Clustering of multiple substance use and psychiatric diagnoses in opiate addicts.

Using a standardized psychiatric interview, the prevalence of and interrelationships among various substance use diagnoses and non-substance use psychiatric diagnoses were examined in a population of opiate addicts (n = 66) enrolled in methadone maintenance treatment. Multiple substance use disorders were found in these patients, and more substance use disorders were found in those patients with, versus without, a non-substance use psychiatric diagnosis. Certain substance use disorders were found to cluster. These results suggest that opiate addicts should be evaluated for multiple substance use disorders as well as for non-substance use disorders, and that certain subpopulations may be at increased risk for multiple substance use disorders.