Incidence trend and epidemiology of tic disorders among youths and adults in Korea from 2003 to 2020: A national population-based study.

Tic disorder is a highly prevalent neurodevelopmental disorder; however, research on its incidence trends is still rare. We aimed to investigate its annual incidence rates and the characteristics of incident cases in the general Korean population using data from the National Health Insurance Service-National Health Information Database as a proxy measurement for true incidence in the community. The total number of incident cases and incidence rates of tic disorders from 2003 to 2020 were compared between youths and adults. Both the number of incident cases and the annual incidence rates of tic disorders significantly increased from 2003 to 2020. The overall increasing trend in the incidence rates was significantly greater in youths than in adults; however, the incidence rates in adults showed a relatively recent increase. The male predominance regarding the newly diagnosed case number in youths was no longer observed in adults. Tic disorders occurred more commonly in the low-income group than in the high-income group. Neurodevelopmental comorbidities in youths and mood or anxiety disorders and schizophrenia in adults were more frequently observed. Antipsychotic medication adherence was higher in youths than in adults. Efforts are required to raise awareness and promote expert education for adult patients with tic disorders.