Suicide among Black youth has increased rapidly over the last two decades, reaching unprecedented levels. While there have been substantive gains in knowledge related to the etiology of suicide ideation and behaviors (SIB), most of this work has included predominantly White samples or have been cross-sectional or short-term longitudinal studies. Less is known about the course of SIB during the adolescent and emerging adult years, and malleable individual-specific and social ecological precursors and correlates associated with this course, among low-income, urban Black youth. Such work is vital to informing developmentally-sensitive preventions and interventions aimed at mitigating this major public health problem. The proposed R01 application aims to address the aforementioned limitations by leveraging data collected among Black youth (N = 630) drawn from Baltimore City over a 20-year period spanning the critical developmental windows of adolescence and emerging adulthood, during which SIB often emerges. Data on mental health, academic and social competence, and life events have been collected annually during early childhood (i.e., ages 6-8), adolescence (i.e., 12-18) and emerging adulthood (i.e., 19-26). In addition, SIB, substance use and social ecological constructs (i.e., life events, racial discrimination, neighborhood characteristics, and social support) have been measured during adolescence and emerging adulthood. Specific aims of the study include: (Aim 1) to identify trajectories of SIB across adolescence and young adulthood, and whether SIB trajectories during adolescence are associated with SIB trajectories in emerging adulthood; and (Aim 2) to determine risk and protective individual-specific and environmental factors during the early childhood, adolescent, and emerging adult years that are associated with SIB trajectories during adolescence and emerging adulthood. We also plan to explore whether the identified risk and protective longitudinal factors in Aim 2 influence the transition or changes in SIB trajectory membership from adolescence to emerging adulthood. Determining salient factors associated with SIB continuity during adolescence and emerging adulthood may inform the identification of pathways that could be promoted or interrupted, which may have long-term implications for SIB across the life course. The investigative team brings together expertise in the etiology and prevention of SIB among Black youth, prevention science, mental health and substance use of adolescent and adult populations, and longitudinal latent variable modeling; thus, we are extremely well- positioned to accomplish the study aims. This study directly responds to recommendations offered in the Congressional Black Caucus’ Ring the Alarm report as it seeks to: 1) identify subgroups of Black youth at increased risk for SIB across the lifespan; 2) determine risk and protective factors that are amenable to early intervention; and 3) examine non-psychiatric fa...