A large, double-blind, randomized clinical trial of methylphenidate in the treatment of adults with attention-deficit/hyperactivity disorder

Background: The few controlled studies of methylphenidate (MPH) in adults with attention deficit/hyperactivity disorder (ADHD) have reported equivocal results. A previous, pilot study by our group suggested that these results were dure to inadequate dosing. Method: We conducted a randomized, 6-week, placebo-controlled, parallel study of MPH in 146 adult patients with DSM-IV ADHD using standardized instruments for diagnosis, separate assessments of ADHD, depressive and anxiety symptoms, and a robust average oral daily doze of 1.1 mg/kg/day. Results: We found a marked therapeutic response for the MPH treatment of ADHD symptoms that exceeded the placebo response (76% vs. 19%). Treatment was safe and well tolerated. Response to MPH was independent of socioeconomic status, gender, and lifetime history of psychiatric comorbidity. Conclusions: These results confirm that robust doses of MPH are effective in the treatment of adult ADHD.