Context: The Agency for Health Care Policy and Research charged the McMaster Evidence-based Practice Center with conducting a comprehensive systematic review of the literature on the treatment of attention-deficit hyperactivity disorder (ADHD), with input from various groups of stakeholders. One strategy used to avoid duplication of work included a critical appraisal of existing systematic reviews and metaanalyses.Objective: To identify and appraise published metaanalyses and systematic reviews on the treatment of ADHD and to produce an annotated bibliography.Data Sources: Medline, Cumulative Index in Nursing and Allied Health (CINAHL), Healthstar, Psycinfo, and Embase were searched to September 1998; the Cochrane Database (1998 issue 3), selected Internet sites, and the files of investigators were also reviewed.Study Selection: Review articles described as systematic reviews or metaanalyses or including a Methods section were identified independently by 3 reviewers.Data Extraction: Two reviewers extracted, by consensus, relevant information on the name, methodological quality, ADHD-related aspects (comorbid disorders, family characteristics) of those reviews; data on the population, study setting, interventions, and outcomes evaluated by the reviews were also retrieved.Results: Thirteen reviews, published from 1982 to 1998, were included. Eight included metaanalysis and 5 a qualitative review. Nonpharmacological treatments were mentioned in 6 reviews and combination therapies in 3. One review focused on the treatment of adults. Forty-seven drugs and 20 adverse effects were mentioned. Most reviews had major methodological flaws.Conclusions: Most published systematic reviews and metaanalyses on the treatment of ADHD have limited value for guiding clinical, policy, and research decisions. A rigorous, systematic review following established methodological criteria is warranted. [ABSTRACT FROM AUTHOR]