Since the positive effects of stimulants on disruptive behavior were described (Bradley & Bowen, 1941), further pediatric studyhas been limited almost exclusively to samples of hyperkinetic school-age children. Because these agents normally were viewed as arousing in their effects on the central nervous system, but were calming in their therapeutic effects on these children, stimulant effects on Attention Deficit Disorder (ADD) were interpreted as being 'paradoxical.' Investigation of effects in normal children and adolescents and in those with disorders unrelated to Attention-Deficit/Hyperactivity Disorder (ADHD), as well as in young adult samples, however, indicate that stimulants appear to have similar behavioral effects in normal and in hyperactive children. This brief report is an update (as of August 2002) on studies of stimulants in ADHD and normal children, with particular focus on MPH.