical thickness with this risk being greater in those on casein-free diets, as a consequence of the low intake of [[Chemistry:Calcium|calcium]] and [[Chemistry:Vitamin D|vitamin D]]; however, suboptimal bone development in ASD has also been associated with lack of exercise and gastrointestinal disorders.<ref name="TyeRunicles2018">{{cite journal |vauthors=Tye C, Runicles AK, Whitehouse AJ, Alvares GA |year=2019 |title=Characterizing the Interplay Between Autism Spectrum Disorder and Comorbid Medical Conditions: An Integrative Review |journal=Frontiers in Psychiatry |type=Review |volume=9 |page=751 |doi=10.3389/fpsyt.2018.00751 |pmc=6354568 |pmid=30733689 |doi-access=free}}</ref> In 2005, botched [[Unsolved:Chelation therapy|chelation therapy]] killed a five-year-old child with autism.<ref name="pmid18775371">{{cite journal |vauthors=Levy SE, Hyman SL |date=October 2008 |title=Complementary and alternative medicine treatments for children with autism spectrum disorders |journal=Child and Adolescent Psychiatric Clinics of North America |type=Review |volume=17 |issue=4 |pages=803–20, ix |doi=10.1016/j.chc.2008.06.004 |pmc=2597185 |pmid=18775371}}</ref><ref>{{cite journal |vauthors=Brown MJ, Willis T, Omalu B, Leiker R |date=August 2006 |title=Deaths resulting from hypocalcemia after administration of edetate disodium: 2003-2005 |url=http://pediatrics.aappublications.org/cgi/content/full/118/2/e534 |journal=Pediatrics |volume=118 |issue=2 |pages=e534–e536 |doi=10.1542/peds.2006-0858 |pmid=16882789 |archive-url=https://web.archive.org/web/20090727080307/http://pediatrics.aappublications.org/cgi/content/full/118/2/e534 |archive-date=27 July 2009 |s2cid=28656831}}</ref> Chelation is not recommended for autistic people since the associated risks outweigh any potential benefits.<ref name="JamesStevenson2015">{{cite journal |vauthors=James S, Stevenson SW, Silove N, Williams K |date=May 2015 |title=Chelation for autism spectrum disorder (ASD) |journal=[[Cochrane Library#The Cochrane Database of Systematic Reviews|The Cochrane Database of Systematic Reviews]] |type=Review |issue=5 |pages=CD010766 |doi=10.1002/14651858.CD010766 |pmid=26106752 |veditors=James S |doi-access=free}}</ref> Another alternative medicine practice with no evidence is [[Unsolved:CEASE therapy|CEASE therapy]], a [[Unsolved:Pseudoscience|pseudoscientific]] mixture of [[Unsolved:Homeopathy|homeopathy]], supplements, and "vaccine detoxing".<ref>{{cite web |vauthors=Loftus Y |date=24 November 2021 |title=CEASE Therapy for Autism: the Controversy of a "Cure" |url=https://www.autismparentingmagazine.com/cease-therapy-controversy-cure/ |url-status=live |archive-url=https://web.archive.org/web/20220922123637/https://www.autismparentingmagazine.com/cease-therapy-controversy-cure/ |archive-date=22 September 2022 |access-date=22 September 2022 |website=Autism Parenting Magazine}}</ref>

Results of a systematic review on interventions to address health outcomes among autistic adults found emerging evidence to support [[Philosophy:Mindfulness|mindfulness]]-based interventions for improving mental health. This includes decreasing stress, anxiety, ruminating thoughts, anger, and aggression.<ref name=":19">{{cite journal |vauthors=Benevides TW, Shore SM, Andresen ML, Caplan R, Cook B, Gassner DL, Erves JM, Hazlewood TM, King MC, Morgan L, Murphy LE, Purkis Y, Rankowski B, Rutledge SM, Welch SP, Wittig K |display-authors=6 |title = Interventions to address health outcomes among autistic adults: A systematic review |journal=Autism |volume=24 |issue=6 |pages=1345–1359 |date=August 2020 |pmid=32390461 |pmc=7787674 |doi=10.1177/1362361320913664 |s2cid=218586379 |doi-access=free}}</ref> An updated Cochrane review (2022) found evidence that [[Medicine:Music therapy|music therapy]] likely improves social interactions, verbal communication, and nonverbal communication skills.<ref>{{cite journal |vauthors=Geretsegger M, Fusar-Poli L, Elefant C, Mössler KA, Vitale G, Gold C |title=Music therapy for autistic people |journal=[[Cochrane Library#The Cochrane Database of Systematic Reviews|The Cochrane Database of Systematic Reviews]] |volume=2022 |issue=5 |pages=CD004381 |date=May 2022 |pmid=35532041 |pmc=9082683 |doi=10.1002/14651858.CD004381.pub4}}</ref> There has been early research on [[Medicine:Hyperbaric medicine|hyperbaric treatments]] in children with autism.<ref>{{cite report |url=https://www.ncbi.nlm.nih.gov/books/NBK56343/ |title=Therapies for Children With Autism Spectrum Disorders |date=April 2011 |publisher=Agency for Healthcare Research and Quality (US) |page=8 |pmid=21834171 |quote=Hyperbaric therapy, in which oxygen is administered in special chambers that maintain a higher air pressure, has shown possible effects in other chronic neurologic conditions and has also undergone preliminary exploration in ASDs. |type=Report No. 11-EHC029-EF |vauthors=Warren Z, Veenstra-VanderWeele J, Stone W, etal |access-date=15 May 2022 |archive-date=8 June 2023 |archive-url=https://web.archive.org/web/20230608230244/https://ncbi.nlm.nih.gov/books/NBK56343/ |url-status=live}}{{Update inline|date=May 2022|reason=There is a 2014 update to the report: https://www.ncbi.nlm.nih.gov/books/NBK241444/ (free to access)}}</ref> Studies on pet therapy have shown positive effects.<ref>{{cite journal |vauthors=Rumayor CB, Thrasher AM |title=Reflections on Recent Research Into Animal-Assisted Interventions in the Military and Beyond |journal=Current Psychiatry Reports |volume=19 |issue=12 |page=110 |date=November 2017 |pmid=29177710 |doi=10.1007/s11920-017-0861-z |s2cid=207338873}}</ref>

=== Prevention ===
While infection with [[Medicine:Rubella|rubella]] during pregnancy causes fewer than 1% of cases of autism,<ref name="Duchan">{{cite journal |vauthors=Duchan E, Patel DR |date=February 2012 |title=Epidemiology of autism spectrum disorders |journal=Pediatric Clinics of North America |volume=59 |issue=1 |pages=27–43, ix–x |doi=10.1016/j.pcl.2011.10.003 |pmid=22284791}}</ref> [[Medicine:Rubella vaccine|vaccination against rubella]] can prevent many of those cases.<ref name="Lancet2015">{{cite journal |vauthors=Lambert N, Strebel P, Orenstein W, Icenogle J, Poland GA |date=June 2015 |title=Rubella |journal=Lancet |volume=385 |issue=9984 |pages=2297–2307 |doi=10.1016/S0140-6736(14)60539-0 |pmc=4514442 |pmid=25576992}}</ref>

