UC Davis

Current theoretical frameworks propose that distinct types of adversity also have distinct effects on brain development in children and adolescents (Mclaughlin & Sheridan, 2016; Mclaughlin, Sheridan, & Lambert, 2014). Yet, few studies have examined the effects of distinct types of adversity on brain function and depression from adolescence into young adulthood. The present dissertation begins to address this gap in prior research by examining two different forms of adversity commonly experienced by Latino youth—discrimination and poverty. Specifically, in a sample of Mexican-American youth, I examined how earlier adolescent experiences of discrimination and poverty longitudinally predict brain activity in late adolescence. I also examined whether brain activity in late adolescence could predict the development of depression symptoms in young adulthood. And critically, I examined how cultural factors (ethnic identity and familism) protect against the aforementioned adversities, brain function, and development of depression. In study one, I hypothesized that brain activity to exclusion would mediate effects of discrimination on depression and that cultural factors would moderate associations between discrimination, brain activity to exclusion, and depression. In study two, I hypothesized that brain activity to rewards would mediate effects of poverty on depression and that cultural factors would moderate associations between poverty, brain activity to rewards, and depression. Hypothesized pathways among experiences of adversity (discrimination and poverty), neural activity to exclusion and rewards, and depression were not significant. For both studies 1 and 2, higher levels of ethnic identity and higher levels of familism at age 19 were associated with less young adult depression. Findings suggest that cultural factors could serve as protective mechanisms for Mexican-American youth facing risk for depression.