PROJECT SUMMARY Discrimination contributes to mental and physical health disparities disproportionately disadvantaging minority populations. Yet, the impact of discrimination on behavioral health outcomes such as substance use (SU) is less clear, particularly in early life (e.g. late childhood and early adolescence). By middle adolescence, SU initiation is set in motion triggering subsequent developmental trajectories. Investigating the onset of SU, starting in late childhood, is critical for mitigating its downstream health consequences. There is even less science focused on multilevel factors that alleviate associations between discrimination and SU. This project addresses these gaps in developmental and health disparities science by investigating adolescents' experiences of multiple forms of discrimination (based on ethnicity/race, country of origin, sexual orientation, weight) and SU (self-report & hair sample metabolites) from late childhood to middle adolescence, and by investigating sleep (parent-report & actigraphy duration & quality) and neighborhood environment (deprivation, crime, noise, structural discrimination from geocodes) as moderators of the health impact of discrimination. Both sleep and neighborhood environment can be targeted by evidence-based programming as levers of change to reduce the impact of discrimination on SU. The project draws from the on-going, national, longitudinal study of Adolescent Brain Cognitive Development (ABCD), the largest national study of its kind that follows 11,875 children (9-10 years old) through adolescence. The project examines three research aims. First, the study investigates concurrent and longitudinal linkages between discrimination and SU, from late childhood to early adolescence, disentangling whether discrimination is a contributing or a resulting factor of SU initiation and continuation. Second, the study investigates the extent to which the linkages between discrimination and SU are conditioned by young people's sleep. Finally, the study investigates the moderating role of neighborhood environment in linking discrimination, sleep, and SU, from late childhood to middle adolescence. For all research aims, the proposed project also explores how the associations of discrimination, SU, sleep, and neighborhood environment change from late childhood to adolescence, by testing multiple development-related differences (i.e., by data collection wave, developmental stage, age, grade level). Findings will elucidate critical developmental periods when interventions are most effective in helping young people from marginalized populations (ethnicity/race, immigration status, sexual orientation, and body shape) navigate the negative health consequences of prejudice and exclusion. Essentially, this project will provide critical insights for youth SU programs including who is most at risk, what to target, and when to intervene.

PROJECT NARRATIVE This project examines how young people's experiences multiple forms of discrimination contribute to the initiation and persistence of substance use from late childhood to middle adolescence, exploring moderating mechanisms at biobehavioral (i.e., sleep) and environmental (i.e., neighborhood) levels. By investigating discrimination and substance use as early as late childhood, the project prospectively disentangles directionality and reciprocal associations between discrimination and substance use, identifies sensitive periods when discrimination is particularly harmful, explores sleep and neighborhood environment as modifiers for targeted interventions, and highlights critical developmental periods when interventions may be most effective in mitigating health disparities. The proposed project advances developmental and health disparities science by elucidating biobehavioral and environmental mechanisms linking social experiences of discrimination to health inequity.