View source for Medicine:Tourette syndrome

{{Short description|Neurodevelopmental disorder involving motor and vocal tics}}
{{pp-semi-indef}}
{{Infobox medical condition (new)
| name = Tourette syndrome
| image = Tourette2.jpg
| alt = Head and shoulders of a man with a shorter Edwardian beard and closely cropped hair, in a circa-1870 French coat and collar
| caption = Georges Gilles de la Tourette (1857–1904),<br /> namesake of Tourette syndrome
| field = [[Medicine:Pediatrics|Pediatrics]], [[Biology:Neurology|neurology]], [[Biology:Psychiatry|psychiatry]]<ref name=EuropeanGuidelines>{{cite journal |vauthors=Müller-Vahl KR, Szejko N, Verdellen C, et al |title=European clinical guidelines for Tourette syndrome and other tic disorders: summary statement |journal=Eur Child Adolesc Psychiatry |date=July 2021 |volume=31 |issue=3 |pages=377–382 |pmid=34244849 |doi=10.1007/s00787-021-01832-4 |pmc=8940881 |s2cid=235781456 }}</ref>
| synonyms = Tourette's syndrome, Tourette's disorder, Gilles de la Tourette syndrome (GTS), combined vocal and multiple motor tic disorder [de la Tourette]
| symptoms = Tics<ref name=Stern2018>{{cite journal |vauthors=Stern JS |title=Tourette's syndrome and its borderland |journal=Pract Neurol |volume=18 |issue=4 |pages=262–270 |date=August 2018 |pmid=29636375 |doi=10.1136/practneurol-2017-001755 |url=https://pn.bmj.com/content/practneurol/18/4/262.full.pdf |type=Historical review |doi-access=free |access-date=November 30, 2018 |archive-date=December 1, 2018 |archive-url=https://web.archive.org/web/20181201093059/https://pn.bmj.com/content/practneurol/18/4/262.full.pdf |url-status=live }}</ref>
| complications = 
| onset = Typically in childhood<ref name=Stern2018 />
| duration = Long term<ref name=NIH2018>{{cite web |url= https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Tourette-Syndrome-Fact-Sheet |title= Tourette syndrome fact sheet |archive-url= https://web.archive.org/web/20181201051258/https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Tourette-Syndrome-Fact-Sheet |archive-date= December 1, 2018 |publisher= National Institute of Neurological Disorders and Stroke |date= July 6, 2018 |access-date= November 30, 2018}}</ref>
| causes = Genetic with environmental influence<ref name=NIH2018 />
| risks = 
| diagnosis = Based on history and symptoms<ref name=Stern2018 />
| differential = 
| prevention = 
| management = Education, behavioral therapy<ref name=Stern2018 /><ref name=PringHoller2019 />
| medication = Usually none, occasionally [[Chemistry:Antipsychotic|neuroleptics]] and [[Biology:Alpha-2A adrenergic receptor|noradrenergics]]<ref name=Stern2018 />
| prognosis = 80% will experience improvement to disappearance of tics beginning in late teens<ref name=NIH2018 />
| frequency = About 1% of children and adolescents<ref name= Hollis /><br />Between 0.3% and 1.0% of general population<ref name= EuropeanPartI/>
| deaths = 
| treatment = 
}}
'''Tourette syndrome''' or '''Tourette's syndrome''' (abbreviated as '''TS''' or '''Tourette's''') is a common [[Medicine:Neurodevelopmental disorder|neurodevelopmental disorder]] that begins in childhood or adolescence. It is characterized by multiple movement (motor) tics and at least one vocal (phonic) tic. Common tics are blinking, coughing, throat clearing, sniffing, and facial movements. These are typically preceded by an unwanted urge or sensation in the affected muscles known as a premonitory urge, can sometimes be suppressed temporarily, and characteristically change in location, strength, and frequency. Tourette's is at the more severe end of a spectrum of [[Medicine:Tic disorder|tic disorder]]s. The tics often go unnoticed by casual observers.

Tourette's was once regarded as a rare and bizarre [[Medicine:Syndrome|syndrome]] and has popularly been associated with coprolalia (the utterance of obscene words or socially inappropriate and derogatory remarks).<!-- Stern2018 --> It is no longer considered rare; about 1% of school-age children and adolescents are [[Medicine:Tourette syndrome#Epidemiology|estimated to have Tourette's]],<ref name=Stern2018 /> though coprolalia occurs only in a minority. There are no specific tests for diagnosing Tourette's; it is not always correctly identified, because most cases are mild, and the severity of tics decreases for most children as they pass through adolescence. Therefore, many go undiagnosed or may never seek medical attention. Extreme Tourette's in adulthood, though sensationalized in the media, is rare, but for a small minority, severely debilitating tics can persist into adulthood. Tourette's does not affect intelligence or [[Biology:Life expectancy|life expectancy]].

There is no cure for Tourette's and no single most effective medication. In most cases, medication for tics is not necessary, and behavioral therapies are the first-line treatment. Education is an important part of any treatment plan, and explanation alone often provides sufficient reassurance that no other treatment is necessary.<ref name=Stern2018 /> Other conditions, such as [[Medicine:Attention deficit hyperactivity disorder|attention deficit hyperactivity disorder]] (ADHD) and [[Medicine:Obsessive–compulsive disorder|obsessive–compulsive disorder]] (OCD), are more likely to be present among those who are referred to specialty clinics than they are among the broader population of persons with Tourette's. These co-occurring conditions often cause more impairment to the individual than the tics; hence it is important to correctly distinguish co-occurring conditions and treat them.

Tourette syndrome was named by French neurologist Jean-Martin Charcot for his intern, Georges Gilles de la Tourette, who published in 1885 an account of nine patients with a "convulsive tic disorder". While the exact cause is unknown, it is believed to involve a combination of [[Biology:Genetics|genetic]] and environmental factors. The mechanism appears to involve dysfunction in [[Neural circuit#Circuitry|neural circuits]] between the [[Biology:Basal ganglia|basal ganglia]] and related structures in the brain.

== Classification ==
Most published research on Tourette syndrome originates in the United States; in international TS research and clinical practice, the ''[[Medicine:Diagnostic and Statistical Manual of Mental Disorders|Diagnostic and Statistical Manual of Mental Disorders]]'' (DSM) is preferred over the [[Organization:World Health Organization|World Health Organization]] (WHO) classification,<ref name= EuropeanPartI/><ref name= DSMAppraisal /><ref name=Liu2020/> which is criticized in the 2021 ''European Clinical Guidelines.<ref name=EuropeanGuidelines/>

In the fifth version of the DSM (DSM-5), published in 2013, Tourette syndrome is classified as a [[Medicine:Motor disorder|motor disorder]] (a disorder of the [[Biology:Nervous system|nervous system]] that causes abnormal and involuntary movements). It is listed in the [[Medicine:Neurodevelopmental disorder|neurodevelopmental disorder]] category.<ref name=DSM5 /> Tourette's is at the more severe end of the spectrum of [[Medicine:Tic disorder|tic disorder]]s; its diagnosis requires multiple motor tics and at least one vocal tic to be present for more than a year. Tics are sudden, repetitive, nonrhythmic movements that involve discrete muscle groups,<ref>{{cite journal |vauthors=Martino D, Hedderly T |title=Tics and stereotypies: A comparative clinical review |journal=Parkinsonism Relat. Disord. |volume=59 |pages=117–124 |date=February 2019 |pmid=30773283 |doi=10.1016/j.parkreldis.2019.02.005 |s2cid=73486351 |type= Review}}</ref> while vocal (phonic) tics involve [[Medicine:Larynx|laryngeal]], [[Biology:Pharynx|pharyngeal]], oral, nasal or respiratory muscles to produce sounds.<ref name=Martino2018>{{cite journal |vauthors=Martino D, Pringsheim TM |title=Tourette syndrome and other chronic tic disorders: an update on clinical management |journal=Expert Rev Neurother |volume=18 |issue=2 |pages=125–137 |date=February 2018 |pmid=29219631 |doi=10.1080/14737175.2018.1413938 |s2cid=205823966 |type=Review}}</ref><ref>{{cite journal |vauthors= Jankovic J |url= http://practicalneurology.com/pdfs/pn0917_SF_Tourettes.pdf |title= Tics and Tourette syndrome |journal= Practical Neurology |date= September 2017 |pages= 22–24 |access-date= March 24, 2019 |archive-url= https://web.archive.org/web/20190324192032/http://practicalneurology.com/pdfs/pn0917_SF_Tourettes.pdf |archive-date= March 24, 2019 |url-status= dead }}</ref> The tics must not be explained by other medical conditions or substance use.<ref name= Fernandez />

Other tic disorders include persistent (chronic) motor or vocal tics, in which one type of tic (motor or vocal, but not both) has been present for more than a year; and provisional tic disorder, in which motor or vocal tics have been present for less than one year.<ref name= Dale2017 />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 242}} The fifth edition of the DSM replaced what had been called ''transient tic disorder'' with ''provisional tic disorder'', recognizing that "transient" can only be defined in retrospect.<ref name="DSMAppraisal">{{cite journal | vauthors = Robertson MM, Eapen V | title = Tourette's: syndrome, disorder or spectrum? Classificatory challenges and an appraisal of the DSM criteria | journal = Asian Journal of Psychiatry | volume = 11 | pages = 106–113 | date = October 2014 | pmid = 25453712 | doi = 10.1016/j.ajp.2014.05.010 | name-list-style = vanc | type = Review | author-link2 = Valsamma Eapen }}</ref><ref name=DSMV>{{cite web |url= http://www.dsm5.org/proposedrevision/Pages/NeurodevelopmentalDisorders.aspx |title= Neurodevelopmental disorders |publisher= American Psychiatric Association |access-date= December 29, 2011|archive-url= https://web.archive.org/web/20110510131026/http://www.dsm5.org/proposedrevision/Pages/NeurodevelopmentalDisorders.aspx |archive-date= May 10, 2011 }}</ref><ref name=Highlights>{{cite web |url= http://www.psychiatry.org/File%20Library/Practice/DSM/DSM-5/Changes-from-DSM-IV-TR--to-DSM-5.pdf |title= Highlights of changes from DSM-IV-TR to DSM-5 |publisher= American Psychiatric Association |date= 2013 |access-date= June 5, 2013|archive-url= https://web.archive.org/web/20130203165749/http://www.psychiatry.org/File%20Library/Practice/DSM/DSM-5/Changes-from-DSM-IV-TR--to-DSM-5.pdf |archive-date= February 3, 2013 }}</ref> Some experts believe that TS and persistent (chronic) motor or vocal tic disorder should be considered the same condition, because vocal tics are also motor tics in the sense that they are muscular contractions of nasal or respiratory muscles.<ref name= EuropeanPartI/><ref name= PringHoller2019 />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 242}}

Tourette syndrome is defined only slightly differently by the WHO;<ref name= Hollis /><!-- p. 1.--><ref name= Liu2020>{{cite journal |vauthors=Liu ZS, Cui YH, Sun D, et al |title=Current status, diagnosis, and treatment recommendation for tic disorders in China |journal=Front Psychiatry |volume=11 |pages=774 |date=2020 |pmid=32903695 |pmc=7438753 |doi=10.3389/fpsyt.2020.00774 |quote= The CCMD-3, DSM-5, and ICD-11 diagnostic criteria for tics are almost the same. Currently, the DSM-5 is mostly used in clinical practice around the world, including China.|doi-access=free }}</ref> in its [[Medicine:ICD-11|ICD-11]], the International Statistical Classification of Diseases and Related Health Problems, Tourette syndrome is classified as a disease of the nervous system and a neurodevelopmental disorder,<ref name=Reed2019>{{cite journal |vauthors=Reed GM, First MB, Kogan CS, et al|title=Innovations and changes in the ICD-11 classification of mental, behavioural and neurodevelopmental disorders |journal=World Psychiatry |volume=18 |issue=1 |pages=3–19 |date=February 2019 |pmid=30600616 |pmc=6313247 |doi=10.1002/wps.20611 |quote= Finally, chronic tic disorders, including Tourette syndrome, are classified in the ICD-11 chapter on diseases of the nervous system, but are cross-listed in the grouping of neurodevelopmental disorders because of their high co-occurrence (e.g., with ADHD) and typical onset during the developmental period.}}</ref><ref name=ICD-11>{{cite web |url= https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/119340957 |title= 8A05.00 Tourette syndrome |publisher= World Health Organization |access-date= March 28, 2022 |quote= Diseases of the nervous system --> Tic disorders: "onset during the developmental period" |archive-date= August 1, 2018 |archive-url= https://archive.ph/20180801205234/https://icd.who.int/browse11/l-m/en%23/http://id.who.int/icd/entity/294762853#/http://id.who.int/icd/entity/119340957 |url-status= live }}</ref> and only one motor tic is required for diagnosis.<ref name=Ueda2021>{{cite journal |vauthors=Ueda K, Black KJ |title=Recent progress on Tourette syndrome |journal=Fac Rev |volume=10 |pages=70 |date=2021 |pmid=34557874 |pmc=8442002 |doi=10.12703/r/10-70 |doi-access=free }}</ref> Older versions of the ICD called it "combined vocal and multiple motor tic disorder [de la Tourette]".<ref>{{cite web |date= 2010 |url=https://icd.who.int/browse10/2019/en#/F95.2 |publisher= [[Organization:World Health Organization|World Health Organization]] |title= International Statistical Classification of Diseases and Related Health Problems 10th Revision: Chapter V: Mental and behavioural disorders |access-date= August 7, 2020|archive-date= March 31, 2020 |archive-url= https://archive.today/20200331004754/https://icd.who.int/browse10/2019/en%23/U07.1#/F95.2 |url-status= live}} See also [http://apps.who.int/classifications/apps/icd/icd10online/?gf90.htm+f950 ICD version 2007.] {{Webarchive|url=https://web.archive.org/web/20120304043704/http://apps.who.int/classifications/apps/icd/icd10online/?gf90.htm+f950 |date=March 4, 2012 }}</ref>

Genetic studies indicate that tic disorders cover a spectrum that is not recognized by the clear-cut distinctions in the current diagnostic framework.<ref name= Fernandez /> Since 2008, studies have suggested that Tourette's is not a unitary condition with a distinct mechanism, as described in the existing classification systems. Instead, the studies suggest that subtypes should be recognized to distinguish "pure TS" from TS that is accompanied by [[Medicine:Attention deficit hyperactivity disorder|attention deficit hyperactivity disorder]] (ADHD), [[Medicine:Obsessive–compulsive disorder|obsessive–compulsive disorder]] (OCD) or other disorders, similar to the way that subtypes have been established for other conditions, such as [[Medicine:Type 1 diabetes|type 1]] and [[Medicine:Type 2 diabetes|type 2 diabetes]].<ref name= Hollis /><!-- p. 4 --><ref name= Fernandez /><ref name= Ueda2021/> Elucidation of these [[Biology:Phenotype|subtypes]] awaits fuller understanding of the [[Biology:Genetics|genetic]] and other causes of tic disorders.<ref name= DSMAppraisal />

== Characteristics ==
=== Tics ===
[[File:Tourette's tic long medium 192kbps.OGG|thumb|thumbtime=3|Examples of tics]]
Tics are movements or sounds that take place "intermittently and unpredictably out of a background of normal motor activity",<ref name=TSADef>{{cite journal |title=Definitions and classification of tic disorders. The Tourette Syndrome Classification Study Group |journal=Arch. Neurol. |volume=50 |issue=10 |pages=1013–1016 |date=October 1993 |pmid=8215958 |doi=10.1001/archneur.1993.00540100012008 | type= Research support |url= http://www.tsa-usa.org/research/definitions.html |archive-url=https://web.archive.org/web/20060426232033/http://www.tsa-usa.org/research/definitions.html |archive-date=April 26, 2006 }}</ref> having the appearance of "normal behaviors gone wrong".<ref name=Dure>{{cite journal |vauthors=Dure LS, DeWolfe J |title=Treatment of tics |journal=Adv Neurol |volume=99 |pages=191–196 |date=2006 |pmid=16536366 |type= Review}}</ref> The tics associated with Tourette's wax and wane; they change in number, frequency, severity, anatomical location, and complexity;<ref name=EuropeanPartI>{{cite journal |vauthors=Szejko N, Robinson S, Hartmann A, et al |title=European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part I: assessment |journal=Eur Child Adolesc Psychiatry |date=October 2021 |volume=31 |issue=3 |pages=383–402 |pmid=34661764 |pmc=8521086 |doi=10.1007/s00787-021-01842-2}}</ref> each person experiences a unique pattern of fluctuation in their severity and frequency. Tics may also occur in "bouts of bouts", which also vary among people.<ref name= Hash2017>{{cite journal |vauthors=Hashemiyoon R, Kuhn J, Visser-Vandewalle V |title=Putting the pieces together in Gilles de la Tourette Syndrome: exploring the link between clinical observations and the biological basis of dysfunction |journal=Brain Topogr |volume=30 |issue=1 |pages=3–29 |date=January 2017 |pmid=27783238 |pmc=5219042 |doi=10.1007/s10548-016-0525-z |type= Review}}</ref> The variation in tic severity may occur over hours, days, or weeks.<ref name= Dale2017 /> Tics may increase when someone is experiencing stress, fatigue, anxiety, or illness,<ref name= Fernandez>{{cite book |vauthors=Fernandez TV, State MW, Pittenger C |title=Neurogenetics, Part I |chapter=Tourette disorder and other tic disorders |series=Handbook of Clinical Neurology |volume=147 |pages=343–354 |date=2018 |pmid=29325623 |doi=10.1016/B978-0-444-63233-3.00023-3 |type= Review |isbn=978-0-444-63233-3 }}</ref><ref name= Ludlow2018 /> or when engaged in relaxing activities like watching TV. They sometimes decrease when an individual is engrossed in or focused on an activity like playing a musical instrument.<ref name= Fernandez />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 243}}

