Black adults show cross-sectional associations between sleep quality and episodic memory retention: an investigation of underlying factors

Non-Hispanic Black adults have poorer sleep quality than non-Hispanic White adults (hereafter, Black, White), which may underlie disparities in cognition. Epidemiological evidence suggests episodic memory may be more sensitive to poor sleep quality in older Black adults as compared to older White adults. Related exacerbating factors of these differences, such as depression and discrimination, are understudied. Here, we aimed to determine mediators of associations between sleep quality and episodic memory retention in an adult lifespan sample (18–74 years) of Black and White adults. We measured sleep quality, depression, and discrimination using self-report questionnaires, and assessed memory retention using a context memory task. We assessed if sleep-memory associations were moderated by age and mediated by depressive symptoms. We also assessed if discrimination mediated the association sleep-memory associations, controlling for age and years of education. In Black and White adults, higher depressive symptoms were associated with poorer sleep quality. Black adults demonstrated reliable sleep-memory associations and associations among higher discrimination, higher depressive symptoms, poorer sleep, and poorer memory, but we found no significant mediation effects. Depression level might affect sleep quality regardless of race or age. Black adults may demonstrate poor memory retention because of associations among discrimination, depression, and sleep.