Editing Tourette syndrome (section)

== Characteristics ==
=== Tics ===
[[File:Tourette's tic long medium 192kbps.OGG|thumb|thumbtime=3|Examples of tics]]
[[Tic]]s 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 [[wikt:wax and wane|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 [[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 urge]]s. 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]], [[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 gestures|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 disorder]]s), such as [[stimming|self-stimulation]] and [[stereotypy (psychiatry)|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]] 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.|[[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 [[biased sample|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 [[mood disorder|mood]] or [[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 [[conduct disorder]] and [[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, [[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 [[autism]] and TS may be partly due to difficulties distinguishing between tics and tic-like behaviors or OCD symptoms seen in autistic people.<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 [[mood disorder]]s are found, and there may be [[self-injurious behavior|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 [[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 [[intelligence quotient|intellectual ability]], [[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 [[motor skill]]s. Comorbid conditions and severity of tics may account for variable results in [[verbal fluency test|verbal fluency]], which can be slightly impaired. There might be slight impairment in [[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 [[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 -->

[[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 [[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}}