In contrast to the abnormal movements associated with other [[Medicine:Movement disorder|movement disorder]]s, the tics of Tourette's are nonrhythmic, often preceded by an unwanted urge, and temporarily suppressible.<ref name= Hash2017 /><ref name=Jankovic2001>{{cite journal |vauthors=Jankovic J |title=Differential diagnosis and etiology of tics |journal=Adv Neurol |volume=85 |pages=15–29 |date=2001 |pmid=11530424 |type= Review}}</ref> Over time, about 90% of individuals with Tourette's feel an urge preceding the tic,<ref name= Dale2017>{{cite journal |vauthors=Dale RC |title=Tics and Tourette: a clinical, pathophysiological and etiological review |journal=Curr. Opin. Pediatr. |volume=29 |issue=6 |pages=665–673 |date=December 2017 |pmid=28915150 |doi=10.1097/MOP.0000000000000546 |s2cid=13654194 |type= Review}}</ref> similar to the urge to sneeze or scratch an itch. The urges and sensations that precede the expression of a tic are referred to as premonitory sensory phenomena or premonitory urges. People describe the urge to express the tic as a buildup of tension, pressure, or energy<ref name=Prado>{{cite journal |vauthors=Prado HS, Rosário MC, Lee J, Hounie AG, Shavitt RG, Miguel EC |title=Sensory phenomena in obsessive-compulsive disorder and tic disorders: a review of the literature |journal=CNS Spectr |volume=13 |issue=5 |pages=425–432 |date=May 2008 |pmid=18496480 |doi=10.1017/s1092852900016606 |s2cid=5694160 |type= Review and meta-anlysis |url=http://www.cnsspectrums.com/aspx/article_pf.aspx?articleid=1540 |archive-url=https://web.archive.org/web/20120210003420/http://www.cnsspectrums.com/aspx/article_pf.aspx?articleid=1540 |url-status=dead |archive-date=February 10, 2012 }}</ref><ref>{{cite journal |vauthors=Bliss J |title=Sensory experiences of Gilles de la Tourette syndrome |journal=Arch. Gen. Psychiatry |volume=37 |issue=12 |pages=1343–1347 |date=December 1980 |pmid=6934713 |doi=10.1001/archpsyc.1980.01780250029002 }}</ref> which they ultimately choose consciously to release, as if they "had to do it"<ref name=Kwak>{{cite journal |vauthors=Kwak C, Dat Vuong K, Jankovic J |title=Premonitory sensory phenomenon in Tourette's syndrome |journal=Mov. Disord. |volume=18 |issue=12 |pages=1530–1533 |date=December 2003 |pmid=14673893 |doi=10.1002/mds.10618 |s2cid=8152205 }}</ref> to relieve the sensation<ref name=Prado /> or until it feels "just right".<ref name=Kwak /><ref name=Swain /> The urge may cause a distressing sensation in the part of the body associated with the resulting tic; the tic is a response that relieves the urge in the anatomical location of the tic.<ref name=Stern2018 /><ref name= Hash2017 /> Examples of this urge are the feeling of having something in one's throat, leading to a tic to clear one's throat, or a localized discomfort in the shoulders leading to shrugging the shoulders. The actual tic may be felt as relieving this tension or sensation, similar to scratching an itch or blinking to relieve an uncomfortable feeling in the eye.<ref name= Stern2018 /><ref name= TSADef /> Some people with Tourette's may not be aware of the premonitory urge associated with tics. Children may be less aware of it than are adults,<ref name=Dale2017 /> but their awareness tends to increase with maturity;<ref name=TSADef /> by the age of ten, most children recognize the premonitory urge.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 243}}

Premonitory urges which precede the tic make suppression of the impending tic possible.<ref name= Hash2017 /> Because of the urges that precede them, tics are described as semi-voluntary or "''unvoluntary''",<!-- Please do NOT CHANGE "UNVOLUNTARY" to "INVOLUNTARY"; it is not a typo, it is the correct term, please read the text and the references. --><ref name=Stern2018 /><ref name=TSADef /> rather than specifically ''involuntary''; they may be experienced as a ''voluntary'', suppressible response to the unwanted premonitory urge.<ref name= Hash2017 />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 243}} The ability to suppress tics varies among individuals, and may be more developed in adults than children.<ref name= Ludolph2012 /> People with tics are sometimes able to suppress them for limited periods of time, but doing so often results in tension or mental exhaustion.<ref name=Stern2018 />{{sfnp|Müller-Vahl|2013|p=629}} People with Tourette's may seek a secluded spot to release the suppressed urge, or there may be a marked increase in tics after a period of suppression at school or work.<ref name= Dale2017 /><ref name=Dure /> Children may suppress tics while in the doctor's office, so they may need to be observed when not aware of being watched.<ref name=emed>{{cite web | vauthors = Black KJ |url= http://emedicine.medscape.com/article/1182258-overview |title= Tourette syndrome and other tic disorders |archive-url=https://web.archive.org/web/20090822025931/http://emedicine.medscape.com/article/1182258-overview |archive-date=August 22, 2009 |publisher= eMedicine |date= March 30, 2007 |access-date= August 10, 2009}}</ref>

Complex tics related to speech include coprolalia, [[Medicine:Echolalia|echolalia]] and palilalia. Coprolalia is the spontaneous utterance of socially objectionable or taboo words or phrases. Although it is the most publicized symptom of Tourette's, only about 10% of people with Tourette's exhibit it, and it is not required for a diagnosis.<ref name=Stern2018 /><ref name=Singer2011>{{cite book |vauthors=Singer HS |volume=100 |pages=641–657 |date=2011 |pmid=21496613 |doi=10.1016/B978-0-444-52014-2.00046-X |type= Historical review |series=Handbook of Clinical Neurology |isbn=978-0-444-52014-2 |chapter=Tourette syndrome and other tic disorders |title=Hyperkinetic Movement Disorders |publisher=Elsevier }} Also see {{cite journal |vauthors=Singer HS |title=Tourette's syndrome: from behaviour to biology |journal=Lancet Neurol |volume=4 |issue=3 |pages=149–59 |date=March 2005 |pmid=15721825 |doi=10.1016/S1474-4422(05)01012-4 |s2cid=20181150 |type= Review}}</ref> Echolalia (repeating the words of others) and palilalia (repeating one's own words) occur in a minority of cases.<ref name=phenomenology>{{cite journal |vauthors=Leckman JF, Bloch MH, King RA, Scahill L |title=Phenomenology of tics and natural history of tic disorders |journal=Adv Neurol |volume=99 |pages=1–16 |date=2006 |pmid=16536348 |type= Historical review}}</ref> Complex motor tics include copropraxia (obscene or forbidden gestures, or inappropriate touching), echopraxia (repetition or imitation of another person's actions) and palipraxia (repeating one's own movements).<ref name=Ludolph2012>{{cite journal |vauthors=Ludolph AG, Roessner V, Münchau A, Müller-Vahl K |title=Tourette syndrome and other tic disorders in childhood, adolescence and adulthood |journal=Dtsch Ärztebl Int |volume=109 |issue=48 |date=November 2012 |pages=821–828 |pmid=23248712 |pmc=3523260 |doi=10.3238/arztebl.2012.0821 |type=Review}}</ref>

=== Onset and progression ===
There is no typical case of Tourette syndrome,<ref name=Zinner>{{cite journal |vauthors=Zinner SH |title=Tourette disorder |journal=Pediatr Rev |volume=21 |issue=11 |pages=372–383 |date=November 2000 |pmid=11077021 |type= Review|doi=10.1542/pir.21-11-372 |s2cid=7774922 }}</ref> but the age of onset and the severity of symptoms follow a fairly reliable course. Although onset may occur anytime before eighteen years, the typical age of onset of tics is from five to seven, and is usually before adolescence.<ref name=Stern2018 /> A 1998 study from the Yale Child Study Center showed that tic severity increased with age until it reached its highest point between ages eight and twelve.<ref name=YaleTicSeverity>{{cite journal |vauthors=Leckman JF, Zhang H, Vitale A, et al |title=Course of tic severity in Tourette syndrome: the first two decades |journal=Pediatrics |volume=102 |issue=1 Pt 1 |pages=14–19 |date=July 1998 |pmid=9651407 |doi=10.1542/peds.102.1.14 |s2cid=24743670 |type= Research support |url= http://childpsych.columbia.edu/brainimaging/PDF/PD10298.pdf|archive-url=https://web.archive.org/web/20120113125604/http://childpsych.columbia.edu/brainimaging/PDF/PD10298.pdf |archive-date=January 13, 2012 }}</ref><!--
NOTE: LANDMARK STUDY cited in almost every TS article since then.
--> Severity declines steadily for most children as they pass through adolescence, when half to two-thirds of children see a dramatic decrease in tics.<ref name=FernandezCitingBloch>{{cite book |vauthors=Fernandez TV, State MW, Pittenger C |title=Neurogenetics, Part I |chapter=Tourette disorder and other tic disorders |series=Handbook of Clinical Neurology |volume=147 |pages=343–354 |date=2018 |pmid=29325623 |doi=10.1016/B978-0-444-63233-3.00023-3 |isbn=978-0-444-63233-3 |type= Review}} Citing {{Harvp|Bloch|2013|p= [https://web.archive.org/web/20220531095349/https://books.google.com/books?id=KoppAgAAQBAJ&pg=PA107&dq=%22Clinical+course+and+adult+outcome+in+Tourette+syndrome%22+Bloch&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwiCyZfAp9nnAhUPlKwKHeMHBP0Q6AEwAHoECAEQAg#v=onepage&q=%22Clinical%20course%20and%20adult%20outcome%20in%20Tourette%20syndrome%22%20Bloch&f=false 109:] No tics when they reach adulthood, 37%; minimal 18%; mild 26%; moderate 14%; worse 5%.}}</ref>

In people with TS, the first tics to appear usually affect the head, face, and shoulders, and include blinking, facial movements, sniffing and throat clearing.<ref name= Dale2017 /> Vocal tics often appear months or years after motor tics but can appear first.<ref name= DSMAppraisal />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p=242}} Among people who experience more severe tics, complex tics may develop, including "arm straightening, touching, tapping, jumping, hopping and twirling".<ref name= Dale2017 /> There are different movements in contrasting disorders (for example, the autism spectrum disorders), such as [[Medicine:Stimming|self-stimulation]] and stereotypies.<ref name=Rapin/>

The severity of symptoms varies widely among people with Tourette's, and many cases may be undetected.<ref name=Stern2018 /><ref name= Hollis>Hollis C, Pennant M, Cuenca J, et al. (January 2016). "[https://www.ncbi.nlm.nih.gov/books/NBK338526/pdf/Bookshelf_NBK338526.pdf Clinical effectiveness and patient perspectives of different treatment strategies for tics in children and adolescents with Tourette syndrome: a systematic review and qualitative analysis] {{Webarchive|url=https://web.archive.org/web/20220603195336/https://www.ncbi.nlm.nih.gov/books/NBK338526/pdf/Bookshelf_NBK338526.pdf |date=June 3, 2022 }}". ''Health Technology Assessment''. Southampton (UK): NIHR Journals Library. '''20''' (4): 1–450. {{doi|10.3310/hta20040}}. {{ISSN|1366-5278}}.</ref><!--p. 8.-->{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 242}}<ref name=phenomenology /> Most cases are mild and almost unnoticeable;<ref name=Robertson2011 /><ref name=Robertson-1-2008>{{cite journal |vauthors=Robertson MM |title=The prevalence and epidemiology of Gilles de la Tourette syndrome. Part 1: the epidemiological and prevalence studies |journal=J Psychosom Res |volume=65 |issue=5 |pages=461–472 |date=November 2008 |pmid=18940377 |doi=10.1016/j.jpsychores.2008.03.006 |type= Review}}</ref> many people with TS may not realize they have tics. Because tics are more commonly expressed in private, Tourette syndrome may go unrecognized,<ref name=Knight>{{cite journal |vauthors=Knight T, Steeves T, Day L, Lowerison M, Jette N, Pringsheim T |title=Prevalence of tic disorders: a systematic review and meta-analysis |journal=Pediatr. Neurol. |volume=47 |issue=2 |pages=77–90 |date=August 2012 |pmid=22759682 |doi=10.1016/j.pediatrneurol.2012.05.002 |type= Review}}</ref> and casual observers might not notice tics.<ref name= Singer2011 /><ref>{{cite journal |vauthors=Kenney C, Kuo SH, Jimenez-Shahed J |title=Tourette's syndrome |journal=Am Fam Physician |volume=77 |issue=5 |pages=651–658 |date=March 2008 |pmid=18350763 |type= Review}}</ref><ref>{{cite journal |vauthors=Black KJ, Black ER, Greene DJ, Schlaggar BL |title=Provisional Tic Disorder: What to tell parents when their child first starts ticcing |journal=F1000Res |volume=5 |date=2016 |page=696 |pmid=27158458 |pmc=4850871 |doi=10.12688/f1000research.8428.1 |type=Review |doi-access=free }}</ref> Most studies of TS involve males, who have a higher [[Prevalence|prevalence]] of TS than females, and gender-based differences are not well studied; a 2021 review suggested that the characteristics and progression for females, particularly in adulthood, may differ and better studies are needed.<ref name= Garris2021/>

Most adults with TS have mild symptoms and do not seek medical attention.<ref name=Stern2018 /> While tics subside for the majority after adolescence, some of the "most severe and debilitating forms of tic disorder are encountered" in adults.<ref name= Robertson2017 /> In some cases, what appear to be adult-onset tics can be childhood tics re-surfacing.<ref name= Robertson2017>{{cite journal |vauthors=Robertson MM, Eapen V, Singer HS, et al |title=Gilles de la Tourette syndrome |journal=Nat Rev Dis Primers |volume=3 |pages=16097 |date=February 2017 |issue=1 |pmid=28150698 |doi=10.1038/nrdp.2016.97 |s2cid=38518566 |type=Review |url=http://discovery.ucl.ac.uk/10045650/1/Hariz_Collated%20NRDP%20GTS%20papers_MMR_ve_4%20Aug.jfledits.pdf |access-date=April 22, 2020 |archive-date=July 22, 2018 |archive-url=https://web.archive.org/web/20180722101100/http://discovery.ucl.ac.uk/10045650/1/Hariz_Collated%20NRDP%20GTS%20papers_MMR_ve_4%20Aug.jfledits.pdf |url-status=live }}</ref>

=== Co-occurring conditions ===
[[File:JFK, Marie-Madeleine Lioux, André Malraux, Jackie, L.B. Johnson, unveiling Mona Lisa at National Gallery of Art.png|thumb|left|alt=Three men and two women stand near the Mona Lisa. All are dressed formally, one woman in a spectacular pink gown.|[[Biography:André Malraux|André Malraux]] (center) was a French Minister of Culture, author and adventurer who may have had Tourette syndrome.<ref name=Kammer>{{cite book |veditors=Bogousslavsky J, Hennerici MG |title=Neurological Disorders in Famous Artists - Part 2 |vauthors=Kammer T |chapter=Mozart in the neurological department – who has the tic? |volume=22 |pages=184–192 |date=2007 |type=Historical biography |chapter-url= https://www.uni-ulm.de/~tkammer/pdf/Kammer_2007_Mozart_preprint.pdf |pmid=17495512 |doi=10.1159/000102880 |archive-url=https://web.archive.org/web/20120207145220/http://www.uni-ulm.de/~tkammer/pdf/Kammer_2007_Mozart_preprint.pdf |archive-date=February 7, 2012 |series=Frontiers of Neurology and Neuroscience |location=Basel |isbn=978-3-8055-8265-0 |publisher=Karger}}</ref><ref>{{cite book | vauthors = Todd O |title= Malraux: A Life |publisher= Alfred A. Knopf |year= 2005|isbn= 978-0375407024 |url= https://archive.org/details/malrauxlife0000todd/page/6/mode/2up?view=theater&q=Tourette%27s |page=7}}</ref><ref>{{cite journal |vauthors=Guidotti TL |title=André Malraux: a medical interpretation |journal=J R Soc Med |volume=78 |issue=5 |pages=401–406 |date=May 1985 |pmid=3886907 |pmc=1289723 |doi=10.1177/014107688507800511 |type= Historical biography}}</ref>]]

Because people with milder symptoms are unlikely to be referred to specialty clinics, studies of Tourette's have an inherent bias towards more severe cases.<ref name=Bloch2011>{{cite journal |vauthors=Bloch M, State M, Pittenger C |title=Recent advances in Tourette syndrome |journal=Curr. Opin. Neurol. |volume=24 |issue=2 |pages=119–125 |date=April 2011 |pmid=21386676 |pmc=4065550 |doi=10.1097/WCO.0b013e328344648c |type= Review}}</ref><ref>See also
* {{cite journal |vauthors=Schapiro NA |title="Dude, you don't have Tourette's:" Tourette's syndrome, beyond the tics |journal=Pediatr Nurs |volume=28 |issue=3 |pages=243–246, 249–53 |date=2002 |pmid=12087644 |type= Review |url=http://www.medscape.com/viewarticle/442029|archive-url=https://web.archive.org/web/20081205082825/http://www.medscape.com/viewarticle/442029 |archive-date=December 5, 2008 |ref=none}}
* {{cite journal |vauthors=Coffey BJ, Park KS |title=Behavioral and emotional aspects of Tourette syndrome |journal=Neurol Clin |volume=15 |issue=2 |pages=277–89 |date=May 1997 |pmid=9115461 |doi=10.1016/s0733-8619(05)70312-1 |type= Review|ref=none}}</ref> When symptoms are severe enough to warrant referral to clinics, ADHD and OCD are often also found.<ref name=Stern2018 /> In specialty clinics, 30% of those with TS also have [[Medicine:Mood disorder|mood]] or [[Medicine:Anxiety disorder|anxiety disorder]]s or disruptive behaviors.<ref name= Dale2017 /><ref name=Hirsch2015>{{cite journal |vauthors=Hirschtritt ME, Lee PC, Pauls DL, et al |title=Lifetime prevalence, age of risk, and genetic relationships of comorbid psychiatric disorders in Tourette syndrome |journal=JAMA Psychiatry |volume=72 |issue=4 |pages=325–333 |date=April 2015 |pmid=25671412 |pmc=4446055 |doi=10.1001/jamapsychiatry.2014.2650 }}</ref> In the absence of ADHD, tic disorders do not appear to be associated with disruptive behavior or functional impairment,<ref name=CommunitySample>{{cite journal |vauthors=Scahill L, Williams S, Schwab-Stone M, Applegate J, Leckman JF |title=Disruptive behavior problems in a community sample of children with tic disorders |journal=Adv Neurol |volume=99 |pages=184–190 |date=2006 |pmid=16536365 |type= Comparative study}}</ref> while impairment in school, family, or peer relations is greater in those who have more comorbid conditions.<ref name=Dure /><ref name= Morand /> When ADHD is present along with tics, the occurrence of [[Medicine:Conduct disorder|conduct disorder]] and [[Medicine:Oppositional defiant disorder|oppositional defiant disorder]] increases.<ref name= Dale2017 /> Aggressive behaviors and angry outbursts in people with TS are not well understood; they are not associated with severe tics, but are connected with the presence of ADHD.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 245}} ADHD may also contribute to higher rates of anxiety, and aggression and anger control problems are more likely when both OCD and ADHD co-occur with Tourette's.<ref name= Robertson2017 />

