Management of attention deficit hyperactivity disorder (ADHD) encompasses two general domains: pharmacologic therapies and nonpharmacologic therapies, including educational, cognitive-behavioral, and other psychological and psychiatric approaches. Within the past year there have been two seminal developments in treatment. The first is that the Evidence-based Practice Center at McMaster University, under contract with the Agency for Health Care Policy and Research, produced an evidence based report on the treatment of ADHD. The topic was proposed to the AHCPR by the American Academy of Pediatrics and American Psychiatric Association, who served as partners to the center. The second is the completion of the Multisite Multimodal Treatment Study of Children with Attention-Deficit/Hyperactivity Disorder (MTA) study by the National Institutes of Mental Health, a 14-month double-blind placebo trial of medication and behavioral therapy in ADHD. In general, the result of the evidence-based review and the MTA study is that stimulants are the most effective agents for the treatment of ADHD. Results from the MTA study indicate that methylphenidate (MPH) and MPH combined with behavioral therapy are superior to behavioral therapy alone and that all three are superior to community therapy. The evidence-based review indicates that each of the stimulants is superior to placebo and the stimulants (regular and sustained-release MPH as well as d and l isomers of the stimulants) are comparable. As for other agents, tricyclic antidepressants, specifically desipramine, are superior to placebo. Only a few studies compared stimulants directly with tricyclic antidepressants, and these were technically inadequate, leading to the conclusion that more rigorous studies are required. Only five studies were found that examined nonpharmacologic treatment, and all contained major limitations in methodology. Despite the limitations, all showed that stimulants were more effective than the nonpharmacologic therapies, consonant with the results of the MTA study. There was lack of evidence to support the superiority of combination multimodal treatment over stimulant therapy alone, again consonant with the MTA study. Both the evidence-based review and the MTA study examined ADHD in middle childhood. Finally, most studies are relatively short-term, including the MTA study (at 14 months). Some evidence suggests that MPH reduces behavioral disturbance as long as it is taken.