Does social class predict substance problems in young adults with ADHD?

The relationship between social class and substance use problems is unclear. We aimed to clarify this association in a sample of young adult males with and without attention-deficit/hyperactivity disorder (ADHD). We included 69 ADHD and 78 control subjects. Substance use problems were measured with the Drug Use Screening Inventory-Revised (DUSI). Among ADHD subjects, we found a U-shaped association, with elevated risk for substance-related problems at both ends of the SES spectrum. No significant association was found in controls. These findings indicate that substance use risk in ADHD subjects is especially vulnerable to social class.