Compulsions that resemble tics are present in some individuals with OCD; "tic-related OCD" is hypothesized to be a subgroup of OCD, distinguished from non-tic related OCD by the type and nature of obsessions and compulsions.<ref name=Hounie>{{cite journal |vauthors=Hounie AG, do Rosario-Campos MC, Diniz JB, et al|title=Obsessive-compulsive disorder in Tourette syndrome |journal=Adv Neurol |volume=99 |pages=22–38 |date=2006 |pmid=16536350 |type= Review}}</ref> Compared to the more typical compulsions of OCD without tics that relate to contamination, tic-related OCD presents with more "counting, [[Medicine:Intrusive thought|aggressive thoughts]], symmetry and touching" compulsions.<ref name= Dale2017 /> Compulsions associated with OCD without tics are usually related to obsessions and anxiety, while those in tic-related OCD are more likely to be a response to a premonitory urge.<ref name= Dale2017 /><ref>{{cite journal |vauthors=Katz TC, Bui TH, Worhach J, Bogut G, Tomczak KK |title=Tourettic OCD: Current understanding and treatment challenges of a unique endophenotype |journal=Front Psychiatry |volume=13 |pages=929526 |date=2022 |pmid=35966462 |pmc=9363583 |doi=10.3389/fpsyt.2022.929526 |doi-access=free }}</ref> There are increased rates of anxiety and depression in those adults with TS who also have OCD.<ref name= Robertson2017 />

Among individuals with TS studied in clinics, between 2.9% and 20% had autism spectrum disorders,<ref>{{cite journal |vauthors=Cravedi E, Deniau E, Giannitelli M, et al |title=Tourette syndrome and other neurodevelopmental disorders: a comprehensive review |journal=Child Adolesc Psychiatry Ment Health |volume=11 |pages=59 |date=2017 |issue=1 |pmid=29225671 |pmc=5715991 |doi=10.1186/s13034-017-0196-x |type= Review |doi-access=free }}</ref> but one study indicates that a high association of [[Medicine:Autism|autism]] and TS may be partly due to difficulties distinguishing between tics and tic-like behaviors or OCD symptoms seen in people with autism.<ref>{{cite journal |vauthors=Darrow SM, Grados M, Sandor P, et al |title=Autism spectrum symptoms in a Tourette's disorder sample |journal=J Am Acad Child Adolesc Psychiatry |volume=56 |issue=7 |pages=610–617.e1 |date=July 2017 |pmid=28647013 |pmc=5648014 |doi=10.1016/j.jaac.2017.05.002 |type= Comparative study}}</ref>

Not all people with Tourette's have ADHD or OCD or other comorbid conditions, and estimates of the rate of pure TS or TS-only vary from 15% to 57%;{{efn| According to Dale (2017), over time, 15% of people with tics have only TS (85% of people with Tourette's will develop a co-occurring condition).<ref name= Dale2017 /> In a 2017 literature review, Sukhodolsky, et al. stated that 37% of individuals in clinical samples had pure TS.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 244}} Denckla (2006) reported that a review of patient records revealed that about 40% of people with Tourette's have TS-only.<ref name=DencklaReview>{{cite journal |vauthors=Denckla MB |title=Attention-deficit hyperactivity disorder (ADHD) comorbidity: a case for "pure" Tourette syndrome? |journal=J. Child Neurol. |volume=21 |issue=8 |pages=701–703 |date=August 2006 |pmid=16970871 |doi=10.1177/08830738060210080701 |s2cid=44775472 |type= Review}}</ref><ref name=Denckla>{{cite journal |vauthors=Denckla MB |title=Attention deficit hyperactivity disorder: the childhood co-morbidity that most influences the disability burden in Tourette syndrome |journal=Adv Neurol |volume=99 |pages=17–21 |date=2006 |pmid=16536349 |type= Review}}</ref> Dure and DeWolfe (2006) reported that 57% of 656 individuals presenting with tic disorders had tics uncomplicated by other conditions.<ref name=Dure />}} in clinical populations, a high percentage of those under care do have ADHD.<ref name=Swain />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 244}} Children and adolescents with pure TS are not significantly different from their peers without TS on ratings of aggressive behaviors or conduct disorders, or on measures of social adaptation.<ref name= Hollis /><!-- p. 3--> Similarly, adults with pure TS do not appear to have the social difficulties present in those with TS plus ADHD.<ref name= Hollis /><!-- p. 3 -->

Among those with an older age of onset, more substance abuse and [[Medicine:Mood disorder|mood disorder]]s are found, and there may be self-injurious tics. Adults who have severe, often treatment-resistant tics are more likely to also have mood disorders and OCD.<ref name= Robertson2017 /> Coprolalia is more likely in people with severe tics plus multiple comorbid conditions.<ref name= Ludolph2012 />

=== Neuropsychological function ===
There are no major impairments in neuropsychological function among people with Tourette's,<!--the ref originally following the sentence after this was<ref name= Morand />--> but conditions that occur along with tics can cause variation in [[Philosophy:Neurocognitive|neurocognitive]] function. A better understanding of comorbid conditions is needed to untangle any neuropsychological differences between TS-only individuals and those with comorbid conditions.<ref name= Morand>{{cite journal |vauthors=Morand-Beaulieu S, Leclerc JB, Valois P, et al |title= A review of the neuropsychological dimensions of Tourette syndrome |journal=Brain Sci |volume=7 |issue=8 |page= 106 |date=August 2017 |pmid=28820427 |pmc=5575626 |doi=10.3390/brainsci7080106 |type= Review|doi-access= free }}</ref>

Only slight impairments are found in [[Philosophy:Intelligence quotient|intellectual ability]], [[Biology:Attentional control|attentional ability]], and nonverbal memory—but ADHD, other comorbid disorders, or tic severity could account for these differences. In contrast with earlier findings, visual motor integration and visuoconstructive skills are not found to be impaired, while comorbid conditions may have a small effect on [[Engineering:Motor skill|motor skill]]s. Comorbid conditions and severity of tics may account for variable results in [[Social:Verbal fluency test|verbal fluency]], which can be slightly impaired. There might be slight impairment in [[Philosophy:Social cognition|social cognition]], but not in the ability to plan or make decisions.<ref name= Morand /> Children with TS-only do not show cognitive deficits.<!-- Hollis, Denckla --> They are faster than average for their age on timed tests of [[Engineering:Motor coordination|motor coordination]], and constant tic suppression may lead to an advantage in switching between tasks because of increased inhibitory control.<ref name= Hollis /><!--p. 6. --><ref name=Denckla /><!-- p. 20 -->

[[Medicine:Learning disability|Learning disabilities]] may be present, but whether they are due to tics or comorbid conditions is controversial; older studies that reported higher rates of learning disability did not control well for the presence of comorbid conditions.{{sfnp|Pruitt|Packer|2013|pp=636–637}} There are often [[Medicine:Dysgraphia|difficulties with handwriting]], and disabilities in written expression and math are reported in those with TS plus other conditions.{{sfnp|Pruitt|Packer|2013|pp=636–637}}

== Causes ==
The exact cause of Tourette's is unknown, but it is well established that both genetic and environmental factors are involved.<ref name= Fernandez /><ref name= Dale2017 /><ref name= Baldermann /> [[Philosophy:Genetic epidemiology|Genetic epidemiology]] studies have shown that Tourette's is highly heritable,<ref name= Cavenna2018 /> and 10 to 100 times more likely to be found among close family members than in the general population.<ref name= Efron2018 /> The exact mode of inheritance is not known; no single gene has been identified,<ref name= EuropeanPartI/> and hundreds of genes are likely involved.<ref name=Bloch2011/><ref name= Cavenna2018>{{cite journal |vauthors=Cavanna AE |title=The neuropsychiatry of Gilles de la Tourette syndrome: The ''état de l'art'' |journal=Rev. Neurol. (Paris) |volume=174 |issue=9 |pages=621–627 |date=November 2018 |pmid=30098800 |doi=10.1016/j.neurol.2018.06.006 |s2cid=51966823 |type= Review}}</ref><ref name= Efron2018>{{cite journal |vauthors=Efron D, Dale RC |title=Tics and Tourette syndrome |journal=J Paediatr Child Health |volume=54 |issue=10 |pages=1148–1153 |date=October 2018 |pmid=30294996 |doi=10.1111/jpc.14165 |hdl=11343/284621 |s2cid=52934981 |type= Review|hdl-access=free }}</ref> [[Philosophy:Genome-wide association study|Genome-wide association studies]] were published in 2013<ref name=Stern2018 /> and 2015<ref name=Dale2017 /> in which no finding reached a threshold for significance;<ref name=Stern2018 /> a 2019 [[Meta-analysis|meta-analysis]] found only a single genome-wide significant locus on chromosome 13, but that result was not found in broader samples.<ref>{{cite journal |vauthors=Yu D, Sul JH, Tsetsos F, et al |title=Interrogating the genetic determinants of Tourette's syndrome and other tic disorders through genome-wide association studies |journal=Am J Psychiatry |volume=176 |issue=3 |pages=217–227 |date=March 2019 |pmid=30818990 |pmc=6677250 |doi=10.1176/appi.ajp.2018.18070857 |type= Meta-analysis}}</ref> [[Biology:Twin study|Twin studies]] show that 50 to 77% of identical twins share a TS diagnosis, while only 10 to 23% of fraternal twins do.<ref name=Fernandez /> But not everyone who inherits the genetic vulnerability will show symptoms.<ref>{{cite journal |vauthors=van de Wetering BJ, Heutink P |title=The genetics of the Gilles de la Tourette syndrome: a review |journal=J. Lab. Clin. Med. |volume=121 |issue=5 |pages=638–645 |date=May 1993 |pmid=8478592 |type= Review}}</ref><ref>{{cite journal |vauthors=Paschou P |title=The genetic basis of Gilles de la Tourette Syndrome |journal=Neurosci Biobehav Rev |volume=37 |issue=6 |pages=1026–1039 |date=July 2013 |pmid=23333760 |doi=10.1016/j.neubiorev.2013.01.016 |s2cid=10515751 |type= Review}}</ref> A few rare [[Biology:Penetrance|highly penetrant]] genetic mutations have been found that explain only a small number of cases in single families (the ''SLITRK1, [[Biology:Histidine decarboxylase|HDC]]'', and ''CNTNAP2'' genes).<ref>{{cite journal |vauthors=Barnhill J, Bedford J, Crowley J, Soda T |title=A search for the common ground between Tic; Obsessive-compulsive and Autism Spectrum Disorders: part I, Tic disorders |journal=AIMS Genet |volume=4 |issue=1 |pages=32–46 |date=2017 |pmid=31435502 |pmc=6690237 |doi=10.3934/genet.2017.1.32 |type= Review}}</ref>

[[Social:Psychosocial|Psychosocial]] or other non-genetic factors—while not causing Tourette's—can affect the severity of TS in vulnerable individuals and influence the expression of the inherited genes.<ref name= Hollis /><ref name=Zinner /><ref name= Baldermann /><ref name= Efron2018 /> Pre-natal and peri-natal events increase the risk that a tic disorder or comorbid OCD will be expressed in those with the genetic vulnerability. These include paternal age; forceps delivery; stress or severe nausea during pregnancy; and use of tobacco, caffeine, alcohol,<ref name= Hollis /><ref name= Ueda2021/> and [[Biology:Cannabis|cannabis]] during pregnancy.<ref name= Stern2018 /> Babies who are born [[Medicine:Preterm birth|premature]] with low birthweight, or who have low [[Engineering:Apgar score|Apgar score]]s, are also at increased risk; in premature twins, the lower birthweight twin is more likely to develop TS.<ref name= Hollis /><!-- p. 6 -->

Autoimmune processes may affect the onset of tics or exacerbate them. Both OCD and tic disorders are hypothesized to arise in a subset of children as a result of a post-[[Biology:Streptococcus|streptococcal]] autoimmune process.<ref name=Hsu2021/> Its potential effect is described by the controversial<ref name=Hsu2021/> hypothesis called [[Medicine:PANDAS|PANDAS]] (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections), which proposes five criteria for diagnosis in children.<ref name= Wilbur2019>{{cite journal |vauthors=Wilbur C, Bitnun A, Kronenberg S, Laxer RM, Levy DM, Logan WJ, Shouldice M, Yeh EA |title=PANDAS/PANS in childhood: Controversies and evidence |journal=Paediatr Child Health |volume=24 |issue=2 |pages=85–91 |date=May 2019 |pmid=30996598 |pmc=6462125 |doi=10.1093/pch/pxy145}}</ref><ref name=Sigra2018>{{cite journal |vauthors=Sigra S, Hesselmark E, Bejerot S |title=Treatment of PANDAS and PANS: a systematic review |journal=Neurosci Biobehav Rev |volume=86 |issue= |pages=51–65 |date=March 2018 |pmid=29309797 |doi=10.1016/j.neubiorev.2018.01.001 |s2cid=40827012 |doi-access=free }}</ref> PANDAS and the newer pediatric acute-onset neuropsychiatric syndrome (PANS) hypotheses are the focus of clinical and laboratory research, but remain unproven.<ref name= Wilbur2019/> There is also a broader hypothesis that links immune-system abnormalities and [[Biology:Immune dysregulation|immune dysregulation]] with TS.<ref name= Dale2017 /><ref name= Hsu2021>{{cite journal |vauthors=Hsu CJ, Wong LC, Lee WT |title=Immunological dysfunction in Tourette syndrome and related disorders |journal=Int J Mol Sci |volume=22 |issue=2 |date=January 2021 |page=853 |pmid=33467014 |pmc=7839977 |doi=10.3390/ijms22020853 |type= Review|doi-access=free }}</ref>

Some forms of OCD may be genetically linked to Tourette's,<ref name=Swain /> although the genetic factors in OCD with and without tics may differ.<ref name= Fernandez /> The genetic relationship of ADHD to Tourette syndrome, however, has not been fully established.<ref name= Hirsch2015/><ref name=Denckla /><ref>{{cite journal |vauthors=Hirschtritt ME, Darrow SM, et al |title=Genetic and phenotypic overlap of specific obsessive-compulsive and attention-deficit/hyperactive subtypes with Tourette syndrome |journal=Psychol Med |volume=48 |issue=2 |pages=279–293 |date=January 2018 |pmid=28651666 |pmc=7909616 |s2cid=26353939 |doi=10.1017/S0033291717001672 }}</ref> A genetic link between autism and Tourette's has not been established as of 2017.<ref name= Robertson2017 />

== Mechanism ==
[[File:Basal ganglia and related structures (2).svg|thumb|upright=1.6|alt=The basal ganglia at the brain's center with the thalamus next to it. Nearby related brain structures are also shown.|The basal ganglia and thalamus are implicated in Tourette syndrome.]]
The exact [[Medicine:Pathophysiology|mechanism]] affecting the inherited vulnerability to Tourette's is not well established.<ref name= Fernandez /> Tics are believed to result from dysfunction in [[Biology:Cerebral cortex|cortical]] and subcortical brain regions: the thalamus, [[Biology:Basal ganglia|basal ganglia]] and [[Biology:Frontal lobe|frontal cortex]].{{sfnp|Walkup|Mink|Hollenback|2006|p=xv}} Neuroanatomic models suggest failures in circuits connecting the brain's cortex and subcortex;<ref name=Zinner /> [[Biology:Neuroimaging|imaging techniques]] implicate the frontal cortex and basal ganglia.<ref name=Bloch2011 /> In the 2010s, neuroimaging and [[Postmortem studies|postmortem brain studies]], as well as [[Social:Animal studies|animal]] and [[Biology:Genetic analysis|genetic studies]],<ref name= Morand />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 246}} made progress towards better understanding the neurobiological mechanisms leading to Tourette's.<ref name= Morand /> These studies support the basal ganglia model, in which [[Biology:Neuron|neuron]]s in the [[Biology:Striatum|striatum]] are activated and inhibit outputs from the basal ganglia.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 245}}

[[Biology:Cortico-basal ganglia-thalamo-cortical loop|Cortico-striato-thalamo-cortical]] (CSTC) [[Neural circuit#Circuitry|circuits]], or neural pathways, provide inputs to the basal ganglia from the cortex. These circuits connect the basal ganglia with other areas of the brain to transfer information that regulates planning and control of movements, behavior, decision-making, and learning.<ref name= Morand /> Behavior is regulated by cross-connections that "allow the integration of information" from these circuits.<ref name= Morand /> Involuntary movements may result from impairments in these CSTC circuits,<ref name= Morand /> including the sensorimotor, [[Philosophy:Limbic system|limbic]], [[Biology:Cerebral cortex#Association areas|language]] and [[Biology:Orbitofrontal cortex|decision making]] pathways.<!-- Cox JH 2018 --> Abnormalities in these circuits may be responsible for tics and premonitory urges.<ref>{{cite journal |vauthors=Cox JH, Seri S, Cavanna AE |title=Sensory aspects of Tourette syndrome |journal=Neurosci Biobehav Rev |volume=88 |pages=170–176 |date=May 2018 |pmid=29559228 |doi=10.1016/j.neubiorev.2018.03.016 |s2cid=4640655 |url=https://publications.aston.ac.uk/id/eprint/33055/1/Sensory_aspects_of_Tourette_syndrome.pdf |type=Review |access-date=March 18, 2020 |archive-date=December 1, 2020 |archive-url=https://web.archive.org/web/20201201152445/https://publications.aston.ac.uk/id/eprint/33055/1/Sensory_aspects_of_Tourette_syndrome.pdf |url-status=live }}</ref>

