Substance use stigma: Reliability and validity of a theory-based scale for substance-using populations

Background: Substance use disorders consistently rank among the most stigmatized conditions worldwide. Thus, substance use stigma fosters health inequities among persons with substance use disorders and remains a key barrier to successful screening and treatment efforts. Current efforts to measure substance use stigma are limited. This study aims to advance measurement efforts by drawing on stigma theory to develop and evaluate the Substance Use Stigma Mechanisms Scale (SU-SMS). The SU-SMS was designed to capture enacted, anticipated, and internalized Substance Use Stigma Mechanisms among persons with current and past substance use disorders, and distinguish between key stigma sources most likely to impact this target population. Methods: This study was a cross-sectional evaluation of the validity, reliability, and generalizability of the SU-SMS across two independent samples with diverse substance use and treatment histories. Results: Findings support the structural and construct validity of the SU-SMS, suggesting the scale was able to capture enacted, anticipated, and internalized stigma as distinct stigma experiences. It also further differentiated between two distinct stigma sources (family and healthcare providers). Analysis of these mechanisms and psychosocial metrics suggests that the scale is also associated with other health-related outcomes. Furthermore, the SU-SMS demonstrated high levels of internal reliability and generalizability across two independent samples of persons with diverse substance use disorders and treatment histories. Conclusion: The SU-SMS may serve as a valuable tool for better understanding the processes through which substance use stigma serves to undermine key health behaviors and outcomes among persons with substance use disorders.