Impulsive aggression in attention-deficit/hyperactivity disorder: symptom severity, co-morbidity, and attention-deficit/hyperactivity disorder subtype.

OBJECTIVE: The aim of this study was to characterize aggression and its relationship to psychiatric co-morbidity, attention-deficit/hyperactivity disorder (ADHD) subtype, and ADHD symptom severity in clinically referred ADHD youngsters. We also wanted to ascertain whether reactive and impulsive aggression is more prevalent than proactive aggression in an ADHD sample.
METHOD: Consecutively referred ADHD children and adolescents (n = 268) and community controls (n = 100) were assessed systematically regarding demographics, psychiatric diagnosis, overt aggression severity, proactive and reactive aggression severity, and ADHD symptom severity using correlational analysis and analysis of covariance (ANCOVA).
RESULTS: Across all aggression measures, ADHD children were more aggressive than community controls. ADHD children with nonanxiety co-morbid disorders were more aggressive than ADHD children without such co-morbidity. The number of co-morbid psychiatric diagnoses and ADHD symptom severity were significantly associated with aggression. ADHD youngsters demonstrated significantly more reactive than proactive forms of aggression across all co-morbid diagnoses.
CONCLUSIONS: Aggression is common in clinically referred ADHD youngsters and should be identified as a legitimate target for psychopharmacological treatment in children and adolescents with moderate to severe ADHD and nonanxiety co-morbid diagnostic disorders.