== Prognosis ==
{{Main|Biology:Prognosis of autism}}
There is no evidence of a cure for autism.<ref name="Myers 2007" /><ref name="Levy 2009" /> The degree of symptoms can decrease, occasionally to the extent that people lose their diagnosis of ASD;<ref name="Helt2008">{{cite journal |vauthors=Helt M, Kelley E, Kinsbourne M, Pandey J, Boorstein H, Herbert M, Fein D |date=December 2008 |title=Can children with autism recover? If so, how? |journal=Neuropsychology Review |volume=18 |issue=4 |pages=339–366 |citeseerx=10.1.1.695.2995 |doi=10.1007/s11065-008-9075-9 |pmid=19009353 |s2cid=4317267}}</ref><ref name="Fein2013">{{cite journal |display-authors=6 |vauthors=Fein D, Barton M, Eigsti IM, Kelley E, Naigles L, Schultz RT, Stevens M, Helt M, Orinstein A, Rosenthal M, Troyb E, Tyson K |date=February 2013 |title=Optimal outcome in individuals with a history of autism |journal=Journal of Child Psychology and Psychiatry, and Allied Disciplines |volume=54 |issue=2 |pages=195–205 |doi=10.1111/jcpp.12037 |pmc=3547539 |pmid=23320807}}</ref> this occurs sometimes after intensive treatment<ref name="Orinstein2014">{{cite journal |display-authors=6 |vauthors=Orinstein AJ, Helt M, Troyb E, Tyson KE, Barton ML, Eigsti IM, Naigles L, Fein DA |date=May 2014 |title=Intervention for optimal outcome in children and adolescents with a history of autism |journal=Journal of Developmental and Behavioral Pediatrics |volume=35 |issue=4 |pages=247–256 |doi=10.1097/DBP.0000000000000037 |pmc=4487510 |pmid=24799263}}</ref> and sometimes not. It is not known how often this outcome happens,<ref name="Rogers">{{cite journal |vauthors=Rogers SJ, Vismara LA |date=January 2008 |title=Evidence-based comprehensive treatments for early autism |journal=Journal of Clinical Child and Adolescent Psychology |publisher=Taylor & Francis |volume=37 |issue=1 |pages=8–38 |doi=10.1080/15374410701817808 |pmc=2943764 |pmid=18444052}}</ref> with reported rates in unselected samples ranging from 3% to 25%.<ref name="Helt2008" /><ref name="Fein2013" /> Although core difficulties tend to persist, symptoms often become less severe with age.<ref name="Rapin" /> Acquiring language before age six, having an [[Philosophy:Intelligence quotient|IQ]] above 50, and having a marketable skill all predict better outcomes; independent living is unlikely in autistic people with higher support needs.<ref>{{cite journal |vauthors=Tidmarsh L, Volkmar FR |date=September 2003 |title=Diagnosis and epidemiology of autism spectrum disorders |journal=Canadian Journal of Psychiatry |volume=48 |issue=8 |pages=517–525 |doi=10.1177/070674370304800803 |pmid=14574827 |doi-access=free |s2cid=38070709}}</ref>

The prognosis of autism describes the [[Biology:Prognosis of autism#Developmental course|developmental course]], gradual autism development, regressive autism development, differential outcomes, [[Biology:Prognosis of autism#Academic performance|academic performance]] and [[Biology:Prognosis of autism#Employment|employment]].

== Epidemiology ==
{{Main|Medicine:Epidemiology of autism}}
[[File:US-autism-6-17-1996-2007.png|alt=Bar chart versus time. The graph rises steadily from 1996 to 2007, from about 0.7 to about 5.3. The trend curves slightly upward.|thumb|Reports of autism cases per 1,000 children rose considerably in the US from 1996 to 2007. It is unknown how much growth came from changes in rates of autism.]]
The World Health Organization (WHO) estimates about 1 in 100 children had autism during the period from 2012 to 2021 as that was the average estimate in studies published during that period with a trend of increasing prevalence over time. However, the study's 1% figure may reflect an underestimate of prevalence in low- and middle-income countries.<ref name="Autism" /><ref>{{cite web |date=30 March 2022 |title=Autism |url=https://www.who.int/news-room/fact-sheets/detail/autism-spectrum-disorders |access-date=8 May 2022 |website=[[Organization:World Health Organization|World Health Organization]] |language=en |archive-date=10 April 2020 |archive-url=https://web.archive.org/web/20200410103835/https://www.who.int/news-room/fact-sheets/detail/autism-spectrum-disorders |url-status=live}}</ref> The number of people diagnosed has increased considerably since the 1990s, which may be partly due to increased recognition of the condition.<ref name="Russell 2021">{{cite journal |display-authors=6 |vauthors=Russell G, Stapley S, Newlove-Delgado T, Salmon A, White R, Warren F, Pearson A, Ford T |date=August 2021 |title=Time trends in autism diagnosis over 20 years: a UK population-based cohort study |journal=Journal of Child Psychology and Psychiatry, and Allied Disciplines |issn=0021-9630 |eissn=1469-7610 |oclc=01307942 |volume=63 |issue=6 |pages=674–682 |doi=10.1111/jcpp.13505 |pmid=34414570 |quote=The figure starkly illustrates an overall 787% increase in recorded incidence of autism diagnosis over 20 years. |s2cid=237242123 |doi-access=free|hdl=10871/126929 |hdl-access=free }}</ref>

While rates of ASD are consistent across cultures, they vary greatly by gender, with boys diagnosed far more frequently than girls: 1 in 70 boys, but only 1 in 315 girls at eight years of age.<ref name="CDC 2020">{{cite journal |display-authors=6 |vauthors=Maenner MJ, Shaw KA, Baio J, Washington A, Patrick M, DiRienzo M, Christensen DL, Wiggins LD, Pettygrove S, Andrews JG, Lopez M, Hudson A, Baroud T, Schwenk Y, White T, Rosenberg CR, Lee LC, Harrington RA, Huston M, Hewitt A, Esler A, Hall-Lande J, Poynter JN, Hallas-Muchow L, Constantino JN, Fitzgerald RT, Zahorodny W, Shenouda J, Daniels JL, Warren Z, Vehorn A, Salinas A, Durkin MS, Dietz PM |date=March 2020 |title=Prevalence of Autism Spectrum Disorder Among Children Aged 8 Years - Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2016 |journal=MMWR. Surveillance Summaries |language=en-us |volume=69 |issue=4 |pages=1–12 |doi=10.15585/mmwr.ss6904a1 |pmc=7119644 |pmid=32214087}}</ref> Girls, however, are more likely to have associated cognitive impairment, suggesting that less severe forms of ASD are likely being missed in girls and women.{{sfn|ICD-11|loc="Females diagnosed with autism spectrum disorder are more frequently diagnosed with co-occurring disorders of intellectual development, suggesting that less severe presentations may go undetected as compared to males"}} Prevalence differences may be a result of gender differences in expression of clinical symptoms, with [[Medicine:Sex differences in autism|women and girls with autism]] showing less atypical behaviors and, therefore, less likely to receive an ASD diagnosis.<ref name="Tsakanikos Underwood 2011">{{cite journal |vauthors=Tsakanikos E, Underwood L, Kravariti E, Bouras N, McCarthy J |title=Gender differences in co-morbid psychopathology and clinical management in adults with autism spectrum disorders |journal=Research in Autism Spectrum Disorders |volume=5 |issue=2 |year=2011 |pages=803–808 |issn=1750-9467 |doi=10.1016/j.rasd.2010.09.009}}</ref>

