Psychological functioning of out-of-treatment drug users.

Co-occurrence of drug use and psychological disorders is prevalent in both clinical and population-based samples. Severity of drug use, including injection drug use, polydrug use, and frequency of drug use, may have negative consequences for psychological treatment outcomes. The current research examines the psychological functioning of 224 out-of-treatment drug users and demographically matched nonusers using the Brief Symptom Inventory (BSI). Results indicate that drug users are more psychologically impaired than nonusers on all 9 dimensions of the BSI. Comparisons of injectors to noninjectors and polydrug users to single-drug users reveal few differences. However, in examining the frequency of drug use, chronic drug users score higher on 7 of the 9 BSI dimensions. Our findings imply injection and polydrug use do not have as much effect on psychological functioning as compared with frequency of drug use. [ABSTRACT FROM AUTHOR]