The effect of methylphenidate on oppositional defiant disorder comorbid with attention deficit/hyperactivity disorder.

OBJECTIVE To assess the effect of methylphenidate on the diagnosis of oppositional-defiant disorder (ODD) comorbid with attention-deficit hyperactivity disorder (ADHD). METHOD We conducted an open-label study in which 10 children and adolescents with a dual diagnosis of ODD and ADHD were assessed for their ODD symptoms and treated with methylphenidate. At least one month after ADHD symptoms were under control, ODD symptoms were reevaluated with the Parent form of the Children Interview for Psychiatric Syndromes (P-ChIPS). RESULTS Nine of the 10 patients no longer fulfilled diagnostic criteria for ODD after they were treated with methylphenidate for ADHD. CONCLUSION Methylphenidate seems to be an effective treatment for ODD, as well as for ADHD itself. The implications for the treatment of patients with ODD not comorbid with ADHD needs further investigation.