Diagnosing adult attention deficit/hyperactivity disorder in patients with cocaine dependence: discriminant validity of Barkley executive dysfunction symptoms.

OBJECTIVE To estimate the prevalence of adult attention deficit/hyperactivity disorder (ADHD) in a sample of cocaine-dependent patients, and to examine the discriminant validity of the Barkley's executive dysfunction scale in differentiating cocaine-dependent patients with and without ADHD. METHODS A cross-sectional design was used. A total of 166 cocaine-dependent subjects were assessed. The assessment instruments included: Conners' Adult ADHD Diagnostic Interview for DSM-IV (CAADID), Psychiatric Research Interview for Substance and Mental Disorders (PRISM-IV) and 9 items from Current Behavior Scale Self-Report by Russell A. Barkley. RESULTS 14.5% (CI95%: 9.2-19.8%) prevalence of ADHD was observed in our sample. The Barkley's executive dysfunction items showed statistically significant differences between cocaine-dependent patients with ADHD and those patients without ADHD diagnosis. CONCLUSIONS The study data support Barkley's model - which posits the relevance of executive dysfunction among ADHD patients within a sample of cocaine dependents, and provides evidence of the discriminant validity of the Current Behavior Scale Self-Report for identifying ADHD symptoms in cocaine users.