Using DSM-5 criteria, 92% of the children diagnosed per DSM-IV with one of the disorders which is now considered part of ASD will still meet the diagnostic criteria of ASD. However, if both ASD and the social (pragmatic) communication disorder categories of DSM-5 are combined, the [[Prevalence|prevalence]] of autism is mostly unchanged from the prevalence per the DSM-IV criteria. The best estimate for prevalence of ASD is 0.7% or 1 child in 143 children.<ref>{{cite book |title=Autism spectrum disorders |vauthors=Hollander E, Hagerman RJ, Fein D |publisher=American Psychiatric Association Publishing |date=30 April 2018 |isbn=978-1-61537-192-1 |edition=First |location=Washington, DC |oclc=1022084798}}</ref> Relatively mild forms of autism, such as Asperger's as well as other developmental disorders, are included in the DSM-5 diagnostic criteria.<ref name= Baio2018>{{cite journal |vauthors=Baio J, Wiggins L, Christensen DL, ''et al'' |title=Prevalence of Autism Spectrum Disorder Among Children Aged 8 Years – Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2014 |journal=MMWR. Surveillance Summaries |volume=67 |issue=6 |pages=1–23 |date=April 2018 |pmid=29701730 |pmc=5919599 |doi=10.15585/mmwr.ss6706a1}}</ref> ASD rates were constant between 2014 and 2016 but twice the rate compared to the time period between 2011 and 2014 (1.25 vs 2.47%). A Canadian meta-analysis from 2019 confirmed these effects as the profiles of people diagnosed with autism became less and less different from the profiles of the general population.<ref>{{cite journal |vauthors=Rødgaard EM, Jensen K, Vergnes JN, Soulières I, Mottron L |title=Temporal Changes in Effect Sizes of Studies Comparing Individuals With and Without Autism: A Meta-analysis |journal=JAMA Psychiatry |volume=76 |issue=11 |pages=1124–1132 |date=August 2019 |pmid=31433441 |pmc=6704749 |doi=10.1001/jamapsychiatry.2019.1956}}</ref> In the US, the rates for diagnosed ASD have been steadily increasing since 2000 when records began being kept.<ref>{{cite web |title=CDC estimates 1 in 68 school-aged children have autism; no change from previous estimate |website=CDC Newsroom |url=https://www.cdc.gov/media/releases/2016/p0331-children-autism.html |publisher=CDC |access-date=31 December 2019 |language=en-us |date=31 March 2016 |archive-date=11 October 2019 |archive-url=https://web.archive.org/web/20191011134225/https://www.cdc.gov/media/releases/2016/p0331-children-autism.html |url-status=live}}</ref> While it remains unclear whether this trend represents a true rise in incidence, it likely reflects changes in ASD diagnostic criteria, improved detection, and increased public awareness of autism.<ref>{{cite book |vauthors = Hill AP |date=2014 |veditors=Volkmar FR |chapter=Epidemiology of autism spectrum disorders |title=Handbook of Autism and Pervasive Developmental Disorders. Diagnosis, Development, and Brain Mechanisms |publisher=Wiley |location=New York |volume=1 |pages=57–96 |doi=10.1002/9781118911389 |isbn=978-1-118-91138-9}}</ref> In 2012, the NHS estimated that the overall prevalence of autism among adults aged 18 years and over in the UK was 1.1%.<ref name="NHSEstimating">{{cite web |display-authors=6 |date=31 January 2012 |title=Estimating the prevalence of autism spectrum conditions in adults: extending the 2007 Adult Psychiatric Morbidity Survey |url=http://www.hscic.gov.uk/catalogue/PUB05061/esti-prev-auti-ext-07-psyc-morb-surv-rep.pdf |archive-url=https://web.archive.org/web/20141230033423/http://www.hscic.gov.uk/catalogue/PUB05061/esti-prev-auti-ext-07-psyc-morb-surv-rep.pdf |archive-date=30 December 2014 |access-date=29 December 2014 |website=The Information Centre for Health and Social Care |publisher=National Health Service, UK |vauthors=Brugha T, Cooper SA, McManus S, Purdon S, Smith J, Scott FJ, Spiers N, Tyrer F}}</ref> A 2016 survey in the United States reported a rate of 25 per 1,000 children for ASD.<ref>{{cite web |date=26 November 2018 |title=Report: Autism Rate Rises to 1 in 40 Children |url=https://www.webmd.com/brain/autism/news/20181126/report-autism-rate-rises-to-1-in-40-children |access-date=26 September 2019 |website=WebMD |vauthors=Mozes A |archive-date=25 September 2019 |archive-url=https://web.archive.org/web/20190925121905/https://www.webmd.com/brain/autism/news/20181126/report-autism-rate-rises-to-1-in-40-children |url-status=live}}</ref> Rates of autism are poorly understood in many low- and middle-income countries, which affects the accuracy of global ASD prevalence estimates,<ref>{{cite web |title=Autism |url=https://www.who.int/news-room/fact-sheets/detail/autism-spectrum-disorders |access-date=15 September 2022 |website=www.who.int |language=en |archive-date=10 April 2020 |archive-url=https://web.archive.org/web/20200410103835/https://www.who.int/news-room/fact-sheets/detail/autism-spectrum-disorders |url-status=live}}</ref> but it is thought that most autistic people live in low- and middle-income countries.<ref name=":8">{{cite journal |vauthors=Hahler EM, Elsabbagh M |date=1 March 2015 |title=Autism: A Global Perspective |journal=Current Developmental Disorders Reports |language=en |volume=2 |issue=1 |pages=58–64 |doi=10.1007/s40474-014-0033-3 |s2cid=73214418 |issn=2196-2987 |doi-access=free}}</ref>

