Prevalence of attention-deficit/hyperactivity disorder and conduct disorder among substance abusers

This cross-sectional study sought to determine the prevalence of attention-deficit/hyperactivity disorder (ADHD) and conduct disorder among adults admitted to 2 chemical dependency treatment centers. It was hypothesized that ADHD alone or in combination with conduct disorder would be overrepresented in a population of patients with psychoactive substance use disorders.

Two hundred one participants were selected randomly from 2 chemical dependency treatment centers. Standardized clinical interviews were conducted using the Structured Clinical Interview for DSM-IV, the Addiction Severity Index, and DSM-IV criteria for ADHD. Reliabilities for the diagnostic categories were established using the Cohen kappa, and the subgroups of individuals with and without ADHD and conduct disorder were compared.

Forty-eight (24%) of the participants were found to meet DSM-IV criteria for ADHD. The prevalence of ADHD was 28% in men (30/106) and 19% in women (18/95; NS). Seventy-nine participants (39%) met criteria for conduct disorder, and 34 of these individuals also had ADHD. Overall, individuals with ADHD (compared with those without ADHD) were more likely to have had more motor vehicle accidents. Women with ADHD (in comparison with women without ADHD) had a higher number of treatments for alcohol abuse. Individuals with conduct disorder (in comparison with those without conduct disorder) were younger, had a greater number of jobs as adults, and were more likely to repeat a grade in school, have a learning disability, be suspended or expelled from school, have an earlier age at onset of alcohol dependence, and have had a greater number of treatments for drug abuse. They were more likely to have a lifetime history of abuse of and/or dependence on cocaine, stimulants, hallucinogens, and/or cannabis.

A significant overrepresentation of ADHD exists among inpatients with psychoactive substance use disorders. Over two thirds of those with ADHD in this sample also met criteria for conduct disorder. Our sample had a very large overlap between ADHD and conduct disorder, and the major comorbidities identified here were attributable largely to the presence of conduct disorder. Individuals who manifest conduct disorder and/or ADHD represent a significant proportion of those seeking treatment for psychoactive substance use disorders. They appear to have greater comorbidity and may benefit from a treatment approach that addresses these comorbidities specifically through medical and behavioral therapies.