Aggressive behaviour in children with Tourette syndrome and comorbid attention-deficit hyperactivity disorder and obsessive-compulsive disorder

Background: Aggressive behaviour, defined as sudden, explosive outbursts of rage, has been reported as a clinical problem in approximately 23% to 40% of Tourette syndrome (TS) patients (1-5). Attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD) are also reported in 50% to 70% of TS patients (6). Objective: To investigate whether aggressive behaviour was associated with TS directly or found primarily in TS with comorbid ADHD or OCD. Method: Aggressive behaviour in 33 nonmedicated patients with TS (ages 6 to 14 years) and 6 healthy control subjects (ages 7 to 12 years) was examined by semistructured interview and multiinformant questionnaires. Results: Aggression subscales on Achenbach's Child Behavior Checklist (CBCL) completed by parents and Teacher's Report Form (TRF) completed by teachers distinguished the TS-only and control groups from the group with TS + Comorbidity (P < 0.046 and P < 0.016) after adjusting for tic severity and age. The conduct disorder subscale on the Conners Parent Rating Scale (CPRS) was also significantly higher (P < 0.005) in the TS + comorbidity group than in the TS-only or control groups, with more problems reported in the older children. Conclusions: These findings provide additional evidence that aggressive behaviour observed in children with TS may be associated with comorbid ADHD or OCD (6), independent of tic severity or age. This is consistent with the clinical observation that most TS patients have only minimal symptoms, which do not interfere with their daily functioning.