In 2020, the Centers for Disease Control's Autism and Developmental Disabilities Monitoring (ADDM) Network reported that approximately 1 in 54 children in the United States (1 in 34 boys, and 1 in 144 girls) is diagnosed with an autism spectrum disorder (ASD), based on data collected in 2016.<ref name="CDC20">{{cite web |url=https://www.cdc.gov/ncbddd/autism/data.html |title=Data and Statistics on Autism Spectrum Disorder {{!}} CDC |last=CDC |date=27 March 2020 |website=Centers for Disease Control and Prevention |language=en-us |access-date=19 June 2021 |archive-date=18 April 2014 |archive-url=https://web.archive.org/web/20140418153648/http://www.cdc.gov/ncbddd/autism/data.html |url-status=live}}</ref><ref>{{cite journal |last1=Maenner |first1=Matthew J. |last2=Warren |first2=Zachary |last3=Williams |first3=Ashley Robinson |last4=Amoakohene |first4=Esther |last5=Bakian |first5=Amanda V. |last6=Bilder |first6=Deborah A. |last7=Durkin |first7=Maureen S. |last8=Fitzgerald |first8=Robert T. |last9=Furnier |first9=Sarah M. |last10=Hughes |first10=Michelle M. |last11=Ladd-Acosta |first11=Christine M. |last12=McArthur |first12=Dedria |last13=Pas |first13=Elise T. |last14=Salinas |first14=Angelica |last15=Vehorn |first15=Alison |display-authors=3 |date=2023 |title=Prevalence and characteristics of autism spectrum disorder among children aged 8 years—Autism and Developmental Disabilities Monitoring Network, 11 sites, United States, 2020 |journal=MMWR. Surveillance Summaries |language=en-us |volume=72 |issue=2 |pages=1{{endash}}14 |doi=10.15585/mmwr.ss7202a1 |issn=1546-0738 |pmid=34855725 |s2cid=257735672 |doi-access=free |last16=Williams1 |first16=Susan |last17=Esler |first17=Amy |last18=Grzybowski |first18=Andrea |last19=Hall-Lande |first19=Jennifer |last20=Nguyen |first20=Ruby H.N. |last21=Pierce |first21=Karen |last22=Zahorodny |first22=Walter |last23=Hudson |first23=Allison |last24=Hallas |first24=Libby |last25=Mancilla |first25=Kristen Clancy |last26=Patrick |first26=Mary |last27=Shenouda |first27=Josephine |last28=Sidwell10 |first28=Kate |last29=DiRienzo |first29=Monica |last30=Gutierrez |first30=Johanna |last31=Spivey |first31=Margaret H. |last32=Lopez |first32=Maya |last33=Pettygrove |first33=Sydney |last34=Schwenk |first34=Yvette D. |last35=Washington |first35=Anita |last36=Shaw |first36=Kelly A. |pmc=8639024}}</ref> This estimate is a 10% increase from the 1 in 59 rate in 2014, a 105% increase from the 1 in 110 rate in 2006, and a 176% increase from the 1 in 150 rate in 2000.<ref name="CDC20" /> Diagnostic criteria for ASD have changed significantly since the 1980s; for example, U.S. special-education autism classification was introduced in 1994.<ref name="Newschaffer 2007" />

In the UK, from 1998 to 2018, the autism diagnoses increased by 787%.<ref name="Russell 2021"/> This increase is largely attributable to changes in diagnostic practices, referral patterns, availability of services, age at diagnosis, and public awareness<ref name="Fombonne-2009">{{cite journal |vauthors=Fombonne E |date=June 2009 |title=Epidemiology of pervasive developmental disorders |journal=Pediatric Research |volume=65 |issue=6 |pages=591–598 |doi=10.1203/PDR.0b013e31819e7203 |pmid=19218885 |doi-access=free}}</ref><ref>{{cite journal |vauthors=Wing L, Potter D |year=2002 |title=The epidemiology of autistic spectrum disorders: is the prevalence rising? |journal=Developmental Disabilities Research Reviews |volume=8 |issue=3 |pages=151–161 |doi=10.1002/mrdd.10029 |pmid=12216059}}</ref><ref>{{cite journal |vauthors=Gernsbacher MA, Dawson M, Goldsmith HH |date=April 2005 |title=Three Reasons Not to Believe in an Autism Epidemic |journal=Current Directions in Psychological Science |volume=14 |issue=2 |pages=55–58 |doi=10.1111/j.0963-7214.2005.00334.x |pmc=4232964 |pmid=25404790}}</ref> (particularly among women),<ref name="Russell 2021"/> though unidentified environmental risk factors cannot be ruled out.<ref name="Rut2005">{{cite journal |vauthors=Rutter M |date=January 2005 |title=Incidence of autism spectrum disorders: changes over time and their meaning |journal=Acta Paediatrica |volume=94 |issue=1 |pages=2–15 |doi=10.1111/j.1651-2227.2005.tb01779.x |pmid=15858952 |s2cid=79259285}}</ref> The available evidence does not rule out the possibility that autism's true prevalence has increased;<ref name="Fombonne-2009" /> a real increase would suggest directing more attention and funding toward psychosocial factors and changing environmental factors instead of continuing to focus on genetics.<ref name="Szpir">{{cite journal |vauthors=Szpir M |date=July 2006 |title=Tracing the origins of autism: a spectrum of new studies |journal=Environmental Health Perspectives |volume=114 |issue=7 |pages=A412–A418 |doi=10.1289/ehp.114-a412 |pmc=1513312 |pmid=16835042}}</ref> It has been established that vaccination is not a risk factor for autism and is not a cause of any increase in autism prevalence rates, if any change in the rate of autism exists at all.<ref name="Taylor 2014"/>

Males have higher likelihood of being diagnosed with ASD than females. The sex ratio averages 4.3:1 and is greatly modified by cognitive impairment: it may be close to 2:1 with intellectual disability and more than 5.5:1 without.<ref name="Newschaffer 2007"/> [[Medicine:Sex differences in autism|Several theories]] about the higher prevalence in males have been investigated, but the cause of the difference is unconfirmed;<ref name="Chaste">{{cite journal |vauthors=Chaste P, Leboyer M |date=September 2012 |title=Autism risk factors: genes, environment, and gene-environment interactions |journal=Dialogues in Clinical Neuroscience |volume=14 |issue=3 |pages=281–292 |doi=10.31887/DCNS.2012.14.3/pchaste |pmc=3513682 |pmid=23226953}}</ref> one theory is that females are underdiagnosed.<ref>{{cite journal |vauthors=Schaafsma SM, Pfaff DW |date=August 2014 |title=Etiologies underlying sex differences in Autism Spectrum Disorders |journal=Frontiers in Neuroendocrinology |volume=35 |issue=3 |pages=255–71 |doi=10.1016/j.yfrne.2014.03.006 |pmid=24705124 |s2cid=7636860}}</ref>

The risk of developing autism is greater with older fathers than with older mothers; two potential explanations are the known increase in mutation burden in older sperm, and the hypothesis that men marry later if they carry genetic liability and show some signs of autism.<ref name="Geschwind"/> Most professionals believe that race, ethnicity, and socioeconomic background do not affect the occurrence of autism.<ref>{{cite journal |vauthors=Bertoglio K, Hendren RL |date=March 2009 |title=New developments in autism |journal=Psychiatric Clinics of North America |volume=32 |issue=1 |pages=1–14 |doi=10.1016/j.psc.2008.10.004 |pmid=19248913}}</ref>

