PROJECT SUMMARY/ABSTRACT Disparities in alcohol and other substance (AOD) use and misuse are well documented between sexual minority adolescents (SMA) and their heterosexual peers. SMA of color also have higher rates of AOD use and misuse than heterosexual peers of the same race/ethnicity and to some extent their White SMA peers. Daily stigma and discrimination-related stressors specific to their marginalized identities (i.e., minority stressors, racism-based stressors) contribute to health disparities among SMA of color. These stressors occur at the interpersonal level (e.g., discrimination) and are reinforced at the structural level (e.g., anti-gay laws, or racist institutional policies). Minority stress at a single axis of identity is directly correlated with AOD use and misuse among sexual and racial/ethnic minority populations. Similarly, structural oppression (i.e., structural heterosexism or racism) during adolescence has long-lasting health effects, including AOD use and misuse. However, this work rarely takes an intersectional lens that considers both sexual orientation and race/ethnicity. Although mounting cross-sectional and recent but limited longitudinal evidence implicates minority stress as a key contributor to disparities in AOD use and misuse, the prospective, daily, and chronic impact of these stressors on SMA of color's AOD use and misuse across adolescence is largely unknown. There is also a lack of research examining the impact of structural oppression on SMA of color's AOD use, how it may play a key etiological role in accelerating the progression of AOD use and misuse over adolescence, and how it may impact the long-term and daily associations between intersectional minority stress and AOD use and misuse in SMA of color's daily lives. In addition, little is known about protective factors between minority stress and AOD use and misuse, which is needed to inform prevention and treatment interventions. Relying on our investigator's team methodological, theoretical, analytic, and clinical expertise and pilot work, we propose a rigorous and innovative study of intersectional stress and structural oppression and how they relate to AOD use and misuse among SMA of color. Using a measurement-burst design, a combination of longitudinal and daily diary methods, our aims are to: 1) test the prospective associations between intersectional stress and structural oppression and AOD use and misuse among a national sample of SMA of color over 2.5 years (N=950) with 6-month time-points; 2) test the daily associations between within-person fluctuations of intersectional stress and AOD craving, use, misuse, and problems among the sample over 10-days at each 6- month time point; 3) test protective and risk factors that attenuate or exacerbate the associations between intersectional stress and AOD use and misuse over adolescence across the 2.5 years and in daily life. The results will allow for more precise understanding of minority stress, struc...