Adults with attention-deficit/hyperactivity disorder (ADHD) symptoms show higher prevalence rates for substance use disorders (SUD).

Few longitudinal studies have been conducted to observe the course of substance use among adults with ADHD.

This study examined the predictive value of ADHD symptoms during the course of substance use in a population sample.

In two waves data from a representative sample of 5103 Swiss men in their early 20s were collected (baseline and 15-month follow-up) in the longitudinal “Cohort Study on Substance Use Risk Factors” (C-SURF). ADHD symptoms and substance use were assessed using the adult ADHD Self-Report Scale (ASRS-v1.1) and self-administered SUD questionnaires, respectively. Individuals who screened positive for ADHD (ADHD+) were compared to those who screened negative (ADHD−).

At baseline, the 215 individuals in the ADHD+ group (4.2%) showed considerably higher prevalence and frequency of substance use and prevalence of alcohol, tobacco, and cannabis use disorders relative to the ADHD− group. While alcohol, tobacco, cannabis, and heroin use remained stable from baseline to follow-up, the ADHD+ group was more likely to begin using illicit drugs (i.e. amphetamines, speed, ecstasy, hallucinogens, and cocaine) and initiate nonmedical use of prescription drugs (i.e. stimulants/amphetamines, hypnotics, and tranquilizers) relative to the ADHD− group.

Young men with ADHD symptoms displayed more severe substance use patterns and were at a high risk of initiating drug use within 15 months. The identification of ADHD symptoms during early adulthood may be relevant in early interventions to lower the risk of drug use.

The author has not supplied his declaration of competing interest.