The caudate nuclei may be smaller in subjects with tics compared to those without tics, supporting the hypothesis of pathology in CSTC circuits in Tourette's.<ref name= Morand /> The ability to suppress tics depends on brain circuits that "regulate response inhibition and cognitive control of motor behavior".{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 246}} Children with TS are found to have a larger [[Biology:Prefrontal cortex|prefrontal cortex]], which may be the result of an adaptation to help regulate tics.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 246}} It is likely that tics decrease with age as the capacity of the frontal cortex increases.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 246}} Cortico-basal ganglia (CBG) circuits may also be impaired, contributing to "sensory, limbic and executive" features.<ref name= Dale2017 /> The release of [[Biology:Dopamine|dopamine]] in the basal ganglia is higher in people with Tourette's, implicating biochemical changes from "overactive and dysregulated dopaminergic transmissions".<ref name= Baldermann />

[[Chemistry:Histamine|Histamine]] and the H3 receptor may play a role in the alterations of neural circuitry.<ref name= Dale2017 /><ref>{{cite journal |vauthors=Rapanelli M, Pittenger C |title=Histamine and histamine receptors in Tourette syndrome and other neuropsychiatric conditions |journal=Neuropharmacology |volume=106 |pages=85–90 |date=July 2016 |pmid=26282120 |doi=10.1016/j.neuropharm.2015.08.019|s2cid=20574808 | type= Review}}</ref><ref>{{cite journal |vauthors=Rapanelli M |title=The magnificent two: histamine and the H3 receptor as key modulators of striatal circuitry |journal=Prog. Neuropsychopharmacol. Biol. Psychiatry |volume=73 |pages=36–40 |date=February 2017 |pmid=27773554 |doi=10.1016/j.pnpbp.2016.10.002 |s2cid=23588346 |type= Review}}</ref><ref>{{cite journal |vauthors=Bolam JP, Ellender TJ |title=Histamine and the striatum |journal=Neuropharmacology |volume=106 |pages=74–84 |date=July 2016 |pmid=26275849 |pmc=4917894 |doi=10.1016/j.neuropharm.2015.08.013 |type= Review}}</ref> A reduced level of histamine in the H3 receptor may result in an increase in other neurotransmitters, causing tics.<ref>{{cite journal |vauthors=Sadek B, Saad A, Sadeq A, Jalal F, Stark H |title=Histamine H3 receptor as a potential target for cognitive symptoms in neuropsychiatric diseases |journal=Behav. Brain Res. |volume=312 |pages=415–430 |date=October 2016 |pmid=27363923 |doi=10.1016/j.bbr.2016.06.051 |s2cid=40024812 |type= Review}}</ref> Postmortem studies have also implicated "dysregulation of neuroinflammatory processes".<ref name= Fernandez />

== Diagnosis ==
According to the ''Diagnostic and Statistical Manual of Mental Disorders'' (DSM-5),{{efn|There were no changes in the fifth text revision of 2022, DSM-5-TR.<ref>{{cite web |url= https://www.psychiatry.org/File%20Library/Psychiatrists/Practice/DSM/DSM-5-TR/APA-DSM5TR-DiagnosesforChildren.pdf |publisher= American Psychiatric Association |title= DSM-5-TR Fact Sheets |date= 2022 |access-date= July 9, 2022 |archive-date= August 18, 2022 |archive-url= https://web.archive.org/web/20220818193942/https://psychiatry.org/File%20Library/Psychiatrists/Practice/DSM/DSM-5-TR/APA-DSM5TR-DiagnosesforChildren.pdf |url-status= live }}</ref>}} Tourette's may be diagnosed when a person exhibits both multiple motor tics and one or more vocal tics over a period of one year. The motor and vocal tics need not be concurrent. The onset must have occurred before the age of 18 and cannot be attributed to the effects of another condition or substance (such as [[Biology:Cocaine|cocaine]]).<ref name=DSM5>{{cite book |chapter= Tourette's Disorder, 307.23 (F95.2) |title= Diagnostic and Statistical Manual of Mental Disorders |date= 2013 |edition = 5th |publisher= American Psychiatric Association |page= 81}}</ref> Hence, other medical conditions that include tics or tic-like movements—for example, [[Medicine:Autism spectrum|autism]] or other causes of tics—must be ruled out.<ref name=WalkupDSMV />

Patients referred for a tic disorder are assessed based on their family history of tics, vulnerability to ADHD, obsessive–compulsive symptoms, and a number of other chronic medical, psychiatric and neurological conditions.<ref name=Assessment />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 247}} In individuals with a typical onset and a family history of tics or OCD, a basic physical and neurological examination may be sufficient.<ref name=Bagheri>{{cite journal |vauthors=Bagheri MM, Kerbeshian J, Burd L |title=Recognition and management of Tourette's syndrome and tic disorders |journal= Am Fam Physician |volume=59 |issue=8 |pages=2263–2272, 2274 |date=April 1999 |pmid=10221310 |type= Review |url= http://www.aafp.org/afp/990415ap/2263.html|archive-url=https://web.archive.org/web/20050331083858/http://www.aafp.org/afp/990415ap/2263.html |archive-date=March 31, 2005 }}</ref> There are no specific medical or screening tests that can be used to diagnose Tourette's;<ref name=Swain>{{cite journal |vauthors=Swain JE, Scahill L, Lombroso PJ, King RA, Leckman JF |title=Tourette syndrome and tic disorders: a decade of progress |journal=J Am Acad Child Adolesc Psychiatry |volume=46 |issue=8 |pages=947–968 |date=August 2007 |pmid=17667475 |doi=10.1097/chi.0b013e318068fbcc |s2cid=343916 |type= Review}}</ref> the diagnosis is usually made based on observation of the individual's symptoms and family history,<ref name=Singer2011 /> and after ruling out secondary causes of tic disorders (tourettism).<ref name= WhatisTS>{{cite web |url= http://tourette.org/media/WhatisEnglish.proof_.r1.pdf |publisher= Tourette Association of America |title= What is Tourette syndrome? | access-date= January 19, 2020 |archive-date= February 26, 2020 |archive-url= https://web.archive.org/web/20200226223254/http://tourette.org/media/WhatisEnglish.proof_.r1.pdf |url-status= live}}</ref>

Delayed diagnosis often occurs because professionals mistakenly believe that TS is rare, always involves coprolalia, or must be severely impairing.{{sfnp|Müller-Vahl|2013|p=625}} The DSM has recognized since 2000 that many individuals with Tourette's do not have significant impairment;<ref name=DSMAppraisal /><ref name=WalkupDSMV /><ref name=DSMIVTRsummary>{{cite web |url= http://www.dsmivtr.org/2-3changes.cfm |title= Summary of Practice: Relevant changes to DSM-IV-TR |publisher= American Psychiatric Association |access-date= December 29, 2011|archive-url= https://web.archive.org/web/20080511220758/http://www.dsmivtr.org/2-3changes.cfm |archive-date= May 11, 2008 }}</ref> diagnosis does not require the presence of coprolalia or a comorbid condition, such as ADHD or OCD.<!--this is sort of a medical tautology isn't it? "Diagnosis of that defined as A, and only A, does not require the presence of that defined as B". See talk. This is here because the NEJM once published an incorrect definition of the condition, a perception that persists.--><ref name=Singer2011 />{{sfnp|Müller-Vahl|2013|p=625}} Tourette's may be misdiagnosed because of the wide expression of severity, ranging from mild (in the majority of cases) or moderate, to severe (the rare but more widely recognized and publicized cases).<ref name=YaleTicSeverity /> About 20% of people with Tourette syndrome do not realize that they have tics.<ref name=Zinner />

Tics that appear early in the course of TS are often confused with allergies, [[Medicine:Asthma|asthma]], vision problems, and other conditions. Pediatricians, allergists and ophthalmologists are among the first to see or identify a child as having tics,<ref name=EuropeanPartI/><ref name=phenomenology /><ref name= Horner2022/> although the majority of tics are first identified by the child's parents.{{sfnp|Müller-Vahl|2013|p=625}} Coughing, blinking, and tics that mimic unrelated conditions such as asthma are commonly misdiagnosed.<ref name=Singer2011 /> In the UK, there is an average delay of three years between symptom onset and diagnosis.<ref name= Hollis /> <!-- p. xl. -->

=== Differential diagnosis ===
{{quote box
|title = Main screening and assessment tools<ref name= Martino2017>{{cite journal |vauthors=Martino D, Pringsheim TM, Cavanna AE, et al |title=Systematic review of severity scales and screening instruments for tics: Critique and recommendations |journal=Mov. Disord. |volume=32 |issue=3 |pages=467–473 |date=March 2017 |pmid=28071825 |pmc=5482361 |doi=10.1002/mds.26891 |type= Review}}</ref>{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 248}}
|quote = {{Bulleted list
|[[Social:Yale Global Tic Severity Scale|Yale Global Tic Severity Scale]] (YGTSS), recommended in international guidelines to assess "frequency, intensity, complexity, distribution, interference and impairment" of or due to tics{{efn|The YGTSS is considered the gold standard in tic assessment.<ref name=EuropeanPartI/>}} 
|[[Social:Tourette Syndrome Clinical Global Impression|Tourette Syndrome Clinical Global Impression]] (TS–CGI) and [[Social:Shapiro TS Severity Scale|Shapiro TS Severity Scale]] (STSS), for a briefer assessment of tics than YGTSS 
|[[Social:Tourette's Disorder Scale|Tourette's Disorder Scale]] (TODS), to assess tics and comorbidities 
|[[Social:Premonitory Urge for Tics Scale|Premonitory Urge for Tics Scale]] (PUTS), for individuals over age ten 
|Motor tic, Obsessions and compulsions, Vocal tic Evaluation Survey (MOVES), to evaluate complex tics and other behaviors 
|Autism—Tics, AD/HD, and other Comorbities (A–TAC), to screen for other conditions }}
|width = 37% |align = right |bgcolor = beige }}

Tics that may appear to mimic those of Tourette's—but are associated with disorders other than Tourette's—are known as tourettism<ref name=Mejia>{{cite journal |vauthors=Mejia NI, Jankovic J |title=Secondary tics and tourettism |journal=Braz J Psychiatry |volume=27 |issue=1 |pages=11–17 |date=March 2005 |pmid=15867978 |doi=10.1590/s1516-44462005000100006 |url= http://www.scielo.br/pdf/rbp/v27n1/23707.pdf|archive-url=https://web.archive.org/web/20070628191850/http://www.scielo.br/pdf/rbp/v27n1/23707.pdf |archive-date=June 28, 2007 |doi-access=free }}</ref> and are ruled out in the [[Medicine:Differential diagnosis|differential diagnosis]] for Tourette syndrome.<ref name=Bagheri /> The abnormal movements associated with choreas, [[Medicine:Dystonia|dystonia]]s, [[Medicine:Myoclonus|myoclonus]], and [[Medicine:Dyskinesia|dyskinesia]]s are distinct from the tics of Tourette's in that they are more rhythmic, not suppressible, and not preceded by an unwanted urge.<ref name= Hash2017 /><ref name=Jankovic2001/> [[Medicine:Developmental disorder|Developmental]] and [[Medicine:Autism spectrum|autism spectrum]] disorders may manifest tics, other stereotyped movements,<ref>{{cite journal |vauthors=Ringman JM, Jankovic J |title=Occurrence of tics in Asperger's syndrome and autistic disorder |journal=J. Child Neurol. |volume=15 |issue=6 |pages=394–400 |date=June 2000 |pmid=10868783 |doi=10.1177/088307380001500608 |s2cid=8596251 |type= Case report}}</ref> and [[Medicine:Stereotypic movement disorder|stereotypic movement disorder]].<ref name=Jankovic2006 /><ref name=FreemanBlog>{{cite web |author= Freeman RD |url= http://www.tourette-confusion.blogspot.com/ |title= Tourette's syndrome: minimizing confusion |archive-url= https://web.archive.org/web/20060411182519/http://www.tourette-confusion.blogspot.com/ |archive-date=April 11, 2006 |publisher= Roger Freeman, MD, blog |access-date= February 8, 2006}}</ref> The stereotyped movements associated with autism typically have an earlier age of onset; are more symmetrical, rhythmical and bilateral; and involve the extremities (for example, flapping the hands).<ref name=Rapin>{{cite journal |vauthors=Rapin I |title=Autism spectrum disorders: relevance to Tourette syndrome |journal=Adv Neurol |volume=85 |pages=89–101 |date=2001 |pmid=11530449 |type= Review}}</ref>

If another condition might better explain the tics, tests may be done; for example, if there is diagnostic confusion between tics and [[Medicine:Seizure|seizure]] activity, an [[Biology:Electroencephalography|EEG]] may be ordered. An MRI can rule out brain abnormalities, but such brain imaging studies are not usually warranted.<ref name=Assessment>{{cite journal |vauthors=Scahill L, Erenberg G, Berlin CM, et al |title=Contemporary assessment and pharmacotherapy of Tourette syndrome |journal=NeuroRx |volume=3 |issue=2 |pages=192–206 |date=April 2006 |pmid=16554257 |pmc=3593444 |doi=10.1016/j.nurx.2006.01.009 |type= Review}}</ref> Measuring [[Biology:Thyroid-stimulating hormone|thyroid-stimulating hormone]] blood levels can rule out [[Medicine:Hypothyroidism|hypothyroidism]], which can be a cause of tics. If there is a family history of liver disease, [[Chemistry:Copper#Deficiency|serum copper]] and [[Chemistry:Ceruloplasmin|ceruloplasmin]] levels can rule out [[Medicine:Wilson's disease|Wilson's disease]].<ref name=Bagheri /> The typical age of onset of TS is before adolescence.<ref name=Stern2018 /> In teenagers and adults with an abrupt onset of tics and other behavioral symptoms, a urine drug screen for stimulants might be requested.<ref name=Bagheri />

Increasing episodes of tic-like behavior among teenagers (predominantly adolescent girls) were reported in several countries during the COVID-19 pandemic.<ref name= Ueda2021/><ref name= Horner2022/> Researchers linked their occurrence to followers of certain [[Software:TikTok|TikTok]] or [[Company:YouTube|YouTube]] artists.<ref name= EuropeanPartI/><ref name= Horner2022>{{cite journal |vauthors=Horner O, Hedderly T, Malik O |title=The changing landscape of childhood tic disorders following COVID-19 |journal=Paediatr Child Health (Oxford) |date=August 2022 |volume=32 |issue=10 |pages=363–367 |pmid=35967969 |pmc=9359930 |doi=10.1016/j.paed.2022.07.007 }}</ref> Described in 2006 as ''[[Medicine:Psychogenic disease|psychogenic]]'',<ref name= Jankovic2006/> abrupt-onset movements resembling tics are referred to as a ''[[Biology:Functional neurologic disorder|functional movement disorder]]''<ref name= Ganos2019>{{cite journal |vauthors=Ganos C, Martino D, Espay AJ, Lang AE, Bhatia KP, Edwards MJ |title=Tics and functional tic-like movements: Can we tell them apart? |journal=Neurology |volume=93 |issue=17 |pages=750–758 |date=October 2019 |pmid=31551261 |doi=10.1212/WNL.0000000000008372 |s2cid=202761321 |url=http://openaccess.sgul.ac.uk/111278/1/WNL.0000000000008372.full.pdf |type=Review |access-date=April 3, 2022 |archive-date=June 3, 2022 |archive-url=https://web.archive.org/web/20220603195351/https://openaccess.sgul.ac.uk/id/eprint/111278/1/WNL.0000000000008372.full.pdf |url-status=live }}</ref> or ''functional tic-like movements''.<ref name=Horner2022/>{{efn|Movement disorders without an organic cause have been referred to over time using terms such as ''hysterical'', ''psychogenic'' and ''psychogenic movement disorders'';<ref name=Baizabal2015>{{cite journal |vauthors=Baizabal-Carvallo JF, Fekete R |title=Recognizing uncommon presentations of psychogenic (functional) movement disorders |journal=Tremor Other Hyperkinet Mov (N Y) |volume=5 |issue= |page=279 |date=2015 |pmid=25667816 |pmc=4303603 |doi=10.7916/D8VM4B13 |type= Review}}</ref><ref name=Thenganatt2019>{{cite journal |vauthors=Thenganatt MA, Jankovic J |title=Psychogenic (functional) movement disorders |journal=Continuum (Minneap Minn) |volume=25 |issue=4 |pages=1121–1140 |date=August 2019 |pmid=31356296 |doi=10.1212/CON.0000000000000755 |s2cid=198984465 |type= Review}}</ref> DSM-5 classifies them under [[Medicine:Conversion disorder|functional neurological symptom disorder/conversion disorder]].<ref name= Espay2018>{{cite journal |vauthors=Espay AJ, Aybek S, Carson A, et al. |title=Current concepts in diagnosis and treatment of functional neurological disorders |journal=JAMA Neurol |volume=75 |issue=9 |pages=1132–1141 |date=September 2018 |pmid=29868890 |pmc=7293766 |doi=10.1001/jamaneurol.2018.1264 |type= Review}}</ref>}} Functional tic-like movements can be difficult to distinguish from tics that have an organic (rather than psychological) cause.<ref name= Ganos2019/><ref name= Thenganatt2019/> They may occur alone or co-exist in individuals with tic disorders.<ref name= Ganos2019/><ref name=Malaty2022>{{cite journal |vauthors=Malaty IA, Anderson S, Bennett SM, et al |title=Diagnosis and management of functional tic-like phenomena |journal=J Clin Med |volume=11 |issue=21 |date=October 2022 |page=6470 |pmid=36362696 |pmc=9656241 |doi=10.3390/jcm11216470 |doi-access=free }}</ref> These tics are inconsistent with the classic tics of TS in several ways:<ref name= Frey2022>{{cite journal |vauthors=Frey J, Black KJ, Malaty IA |title=TikTok Tourette's: are we witnessing a rise in functional tic-like behavior driven by adolescent social media use? |journal=Psychol Res Behav Manag |volume=15 |issue= |pages=3575–3585 |date=2022 |pmid=36505669 |pmc=9733629 |doi=10.2147/PRBM.S359977 |doi-access=free }}</ref> the premonitory urge (present in 90% of those with tics disorders<ref name= Baizabal2015/>) is absent in functional tic-like movements; the suppressibility seen in tic disorders is lacking;<ref name= Ganos2019/><ref name= Baizabal2015/><ref name= Thenganatt2019/><ref name= Espay2018/> there is no family or childhood history of tics and there is a female predominance in functional tics,<ref name= Horner2022/> with a later-than-typical age of first presentation;<ref name= Ganos2019/><ref name= Baizabal2015/><ref name= Thenganatt2019/> onset is more abrupt than typical with movements that are more suggestible;<ref name= Baizabal2015/> and there is less co-occurring OCD or ADHD and more co-occurring disorders.<ref name= Thenganatt2019/> Functional tics are "not fully stereotypical",<ref name=Espay2018/> do not respond to medications, do not demonstrate the classic waxing and waning pattern of Tourettic tics,<ref name= Ganos2019/> and do not progress in the typical fashion, in which tics often first appear in the face and gradually move to limbs.<ref name= Thenganatt2019/>

