Mediators of increased self-harm and suicidal ideation in sexual minority youth: a longitudinal study.

BACKGROUND: Sexual minority youth have elevated suicidal ideation and self-harm compared with heterosexual young people; however, evidence for mediating mechanisms is predominantly cross-sectional. Using a longitudinal design, we investigated self-esteem and depressive symptoms as mediators of increased rates of suicidal ideation or self-harm (SISH) among sexual minority youth, and the roles of childhood gender nonconformity (CGN) and sex as moderators of these relationships.

METHOD: In total, 4274 youth from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort reported sexual orientation at age 15 years, and past-year SISH at age 20 years. Self-esteem and depressive symptoms were assessed at ages 17 and 18 years, respectively. CGN was measured at 30-57 months. Covariates included sociodemographic variables and earlier measures of mediator and outcome variables. Mediation pathways were assessed using structural equation modelling.

RESULTS: Sexual minority youth (almost 12% of the sample) were three times more likely than heterosexual youth to report past-year SISH (95% confidence interval 2.43-3.64) at 20 years. Two mediation pathways were identified: a single mediator pathway involving self-esteem and a multiple-mediated pathway involving self-esteem and depressive symptoms. Although CGN was associated with past-year SISH, it did not moderate any mediation pathways and there was no evidence for moderation by sex.

CONCLUSIONS: Lower self-esteem and increased depressive symptoms partly explain the increased risk for later suicidal ideation and self-harm in sexual minority youth. Preventive strategies could include self-esteem-enhancing or protecting interventions, especially in female sexual minority youth, and treatment of depression.