== History ==
{{Main|Medicine:History of autism}}

== Society and culture ==
An autistic culture has emerged, accompanied by the autistic rights and [[Biology:Neurodiversity|neurodiversity]] movements, that argues autism should be accepted as a difference to be accommodated instead of cured,<ref>{{cite web |date=26 June 2006 |title=Autism Movement Seeks Acceptance, Not Cures |url=https://www.npr.org/templates/story/story.php?storyId=5488463 |access-date=10 November 2015 |publisher=NPR |vauthors=Shapiro J |archive-date=10 May 2019 |archive-url=https://web.archive.org/web/20190510154818/https://www.npr.org/templates/story/story.php?storyId=5488463 |url-status=live}}</ref><ref>{{cite magazine |title=Autistic and proud of it |url=https://www.newscientist.com/article/mg18625041-500-autistic-and-proud-of-it/ |access-date=10 November 2015 |publisher=Reed Elsevier |issn=0262-4079 |magazine=New Scientist |vauthors=Trivedi B |archive-date=23 April 2019 |archive-url=https://web.archive.org/web/20190423120053/https://www.newscientist.com/article/mg18625041-500-autistic-and-proud-of-it/ |url-status=live}}</ref><ref name="Solomon"/><ref>{{cite book |title=The Economic World |publisher=Chronicle Publishing Company |year=1917 |location=New York city |page=366}}</ref><ref name="Silverman 2008">
{{cite journal |vauthors=Silverman C |year=2008 |title=Fieldwork on another planet: social science perspectives on the autism spectrum |journal=[[Biology:BioSocieties|BioSocieties]] |volume=3 |issue=3 |pages=325–341 |doi=10.1017/S1745855208006236 |s2cid=145379758 |doi-access=free}}</ref> although a minority of autistic people might still accept a cure.<ref>{{cite web |date=23 March 2022 |title=Results and Analysis of the Autistic Not Weird 2022 Autism Survey - Autistic Not Weird |url=https://autisticnotweird.com/autismsurvey/ |access-date=29 April 2022 |language=en-GB |archive-date=8 June 2023 |archive-url=https://web.archive.org/web/20230608144053/https://autisticnotweird.com/autismsurvey/ |url-status=live}}</ref> Worldwide, events related to autism include [[Medicine:World Autism Awareness Day|World Autism Awareness Day]], [[Medicine:Autism Sunday|Autism Sunday]], Autistic Pride Day, Autreat, and others.<ref>{{cite web |title=World Autism Awareness Day, 2 April |url=https://www.un.org/en/events/autismday/ |access-date=17 November 2015 |publisher={{wipe|United Nations}} |archive-date=31 March 2018 |archive-url=https://web.archive.org/web/20180331054119/https://www.un.org/en/events/autismday/ |url-status=live}}</ref><ref>{{cite web |date=18 June 2015 |title=Autistic Pride Day 2015: A Message to the Autistic Community |url=http://autisticadvocacy.org/2015/06/autistic-pride-day-2015-a-message-to-the-autistic-community/ |access-date=18 November 2015 |vauthors=Bascom J |archive-date=19 November 2015 |archive-url=https://web.archive.org/web/20151119190817/http://autisticadvocacy.org/2015/06/autistic-pride-day-2015-a-message-to-the-autistic-community/ |url-status=live}}</ref><ref>{{cite web |year=2010 |title=Autism Sunday – Home |url=http://www.autismsunday.co.uk/ |archive-url=https://web.archive.org/web/20100303043146/http://www.autismsunday.co.uk/ |archive-date=3 March 2010 |access-date=17 November 2015 |website=Autism Sunday}}</ref><ref>{{cite web |year=2013 |title=About Autreat |url=http://www.autreat.com/autreat.html |access-date=17 November 2015 |publisher=Autreat.com |archive-date=1 December 2015 |archive-url=https://web.archive.org/web/20151201181250/http://www.autreat.com/autreat.html |url-status=live}}</ref>

Social-science scholars study those with autism in hopes to learn more about "autism as a culture, transcultural comparisons&nbsp;... and research on social movements."<ref>{{cite journal |vauthors=Silverman C |year=2008 |title=Fieldwork on Another Planet: Social Science Perspectives on the Autism Spectrum |journal=[[Biology:BioSocieties|BioSocieties]] |volume=3 |issue=3 |pages=325–341 |doi=10.1017/S1745855208006236 |issn=1745-8552 |s2cid=145379758 |doi-access=free}}</ref> Many autistic people have been successful in their fields.<ref>{{cite journal |vauthors=Russell G, Kapp SK, Elliott D, Elphick C, Gwernan-Jones R, Owens C |title=Mapping the Autistic Advantage from the Accounts of Adults Diagnosed with Autism: A Qualitative Study |journal=Autism in Adulthood |date=13 April 2019 |volume=1 |issue=2 |pages=124–133 |doi=10.1089/aut.2018.0035 |pmid=31058260 |pmc=6493410 |s2cid=142504027}}</ref>

=== Neurodiversity movement ===
Some autistic people, as well as a growing number of researchers,<ref name="Pellicano"/> have advocated a shift in attitudes toward the view that autism spectrum disorder is a difference, rather than a disease that must be treated or cured.<ref name=Clarke>{{cite journal |journal=Disability & Society |year=2007 |volume=22 |issue=7 |pages=761–76 |title='Surplus suffering': differences between organizational understandings of Asperger's syndrome and those people who claim the 'disorder' |vauthors=Clarke J, van Amerom G |doi=10.1080/09687590701659618 |s2cid=145736625}}</ref><ref name=BaronCohen2002>{{cite journal |journal=Focus Autism Other Dev Disabl |year=2002 |volume=17 |issue=3 |pages=186–91 |title=Is Asperger syndrome necessarily viewed as a disability? |vauthors=Baron-Cohen S |doi=10.1177/10883576020170030801 |s2cid=145629311}} A preliminary, freely readable draft, with slightly different wording in the quoted text, is in: {{cite web |url=http://autismresearchcentre.com/docs/papers/2002_BC_ASDisability.pdf |access-date=2 December 2008 |year=2002 |vauthors=Baron-Cohen S|title=Is Asperger's syndrome necessarily a disability? |publisher=Autism Research Centre |location=Cambridge |archive-url=https://web.archive.org/web/20081217140628/http://autismresearchcentre.com/docs/papers/2002_BC_ASDisability.pdf |archive-date=17 December 2008}}</ref> Critics have bemoaned the entrenchment of some of these groups' opinions.<ref name="Solomon2">{{cite web |title=The Autism Rights Movement |url=https://nymag.com/news/features/47225/ |access-date=26 October 2021 |website=nymag.com |date=23 May 2008}}</ref><ref name=":10">{{cite journal |vauthors=Morgan J |date=1 October 2016 |title=Autism spectrum disorder: difference or disability? |url=https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(16)30002-3/abstract |journal=The Lancet Neurology |language=en |volume=15 |issue=11 |page=1126 |doi=10.1016/S1474-4422(16)30002-3 |issn=1474-4422 |s2cid=54341655}}</ref><ref name=":11">{{cite journal |vauthors=Silverman C |date=1 September 2008 |title=Fieldwork on Another Planet: Social Science Perspectives on the Autism Spectrum |journal=BioSocieties |volume=3 |issue=3 |pages=325–341 |doi=10.1017/S1745855208006236 |issn=1745-8560 |s2cid=145379758 |doi-access=free}}</ref><ref>{{cite news |title=A medical condition or just a difference? The question roils autism community. |language=en-US |newspaper={{wipe|The Washington Post}} |url=https://www.washingtonpost.com/national/health-science/a-medical-condition-or-just-a-difference-the-question-roils-autism-community/2019/05/03/87e26f7e-6845-11e9-8985-4cf30147bdca_story.html |access-date=15 October 2021 |issn=0190-8286}}</ref>

