Sexual orientation and adolescent suicide attempt and self-harm: a co-twin control study

Background: Research has demonstrated that individuals who identify as a sexual minority (e.g., gay/lesbian, bisexual) are at increased risk for suicidality-related outcomes. However, previous research is primarily limited by the lack of adjustment for unmeasured (i.e., genetic and environmental) confounding factors and previous psychopathology.

Methods: Using the Child and Adolescent Twin Study in Sweden, we employed a co-twin control design to examine the extent to which the association between sexual orientation and adolescent suicide attempt and self-harm (SA/SH) was independent of genetic and environmental factors shared by twins, as well as measured symptoms of childhood psychopathology.

Results: Adolescents who identified as a sexual minority (i.e., gay/lesbian, bisexual, or other sexual orientation) were at two-fold increased odds for SA/SH (OR, 2.01 [95% confidence interval, 1.63-2.49) compared to heterosexual adolescents. When adjusting for all genetic and shared environmental factors that make twins similar and for measured childhood psychopathology, the association remained positive but attenuated to OR, 1.55 (1.11-2.16).

Conclusions: Identifying as a sexual minority was associated with approximately 50% increased odds of SA/SH in adolescence after adjusting for unmeasured genetic and environmental factors shared by twins and for childhood psychopathology. The results support that environmental factors specifically associated with identifying as a sexual minority likely increase risk for SA/SH. Our findings highlight the need to monitor suicidality risk among this group.