Long-acting methylphenidate has an effect on aggressive behavior in children with attention-deficit/hyperactivity disorder.

INTRODUCTION: Aggression is frequently observed in children and adolescents with attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to assess the efficacy with regard to oppositional and aggressive behavior of a new long-acting methylphenidate preparation (Medikinet retard, MPH-MR), with equal portions of the immediate-release and the sustained-release active substance, and especially to look at correlations between either teacher or parent assessment of aggression and ADHD sub-symptomatology.

METHODS: Eighty five children and adolescents (6-16 years) were investigated in a double-blind, randomized, clinical trial over 5 weeks under a treatment with MPH-MR using symptom checklists for ADHD, oppositional-defiant and conduct disorder according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV).

RESULTS: A total of 64.9% of the children showed oppositional defiant disorder/conduct disorder (ODD/CD) symptoms. A statistically significant effect was found in the group treated with MPH (verum-group). On the basis of Cohen's criteria, high effects were found for aggressive symptoms in school (d = 1.0), but not in the afternoon (d = 0.4). There were also lower effect sizes for more severe aggressive symptoms. We found characteristic correlations between ODD/CD symptoms and the ADHD subscale hyperactivity/impulsivity compared to the subscale inattention.

CONCLUSIONS: Long-acting MPH is effective in the treatment of oppositional-defiant and aggressive behavior, especially concerning milder symptoms. The expected correlation between impulsivity and aggressiveness could be confirmed.