The neurodiversity movement and the autism rights movement are [[Social:Social movement|social movement]]s within the context of disability rights, emphasizing the concept of [[Biology:Neurodiversity|neurodiversity]], which describes the autism spectrum as a result of natural variations in the [[Biology:Human brain|human brain]] rather than a disorder to be cured.<ref name="Solomon">{{cite news |work=New York Magazine |issn=0028-7369 |title=The autism rights movement |vauthors=Solomon A |date=25 May 2008 |access-date=27 May 2008 |url=https://nymag.com/news/features/47225/ |archive-url=https://web.archive.org/web/20080527025140/http://nymag.com/news/features/47225/ |archive-date=27 May 2008 |url-status=live}}</ref><ref name="auto"/> The autism rights movement advocates for including greater acceptance of autistic behaviors; therapies that focus on coping skills rather than imitating the behaviors of those without autism;<ref name="Bigthink">{{cite web |vauthors=Ratner P |title=Should Autism Be Cured or Is "Curing" Offensive? |url=https://bigthink.com/paul-ratner/should-autism-be-cured-or-is-curing-offfensive |website=Big Think |access-date=16 June 2019 |date=10 July 2016}}</ref> and the recognition of the autistic community as a minority group.<ref name="Bigthink" /><ref name="Jaarsma2012">{{cite journal |vauthors=Jaarsma P, Welin S |title=Autism as a natural human variation: reflections on the claims of the neurodiversity movement |journal=Health Care Analysis |volume=20 |issue=1 |pages=20–30 |date=March 2012 |pmid=21311979 |doi=10.1007/s10728-011-0169-9 |s2cid=18618887 |url=http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-72172}}</ref>

Autism rights or neurodiversity advocates believe that the autism spectrum is genetic and should be accepted as a natural variation in the [[Biology:Human genome|human genome]].<ref name="Solomon" /> These movements are not without detractors; a common argument against neurodiversity activists is that most of them have relatively low support needs, or are [[Medicine:Self-diagnosis|self-diagnosed]], and do not represent the views of autistic people with higher support needs.<ref name="Jaarsma2012" /><ref>{{cite journal |vauthors=McGee M |date=August 2012 |title=Neurodiversity |journal=Contexts |volume=11 |issue=3 |pages=12–13 |doi=10.1177/1536504212456175 |s2cid=220720495 |doi-access=free}}</ref><ref>{{cite web |vauthors=Sarrett J |date=April 2016 |title=Biocertification and Neurodiversity the Role and Implications of Self-Diagnosis in Autistic Communities |url=https://www.researchgate.net/publication/291949788 |access-date=6 March 2022 |website=www.researchgate.net}}</ref> Jacquiline den Houting explores this critique, determining that the voices of low-support needs autistics are "some of the most influential within the neurodiversity movement, although admittedly these voices are a minority within the advocacy community"; she suggests this is in part a shortcoming of the wider neurotypical community, referencing non-speaking self-advocate Amy Sequenzia's writing.<ref>{{cite journal |last1=den Houting |first1=J. |date=2019 |title=Neurodiversity: An insider's perspective. |journal=Autism |volume=23 |issue=2 |pages=271–273 |doi=10.1177/1362361318820762 |pmid=30556743 |s2cid=58767898 |doi-access=free}}</ref><ref>{{cite book |editor-last=Bascom |editor-first=Julia |last=Sequenzia |first=Amy |date=7 December 2012 |title=Loud Hands: Autistic People, Speaking |publisher=The Autistic Press |pages=159–160 |isbn=978-1-938800-02-3}}</ref>{{Undue weight inline|1=Neurodiversity criticism discussion|date=June 2023}} Pier Jaarsma and Stellan Welin make the argument that only high-functioning autistic people should be included under the neurodiversity banner, as low-functioning autists' condition may rightfully be viewed as a disability.<ref>{{cite journal |last1=Jaarsma |first1=Pier |last2=Welin |first2=Stellan |date=1 March 2012 |title=Autism as a Natural Human Variation: Reflections on the Claims of the Neurodiversity Movement |journal=Health Care Analysis |language=en |volume=20 |issue=1 |pages=20–30 |doi=10.1007/s10728-011-0169-9 |pmid=21311979 |s2cid=18618887 |issn=1573-3394 |url=http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-72172}}</ref> The concept of neurodiversity is contentious in autism advocacy and research groups and has led to infighting.<ref>{{cite journal |last=Morgan |first=Jules |date=1 October 2016 |title=Autism spectrum disorder: difference or disability? |url=https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(16)30002-3/fulltext |journal=The Lancet Neurology |language=English |volume=15 |issue=11 |page=1126 |doi=10.1016/S1474-4422(16)30002-3 |s2cid=54341655 |issn=1474-4422}}</ref><ref>{{cite journal |last=Silverman |first=Chloe |date=1 September 2008 |title=Fieldwork on Another Planet: Social Science Perspectives on the Autism Spectrum |journal=BioSocieties |language=en |volume=3 |issue=3 |pages=325–341 |doi=10.1017/S1745855208006236 |s2cid=145379758 |issn=1745-8560 |doi-access=free}}</ref>