Other conditions that may manifest tics include [[Medicine:Sydenham's chorea|Sydenham's chorea]]; idiopathic dystonia; and genetic conditions such as [[Medicine:Huntington's disease|Huntington's disease]], [[Medicine:Neuroacanthocytosis|neuroacanthocytosis]], [[Medicine:Pantothenate kinase-associated neurodegeneration|pantothenate kinase-associated neurodegeneration]], [[Medicine:Duchenne muscular dystrophy|Duchenne muscular dystrophy]], Wilson's disease, and [[Medicine:Tuberous sclerosis|tuberous sclerosis]]. Other possibilities include chromosomal disorders such as [[Medicine:Down syndrome|Down syndrome]], [[Medicine:Klinefelter syndrome|Klinefelter syndrome]], [[Medicine:XYY syndrome|XYY syndrome]] and [[Medicine:Fragile X syndrome|fragile X syndrome]]. Acquired causes of tics include drug-induced tics, head trauma, [[Medicine:Encephalitis|encephalitis]], [[Medicine:Stroke|stroke]], and [[Medicine:Carbon monoxide poisoning|carbon monoxide poisoning]].<ref name=Bagheri /><ref name=Mejia /> The extreme self-injurious behaviors of Lesch-Nyhan syndrome may be confused with Tourette syndrome or stereotypies, but self-injury is rare in TS even in cases of violent tics.<ref name=Rapin /> Most of these conditions are rarer than tic disorders and a thorough history and examination may be enough to rule them out without medical or screening tests.<ref name=Stern2018 /><ref name=Zinner /><ref name=Mejia />

=== Screening for other conditions ===
Although not all those with Tourette's have comorbid conditions, most presenting for clinical care exhibit symptoms of other conditions along with their tics.<ref name=Denckla /> ADHD and OCD are the most common, but autism spectrum disorders or [[Medicine:Anxiety disorder|anxiety]], [[Medicine:Mood disorder|mood]], [[Medicine:Personality disorder|personality]], [[Medicine:Oppositional defiant disorder|oppositional defiant]], and [[Medicine:Conduct disorder|conduct disorder]]s may also be present.<ref name=Martino2018 /> Learning disabilities and [[Medicine:Sleep disorder|sleep disorder]]s may be present;<ref name=Singer2011 /> higher rates of sleep disturbance and migraine than in the general population are reported.<ref name=SingerBehavior /><ref name= Jimenez2020>{{cite journal |vauthors=Jiménez-Jiménez FJ, Alonso-Navarro H, García-Martín E, Agúndez JA|title=Sleep disorders in tourette syndrome |journal=Sleep Med Rev |volume=53 |issue= |pages=101335 |date=October 2020 |pmid=32554211 |doi=10.1016/j.smrv.2020.101335 |s2cid=219467176 |type= Review}}</ref> A thorough evaluation for comorbidity is called for when symptoms and impairment warrant,{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 247}}<ref name=Bagheri /> and careful assessment of people with TS includes comprehensive screening for these conditions.<ref name= Martino2018 /><ref name= Efron2018 />

Comorbid conditions such as OCD and ADHD can be more impairing than tics, and cause greater impact on overall functioning.<ref name= PringHoller2019>{{cite journal |vauthors=Pringsheim T, Holler-Managan Y, Okun MS, et al |title=Comprehensive systematic review summary: Treatment of tics in people with Tourette syndrome and chronic tic disorders |journal=Neurology |volume=92 |issue=19 |pages=907–915 |date=May 2019 |pmid=31061209 |pmc=6537130 |doi=10.1212/WNL.0000000000007467 |type= Review}}</ref><ref name=Zinner /> Disruptive behaviors, impaired functioning, or cognitive impairment in individuals with comorbid Tourette's and ADHD may be accounted for by the ADHD, highlighting the importance of identifying comorbid conditions.<ref name= Dale2017 /><ref name=Swain /><ref name=Singer2011 /><ref name=Disentangling>{{cite journal |vauthors=Spencer T, Biederman J, Harding M, et al|title=Disentangling the overlap between Tourette's disorder and ADHD |journal=J Child Psychol Psychiatry |volume=39 |issue=7 |pages=1037–1044 |date=October 1998 |pmid=9804036 |type= Comparative study |doi= 10.1111/1469-7610.00406}}</ref> Children and adolescents with TS who have learning difficulties are candidates for psychoeducational testing, particularly if the child also has ADHD.<ref name=Assessment />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 247}}

== Management ==

There is no cure for Tourette's.<ref>{{cite journal |vauthors=Morand-Beaulieu S, Leclerc JB |title=[Tourette syndrome: Research challenges to improve clinical practice] |language=fr |journal=Encephale |date=January 2020 |volume=46 |issue=2 |pmid=32014239 |doi=10.1016/j.encep.2019.10.002 | pages=146–52 |s2cid=226212092 }}</ref> There is no single most effective medication,<ref name= Stern2018 /> and no one medication effectively treats all symptoms. Most medications prescribed for tics have not been approved for that use, and no medication is without the risk of significant [[Medicine:Adverse effect|adverse effect]]s.<ref name= PringHoller2019 /><ref name= Singer2011 /><ref>{{cite web |url= https://www.cdc.gov/ncbddd/tourette/treatments.html |title= Tourette syndrome treatments |date= 2019 |publisher= U.S. Centers for Disease Control and Prevention (CDC) |access-date= February 26, 2020 |archive-date= February 26, 2020 |archive-url= https://web.archive.org/web/20200226173153/https://www.cdc.gov/ncbddd/tourette/treatments.html |url-status= live}}</ref> Treatment is focused on identifying the most troubling or impairing symptoms and helping the individual manage them.<ref name= Singer2011 /> Because comorbid conditions are often a larger source of impairment than tics,<ref name=Ueda2021/> they are a priority in treatment.<ref name=Pringsheim2019 /> The management of Tourette's is individualized and involves [[Medicine:Shared decision-making in medicine|shared decision-making]] between the clinician, patient, family and caregivers.<ref name=Pringsheim2019>{{cite journal |vauthors=Pringsheim T, Okun MS, Müller-Vahl K, et al |title=Practice guideline recommendations summary: Treatment of tics in people with Tourette syndrome and chronic tic disorders |journal=Neurology |volume=92 |issue=19 |pages=896–906 |date=May 2019 |pmid=31061208 |pmc=6537133 |doi=10.1212/WNL.0000000000007466 |type= Review }}</ref>{{sfnp|Müller-Vahl|2013|p=628}} Practice guidelines for the treatment of tics were published by the American Academy of Neurology in 2019.<ref name=Pringsheim2019 />

Education, reassurance and psychobehavioral therapy are often sufficient for the majority of cases.<ref name=Stern2018 /><ref name=Singer2011 /><ref name="Robertson2005PMJ">{{cite journal |vauthors=Stern JS, Burza S, Robertson MM |title=Gilles de la Tourette's syndrome and its impact in the UK |journal=Postgrad Med J |volume=81 |issue=951 |pages=12–19 |date=January 2005 |pmid=15640424 |pmc=1743178 |doi=10.1136/pgmj.2004.023614 |type= Review|quote= Reassurance, explanation, supportive psychotherapy, and psychoeducation are important and ideally the treatment should be multidisciplinary. In mild cases the previous methods may be all that is required, supplemented with contact with the Tourette Syndrome Association where the patient or parents wish.}}</ref> In particular, [[Medicine:Psychoeducation|psychoeducation]] targeting the patient and their family and surrounding community is a key management strategy.<ref>{{cite journal |vauthors=Robertson MM |title=Tourette syndrome, associated conditions and the complexities of treatment |journal=Brain |volume=123 |issue= Pt 3|pages=425–462 |date=March 2000 |pmid=10686169 |doi=10.1093/brain/123.3.425 |type= Review |doi-access=free }}</ref><ref name=Pete1998>{{cite journal |vauthors=Peterson BS, Cohen DJ |title=The treatment of Tourette's syndrome: multimodal, developmental intervention |journal=J Clin Psychiatry |volume=59 |issue= Suppl 1|pages=62–74 |date=1998 |pmid=9448671 |type= Review |quote= Because of the understanding and hope that it provides, education is also the single most important treatment modality that we have in TS.}} Also see Zinner 2000, {{PMID|11077021}}.</ref> [[Social:Watchful waiting|Watchful waiting]] "is an acceptable approach" for those who are not functionally impaired.<ref name=Pringsheim2019 /> Symptom management may include behavioral, psychological and [[Medicine:Pharmacotherapy|pharmacological]] therapies. Pharmacological intervention is reserved for more severe symptoms, while psychotherapy or [[Medicine:Cognitive behavioral therapy|cognitive behavioral therapy]] (CBT) may ameliorate [[Medicine:Depression (mood)|depression]] and [[Social:Social isolation|social isolation]], and improve family support.<ref name= Singer2011 /> The decision to use behavioral or pharmacological treatment is "usually made after the educational and supportive interventions have been in place for a period of months, and it is clear that the tic symptoms are persistently severe and are themselves a source of impairment in terms of self-esteem, relationships with the family or peers, or school performance".{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 248}}

=== Psychoeducation and social support ===
Knowledge, education and understanding are uppermost in management plans for tic disorders,<ref name=Singer2011 /> and [[Medicine:Psychoeducation|psychoeducation]] is the first step.{{sfnp|Müller-Vahl|2013|p=623}}<ref name= EuropeanPartII/> A child's parents are typically the first to notice their tics;{{sfnp|Müller-Vahl|2013|p=625}} they may feel worried, imagine that they are somehow responsible, or feel burdened by misinformation about Tourette's.{{sfnp|Müller-Vahl|2013|p=623}} Effectively educating parents about the diagnosis and providing [[Social:Social support|social support]] can ease their anxiety. This support can also lower the chance that their child will be unnecessarily medicated{{sfnp|Müller-Vahl|2013|loc=p. 626; "Quite often, the unimpaired child receives medical treatment to reduce tics, when instead the parents should more appropriately receive psychoeducation and social support to better cope with the condition"}} or experience an exacerbation of tics due to their parents' emotional state.<ref name= Martino2018 />

People with Tourette's may suffer socially if their tics are viewed as "bizarre". If a child has disabling tics, or tics that interfere with social or academic functioning, supportive [[Medicine:Psychotherapy|psychotherapy]] or school accommodations can be helpful.<ref name=WhatisTS /> Even children with milder tics may be angry, depressed or have low self-esteem as a result of increased teasing, bullying, rejection by peers or social stigmatization, and this can lead to social withdrawal. Some children feel empowered by presenting a peer awareness program to their classmates.<ref name= Efron2018 />{{sfnp|Müller-Vahl|2013|p=628}}{{sfnp|Pruitt|Packer|2013|pp=646–647}} It can be helpful to educate teachers and school staff about typical tics, how they fluctuate during the day, how they impact the child, and how to distinguish tics from naughty behavior. By learning to identify tics, adults can refrain from asking or expecting a child to stop ticcing,{{sfnp|Müller-Vahl|2013|p=629}}{{sfnp|Pruitt|Packer|2013|pp=646–647}} because "tic suppression can be exhausting, unpleasant, and attention-demanding and can result in a subsequent rebound bout of tics".{{sfnp|Müller-Vahl|2013|p=629}}

Adults with TS may withdraw socially to avoid stigmatization and discrimination because of their tics.{{sfnp|Müller-Vahl|2013|p=627}} Depending on their country's healthcare system, they may receive social services or help from support groups.{{sfnp|Müller-Vahl|2013|p=633}}

=== Behavioral ===
Behavioral therapies using habit reversal training (HRT) and [[Philosophy:Exposure therapy|exposure and response prevention]] (ERP) are first-line interventions in the management of Tourette syndrome,<ref name=Ueda2021/><ref name= EuropeanPartII>{{cite journal |vauthors=Andrén P, Jakubovski E, Murphy TL, et al |title=European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part II: psychological interventions |journal=Eur Child Adolesc Psychiatry |date=July 2021 |volume=31 |issue=3 |pages=403–423 |pmid=34313861 |pmc=8314030 |doi=10.1007/s00787-021-01845-z }}</ref> and have been shown to be effective.<ref name= Fernandez /> Because tics are somewhat suppressible, when people with TS are aware of the premonitory urge that precedes a tic, they can be trained to develop a response to the urge that competes with the tic.<ref name= Dale2017 /><ref name=Frundt2017>{{cite journal |vauthors=Fründt O, Woods D, Ganos C |title=Behavioral therapy for Tourette syndrome and chronic tic disorders |journal=Neurol Clin Pract |volume=7 |issue=2 |pages=148–156 |date=April 2017 |pmid=29185535 |pmc=5669407 |doi=10.1212/CPJ.0000000000000348 |type= Review}}</ref> Comprehensive behavioral intervention for tics (CBIT) is based on HRT, the best researched behavioral therapy for tics.<ref name= Frundt2017 /> TS experts debate whether increasing a child's awareness of tics with HRT/CBIT (as opposed to ignoring tics) can lead to more tics later in life.<ref name= Frundt2017 />

When disruptive behaviors related to comorbid conditions exist, anger control training and [[Social:Parent management training|parent management training]] can be effective.<ref name= Hollis /><!-- p. xxxviii.-->{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 250}}<ref name=Bloch2009 /> CBT is a useful treatment when OCD is present.<ref name= Dale2017 /> [[Social:Relaxation technique|Relaxation technique]]s, such as exercise, yoga and meditation may be useful in relieving the stress that can aggravate tics. Beyond HRT, the majority of behavioral interventions for Tourette's (for example, relaxation training and [[Biology:Biofeedback|biofeedback]]) have not been systematically evaluated and are not empirically supported.<ref>{{cite journal |vauthors=Woods DW, Himle MB, Conelea CA |title=Behavior therapy: other interventions for tic disorders |journal=Adv Neurol |volume=99 |pages=234–240 |date=2006 |pmid=16536371 |type= Review}}</ref>

=== Medication ===
[[File:Clonidine pills and patch.jpg|thumb|alt=Little white pills on a counter, next to a pill bottle and labels|Clonidine is one of the medications typically tried first when medication is needed for Tourette's.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 251}}]]
Children with tics typically present when their tics are most severe, but because the condition waxes and wanes, medication is not started immediately or changed often.<ref name=Zinner /> Tics may subside with education, reassurance and a supportive environment.<ref name=Stern2018 /><ref name= Efron2018 /> When medication is used, the goal is not to eliminate symptoms. Instead, the lowest dose that manages symptoms without adverse effects is used, because adverse effects may be more disturbing than the symptoms being treated with medication.<ref name=Zinner />

The classes of medication with proven efficacy in treating tics—typical and [[Chemistry:Atypical antipsychotic|atypical]] [[Chemistry:Antipsychotic|neuroleptics]]—can have long-term and short-term adverse effects.<ref name= Efron2018 /> Some antihypertensive agents are also used to treat tics; studies show variable efficacy but a lower side effect profile than the neuroleptics.<ref name= Fernandez />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 251}} The antihypertensives [[Chemistry:Clonidine|clonidine]] and [[Chemistry:Guanfacine|guanfacine]] are typically tried first in children; they can also help with ADHD symptoms,<ref name= Efron2018 />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 251}} but there is less evidence that they are effective for adults.<ref name= Stern2018 /> The neuroleptics [[Chemistry:Risperidone|risperidone]] and [[Chemistry:Aripiprazole|aripiprazole]] are tried when antihypertensives are not effective,<ref name= PringHoller2019 /><ref name= Efron2018 /> and are generally tried first for adults.<ref name= Stern2018 /> Because of lower side effects, aripiprazole is preferred over other antipsychotics.<ref name= EuropeanPartIII>{{cite journal |vauthors=Roessner V, Eichele H, Stern JS, et al |title=European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part III: pharmacological treatment |journal=Eur Child Adolesc Psychiatry |date=November 2021 |volume=31 |issue=3 |pages=425–441 |pmid=34757514 |doi=10.1007/s00787-021-01899-z|pmc=8940878 |s2cid=243866351 }}</ref> The most effective medication for tics is [[Chemistry:Haloperidol|haloperidol]], but it has a higher risk of side effects.<ref name= Efron2018 /> [[Chemistry:Methylphenidate|Methylphenidate]] can be used to treat ADHD that co-occurs with tics, and can be used in combination with clonidine.<ref name= Dale2017 /><ref name= Efron2018 /> [[Chemistry:Selective serotonin reuptake inhibitor|Selective serotonin reuptake inhibitor]]s are used to manage anxiety and OCD.<ref name= Dale2017 />

