Psychostimulant treatment and risk for substance abuse among young adults with a history of attention-deficit/hyperactivity disorder: A population-based, birth cohort study

Objective: The aim of this study was to evaluate the association between stimulant treatment and the risk for substance abuse among young adults with a childhood diagnosis of attention-deficit/hyperactivity disorder (ADHD). Methods: Subjects included 295 research-identified ADHD incidence cases treated with psychostimulant medication and 84 ADHD cases not treated with psychostimulants. These subjects are from a 1976-1982 population-based birth cohort, retrospectively, followed from birth until emigration, death, or last follow-up (mean = 17.2 years of follow-up). Medical and school records were reviewed for documented substance abuse and psychostimulant treatment. The association was evaluated using logistic regression models. Results: Socioeconomic characteristics at birth, and comorbidities, were similar between treated and untreated ADHD cases. Sixty (20.3%) of treated ADHD cases had documented substance abuse compared to 23 (27.4%) of cases not treated (OR = 0.7; 95% CI = 0.4-1.2). Among treated ADHD boys, 21.8% had substance abuse compared to 36.4% not-treated ADHD boys (OR = 0.5; 95% CI = 0.3-0.9). Among treated ADHD girls, 15.2% had substance abuse compared to 10.3% not-treated ADHD girls (OR = 1.5; 95% CI = 0.4-6.1). Conclusion: While these results cannot demonstrate cause and effect, our findings indicate that psychostimulant treatment of childhood ADHD is associated with reduced risk for later substance abuse among boys with ADHD.