=== Symbols and flags ===
Over the years, multiple organizations have tried to capture the essence of autism in symbols. In 1963, the board for the National Autistic Society, led by Gerald Gasson, proposed the "puzzle piece" as a symbol for autism, because it fit their view of autism as a "puzzling condition".<ref name=":15">{{cite web |last=Solomon |first=Debra |date=2 May 2018 |title=The History of the Autism Puzzle Piece Ribbon {{!}} Autism Career Coach Queens |url=https://spectrumroadmap.com/the-history-of-the-autism-puzzle-piece-ribbon/ |access-date=10 October 2023 |website=Spectrum Strategies |language=en-US}}</ref> In 1999, the Autism Society adopted the puzzle ribbon as the universal sign of autism awareness.<ref name=":15" /> In 2004, neurodiversity advocates Amy and Gwen Nelson conjured the "rainbow infinity symbol". It was initially the logo for their website, Aspies for Freedom. Nowadays, the prismatic colors are often associated with the neurodiversity movement in general.<ref name=":21">{{cite web |last=Morgan |first=Julian |date=11 March 2018 |title=Going Gold For Autism Acceptance |url=https://www.autisticuk.org/post/going-gold-for-autism-acceptance |access-date=10 October 2023 |website=Autistic UK CIC |language=en}}</ref> The autism spectrum has also been symbolized by the infinity symbol itself.<ref>{{cite web |last=Muzikar |first=Debra |date=20 April 2019 |title=The Autism Puzzle Piece: A symbol that's going to stay or go? |url=https://the-art-of-autism.com/the-autism-puzzle-piece-a-symbol-of-what/ |access-date=10 October 2023 |website=The Art of Autism |language=en-US}}</ref> In 2018, Julian Morgan wrote the article "Light It Up Gold", a response to Autism Speaks's "Light It Up Blue" campaign, launched in 2007.<ref>{{cite magazine |last=Willingham |first=Emily |title=No Foolin': Forget About Autism Awareness And Lighting Up Blue |url=https://www.forbes.com/sites/emilywillingham/2017/04/01/no-foolin-forget-about-autism-awareness-and-lighting-up-blue/ |access-date=10 October 2023 |magazine={{wipe|Forbes}} |language=en}}</ref><ref>{{cite web |last=Franco |first=Janelle |date=2014 |url=https://campussuite-storage.s3.amazonaws.com/prod/1558550/996e2c54-539e-11e8-b9a1-0a0344361b00/1954741/f51bb58c-a4c7-11e9-8c86-121ab0aa6810/file/puzzlepieceproject_educational_tool_kit.pdf |title=Puzzle Piece Project and Autism Awareness Month |publisher=Autism Speaks}}</ref> ''Aurum'' is Latin for gold,<ref name=":21" /> and gold has been used to symbolize autism, since both words start with "Au". Though a consensus for a flag to unite autism and neurodiversity has not yet been established, one has gained traction on Reddit.<ref>There have been multiple conversations about the flag on Reddit. Take for example: Reddit (2019). [https://www.reddit.com/r/AutisticPride/comments/fzy88g/i_tried_creating_an_autismneurodiversity_flag_its/ "I tried creating an autism/neurodiversity flag. It's a work in progress"]" Reddit (2022). [https://www.reddit.com/r/vexillology/comments/y1qegd/autism_pride_flag_goes_hard/ "Autism pride flag goes hard"]. Reddit (2022). [https://www.reddit.com/r/autism/comments/y66fwy/where_did_this_flag_even_come_from_first_time_i/ "where did this flag even come from? first time i ever saw it was during r/place, now i see it everywhere"].</ref> The flag implements a gradient to represent the Pride Movement and incorporates a golden infinity symbol as its focal point.<ref>{{cite web |author=AU-TI |date=2021 |url=https://au-ti.com/2021/12/23/a-new-autistic-pride-flag-has-suddenly-appeared-its-amazing/ |title=A New Autistic Pride Flag Has Suddenly Appeared & It's Amazing |website=AU-TI}}</ref> While flags are symbols of solidarity, they may trigger negative associations, such as apparent rivalry among two or more flags.<ref>{{cite journal |last=Shanafelt |first=Robert |date=September 2008 |title=The nature of flag power: How flags entail dominance, subordination, and social solidarity |url=https://www.cambridge.org/core/journals/politics-and-the-life-sciences/article/abs/nature-of-flag-power-how-flags-entail-dominance-subordination-and-social-solidarity/DB73F478AC2B16D4AFF64A10F85581FC |journal=[[Biology:Politics and the Life Sciences|Politics and the Life Sciences]] |language=en |volume=27 |issue=2 |pages=13–27 |doi=10.2990/27_2_13 |pmid=19267587 |s2cid=34479212 |issn=0730-9384}}</ref> For this reason, flags are sought that can be tailored to the personal preferences of any neurotype.<ref>{{cite journal |url=https://www.emerald.com/insight/content/doi/10.1108/09576060310477799/full/html |doi=10.1108/09576060310477799 |title=Identifying customer need patterns for customization and personalization |year=2003 |last1=Du |first1=Xuehong |last2=Jiao |first2=Jianxin |last3=Tseng |first3=Mitchell M. |journal=Integrated Manufacturing Systems |volume=14 |issue=5 |pages=387–396}}</ref><ref>{{cite journal |last1=Kalyanaraman |first1=Sriram |last2=Sundar |first2=S. Shyam |date=1 March 2006 |title=The Psychological Appeal of Personalized Content in Web Portals: Does Customization Affect Attitudes and Behavior? |url=https://academic.oup.com/joc/article/56/1/110-132/4102581 |journal=Journal of Communication |language=en |volume=56 |issue=1 |pages=110–132 |doi=10.1111/j.1460-2466.2006.00006.x |issn=0021-9916}}</ref>

<gallery widths="200px" heights="200px">
File:Autism spectrum infinity awareness symbol.svg|Autism [[Infinity symbol|infinity symbol]]
File:The Autistic Pride Flag.png|Autistic pride flag
File:Autismawareness.png|The puzzle piece symbol as used in the autism awareness ribbon used by Autism Speaks
File:Autistic_Pride_Flag_-_Pride_is_a_Protest.jpg|An Autistic Pride flag at a "Pride is a Protest" march in June 2021.
</gallery>

=== Caregivers ===
Families who care for an autistic child face added stress from a number of different causes.<ref name="Volkmar">{{cite book |url={{Google books|4yzqAgAAQBAJ|page=301|plainurl=yes}} |title=Handbook of Autism and Pervasive Developmental Disorders: Volume Two: Assessment, Interventions, and Policy |publisher={{wipe|John Wiley & Sons}} |year=2014 |isbn=978-1-118-28220-5 |veditors=Volkmar FR, Paul R, Pelphrey KA, Rogers SJ |edition=4th |volume=2 |location=Hoboken, New Jersey |page=301 |lccn=2013034363 |oclc=946133861 |access-date=1 March 2019}}</ref><ref>{{cite journal |vauthors=Aguiar MC, de Pondé MP |date=March 2019 |title=Parenting a child with autism |journal=Jornal Brasileiro de Psiquiatria |language=en |volume=68 |issue=1 |pages=42–47 |doi=10.1590/0047-2085000000223 |issn=0047-2085 |s2cid=165119472 |doi-access=free}}</ref> Parents may struggle to understand the diagnosis and to find appropriate care options. They often take a negative view of the diagnosis, and may struggle emotionally.<ref>{{cite news |date=29 April 2015 |title=An Alternative-Medicine Believer's Journey Back to Science |newspaper=WIRED |url=https://www.wired.com/2015/04/alternative-medicine-believers-journey-back-science/ |access-date=13 February 2017 |quote=The entire diagnosis and explanation took no more than 45 minutes. 'In the moment of diagnosis, it feels like the death of your hopes and dreams,' Louise [Laidler] says. There's a quiet grief in her voice, even though two decades have passed. 'In a way, it's even harder than a death, because you can't mourn and go on,' she says. 'You have to figure out how to care for your new child.' |vauthors=Levinovitz A}}</ref> More than half of parents over age 50 are still living with their child, as about 85% of autistic people have difficulties living independently.<ref name="Kar2012">{{cite journal |vauthors=Karst JS, Van Hecke AV |date=September 2012 |title=Parent and family impact of autism spectrum disorders: a review and proposed model for intervention evaluation |journal=Clinical Child and Family Psychology Review |volume=15 |issue=3 |pages=247–77 |doi=10.1007/s10567-012-0119-6 |pmid=22869324 |s2cid=19170894}}</ref> Some studies also find decreased earnings among parents who care for autistic children.<ref>{{cite journal |vauthors=Montes G, Halterman JS |date=April 2008 |title=Association of childhood autism spectrum disorders and loss of family income |url=http://pediatrics.aappublications.org/cgi/content/full/121/4/e821 |journal=Pediatrics |volume=121 |issue=4 |pages=e821–e826 |doi=10.1542/peds.2007-1594 |pmid=18381511 |archive-url=https://web.archive.org/web/20100304071520/http://pediatrics.aappublications.org/cgi/content/full/121/4/e821 |archive-date=4 March 2010 |s2cid=55179}}</ref><ref>{{cite journal |vauthors=Montes G, Halterman JS |date=July 2008 |title=Child care problems and employment among families with preschool-aged children with autism in the United States |url=http://pediatrics.aappublications.org/cgi/content/full/122/1/e202 |journal=Pediatrics |volume=122 |issue=1 |pages=e202–e208 |doi=10.1542/peds.2007-3037 |pmid=18595965 |archive-url=https://web.archive.org/web/20091206190622/http://pediatrics.aappublications.org/cgi/content/full/122/1/e202 |archive-date=6 December 2009 |s2cid=22686553}}</ref> Siblings of children with ASD report greater admiration and less conflict with the affected sibling than siblings of unaffected children, like siblings of children with [[Medicine:Down syndrome|Down syndrome]]. But they reported lower levels of closeness and intimacy than siblings of children with Down syndrome; siblings of people with ASD have a greater risk of negative well-being and poorer sibling relationships as adults.<ref>{{cite journal |vauthors=Orsmond GI, Seltzer MM |year=2007 |title=Siblings of individuals with autism spectrum disorders across the life course |url=http://www.waisman.wisc.edu/family/pubs/Autism/2007%20siblings_autism_life-course.pdf |journal=Developmental Disabilities Research Reviews |volume=13 |issue=4 |pages=313–320 |citeseerx=10.1.1.359.7273 |doi=10.1002/mrdd.20171 |pmid=17979200 |archive-url=https://web.archive.org/web/20130530100939/http://www.waisman.wisc.edu/family/pubs/Autism/2007%20siblings_autism_life-course.pdf |archive-date=30 May 2013}}</ref>

