Objectives: To determine whether attention-deficit/hyperactivity disorder (ADHD) in adolescence is related to substance use disorders (SUDs) in adulthood and whether conduct disorder (CD) mediates this relationship.
Design: A prospective design incorporating 5 assessments in participants spanning the mean ages of 14 to 37 years. Two baseline assessments were taken at ages 14 and 16 years, and 3 outcome assessments were taken between ages 27 and 37 years.
Setting: United States.
Participants: A community sample of individuals initially drawn from upstate New York in 1975 and observed to a mean age of 37 years.
Interventions: The Diagnostic Interview Schedule for Children was used to assess ADHD and CD and the University of Michigan Composite International Diagnostic Interview was used to assess SUDs.
Main outcome measure: A diagnosis of SUDs given to participants in adulthood.
Results: The odds ratios for ADHD and CD in adolescence as related to SUDs in adulthood were 1.9 and 3.5, respectively. The association between ADHD and SUDs, however, was indirect because CD served as a mediator between ADHD and SUDs.
Conclusions: Pediatricians should focus on adolescent ADHD when it progresses to CD because CD is a major predictor of SUDs in adulthood.