INTRODUCTION: Sexual and gender minority (SGM) individuals report a higher prevalence rate of nonsuicidal self-injury (NSSI) compared to their cisgender heterosexual peers. Minority stress theory posits that the unique stressors experienced by those with a minoritized sexual orientation and/or gender identity increase the risk of negative health outcomes. As such, SGM stress may be a significant risk factor for NSSI and may help explain the disparate prevalence rates in the community. METHOD: Thus, a meta-analysis was conducted to assess the relationship between SGM stress and NSSI (k = 42
N = 253,686). RESULTS: Broadly, SGM stress was significantly positively related to NSSI engagement (r = 0.15). While this effect size is small in absolute size, it is comparable to other evidence-based risk factors for NSSI, such as impulsivity. Contrary to our hypothesis, the number of items used to assess NSSI engagement did not significantly moderate the relationship (b = -0.001). Exploratory analyses found no significant difference between proximal and distal SGM stressors (b = 0.07), sexual minority stress and gender minority stress (b = 0.03), nor assessment of lifetime compared to past year NSSI engagement (b = 0.08). CONCLUSION: Overall, the results of this meta-analysis support that SGM stress is a significant risk factor for NSSI and should be integrated into interventions for NSSI.