=== LGBT identity and religious beliefs ===
Research [[Medicine:Autism and LGBT identities|indicates that autistic people]] are substantially more likely to be [[Social:LGBT community|LGBT]]&mdash;particularly transgender or [[History:Non-binary gender|non-binary]]&mdash;than the general population.<ref name="Graham Holmes-2022">{{cite journal |last1=Graham Holmes |first1=Laura |last2=Ames |first2=Jennifer L. |last3=Massolo |first3=Maria L. |last4=Nunez |first4=Denise M. |last5=Croen |first5=Lisa A. |date=2022-04-01 |title=Improving the Sexual and Reproductive Health and Health Care of Autistic People |journal=Pediatrics |publisher=American Academy of Pediatrics |volume=149 |issue=Supplement 4 |pages=e2020049437J |doi=10.1542/peds.2020-049437J |issn=0031-4005 |pmid=35363286 |quote=A substantial proportion of autistic adolescents and adults are LGBTQIA+. Autistic people are more likely to be transgender or gender nonconforming compared with non-autistic people, and findings from a recent autism registry study suggest that among autistic people able to self-report on a survey, up to 18% of men and 43% of women may be sexual minorities. |doi-access=free}}</ref>

They are also significantly more likely to be [[Philosophy:Nontheism|non-theistic]].<ref name=":42">{{cite journal |last1=Norenzayan |first1=Ara |last2=Gervais |first2=Will M. |last3=Trzesniewski |first3=Kali H. |date=2012 |title=Mentalizing deficits constrain belief in a personal God |journal=PLOS ONE |volume=7 |issue=5 |pages=e36880 |doi=10.1371/journal.pone.0036880 |issn=1932-6203 |pmc=3364254 |pmid=22666332 |bibcode=2012PLoSO...736880N |doi-access=free}}</ref>

== See also ==
{{div col|colwidth=35em}}
* [[Biology:Outline of autism|Outline of autism]]
* [[Biology:Animal model of autism|Animal model of autism]]
* [[Medicine:Autism and memory|Autism and memory]]
* [[Medicine:Autism spectrum disorders in the media|Autism spectrum disorders in the media]]
* [[Medicine:Autistic art|Autistic art]]
* [[Unsolved:Controversies in autism|Controversies in autism]]
* [[Medicine:Global perceptions of autism|Global perceptions of autism]]
* [[Medicine:List of autistic fictional characters|List of autistic fictional characters]]
* List of films about autism
* [[Medicine:Sex and gender differences in autism|Sex and gender differences in autism]]
* [[Biology:Violence and autism|Violence and autism]]
{{div col end}}

== References ==
{{Reflist|colwidth=30em}}

=== Sources ===
* <!-- To cite the DSM-5-TR ebook, use {{sfn|DSM-5-TR}} -->{{cite book |title=Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) |title-link=DSM-5-TR |chapter=Neurodevelopmental Disorders |publisher=American Psychiatric Association |place=Washington, DC |date=18 March 2022 |lccn=2021051782 |isbn=978-0-89042-577-0 <!-- ebook version; it doesn't have page numbers. -->|ref={{harvid|DSM-5-TR}}}}
* <!-- To cite the ICD-11, use {{sfn|ICD-11}} -->{{cite encyclopedia |title=6A02 Autism spectrum disorder |date=February 2022<!-- The most recent update as of the access date --> |orig-date=adopted in 2019<!-- This is when it was adopted by the World Health Assembly --> |url=https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/437815624 |encyclopedia=International Classification of Diseases 11th Revision (ICD-11) |publisher=World Health Organisation |access-date=14 May 2022 |id={{ICD11|6A02|437815624}} |ref={{harvid|ICD-11}}}}

== Further reading ==
{{Library resources box |onlinebooks=yes}}
* Gabovitch, Elaine; Dutra, Courtney; Lauer, Emily. (2016). [https://shriver.umassmed.edu/research/massachusetts-healthy-people-2020-autism-roadmap-report-understanding-needs-measuring-outcomes/ ''The Healthy People 2020 Roadmap for Massachusetts Children & Youth with ASD/DD: Understanding Needs and Measuring Outcomes'' (Report)]. Worcester: UMass Chan Medical School. Retrieved 30 June 2022.
* {{cite journal |vauthors=Matson JL, Dempsey T |date=2008 |title=Stereotypy in Adults with Autism Spectrum Disorders: Relationship and Diagnostic Fidelity |journal=Journal of Developmental and Physical Disabilities |volume=20 |number=2 |pages=155–165 |doi=10.1007/s10882-007-9086-0 |s2cid=143874013}}
* {{cite Q|Q28240738}}
* {{cite Q|Q37552242}} eISSN 1873-3379
* {{cite journal |vauthors=Pedersen AL, Pettygrove S, Lu Z, Andrews J, Meaney FJ, Kurzius-Spencer M, Lee LC, Durkin MS, Cunniff C |display-authors=6 |title=DSM Criteria that Best Differentiate Intellectual Disability from Autism Spectrum Disorder |journal=Child Psychiatry and Human Development |volume=48 |issue=4 |pages=537–545 |date=August 2017 |pmid=27558812 |doi=10.1007/s10578-016-0681-0 |s2cid=4377173}}
* {{cite book |vauthors=Volkmar FR, Wiesner LA |title=A practical guide to autism: what every parent, family member, and teacher needs to know |date=2009 |publisher=Wiley |location=Hoboken |isbn=978-0-470-39473-1 |url=https://archive.org/details/practicalguideto0000volk |access-date=12 July 2022 |oclc=748908084}}

== External links ==
* [https://www.who.int/news-room/fact-sheets/detail/autism-spectrum-disorders WHO fact sheet on autism]

{{Medical condition classification and resources
<!-- first row: classification -->
| ICD11           = {{ICD11|6A02}}
| ICD10           = {{ICD10|F84.0}}
| ICD9           = {{ICD9|299.00}}
| OMIM            = 209850
| MeSH            = D000067877
<!-- second row: external resources -->
| Curlie          = Health/Mental_Health/Disorders/Neurodevelopmental/Autism_Spectrum
| MedlinePlus     = 001526
| eMedicine_mult  = {{eMedicine2|ped|180}}
| PatientUK       = autism
}}
{{Pervasive developmental disorders}}
{{Mental and behavioural disorders|selected=neurological}}
{{Digital media use and mental health}}
{{Subject bar|c=Category:Autism|b=y|q=Autism|d=Q1436063|n=Category:Autism|wikt=autism spectrum}}

[[Category:Developmental neuroscience]]

{{Sourceattribution|Autism spectrum|1}}