This paper reviews recent studies of attention deficit-hyperactivity disorder, focusing on research with implications for adolescents. Only 10 of the 31 recent investigations discussed employed an exclusively adolescent sample, necessitating considerable extrapolation from studies of children or adults or mixed samples with a wide range of ages. Significant advances include increased accuracy of predicting negative outcomes and the identification of adaptive skill dysfunction. Further information has become available on the long-term impact of attention deficit-hyperactivity disorder, and additional data have been reported on risk factors. Other reports have described typical services provided by pediatric and family medicine practices for attention deficit-hyperactivity disorder; beneficial effects of combined behavioral and pharmacologic treatment; absence of adverse effects of methylphenidate on cognitive constriction or tics; and disappointing results for nonstimulant pharmacotherapy. A National Institute of Mental Health multisite treatment study has recently been initiated.