AN EPIDEMIOLOGIC-STUDY OF GILLES-DE-LA-TOURETTES SYNDROME IN ISRAEL

Objectives: The goal of this study was to estimate the lifetime preval ence of Gilles de la Tourette's syndrome (GTS) in adolescents aged 16 to 17 years. Design: Population-based epidemiologic study. Subjects: E ighteen thousand three hundred sixty-four males and 9673 females aged 16 to 17 years screened for induction into the Israel Defense Force. R esults: Of the 28 037 individuals screened, 12 met diagnostic criteria for GTS. The point prevalence in this population was 4.3+/-1.2 (mean/-SE) per 10 000. The 95% confidence interval for this estimate is 1.9 to 6.7 per 10 000. The point prevalence was 4.9+/-1.6 per 10 000 for males (95% confidence interval, 1.8 per 10 000) and 3.1+/-1.8 per 10 0 00 for females (95% confidence interval, 0 to 6.6 per 10 000). The rat e of obsessive-compulsive disorder (OCD) was significantly elevated am ong the subjects with GTS (41.7%) compared with the population point p revalence of OCD (3.4) in those without GTS. In contrast, the rate of attention deficit hyperactivity disorder was only 8.3% compared with t he population point prevalence of 3.9% in those individuals without GT S. Conclusions: The prevalence estimates from this population-based st udy are in agreement with previous results based on surveys of younger children. The sex ratio observed in this study is not as large as rep orted in previous studies and remains to be explored in other studies of adolescents and adults.