=== Other ===
Complementary and alternative medicine approaches, such as dietary modification, [[Philosophy:Neurofeedback|neurofeedback]] and [[Medicine:Allergy test|allergy test]]ing and control have popular appeal, but they have no proven benefit in the management of Tourette syndrome.<ref name=Zinner2004>{{cite journal | vauthors = Zinner SH |title= Tourette syndrome—much more than tics |journal= Contemporary Pediatrics |date= Aug 2004 |volume= 21 |issue= 8 |pages= 22–49 |url= http://www.tsa-usa.org/Medical/images/cntped0804_022-036T1R2.pdf |access-date= May 20, 2019 |archive-url= https://web.archive.org/web/20070930181455/http://www.tsa-usa.org/Medical/images/cntped0804_022-036T1R2.pdf |archive-date= September 30, 2007 |url-status= dead }}</ref><ref>{{cite journal |vauthors=Kumar A, Duda L, Mainali G, Asghar S, Byler D |title=A comprehensive review of Tourette syndrome and complementary alternative medicine |journal=Curr Dev Disord Rep |volume=5 |issue=2 |pages=95–100 |date=2018 |pmid=29755921 |pmc=5932093 |doi=10.1007/s40474-018-0137-2 |type= Review}}</ref> Despite this lack of evidence, up to two-thirds of parents, caregivers and individuals with TS use dietary approaches and alternative treatments and do not always inform their physicians.<ref name= Ludlow2018>{{cite journal |vauthors=Ludlow AK, Rogers SL |title=Understanding the impact of diet and nutrition on symptoms of Tourette syndrome: A scoping review |journal=J Child Health Care |volume=22 |issue=1 |pages=68–83 |date=March 2018 |pmid=29268618 |doi=10.1177/1367493517748373 |type= Review|doi-access=free |hdl=2299/19887 |hdl-access=free }}</ref>{{sfnp|Müller-Vahl|2013|p=628}}

There is low confidence that tics are reduced with [[Biology:Tetrahydrocannabinol|tetrahydrocannabinol]],<ref name= PringHoller2019 /> and insufficient evidence for other [[Biology:Cannabis (drug)|cannabis]]-based medications in the treatment of Tourette's.<ref name=Pringsheim2019 /><ref>{{cite journal |vauthors=Black N, Stockings E, Campbell G, et al|title=Cannabinoids for the treatment of mental disorders and symptoms of mental disorders: a systematic review and meta-analysis |journal=Lancet Psychiatry |volume=6 |issue=12 |pages=995–1010 |date=December 2019 |pmid=31672337 |pmc=6949116 |doi=10.1016/S2215-0366(19)30401-8}}</ref> There is no good evidence supporting the use of [[Unsolved:Acupuncture|acupuncture]] or [[Physics:Transcranial magnetic stimulation|transcranial magnetic stimulation]]; neither is there evidence supporting intravenous immunoglobulin, plasma exchange, or antibiotics for the treatment of [[Medicine:PANDAS|PANDAS]].<ref name= Hollis /><!-- p. xxxix.-->

[[Biology:Deep brain stimulation|Deep brain stimulation]] (DBS) has become a valid option for individuals with severe symptoms that do not respond to conventional therapy and management,<ref name= Baldermann>{{cite journal |vauthors=Baldermann JC, Schüller T, Huys D, et al |title=Deep brain stimulation for Tourette syndrome: a systematic review and meta-analysis |journal=Brain Stimul |volume=9 |issue=2 |pages=296–304 |date=2016 |pmid=26827109 |doi=10.1016/j.brs.2015.11.005 |s2cid=22929403 |type= Review}}</ref> although it is an experimental treatment.<ref name= EuropeanPartIV>{{cite journal |vauthors=Szejko N, Worbe Y, Hartmann A, et al|title=European clinical guidelines for Tourette syndrome and other tic disorders-version 2.0. Part IV: deep brain stimulation |journal=Eur Child Adolesc Psychiatry |date=October 2021 |volume=31 |issue=3 |pages=443–461 |pmid=34605960 |doi=10.1007/s00787-021-01881-9|pmc=8940783 |s2cid=238254975 }}</ref> Selecting candidates who may benefit from DBS is challenging, and the appropriate lower age range for surgery is unclear;<ref name=Martino2018 /> it is potentially useful in less than 3% of individuals.<ref name=EuropeanGuidelines/> The ideal brain location to target has not been identified as of 2019.<ref name=Pringsheim2019 /><ref name=Viswanathan>{{cite journal |vauthors=Viswanathan A, Jimenez-Shahed J, Baizabal Carvallo JF, Jankovic J |title=Deep brain stimulation for Tourette syndrome: target selection |journal=Stereotact Funct Neurosurg |volume=90 |issue=4 |pages=213–224 |date=2012 |pmid=22699684 |doi=10.1159/000337776 |type=Review |url=https://www.karger.com/Article/FullText/337776 |doi-access=free |access-date=January 25, 2020 |archive-date=August 29, 2017 |archive-url=https://web.archive.org/web/20170829174430/https://www.karger.com/Article/Fulltext/337776 |url-status=live }}</ref>

=== Pregnancy ===
A quarter of women report that their tics increase before [[Medicine:Menstruation|menstruation]]; however, studies have not shown consistent evidence of a change in frequency or severity of tics related to pregnancy<ref name= Rabin2014>{{cite journal |vauthors=Rabin ML, Stevens-Haas C, Havrilla E, Devi T, Kurlan R |title=Movement disorders in women: a review |journal=Mov. Disord. |volume=29 |issue=2 |pages=177–183 |date=February 2014 |pmid=24151214 |doi=10.1002/mds.25723 |s2cid=27527571 |type= Review}}</ref><ref name= Ba2020>{{cite book |vauthors=Ba F, Miyasaki JM |title=Neurology and Pregnancy: Neuro-Obstetric Disorders |chapter=Movement disorders in pregnancy |series=Handbook of Clinical Neurology |volume=172 |pages=219–239 |date=2020 |pmid=32768090 |doi=10.1016/B978-0-444-64240-0.00013-1 |isbn=9780444642400 |s2cid=226513843 |type= Review}}</ref> or hormonal levels.<ref name="García-Ramos">{{cite journal |vauthors=García-Ramos R, Santos-García D, Alonso-Cánovas et al |title=Management of Parkinson's disease and other movement disorders in women of childbearing age: Part 2 |journal=Neurologia (Engl Ed) |volume=36 |issue=2 |pages=159–168 |date=March 2021 |pmid=32980194 |doi=10.1016/j.nrl.2020.05.012|s2cid=224905452 |issn=0213-4853 |language=es |type= Review|doi-access=free |hdl=2445/175997 |hdl-access=free }}</ref> Overall, symptoms in women respond better to haloperidol than they do for men.<ref name=Rabin2014 />

Most women find they can withdraw from medication during pregnancy without much trouble.<ref name= Kranick2010>{{cite journal |vauthors=Kranick SM, Mowry EM, Colcher A, Horn S, Golbe LI |title=Movement disorders and pregnancy: a review of the literature |journal=Mov. Disord. |volume=25 |issue=6 |pages=665–671 |date=April 2010 |pmid=20437535 |doi=10.1002/mds.23071 |s2cid=41160705 |type= Review}}</ref> When needed, medications are used at the lowest doses possible.<ref name="García-Ramos"/> During pregnancy, neuroleptic medications are avoided when possible because of the risk of pregnancy complications.<ref name= Ba2020/> When needed, [[Chemistry:Olanzapine|olanzapine]], [[Chemistry:Risperidone|risperidone]] and [[Chemistry:Quetiapine|quetiapine]] are most often used as they have not been shown to cause fetal abnormalities.<ref name= Ba2020/> One report found that [[Chemistry:Haloperidol|haloperidol]] could be used during pregnancy,<ref name= Kranick2010 /> to minimize the side effects in the mother, including [[Medicine:Hypotension|low blood pressure]], and [[Medicine:Anticholinergic|anticholinergic]] effects,<ref>{{cite journal |author=Committee on Drugs: American Academy of Pediatrics |title=Use of psychoactive medication during pregnancy and possible effects on the fetus and newborn |journal=Pediatrics |volume=105 |issue=4 |pages=880–887 |date=April 2000 |pmid=10742343 |doi=10.1542/peds.105.4.880 |doi-access=free |url=https://pediatrics.aappublications.org/content/105/4/880 |access-date=June 17, 2020 |archive-date=June 17, 2020 |archive-url=https://web.archive.org/web/20200617205559/https://pediatrics.aappublications.org/content/105/4/880 |url-status=live }}</ref> although it may cross the [[Biology:Placenta|placenta]].<ref name= Ba2020/>

If severe tics might interfere with administration of [[Medicine:Local anesthesia|local anesthesia]], other anesthesia options are considered.<ref name= Ba2020/> Neuroleptics in low doses may not affect the [[Social:Breastfeeding|breastfed]] infant, but most medications are avoided.<ref name= Ba2020/> [[Chemistry:Clonidine|Clonidine]] and amphetamines may be present in breast milk.<ref name="García-Ramos"/>

== Prognosis ==
[[File:TimHoward USMNT 20060511.jpg|thumb|left|alt=Top half of a male athlete who appears to be running| Tim Howard, described in 2019 by a staff writer for the ''{{wipe|Los Angeles Times}}'' as the "greatest goalkeeper in U.S. soccer history",<ref>{{cite news | vauthors = Baxter K |date= October 5, 2019 |url= https://www.latimes.com/sports/soccer/story/2019-10-05/tim-howard-retire-colorado-rapids-united-states-lafc |title= Column: Tim Howard, whose career is likely to end Sunday, will retire as the best U.S. goalkeeper ever |work= {{wipe|Los Angeles Times}} |access-date= December 28, 2019 |archive-date= December 25, 2019 |archive-url= https://web.archive.org/web/20191225204713/https://www.latimes.com/sports/soccer/story/2019-10-05/tim-howard-retire-colorado-rapids-united-states-lafc |url-status= live}}</ref> attributes his success in the sport to his Tourette's.<ref name=HowardKeeper />]]
Tourette syndrome is a spectrum disorder—its severity ranges from mild to severe.<ref name=WhatisTS /> Symptoms typically subside as children pass through adolescence.<ref name= Baldermann /> In a group of ten children at the average age of highest tic severity (around ten or eleven), almost four will see complete remission by adulthood. Another four will have minimal or mild tics in adulthood, but not complete remission. The remaining two will have moderate or severe tics as adults, but only rarely will their symptoms in adulthood be more severe than in childhood.<ref name=FernandezCitingBloch />

Regardless of symptom severity, individuals with Tourette's have a normal [[Biology:Life expectancy|life span]].<ref name= Novotny2018/> Symptoms may be lifelong and chronic for some, but the condition is not [[Medicine:Degeneration (medical)|degenerative]] or life-threatening.<ref name= Novotny2018>{{cite journal |vauthors=Novotny M, Valis M, Klimova B |title=Tourette syndrome: a mini-review |journal=Front Neurol |volume=9 |page=139 |date=2018 |pmid=29593638 |pmc=5854651 |doi=10.3389/fneur.2018.00139 |type= Review|doi-access=free }}</ref> [[Philosophy:Intelligence|Intelligence]] among those with pure TS follows a normal curve, although there may be small differences in intelligence in those with comorbid conditions.<ref name=Ueda2021/>{{sfnp|Pruitt|Packer|2013|pp=636–637}} The severity of tics early in life does not predict their severity in later life.<ref name=Singer2011 /> There is no reliable means of predicting the course of symptoms for a particular individual,<ref name=SingerBehavior /> but the [[Medicine:Prognosis|prognosis]] is generally favorable.<ref name=SingerBehavior>{{cite journal |vauthors=Singer HS |title=Tourette's syndrome: from behaviour to biology |journal=Lancet Neurol |volume=4 |issue=3 |pages=149–159 |date=March 2005 |pmid=15721825 |doi=10.1016/S1474-4422(05)01012-4 |s2cid=20181150 |type= Review}}</ref> By the age of fourteen to sixteen, when the highest tic severity has typically passed, a more reliable prognosis might be made.{{sfnp|Müller-Vahl|2013|p=627}}

Tics may be at their highest severity when they are diagnosed, and often improve as an individual's family and friends come to better understand the condition.<ref name= Dale2017 /><ref name=FernandezCitingBloch /> Studies report that almost eight out of ten children with Tourette's experience a reduction in the severity of their tics by adulthood,<ref name= Dale2017 /><ref name=FernandezCitingBloch /> and some adults who still have tics may not be aware that they have them. A study that used video to record tics in adults found that nine out of ten adults still had tics, and half of the adults who considered themselves tic-free displayed evidence of mild tics.<ref name=Dale2017 /><ref name=outcome>{{cite journal |vauthors=Pappert EJ, Goetz CG, Louis ED, Blasucci L, Leurgans S |title=Objective assessments of longitudinal outcome in Gilles de la Tourette's syndrome |journal=Neurology |volume=61 |issue=7 |pages=936–940 |date=October 2003 |pmid=14557563 |doi=10.1212/01.wnl.0000086370.10186.7c |s2cid=7815576 }}</ref>
{{clear}}

=== Quality of life ===
People with Tourette's are affected by the consequences of tics and by the efforts to suppress them.<ref name= Evans /> Head and eye tics can interfere with reading or lead to headaches, and forceful tics can lead to repetitive strain injury.{{sfnp|Abi-Jaoude|Kideckel|Stephens|Lafreniere-Roula|2009|p=[https://books.google.com/books?id=4Tkdm1vRFbUC&pg=PA564 564]}} Severe tics can lead to pain or injuries; as an example, a rare cervical disc herniation was reported from a neck tic.<ref name= Robertson2017 /><ref name= Efron2018 /> Some people may learn to camouflage socially inappropriate tics or channel the energy of their tics into a functional endeavor.<ref name= phenomenology />

A supportive family and environment generally give those with Tourette's the skills to manage the disorder.<ref name= Evans /><ref>{{harvp|Leckman|Cohen|1999|p=37}}. "For example, individuals who were misunderstood and punished at home and at school for their tics or who were teased mercilessly by peers and stigmatized by their communities will fare worse than a child whose interpersonal environment was more understanding and supportive."</ref><ref name= Derail>{{cite journal |vauthors= Cohen DJ, Leckman JF, Pauls D |title= Neuropsychiatric disorders of childhood: Tourette's syndrome as a model |journal= Acta Paediatr Suppl |volume= 422 |pages= 106–111 |publisher= Scandinavian University Press |date= 1997 |quote= The individuals with TS who do the best, we believe, are: those who have been able to feel relatively good about themselves and remain close to their families; those who have the capacity for humor and for friendship; those who are less burdened by troubles with attention and behavior, particularly aggression; and those who have not had development derailed by medication.|pmid= 9298805 |doi= 10.1111/j.1651-2227.1997.tb18357.x |s2cid= 19687202 }}</ref> Outcomes in adulthood are associated more with the perceived significance of having tics as a child than with the actual severity of the tics. A person who was misunderstood, punished or teased at home or at school is likely to fare worse than a child who enjoyed an understanding environment.<ref name=phenomenology /> The long-lasting effects of bullying and teasing can influence self-esteem, self-confidence, and even employment choices and opportunities.<ref name= Evans>{{cite journal |vauthors=Evans J, Seri S, Cavanna AE |title=The effects of Gilles de la Tourette syndrome and other chronic tic disorders on quality of life across the lifespan: a systematic review |journal=Eur Child Adolesc Psychiatry |volume=25 |issue=9 |pages=939–948 |date=September 2016 |pmid=26880181 |pmc=4990617 |doi=10.1007/s00787-016-0823-8 |type= Review}}</ref>{{sfnp|Müller-Vahl|2013|p=630}} Comorbid ADHD can severely affect the child's well-being in all realms, and extend into adulthood.<ref name= Evans />

Factors impacting [[Philosophy:Quality of life|quality of life]] change over time, given the natural fluctuating course of tic disorders, the development of [[Social:Coping|coping]] strategies, and a person's age. As ADHD symptoms improve with maturity, adults report less negative impact in their occupational lives than do children in their educational lives.<ref name= Evans /> Tics have a greater impact on adults' [[Social:Psychosocial|psychosocial]] function, including financial burdens, than they do on children.{{sfnp|Müller-Vahl|2013|p=627}} Adults are more likely to report a reduced quality of life due to depression or anxiety;<ref name=Evans /> depression contributes a greater burden than tics to adults' quality of life compared to children.{{sfnp|Müller-Vahl|2013|p=627}} As coping strategies become more effective with age, the impact of OCD symptoms seems to diminish.<ref name= Evans />

== Epidemiology ==
Tourette syndrome is a common but underdiagnosed condition<ref name= EuropeanPartI/> that reaches across all social, racial and ethnic groups.<ref name= Hollis /><ref name=Swain /><ref name=Singer2011 /><ref>{{cite journal |vauthors= Gulati, S |title= Tics and Tourette Syndrome – Key Clinical Perspectives: Roger Freeman (ed) |journal= Indian J Pediatr |volume= 83 |page= 1361 |date= 2016 |issue= 11 |doi= 10.1007/s12098-016-2176-1 |quote= Tic disorder is a common neurodevelopmental disorder of childhood. It is one of the commonest condition encountered by a pediatrician in office practice, especially in developed countries. |doi-access= free }}</ref> It is three to four times more frequent in males than in females.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 244}} Observed [[Prevalence|prevalence]] rates are higher among children than adults because tics tend to remit or subside with maturity and a diagnosis may no longer be warranted for many adults.<ref name=YaleTicSeverity /> Up to 1% of the overall population experiences tic disorders, including chronic tics and transient (provisional or unspecified) tics in childhood.<ref name=CommunitySample /> Chronic tics affect 5% of children and transient tics affect up to 20%.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 244}}<ref name= Bloch2009>{{cite journal |vauthors=Bloch MH, Leckman JF |title=Clinical course of Tourette syndrome |journal=J Psychosom Res |volume=67 |issue=6 |pages=497–501 |date=December 2009 |pmid=19913654 |pmc=3974606 |doi=10.1016/j.jpsychores.2009.09.002 |type= Review}}</ref>

