Prevalence of tic disorders: a systematic review and meta-analysis

This study evaluated the prevalence of tic disorders. MEDLINE and EMBASE databases were searched, using terms specific to Tourette syndrome and tic disorders, for studies of incidence, prevalence, and epidemiology. Thirty-five studies reporting data from 1985-2011 on the incidence or prevalence of tic disorders in a defined population were included. One reported incidence, and 34 reported prevalence. Meta-analysis of 13 studies of children yielded a prevalence of Tourette syndrome at 0.77% (95% confidence interval, 0.39-1.51%). Prevalence is higher in boys: 1.06% of boys were affected (95% confidence interval, 0.54-2.09%) vs 0.25% of girls (95% confidence interval, 0.05-1.20%). Transient tic disorder comprised the most common tic disorder in children, affecting 2.99% (95% confidence interval, 1.60-5.61%). Meta-analysis of two studies assessing adults for Tourette syndrome revealed a prevalence of 0.05% (95% confidence interval, 0.03-0.08%). The prevalence of tic disorders was higher in all studies performed in special education populations. Tic disorders are more common in children than adults, in boys than girls, and in special education populations. Parents, educators, healthcare professionals, and administrators should be aware of the frequency with which tic disorders occur, and ensure proper access to appropriate care.