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

Biol Psychiatry. 2005 Mar 1;57(5):456-63. doi: 10.1016/j.biopsych.2004.11.043.


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 due 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 dose 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.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Attention Deficit Disorder with Hyperactivity / drug therapy*
  • Central Nervous System Stimulants / therapeutic use*
  • Demography
  • Double-Blind Method
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Methylphenidate / therapeutic use*
  • Middle Aged
  • Neuropsychological Tests
  • Placebos
  • Psychiatric Status Rating Scales
  • Treatment Outcome


  • Central Nervous System Stimulants
  • Placebos
  • Methylphenidate