The effect of psychological interventions for reducing internalised stigma in sexual and gender minorities: a systematic review and meta-analysis

Internalised stigma towards sexual and gender minorities (SGM) contributes to significant health disparities, prompting psychological interventions to address it. This systematic review and meta-analysis synthesised evidence from 18 randomised controlled trials (11 in quantitative synthesis) on their impacts on internalised stigma. Searches were conducted across five major databases. Study quality was assessed via Cochrane RoB-2. Most studies (n=15) were US-based, targeting diverse SGM groups, with samples of 20-641 participants (mean ages: early adulthood to mid-fifties). Narrative synthesis showed mixed results: some reductions in internalised stigma, especially among transgender/bisexual participants, while others showed null results. Pooled analyses indicated no significant effects at post-intervention (g = 0.018, 95% CI: −0.161 to 0.197, p = 0.84) or follow-up (g = 0.101, 95% CI: −0.108 to 0.309, p = 0.34), with substantial heterogeneity (I2 = 76%). Subgroup findings suggested a trend favouring onsite delivery (g = 0.26, 95% CI: −0.04, 0.56, p = 0.09) and cognitive-behavioural therapy-based approaches (g = 0.22, 95% CI: −0.01 to 0.46, p = 0.06). However, some interventions showed less improvement in internalised stigma than comparison conditions (g = -0.18, 95% CI: −0.31 to −0.05, p = 0.006). These findings should be interpreted cautiously due to few studies, underpowered subgroups, and heterogeneity. Overall, current evidence provides tentative support for psychological interventions and highlights the need for larger, theory-driven, and adequately powered trials.