Many individuals with tics do not know they have tics,<ref name= Ueda2021/> or do not seek a diagnosis, so epidemiological studies of TS "reflect a strong ascertainment bias" towards those with co-occurring conditions.<ref name=Bloch2011 /> The reported prevalence of TS varies "according to the source, age, and sex of the sample; the ascertainment procedures; and diagnostic system",<ref name=Swain /> with a range reported between 0.15% and 3.0% for children and adolescents.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 244}} Sukhodolsky, et al. wrote in 2017 that the best estimate of TS prevalence in children was 1.4%.{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 244}} Both Robertson<ref name=Robertson2011>{{cite journal |vauthors=Robertson MM |title=Gilles de la Tourette syndrome: the complexities of phenotype and treatment |journal=Br J Hosp Med (Lond) |volume=72 |issue=2 |pages=100–107 |date=February 2011 |pmid=21378617 |doi=10.12968/hmed.2011.72.2.100 }}</ref> and Stern state that the prevalence in children is 1%.<ref name= Stern2018 /> The prevalence of TS in the general population is estimated as 0.3% to 1.0%.<ref name= EuropeanPartI/> According to turn of the century census data, these prevalence estimates translated to half a million children in the US with TS and half a million people in the UK with TS, although symptoms in many older individuals would be almost unrecognizable.{{efn|A prevalence range of 0.1% to 1% yields an estimate of 53,000 to 530,000&nbsp;school-age children with Tourette's in the United States, using 2000&nbsp;census data.<ref name=CommunitySample /> In the United Kingdom, a prevalence estimate of 1.0% based on the 2001 census meant that about half a million people aged five or older would have Tourette's, although symptoms in older individuals would be almost unrecognizable.<ref name=Robertson-1-2008 /><!-- "Thus, to give a figure, in the UK, for example, in the 2001 census, there was a total of 55 302 941 individuals (from the ages 5 to above 90 years), and thus, approximately 553 thousand individuals in the UK over the age of 5 years would have GTS, albeit mild and almost unrecognizable by the time they were older"--> Prevalence rates in special education populations are higher.<ref name=Robertson2011 /> }}

Tourette syndrome was once thought to be rare: in 1972, the US [[Organization:National Institutes of Health|National Institutes of Health]] (NIH) believed there were fewer than 100&nbsp;cases in the United States,{{sfnp|Cohen|Jankovic|Goetz|2001|p= xviii}} and a 1973 registry reported only 485&nbsp;cases worldwide.<ref>{{cite journal |vauthors=Abuzzahab FE, Anderson FO |title=Gilles de la Tourette's syndrome; international registry |journal=Minn Med |volume=56 |issue=6 |pages=492–496 |date=June 1973 |pmid=4514275 }}</ref> However, numerous studies published since 2000 have consistently demonstrated that the prevalence is much higher.<ref name=ScahillTSA>{{cite web | vauthors = Scahill L |title= Epidemiology of tic disorders |work= Medical letter: 2004 retrospective summary of TS literature |publisher= Tourette Syndrome Association |url= http://tsa-usa.org/Medical/images/MedLetr2004_M114g_pg1.pdf |access-date= June 11, 2007|archive-url= https://web.archive.org/web/20101225113733/http://tsa-usa.org/Medical/images/MedLetr2004_M114g_pg1.pdf |archive-date= December 25, 2010 }}</ref> Recognizing that tics may often be undiagnosed and hard to detect,{{efn|The discrepancy between current and prior prevalence estimates arises from several factors: the ascertainment bias caused by [[Sampling (statistics)|samples]] that were drawn from clinically referred cases; assessment methods that failed to detect milder cases; and the use of different diagnostic criteria and thresholds.<ref name=ScahillTSA /> There were few broad-based community studies published before 2000, and most older epidemiological studies were based only on individuals referred to tertiary care or specialty clinics.<ref name=Bloch2011/><ref>See also Zohar AH, Apter A, King RA, et al (1999). "Epidemiological studies" in {{harvp|Leckman|Cohen|1999|pp= 177–192}}.</ref> People with mild symptoms may not have sought treatment and physicians may have avoided an official diagnosis of TS in children due to concerns about stigmatization.<ref name=Knight /> Studies are vulnerable to further error because tics vary in intensity and [[Biology:Penetrance|expression]], are often intermittent, and are not always recognized by clinicians, individuals with TS, family members, friends or teachers.<ref name=Zinner /><ref name=Hawley>{{cite web | vauthors = Hawley JS |url = http://emedicine.medscape.com/article/289457-overview |publisher= eMedicine |date= June 23, 2008 |access-date= August 10, 2009 |title= Tourette syndrome|archive-url = https://web.archive.org/web/20090804061041/http://emedicine.medscape.com/article/289457-overview |archive-date = August 4, 2009 }}</ref>}} newer studies use direct classroom observation and multiple informants (parents, teachers and trained observers), and therefore record more cases than older studies.<ref name="Robertson2005PMJ" /><ref>{{cite journal |vauthors=Leckman JF |title=Tourette's syndrome |journal=Lancet |volume=360 |issue=9345 |pages=1577–1586 |date=November 2002 |pmid=12443611 |doi=10.1016/S0140-6736(02)11526-1 |s2cid=27325780 |type= Review}}</ref> As the diagnostic threshold and assessment methodology have moved towards recognition of milder cases, the estimated prevalence has increased.<ref name=ScahillTSA />

Because of the high male prevalence of TS, there is limited data on females from which conclusion about gender-based differences can be drawn; caution may be warranted in extending conclusions to females regarding the characteristics and treatment of tics based on studies of mostly males.<ref name= Garris2021>{{cite journal |vauthors=Garris J, Quigg M |title=The female Tourette patient: sex differences in Tourette disorder |journal=Neurosci Biobehav Rev |volume=129 |pages=261–268 |date=October 2021 |pmid=34364945 |doi=10.1016/j.neubiorev.2021.08.001 |s2cid=236921688 |type= Review}}</ref> A 2021 review stated that females may see a later peak than males in symptoms, with less remission over time, along with a higher prevalence of anxiety and mood disorders.<ref name= Garris2021/>

== History ==
[[File:Charcot experience histeric-hipnotic.JPG|thumb|upright=1.6|alt=A painting of a 19th-century medical lecture. At the front of the class, a woman faints into the arms of a man standing behind her, as another woman, apparently a nurse, reaches to help. An older man, the professor, stands beside her and gestures as if making a point. Two dozen male students watch them.|Jean-Martin Charcot was a French neurologist and professor who named Tourette syndrome for his intern, Georges Gilles de la Tourette. In ''A Clinical Lesson at the Salpêtrière'' (1887), André Brouillet portrays a medical lecture by Charcot (the central standing figure) and shows de la Tourette in the audience (seated in the first row, wearing an apron).]]

A French doctor, Jean Marc Gaspard Itard, reported the first case of Tourette syndrome in 1825,<ref>{{cite journal |vauthors= Itard J |title= Mémoire sur quelques functions involontaires des appareils de la locomotion, de la préhension et de la voix |journal= Arch Gen Med |date= 1825 |volume= 8 |pages= 385–407}} As cited in {{cite journal | vauthors = Newman S | title = 'Study of several involuntary functions of the apparatus of movement, gripping, and voice' by Jean-Marc Gaspard Itard (1825) | journal = History of Psychiatry | volume = 17 | issue = 67 Pt 3 | pages = 333–339 | date = September 2006 | pmid = 17214432 | doi = 10.1177/0957154X06067668 | s2cid = 44541188 | url = https://hal.archives-ouvertes.fr/hal-00570864/file/PEER_stage2_10.1177%252F0957154X06067668.pdf | access-date = January 25, 2020 | archive-date = January 25, 2020 | archive-url = https://web.archive.org/web/20200125174627/https://hal.archives-ouvertes.fr/hal-00570864/file/PEER_stage2_10.1177%25252F0957154X06067668.pdf | url-status = live }}</ref> describing the Marquise de Dampierre, an important woman of nobility in her time.{{sfnp|Walusinski|2019|pp=167–169}}<ref name=TSAWhat>{{cite web |url= http://www.tsa-usa.org/aMedical/whatists.html |title= What is Tourette syndrome? |publisher= Tourette Syndrome Association |access-date= January 14, 2012|archive-url= https://web.archive.org/web/20120114211252/http://www.tsa-usa.org/aMedical/whatists.html |archive-date= January 14, 2012 }}</ref> In 1884, Jean-Martin Charcot, an influential French physician, assigned his student{{sfnp|Walusinski|2019|pp=[https://books.google.com/books?id=lLhwDwAAQBAJ&q=Still+a+medical+student xvii–xviii, 23]}} and intern Georges Gilles de la Tourette, to study patients with movement disorders at the Salpêtrière Hospital, with the goal of defining a condition distinct from hysteria and chorea.<ref name= Rickards>{{cite journal | vauthors = Rickards H, Cavanna AE | title = Gilles de la Tourette: the man behind the syndrome | journal = Journal of Psychosomatic Research | volume = 67 | issue = 6 | pages = 469–474 | date = December 2009 | pmid = 19913650 | doi = 10.1016/j.jpsychores.2009.07.019 }}</ref> In 1885, Gilles de la Tourette published an account in ''Study of a Nervous Affliction'' of nine people with "convulsive tic disorder", concluding that a new clinical category should be defined.<ref>{{cite journal |vauthors= Gilles de la Tourette G, Goetz CG, Llawans HL |title= Étude sur une affection nerveuse caractérisée par de l'incoordination motrice accompagnée d'echolalie et de coprolalie |journal= Advances in Neurology: Gilles de la Tourette Syndrome |volume= 35 |date= 1982 |pages= 1–16}} As discussed at {{cite web | vauthors = Black KJ |title= Tourette syndrome and other tic disorders |url=http://emedicine.medscape.com/article/1182258-overview |publisher= eMedicine |date= March 30, 2007 |access-date= August 10, 2009 |archive-url= https://web.archive.org/web/20090822025931/http://emedicine.medscape.com/article/1182258-overview |archive-date= August 22, 2009 }}</ref><ref>{{cite journal | vauthors = Robertson MM, Reinstein DZ | title = Convulsive tic disorder: Georges Gilles de la Tourette, Guinon and Grasset on the phenomenology and psychopathology of Gilles de la Tourette syndrome | journal = Behavioural Neurology | volume = 4 | issue = 1 | pages = 29–56 | date = 1991 | pmid = 24487352 | doi = 10.1155/1991/505791 | url = http://downloads.hindawi.com/journals/bn/1991/505791.pdf | doi-access = free | access-date = June 17, 2020 | archive-date = November 25, 2020 | archive-url = https://web.archive.org/web/20201125060151/http://downloads.hindawi.com/journals/bn/1991/505791.pdf | url-status = live }}</ref> The eponym was bestowed by Charcot after and on behalf of Gilles de la Tourette, who later became Charcot's senior resident.<ref name=emed />{{sfnp|Walusinski|2019|loc = [https://books.google.com/books?id=lLhwDwAAQBAJ&q=resident pp. xi, 398]: "''Interne'': House physician or house officer. The internes lived at the hospital and had diagnostic and therapeutic responsibilities. ''Chef de Clinique'': Senior house officer or resident. In 1889, when Gilles de la Tourette was ''Chef de Clinique'' under Charcot ... "}}

Following the 19th-century descriptions, a [[Medicine:Psychogenic disease|psychogenic]] view prevailed and little progress was made in explaining or treating tics until well into the 20th century.<ref name=emed /> The possibility that movement disorders, including Tourette syndrome, might have an organic origin was raised when an [[Medicine:Encephalitis lethargica|encephalitis lethargica]] epidemic from 1918 to 1926 was linked to an increase in tic disorders.<ref name=emed /><ref name=Pagewise>Blue T (2002). [https://web.archive.org/web/20080412061921/http://www.essortment.com/all/tourettesyndrom_rnkl.htm Tourette syndrome.] ''Essortment,'' Pagewise Inc. Retrieved on August 10, 2009.</ref>

During the 1960s and 1970s, as the beneficial effects of [[Chemistry:Haloperidol|haloperidol]] on tics became known, the psychoanalytic approach to Tourette syndrome was questioned.<ref name=Jankovic2006>{{cite journal |vauthors=Jankovic J, Mejia NI |title=Tics associated with other disorders |journal=Adv Neurol |volume=99 |issue= |pages=61–68 |date=2006 |pmid=16536352 |type= Review}}</ref><ref>{{cite journal |vauthors=Rickards H, Hartley N, Robertson MM |title=Seignot's paper on the treatment of Tourette's syndrome with haloperidol. Classic Text No. 31 |journal=Hist Psychiatry |volume=8 |issue=31 Pt 3 |pages=433–436 |date=September 1997 |pmid=11619589 |doi=10.1177/0957154X9700803109 |s2cid=2009337 |type= Historical biography}}</ref> The turning point came in 1965, when Arthur K. Shapiro—described as "the father of modern tic disorder research"<ref>{{cite journal |vauthors=Gadow KD, Sverd J |title=Attention deficit hyperactivity disorder, chronic tic disorder, and methylphenidate |journal=Adv Neurol |volume=99 |pages=197–207 |date=2006 |pmid=16536367 |type= Review}}</ref>—used haloperidol to treat a person with Tourette's, and published a paper criticizing the psychoanalytic approach.<ref name=Pagewise /> In 1975, ''{{wipe|The New York Times}}'' headlined an article with "Bizarre outbursts of Tourette's disease victims linked to chemical disorder in brain", and Shapiro said: "The bizarre symptoms of this illness are rivaled only by the bizarre treatments used to treat it."<ref>{{cite news |title= Bizarre outbursts of Tourette's disease victims linked to chemical disorder in brain |work= {{wipe|The New York Times}} | url= https://www.nytimes.com/1975/05/29/archives/bizarre-outbursts-of-tourettes-disease-victims-linked-to-chemical.html |date= May 29, 1975 |access-date= January 19, 2020 | vauthors = Brody JE |archive-date= February 12, 2020 |archive-url= https://web.archive.org/web/20200212230733/https://www.nytimes.com/1975/05/29/archives/bizarre-outbursts-of-tourettes-disease-victims-linked-to-chemical.html |url-status= live}}</ref>

During the 1990s, a more neutral view of Tourette's emerged, in which a genetic predisposition is seen to [[Biology:Behavioural genetics|interact]] with [[Biology:Epigenetics|non-genetic]] and environmental factors.<ref name=emed />{{sfnp|Kushner|2000|pp=142–143, 187, 204, 208–212}}<ref>{{cite journal |vauthors=Cohen DJ, Leckman JF |title=Developmental psychopathology and neurobiology of Tourette's syndrome |journal=J Am Acad Child Adolesc Psychiatry |volume=33 |issue=1 |pages=2–15 |date=January 1994 |pmid=8138517 |doi=10.1097/00004583-199401000-00002 |type= Review|quote="[Pathogenesis of tic disorders involves] interactions among genetic factors, neurobiological substrates, and environmental factors in the production of the clinical phenotypes. The genetic vulnerability factors that underlie Tourette's syndrome and other tic disorders undoubtedly influence the structure and function of the brain, in turn producing clinical symptoms. Available evidence ... also indicates that a range of epigenetic or environmental factors ... are critically involved in the pathogenesis of these disorders."|doi-access=free }}</ref> The fourth revision of the DSM (DSM-IV) in 1994 added a diagnostic requirement for "marked distress or significant impairment in social, occupational, or other important areas of functioning", which led to an outcry from TS experts and researchers, who noted that many people were not even aware they had TS, nor were they distressed by their tics; clinicians and researchers resorted to using the older criteria in research and practice.<ref name=DSMAppraisal /> In 2000, the American Psychiatric Association revised its diagnostic criteria in the fourth text revision of the DSM (DSM-IV-TR) to remove the impairment requirement,<ref name=WalkupDSMV>{{cite journal |vauthors=Walkup JT, Ferrão Y, Leckman JF, Stein DJ, Singer H |title=Tic disorders: some key issues for DSM-V |journal=Depress Anxiety |volume=27 |issue=6 |pages=600–610 |date=June 2010 |pmid=20533370 |doi=10.1002/da.20711 |s2cid=5469830 |type= Review | url=http://www.dsm5.org/Research/Documents/Walkup_Tic.pdf |archive-url=https://web.archive.org/web/20120120072521/http://www.dsm5.org/Research/Documents/Walkup_Tic.pdf |archive-date=January 20, 2012 }}</ref> recognizing that clinicians often see people who have Tourette's without distress or impairment.<ref name=DSMIVTRsummary />

== Society and culture ==
[[File:Samuel Johnson by Joshua Reynolds.jpg|thumb|right|alt=Half-length portrait of a large, squinting man with a fleshy face, dressed in brown and wearing an 18th-century wig|Samuel Johnson {{circa}} 1772. Johnson is likely to have had Tourette syndrome.]]
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Not everyone with Tourette's wants treatment or a cure, especially if that means they may lose something else in the process.{{sfnp|Müller-Vahl|2013|p=623}}{{sfnp|Leckman|Cohen|1999|p=408}} The researchers Leckman and Cohen believe that there may be latent advantages associated with an individual's genetic vulnerability to developing Tourette syndrome that may have adaptive value, such as heightened awareness and increased attention to detail and surroundings.{{sfnp|Leckman|Cohen|1999|pp=18–19, 148–151, 408}}{{sfnp|Müller-Vahl|2013|loc=p. 624; "... a few 'positive' aspects may be closely linked to TS. People with TS, for example, may have positive personality characteristics and talents such as punctuality, correctness, conscientiousness, a sense of justice, quick comprehension, good intelligence, creativity, musicality, and athletic abilities. For that reason, some people with TS even hesitate when asked whether they wish the disorder would disappear completely"}}

