OBJECTIVE: To examine the impact of stimulant treatment during childhood and high school on risk for substance use, dependence, and abuse by young adulthood.

METHODS: A total of 147 clinic-referred hyperactive children were followed approximately 13 years into adulthood (mean: 21 years old; range: 19-25). At adolescent (age 15) and adult follow-up, probands were interviewed about their use of various substances and duration of stimulant treatment.

RESULTS: Duration of stimulant treatment was not significantly associated with frequency of any form of drug use by young adulthood. Stimulant-treated children had no greater risk of ever trying drugs by adolescence or any significantly greater frequency of drug use by young adulthood. Stimulant treatment in high school also did not influence drug use in adulthood except for greater use of cocaine. This difference was no longer significant after controlling for severity of attention-deficit/hyperactivity disorder and conduct disorder in childhood, adolescence, and adulthood. Stimulant treatment in either childhood or high school was not associated with any greater risk for any formal Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised drug dependence or abuse disorders by adulthood. Treatment with stimulants did not increase the risk of ever having tried most illegal substances by adulthood except for cocaine. Subsequent analyses showed that this elevated risk was primarily mediated by severity of conduct disorder by young adulthood and not by stimulant treatment in childhood.

CONCLUSION: This study concurs with 11 previous studies in finding no compelling evidence that stimulant treatment of children with attention-deficit/hyperactivity disorder leads to an increased risk for substance experimentation, use, dependence, or abuse by adulthood.