The association of disruptive behavior with social, adaptive, and family functioning in Tourette syndrome (TS), with and without comorbid attention-deficit/hyperactivity disorder (ADHD), was evaluated in 207 children (144 boys and 63 girls) between the ages of 7 and 18 years, in a study at Yale University School of Medicine, New Haven, CT. Children with TS-only (n=42) did not differ from unaffected controls (61) on the parent ratings of aggression and delinquent behavior or on the teacher ratings of conduct disorders. Children with TS+ADHD (n=52) had significantly greater ratings of disruptive behavior than controls and similar to children with ADHD only (n=52). Aggression and delinquency contributed to impaired social and family functioning. Comorbid ADHD is highly associated with disruptive behavior and functional impairment in children with TS. Disruptive behavior adds to the burden of social and family dysfunction. 
COMMENT. Children and adolescents with uncomplicated Tourette syndrome (TS) are not at risk for aggressive and disruptive behavior, whereas those with comorbid TS+ADHD have a significantly higher prevalence of behavioral and conduct disorders, similar to that found with ADHD alone. Aggressive and delinquent behaviors have a negative impact on social and family functioning, adding further burdens to the quality of life of children with comorbid TS/ADHD.