Suicide thought and behaviors, non-suicidal self-injury, and perceived life stress among sexual minority Mexican college students

•Sexual minority college students are at higher risk for suicide and self-harm.•Heterosexual students with same-gender attraction are also at a higher risk.•Perceived life stress partially mediated suicide and self-injurious behaviors.•Asexual students did not differ from heterosexuals with no same-sex attraction. Sexual minority college students are at a higher risk for suicidal thoughts and self-injurious behaviors compared to heterosexual students. Minority stress theory proposes sexual minority individuals experience higher stress due to stigma. Using a sample of Mexican college students, this study tested perceived life stress as a mediator of suicide and self-injury outcomes across various sexual orientation groups. The sample of college students (N=7882) was recruited from nine Mexican universities as part of the WHO World Mental Health International College Student (WMH-ICS) initiative. Participants completed an online survey including demographic questions, measure of perceived life stress, suicide outcomes, and non-suicidal self-injury (NSSI) in the past 12 months. Logistic regression analyses revealed identifying as a sexual minority significantly predicted a higher likelihood of suicide ideation (ORs 2.05-3.00), suicide attempts (ORs 2.48-8.73), and NSSI (ORs 2.92-4.18) compared to heterosexual students reporting no same-gender attraction. Significant indirect effects from mediation path analyses showed perceived life stress mediated the relationship between a sexual minority identity and suicide ideation (range of proportion mediated 10.48-31.48%), attempts (10.48-31.48%), and NSSI (7.69-20.09%) across each group except among asexual students. The cross-sectional nature of the survey design precludes drawing causal inferences. Findings from this study contribute to minority stress theory by elucidating the role of perceived life stress as a mediator of suicide ideation and attempts and NSSI among sexual minority college students. Clinical interventions may benefit in focusing on experiences of stress across various life areas when supporting sexual minority college students.