Objective: To examine late adolescent substance use outcomes in relation to childhood conduct disorder (CD) and psychostimulant treatment in urban youth found to have attention-deficit/hyperactivity disorder (ADHD) in childhood.
Methods: Ninety-seven adolescents, evaluated during childhood, were seen for follow-up on average 9.30 (SD = 1.65) years later along with a well-matched never-ADHD control group. Stimulant treatment history was coded: Never (n = 28), up to 1 year (n = 19), 1 to 5 years (n = 28), and greater than 5 years (n = 22). Substance use at outcome was coded dimensionally for severity (frequency × intensity) and categorically for substance use disorders (SUDs).
Results: Individuals with ADHD+CD in childhood had significantly higher rates of SUD and substance use severity than those with childhood ADHD and controls. The ADHD and control groups did not differ significantly. Among those with childhood ADHD, there were no significant differences in SUD status or substance use severity as a function of medication history.
Conclusions: Within an ethnically diverse urban sample, the increased rate of substance use associated with ADHD was fully accounted for by the presence of CD. These results extend previous findings indicating little impact of psychostimulant treatment on later substance use to an ethnically diverse urban sample and to individuals who received treatment for up to 12 years.