Disruptive behavior in children with Tourette's syndrome: Association with ADHD comorbidity, tic severity, and functional impairment

Objective: To examine the association of disruptive behavior with social, adaptive, and family functioning in Tourette's syndrome (TS) With and Without comorbid attention-deficit/hyperactivity disorder (ADHD). Method: The sample included 207 children (144 boys and 63 girls) between the ages of 7 and 18 years. Forty-two children received a diagnosis of TS-only, 52 received a diagnosis of ADHD-only, 52 children had TS+ADHD, and there were 61 unaffected control children. Best-estimate DSM-IV diagnoses were assigned on the basis of structured interviews and clinical ratings. Dependent measures included parent and teacher ratings of disruptive behavior, parent ratings of social and family functioning, and the Vineland Adaptive Behavior Scales. Results: Children with TS-only did not differ from unaffected controls on the parent ratings of aggression and delinquent behavior or on the teacher ratings of conduct problems, By contrast, children with TS+ADHD were rated significantly above unaffected controls and similar to children with ADHD-only on these indices of disruptive behavior. Hierarchical regression analyses revealed that aggression and delinquency scores added unique contributions to impairment in social and family functioning, controlling for age, gender, and diagnostic status. Conclusions: Comorbid ADHD is highly associated with disruptive behavior and functional impairment in children with TS. When disruptive behavior problems are present, there is an additional burden on children's social and family functioning.