Tourette's disorder: epidemiology and comorbidity in primary school children.

OBJECTIVE: To study prevalence and comorbidity of Tourette's disorder in the general population of children and in a clinical setting.

METHODS: School-age children in the general population and children attending a county-wide tic disorder clinic were screened and examined by the same doctor. Behavioral-psychometric instruments with demonstrated reliability and validity were used.

RESULTS: Depending on the sample characteristics, 0.15% to 1.1% of all children had Tourette's disorder. Boys outnumbered girls by 4:1 through 6:1. Attention deficits and empathy/autism spectrum problems (including Asperger's disorder) were very common, each type of comorbidity affecting approximately two thirds of individuals with Tourette's disorder. Overall behavior problem scores were high, and affected children exhibited a marked degree of functional impairment.

CONCLUSIONS: Tourette's disorder is a common disorder with high rates of significant comorbidity. In most cases, attention deficits and empathy problems are likely to cause more suffering than the tics per se.