PROJECT SUMMARY The overarching goal of this study is to determine how different trajectories of minority stress experienced throughout adolescence may predict behavioral health outcomes for SMA. Relying on methods established and tested in our preliminary work, we will recruit a national sample of diverse SMA (e.g., race and ethnicity, gender, urban vs. rural; N = 1,500) through both social media and respondent-driven sampling strategies in the first year of the project. We will follow participants for three years, incorporating the fundamental tenets of developmental psychopathology, which suggest that examining risk and protective factors for adolescents necessitates longitudinal exploration across critical stages of development. Guiding the proposal are three specific aims: Aim 1: Describe the individual and group trajectories of minority stress over time by following a national sample of SMA (N = 1,500) for 3 years. WH1: There will be differences in minority stress across adolescent development. Aim 2: Determine whether trajectories of minority stress are associated with differences in behavioral health outcomes over time. WH2.1: Trajectories of minority stress and behavioral health outcomes will be associated over time. WH2.2: Reporting higher levels of minority stress in early adolescence will be associated with poorer behavioral health outcomes in later adolescence. Aim 3: Determine whether the association between minority stress and behavioral health over time is different based on sociodemographic characteristics (e.g., urbanicity, gender, race and ethnicity). WH3: There will be significant differences in outcome trajectories by demographic subgroup. WH4: Trajectories of minority stress will be inversely associated with protective factors over time and will differ by demographic subgroup. To test our hypotheses, we propose cutting-edge longitudinal quantitative methodology including latent growth-curve modeling, which are rarely used to examine longitudinal risk among SMAs. The proposed research will be the first to determine how minority stress may influence health across adolescence, and this information can be used directly to inform clinical assessment and the development of targeted behavioral health interventions for this high-need population.