Transtheoretical Model and substance use in HIV-positive youth.

The purpose of the study was to test constructs of the Transtheoretical Model (TTM) for predicting alcohol and other drug use in HIV-positive youth (ages 16-25). Questionnaires and interviews about alcohol and other drug use, stage of change, self-efficacy, emotional distress and social support were obtained from 64 HIV-positive youth. Structural equation modeling with standard errors determined by methods appropriate to small samples, demonstrated that self-efficacy mediated the relationship between stage of change and alcohol use and between social support and alcohol use. The same pattern of results emerged for marijuana use. The models predicted 47% of the variance in alcohol use and 69% of the variance in marijuana use. Results supported the TTM and highlight the potential of interventions that seek to boost self-efficacy and social support specific to reducing substance use.