Does sleep partially mediate the effect of everyday discrimination on future mental and physical health

Abstract Objective The current study examined whether sleep mediates the effect of discrimination experiences on mental and physical health over time. Prior research suggests a partially mediated relation; however, these studies used cross-sectional designs which provide insufficient causal evidence. Method The study used longitudinal data available from the Midlife in the United States Study (MIDUS II, Biomarker project, and MIDUS III) applying structural equation modeling to evaluate whether self-reported sleep ( N  = 866) mediated the impact of discrimination on mental and physical health outcomes. Results Self-reported sleep quality partially mediated the effect of discrimination on mental and physical health. Analyses also indicated self-reported daytime dysfunction (i.e., difficulties maintaining alertness and motivation during the day) as a key component of sleep that mediates the discrimination and mental and physical health relations. Interestingly, having multiple marginalized identities did not amplify the impact of discrimination on sleep and health. Conclusions These findings build upon previous cross-sectional research by better supporting the causal assertion that experiences of discrimination undermine sleep, which in turn worsens both mental and physical health. Altogether, results underscore the harmful impact of discrimination on health indirectly through sleep and offer insight into directions for future research.