Substance Use Motives and Severe Mental Illness

Objective: The purpose of this study was to validate the construct validity of the Drinking Motives Questionnaire-Revised (DMQ-R) and to test the hypothesis that coping motives for using substances will vary directly with alcohol use, drug use, and substance use problems when controlling for psychiatric symptoms of severe mental illness. Methods: Data from this survey of 120 people with severe mental illness who drank in the previous six months were collected in face-to-face interviews as part of routine community mental health care by line clinical staff including psychiatric nurses, social workers, and case managers. Measures included the DMQ-R, the BASIS-24, and a quantity-frequency measure of alcohol use, frequency of drugs used, and substance use problems. Results: A three-factor version of the DMQ-R was well replicated, and linear regression revealed that coping motives varied positively and significantly with alcohol use and substance use problems. Logistic regression demonstrated that personal enhancement motives varied with drug use. Conclusions: Results suggest that although coping motives appear to be associated with more problematic substance use overall, coping and personal enhancement motives could be associated with the use of different substances. Future research should emphasize links among psychiatric symptoms, motives, and specific substances in order to identify potential links that might inform assessment and intervention with people who have severe mental illnesses. Limitations of the study include the lack of a structured diagnostic interview and modest cross-sectional sample size. (Journal of Dual Diagnosis, 8: 171-179, 2012)