Project Summary/Abstract In response to NOT-MD-22-012: Gender minority adolescents (GMAs; adolescents whose gender identity is different than their sex assigned at birth) have higher risk for suicidal behavior when compared to non-GMAs. In preliminary data, 85% of GMAs ages 14–18 seriously considered suicide in their lifetime, and 50% of GMAs have engaged in suicidal behavior. Despite alarmingly high rates of suicidal behavior, very little is known about how psychosocial experiences predict risk for suicidal behavior among GMAs. In particular, longitudinal data examining GMA risk for suicidal behavior over time remain limited. The proposed study will be the first to identify how multiple psychosocial experiences predict changes in risk for suicidal behavior over a 12-month period in a large, diverse, nationwide sample of GMAs and a comparison group of non-GMAs. GMAs report higher levels of general stressors than non-GMAs, including peer victimization and low parental support. GMAs also have unique psychosocial experiences, including undergoing social and medical gender transition steps to increase congruence between gender identity and gender expression as well as experiencing minority stress and discrimination. These psychosocial experiences likely increase risk for suicidal behavior among GMAs, but current empirical knowledge is critically limited, including a dearth of longitudinal studies. We propose to examine how risk for suicidal behavior changes over time among GMAs, including how changes in general stressors and unique psychosocial experiences predict changes in established risk factors for suicidal behavior among a large, diverse sample of GMAs and non-GMAs. This study will be the first to integrate constructs from minority stress theory and the interpersonal theory of suicide to explicate pathways between psychosocial predictors and established risk factors for suicidal behavior over time among GMAs, elucidating novel intervention targets to reduce their risk for suicidal behavior. We will recruit 1,500 diverse adolescents ages 14–18 through social media advertisements, including 1,000 GMAs, and participants will complete a clinical interview and survey protocol at baseline and follow-ups at 3-, 6-, and 12-months. We aim to examine how risk for suicidal behavior changes over time among GMAs as compared to non-GMAs during adolescence, how general stressors predict risk for suicidal behavior among GMAs as compared to non-GMAs, and how unique psychosocial experiences predict risk for suicidal behavior among GMAs. Gender minority individuals are an NIH-designated health disparities population, and the proposed study will advance our understanding of the psychosocial predictors of risk for suicidal behavior among GMAs, a pressing health disparity between GMAs and non-GMAs. Our proposed longitudinal investigation is responsive to NIMHD scientific priorities, represents a pioneering effort to move the field of GMA health equity forward, an...