The association between attention deficit hyperactivity disorder (ADHD) and psychoactive substance use disorders in 120 adults with childhood-onset ADHD was evaluated with attention to comorbid mood, anxiety, and antisocial disorders in the Pediatric Psychopharmacology Unit, Psychiatric Service, Massachusetts General Hospital, Harvard Medical School, Boston. The lifetime risk of drug and drug plus alcohol use disorders in the ADHD adults was 52% compared to 27% of 268 control non-ADHD adults. The increased risk of drug and alcohol abuse or dependence related to ADHD was independent of psychiatric comorbidity. Antisocial disorders increased risk of drug abuse independent of ADHD. Mood and anxiety disorders were associated with increased drug abuse in both ADHD and control non-ADHD adults. 
COMMENT. Childhood onset ADHD persisting in adults without comorbidity carried a 40% risk of a lifetime diagnosis of substance use disorders. Drug abuse or dependence and drug plus alcohol abuse, but not alcohol abuse alone, were significantly increased in grown-up ADHD children compared to non-ADHD adult controls. Psychiatric comorbidity increased the risk of drug abuse. Marijuana was most commonly used (30 ADHD adults), cocaine in 10, and stimulants in 8. There were no differences in the preferred drugs of abuse between ADHD adults and normal comparison subjects. These results contradict the commonly held view that ADHD patients may show a predilection for stimulant drug abuse.