\\\

Epidemiology

Several studies have addressed the prevalence and incidence of Tourette syndrome and chronic tic disorders.  A systematic review and meta-analysis showed a global prevalence of TS of 0.5-0.6% and of 0.7% in the population of children and adolescents \cite{Jafari2022}.\citet{Tinker2022}, from the CDC, estimates that "350,000–450,000 U.S. children and adults have Tourette syndrome," while about a million have other chronic tic disorders.
In Asia, the National Taiwan Insurance Research Database was used to estimate incidence and prevalence of TS and chronic tic disorders from 2007-2015 \cite{Chou2022}. An increase in annual incidence rates was seen during this period in childhood and adolescence, and a decrease in adulthood. Furthermore, an increase in prevalence of TS and chronic tic disorders was seen. 
In China, prevalence of tic disorders in school students between 6 and 16 years was shown to be 1.37% \cite{Yan2022}. There was seen a high comorbidity between TS and OCD.
Using 2016-2017 National Survey of Children´s Health data on children and adolescents between 6 and 17 years, parents reported that 0.3% of the children ever had been diagnosed with TS \cite{Charania2022}.