The authors examine the relationship between the treatment of attention-deficit/hyperactivity disorder (ADHD) with stimulants and substance use disorders by reviewing their published meta-analysis of 6 studies and adding preliminary data from a seventh study. Despite some discrepancies among the findings of the 7 studies, the meta-analysis demonstrated that exposure to stimulant therapy for ADHD does not increase the risk for developing substance use disorders but is, in fact, protective against it. Stimulant treatment of ADHD appears to reduce the risk for substance use disorders by 50%, thus reducing the risk for substance use disorders in ADHD youth to levels well within the normal population risk. The implication of this finding is unquestionably one with enormous value both clinically and as a matter of public health.