Article AbstractConflicting studies of the relationship between therapeutic use of psychostimulant medication andsubstance abuse have long been a subject of concern among clinicians and researchers. One controlledlongitudinal study examined this relationship in 147 patients who were diagnosed with hyperactivityas young children and were surveyed with regard to their substance use both as adolescents and asadults. This study found that stimulant therapy for attention-deficit/hyperactivity disorder in childhoodis not associated with increased risk of adolescent experimentation with substance use, frequencyof such use, or the risk of developing psychoactive substance use disorders by young adulthood.Moreover, stimulant therapy in high school may well have provided a protective effect againsthallucinogen abuse by adulthood. A possible explanation for contradictory findings previously publishedwas suggested by the existence of a number of potentially confounding variables, particularlyconduct disorders, for which prior studies have failed to control.