Social engagement moderates the relationship between cognitive functioning, depressive symptoms, and restless sleep in older black adults

INTRODUCTION: Older Black adults face higher dementia risk, but it is unclear whether social engagement offsets the effects of depression and restless sleep. METHODS: We analyzed 1,905 Black adults aged 50+ from the 2016-2020 Health and Retirement Study (HRS). Linear mixed-effects models tested how depressive symptoms, restless sleep, and social engagement predicted baseline cognition and cognitive decline. RESULTS: Higher depressive symptoms and restless sleep were associated with lower baseline cognition (about 0.2 and 0.5 points lower) and faster decline (β×time ≈ −0.07 and −0.05). Greater social engagement predicted higher baseline cognition (about 0.6 points higher) and slower decline (β×time ≈ 0.08). Social engagement also buffered the negative effects of depressive symptoms and restless sleep on cognitive decline but did not affect their baseline associations. DISCUSSION: Social engagement may help older Black adults preserve cognitive health despite depression or poor sleep through accessible community, religious, and volunteer activities. Highlights: Depressive symptoms and restless sleep independently predicted poorer baseline cognition and faster cognitive decline among older Black adults, underscoring their distinct and additive roles in late-life neurocognitive vulnerability. Higher social engagement, measured through volunteering, religious participation, and group involvement was associated with better cognitive functioning and slower decline across three Health and Retirement Study (HRS) waves, even after full adjustment for demographic, socioeconomic, and health covariates. Interaction effects showed that social engagement buffered the adverse cognitive effects of both depressive symptoms and restless sleep, indicating its role as a behavioral resilience factor in aging. Culturally embedded forms of engagement, particularly faith-based and community-centered participation, emerged as salient protective pathways that align with existing social practices within Black communities. Findings highlight the potential of community and faith-based interventions to mitigate disparities in cognitive aging and to promote culturally meaningful strategies for sustaining brain health in older Black adults.