<!-- Please do not add your own speculations here – Wikipedia is not for original research. Please add suggested inclusions to the talk page. -->Accomplished musicians, athletes, public speakers and professionals from all walks of life are found among people with Tourette's.{{sfnp|Müller-Vahl|2013|p=625}}<ref>[https://web.archive.org/web/20110716124051/http://www.tsa-usa.org/People/LivingWithTS/LivingTS.htm Portraits of adults with TS.] Tourette Syndrome Association. Retrieved from July 16, 2011, archive.org version on December 21, 2011.</ref> The athlete Tim Howard, described by the ''Chicago Tribune'' as the "rarest of creatures—an American soccer hero",<ref>{{cite news | vauthors = Keilman J |url= http://www.chicagotribune.com/lifestyles/books/ct-prj-keeper-tim-howard-game-of-our-lives-david-goldblatt-20150121-story.html#page=1 |title= Reviews: ''The Game of Our Lives'' by David Goldblatt, ''The Keeper'' by Tim Howard |archive-url= https://web.archive.org/web/20150402152617/http://www.chicagotribune.com/lifestyles/books/ct-prj-keeper-tim-howard-game-of-our-lives-david-goldblatt-20150121-story.html#page=1 |archive-date=April 2, 2015 |work= Chicago Tribune |date= January 22, 2015 |access-date= March 21, 2015}}</ref> and by the Tourette Syndrome Association as the "most notable individual with Tourette Syndrome around the world",<ref>[http://www.tsa-usa.org/news/TimHowardAward.html Tim Howard receives first-ever Champion of Hope Award from the National Tourette Syndrome Association.] {{Webarchive|url=https://web.archive.org/web/20150330163000/http://www.tsa-usa.org/news/TimHowardAward.html |date=March 30, 2015 }} Tourette Syndrome Association. October 14, 2014. Retrieved on March 21, 2015.</ref> says that his neurological makeup gave him an enhanced perception and an acute focus that contributed to his success on the field.<ref name=HowardKeeper>{{cite news | vauthors = Howard T|url= https://www.theguardian.com/football/2014/dec/06/everton-tim-howard-goalkeeper-tourette-syndrome-ocd-autobiography-the-keeper |title= Tim Howard: Growing up with Tourette syndrome and my love of football |archive-url= https://web.archive.org/web/20161115102856/https://www.theguardian.com/football/2014/dec/06/everton-tim-howard-goalkeeper-tourette-syndrome-ocd-autobiography-the-keeper |archive-date=November 15, 2016 |work= The Guardian |date= December 6, 2014 |access-date= March 21, 2015}}</ref>

Samuel Johnson is a historical figure who likely had Tourette syndrome, as evidenced by the writings of his friend James Boswell.<ref>[https://web.archive.org/web/20050407083830/http://www.tsa-usa.org/what_is/johnson.html Samuel Johnson.] Tourette Syndrome Association. Retrieved from April 7, 2005, archive.org version on December 30, 2011.</ref><ref>{{cite journal |vauthors=Pearce JM |title=Doctor Samuel Johnson: 'the great convulsionary' a victim of Gilles de la Tourette's syndrome |journal=J R Soc Med |volume=87 |issue=7 |pages=396–399 |date=July 1994 |doi=10.1177/014107689408700709 |pmid=8046726 |pmc=1294650 |type= Historical biography}}</ref> Johnson wrote ''A Dictionary of the English Language'' in 1747, and was a prolific writer, poet, and critic. There is little support<ref>{{cite journal |vauthors=Powell H, Kushner HI |title=Mozart at play: the limitations of attributing the etiology of genius to tourette syndrome and mental illness |journal=Prog. Brain Res. |volume=216 |pages=277–291 |date=2015 |pmid=25684294 |doi=10.1016/bs.pbr.2014.11.010 |type= Historical biography}}</ref><ref>{{cite journal |vauthors=Bhattacharyya KB, Rai S |title=Famous people with Tourette's syndrome: Dr. Samuel Johnson (yes) & Wolfgang Amadeus Mozart (may be): Victims of Tourette's syndrome? |journal=Ann Indian Acad Neurol |volume=18 |issue=2 |pages=157–161 |date=2015 |pmid=26019411 |pmc=4445189 |doi=10.4103/0972-2327.145288 |doi-access=free }}</ref> for speculation that Mozart had Tourette's:<ref name=Byways>{{cite journal |vauthors=Simkin B |title=Mozart's scatological disorder |journal=BMJ |volume=305 |issue=6868 |pages=1563–1567 |date=1992 |pmid=1286388 |pmc=1884718 |doi=10.1136/bmj.305.6868.1563 |type= Historical biography}} Also see: Simkin, Benjamin. ''Medical and musical byways of Mozartiana.'' Fithian Press. 2001. {{ISBN|1-56474-349-7}} [http://www.danielpublishing.com/books/suppl/simkin.html Review] {{Webarchive|url=https://web.archive.org/web/20051207023102/http://www.danielpublishing.com/books/suppl/simkin.html |date=December 7, 2005 }}, Retrieved on May 14, 2007.</ref> the potentially coprolalic aspect of vocal tics is not transferred to writing, so Mozart's scatological writings are not relevant; the composer's available medical history is not thorough; the side effects of other conditions may be misinterpreted; and "the evidence of motor tics in Mozart's life is doubtful".<ref>Mozart:
* {{cite book |veditors=Bogousslavsky J, Hennerici MG |title=Neurological Disorders in Famous Artists - Part 2 |vauthors=Kammer T |chapter=Mozart in the neurological department – who has the tic? |volume=22 |pages=184–192 |date=2007 |location=Basel |publisher=Karger |type=Historical biography |chapter-url= https://www.uni-ulm.de/~tkammer/pdf/Kammer_2007_Mozart_preprint.pdf |pmid=17495512 |doi=10.1159/000102880 |archive-url=https://web.archive.org/web/20120207145220/http://www.uni-ulm.de/~tkammer/pdf/Kammer_2007_Mozart_preprint.pdf |archive-date=February 7, 2012 |series=Frontiers of Neurology and Neuroscience |isbn=978-3-8055-8265-0 |ref=none}}
* {{cite journal |vauthors=Ashoori A, Jankovic J |title=Mozart's movements and behaviour: a case of Tourette's syndrome? |journal=J. Neurol. Neurosurg. Psychiatry |volume=78 |issue=11 |pages=1171–1175 |date=November 2007 |pmid=17940168 |pmc=2117611 |doi=10.1136/jnnp.2007.114520 |type= Historical biography|ref=none}}
* {{cite journal |vauthors=Sacks O |title=Tourette's syndrome and creativity |journal=BMJ |volume=305 |issue=6868 |pages=1515–1516 |date=1992 |pmid=1286364 |pmc=1884721 |doi=10.1136/bmj.305.6868.1515 |type= Editorial comment|ref=none}}</ref>
<!-- Please do not add your own speculations here – Wikipedia is not for original research. Please add suggested inclusions to the talk page. -->

Likely portrayals of TS or tic disorders in fiction predating Gilles de la Tourette's work are "Mr. Pancks" in [[Biography:Charles Dickens|Charles Dickens]]'s ''Little Dorrit'' and "Nikolai Levin" in [[Biography:Leo Tolstoy|Leo Tolstoy]]'s ''Anna Karenina''.<ref>{{cite journal |vauthors=Voss H |title=The representation of movement disorders in fictional literature |journal=J. Neurol. Neurosurg. Psychiatry |volume=83 |issue=10 |pages=994–999 |date=October 2012 |pmid=22752692 |doi=10.1136/jnnp-2012-302716 |s2cid=27902880 |type= Review}}</ref> The entertainment industry has been criticized for depicting those with Tourette syndrome as social misfits whose only tic is coprolalia, which has furthered the public's misunderstanding and stigmatization of those with Tourette's.<ref>{{cite journal |title= Tourette syndrome in film and television |vauthors= Calder-Sprackman S, Sutherland S, Doja A |journal= The Canadian Journal of Neurological Sciences |volume= 41 |issue= 2 |date= March 2014 |pages= 226–232|doi= 10.1017/S0317167100016620 |pmid= 24534035 |s2cid= 39288755 |doi-access= free }}</ref><ref>{{cite journal |title= Public perception of Tourette syndrome on YouTube |vauthors= Lim Fat MJ, Sell E, Barrowman N, Doja A | journal= Journal of Child Neurology |volume= 27 |issue= 8 |date= 2012 |pages= 1011–1016|citeseerx = 10.1.1.997.9069|doi = 10.1177/0883073811432294|pmid = 22821136 |s2cid= 21648806 }}</ref><ref name="Holtgren">{{cite news | vauthors = Holtgren B |title= Truth about Tourette's not what you think |work= Cincinnati Enquirer |date= January 11, 2006 |quote=As medical problems go, Tourette's is, except in the most severe cases, about the most minor imaginable thing to have. ... the freak-show image, unfortunately, still prevails overwhelmingly. The blame for the warped perceptions lies overwhelmingly with the video media—the Internet, movies and TV. If you search for 'Tourette' on Google or YouTube, you'll get a gazillion hits that almost invariably show the most outrageously extreme examples of motor and vocal tics. Television, with notable exceptions such as Oprah, has sensationalized Tourette's so badly, for so long, that it seems beyond hope that most people will ever know the more prosaic truth.}}</ref> The coprolalic symptoms of Tourette's are also fodder for radio and television talk shows in the US<ref>US media:
* {{cite press release |archive-url= https://web.archive.org/web/20011006192716/http://tsa-usa.org/drlaura.html |title= Oprah and Dr. Laura|publisher= Tourette Syndrome Association |date= May 31, 2001 |archive-date= October 6, 2001 |access-date= December 21, 2011 |url= http://tsa-usa.org/drlaura.html}}
* {{cite press release |archive-url= https://web.archive.org/web/20080831055605/http://www.tsa-usa.org/news/DrPhil.htm |title= Letter of response to Dr. Phil. |publisher= Tourette Syndrome Association |archive-date= August 31, 2008 |access-date= December 21, 2011 |url= http://www.tsa-usa.org/news/DrPhil.htm}}
* {{cite press release |archive-url= https://web.archive.org/web/20090207194952/http://www.tsa-usa.org/news/Garrison-Keillor.htm |title= Letter of response to Garrison Keillor radio show |publisher= Tourette Syndrome Association |url= http://www.tsa-usa.org/news/Garrison-Keillor.htm |archive-date= February 7, 2009 |access-date= December 21, 2011}}</ref> and for the British media.<ref>{{cite news | vauthors = Guldberg H|url= http://www.spiked-online.com/index.php?/site/article/321/ |title= Stop celebrating Tourette's |archive-url= https://web.archive.org/web/20170314063258/http://www.spiked-online.com/index.php?%2Fsite%2Farticle%2F321%2F |archive-date=March 14, 2017 |work= [[Earth:Spiked (magazine)|Spiked]] |date= May 26, 2006 |access-date= December 26, 2006}}</ref> High-profile media coverage focuses on treatments that do not have established safety or efficacy, such as [[Biology:Deep brain stimulation|deep brain stimulation]], and alternative therapies involving unstudied efficacy and side effects are pursued by many parents.<ref name=Swerdlow>{{cite journal |vauthors=Swerdlow NR |title=Tourette syndrome: current controversies and the battlefield landscape |journal=Curr Neurol Neurosci Rep |volume=5 |issue=5 |pages=329–331 |date=September 2005 |pmid=16131414 |doi=10.1007/s11910-005-0054-8|s2cid=26342334 }}</ref>

== Research directions ==

Research since 1999 has advanced knowledge of Tourette's in the areas of genetics, [[Biology:Neuroimaging|neuroimaging]], [[Biology:Neurophysiology|neurophysiology]], and [[Biology:Neuropathology|neuropathology]], but questions remain about how best to classify it and how closely it is related to other movement or [[Biology:Psychiatry|psychiatric]] disorders.<ref name= Hollis /><!-- p. 4 --><ref name= Fernandez /><ref name= Dale2017 />{{sfnp|Sukhodolsky|Gladstone|Kaushal|Piasecka|2017|p= 242}} Modeled after genetic breakthroughs seen with large-scale efforts in other neurodevelopmental disorders, three groups are collaborating in research of the genetics of Tourette's:
*The Tourette Syndrome Association International Consortium for Genetics (TSAICG)
*Tourette International Collaborative Genetics Study (TIC Genetics)
*European Multicentre Tics in Children Studies (EMTICS)

Compared to the progress made in [[Biology:Gene|gene]] discovery in certain neurodevelopmental or mental health disorders—autism, [[Medicine:Schizophrenia|schizophrenia]] and [[Medicine:Bipolar disorder|bipolar disorder]]—the scale of related TS research is lagging in the United States due to funding.<ref name= FernandezFunding>{{cite book |vauthors=Fernandez TV, State MW, Pittenger C |title=Neurogenetics, Part I |chapter=Tourette disorder and other tic disorders |series=Handbook of Clinical Neurology |volume=147 |pages=343–354 |date=2018 |pmid=29325623 |doi=10.1016/B978-0-444-63233-3.00023-3 |type= Review |isbn=978-0-444-63233-3 |quote= Regardless of whether the focus is on discovering rare or common sequence or structural genetic variation, it is clear that large collections of biomaterials (likely in the tens of thousands) that are accessible by multiple research groups will be essential for success. Three consortia are now beginning to work toward this goal (TSAICG and TIC Genetics in the United States, and EMTics in the European Union); there is active collaboration among these groups, which will also be essential for success. However, the scale of the funded collection efforts, particularly in the United States, remains quite modest compared to other neuropsychiatric disorders in which there has been success in gene discovery.}}</ref>

== Notes ==
{{notelist|32em}}

== References ==
{{Reflist|colwidth=32em}}

=== Book sources ===
{{refbegin|32em|indent=yes}}
* {{cite book | vauthors = Abi-Jaoude E, Kideckel D, Stephens R, Lafreniere-Roula M, Deutsch J, Sandor P | date = 2009 | chapter = Tourette syndrome: a model of integration | veditors = Carlstedt RA |display-authors=3| title = Handbook of Integrative Clinical Psychology, Psychiatry, and Behavioral Medicine: Perspectives, Practices, and Research | location = New York | publisher = Springer Publishing Company | isbn = 978-0-8261-1095-4}}
* {{cite book | veditors = Cohen DJ, Jankovic J, Goetz CG |  editor-link2 = Joseph Jankovic | series = Advances in Neurology | title = Tourette Syndrome | volume = 85 | location = Philadelphia, PA | publisher = Lippincott Williams & Wilkins |date=2001| isbn = 0-7817-2405-8 }}
* {{cite book |vauthors=Kushner HI |title=A Cursing Brain?: The Histories of Tourette Syndrome |publisher=Harvard University Press |date=2000 |isbn=0-674-00386-1}}
* {{cite book | vauthors = Leckman JF, Cohen DJ |  author-link2 = Donald J. Cohen | date = 1999 | title = Tourette's Syndrome—Tics, Obsessions, Compulsions: Developmental Psychopathology and Clinical Care | publisher = John Wiley & Sons, Inc. | location = New York | isbn = 978-0471160373 }}
* {{cite book | veditors = Martino D, Leckman JF | date = 2013 | title = Tourette syndrome | publisher = Oxford University Press | isbn = 978-0199796267 |ref=none}}
** {{cite book | vauthors = Bloch MH | date = 2013 | chapter = Clinical course and adult outcome in Tourette syndrome | veditors = Martino D, Leckman JF | title = Tourette syndrome | publisher = Oxford University Press | pages = 107–120 }}
** {{cite book | vauthors = Müller-Vahl KR | date = 2013 | chapter = Information and social support for patients and families | veditors = Martino D, Leckman JF | title = Tourette syndrome | publisher = Oxford University Press | pages = 623–635 }}
** {{cite book | vauthors = Pruitt SK, Packer LE | date = 2013 | title = Information and support for educators | veditors = Martino D, Leckman JF | chapter = Tourette syndrome | publisher = Oxford University Press | pages = 636–655 }}
* {{cite book | vauthors = Sukhodolsky DG, Gladstone TR, Kaushal SA, Piasecka JB, Leckman JF |  date = 2017 | chapter = Tics and Tourette Syndrome | veditors = Matson JL | title = Handbook of Childhood Psychopathology and Developmental Disabilities Treatment | series = Autism and Child Psychopathology Series. | publisher = Springer | pages = 241–256 | doi = 10.1007/978-3-319-71210-9_14 | isbn = 978-3-319-71209-3 }}
* {{cite book | veditors = Walkup JT, Mink JW, Hollenback PJ | date = 2006 | title = Advances in Neurology, Tourette Syndrome | volume = 99 | location = Philadelphia, PA | publisher = Lippincott Williams & Wilkins | isbn = 0-7817-9970-8 }}
* {{Cite book |title=Georges Gilles de la Tourette: Beyond the Eponym, a Biography | vauthors = Walusinski O |date=2019 |publisher=Oxford University Press |isbn=978-0-19-063603-6}}
{{refend}}

== Further reading ==
{{refbegin}}
* {{cite book | vauthors = McGuire JF, Murphy TK, Piacentini J, Storch EA | date = 2018 | title = The Clinician's Guide to Treatment and Management of Youth with Tourette Syndrome and Tic Disorders | publisher = Academic Press | isbn = 978-0128119808 }}
* {{cite journal | vauthors = Olson S |title=Neurobiology. Making sense of Tourette's |journal=Science |volume=305 |issue=5689 |pages=1390–92 |date=September 2004 |pmid=15353772 |doi=10.1126/science.305.5689.1390|s2cid=177963554 }}
{{refend}}

== External links ==
<!--Please do not add external links without a strong justification, per WP:EL, WP:NOT and Wikipedia:WikiProject Clinical medicine/Writing medical articles. Websites can be added to the appropriate DMOZ category. -->
* {{Curlie|Health/Conditions_and_Diseases/Neurological_Disorders/Tourette_Syndrome/}}

{{Medical condition classification and resources
|ICD11 ={{ICD11|8A05|119340957}}
|ICD10 = {{ICD10|F|95|2}}
|ICD9 = {{ICD9|307.23}}
|eMedicineSubj = 
|eMedicineTopic = 
|eMedicine_mult = {{eMedicine2|neuro|664}}
|MedlinePlus=
|DiseasesDB=5220
|OMIM=137580
|MeSH=
|GeneReviewsNBK=
|GeneReviewsName=
}}

{{Emotional and behavioral disorders}}

<!--Categories: alphabetical -->

[[Category:Neurogenetic disorders]]

{{Sourceattribution|Tourette syndrome}}