Interventions to reduce self-stigma in people who use drugs: A systematic review

Substance use stigma is a key barrier to treatment and harm reduction engagement among people who use drugs (PWUD). Previous systematic reviews have focused on interventions to reduce stigma in healthcare providers and the public; less is known about interventions to address self-stigma among PWUD. The purpose of this review is to evaluate the evidence for substance use self-stigma reduction interventions. We reviewed English-language studies published between 2011 and 2023 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO #CRD42022321305). We searched seven bibliographic databases (PubMed; SCOPUS; APA PsycInfo; CINAHL; Social Work Abstracts; Sociological Abstracts; ProQuest Dissertations & Theses). This review included studies if 1) they evaluated the effectiveness of a psychosocial intervention, 2) participants were PWUD, 3) authors reported self-stigma as a primary outcome, 4) the study design was experimental or quasi-experimental. We reviewed, interpreted and reported intervention characteristics and effectiveness using narrative synthesis. We assessed study quality with the Downs & Black checklist. Among 1195 screened studies, 15 met the inclusion criteria (N = 2280 PWUD). We categorized the interventions according to three approaches: psychotherapeutic (n = 8), psychoeducational (n = 5), and multimodal (n = 2). Most interventions were delivered in clinical settings (n = 11) and in a group format (n = 13). Study quality was fair-to-good and included nine randomized controlled trials (RCTs) and six quasi-experiments. Measurement heterogeneity was high, with 11 different stigma-related scales used across the 15 studies. Eleven studies showed significant favorable effects in at least one stigma measure. Six of these demonstrated positive effects in all stigma measures. Evidence was mixed for all three intervention categories; however, Acceptance and Commitment Therapy, a form of group psychotherapy, demonstrated effectiveness in four of five RCTs incorporating this approach. Overall, there is promising evidence for the effectiveness of substance use self-stigma interventions, although more studies are needed to determine which approaches are most effective. Consistent conceptualization and measurement of self-stigma across studies will improve comparability in future intervention trials. Current offerings are largely limited to clinical settings and group-based formats; self-help interventions, av