Social Isolation, Loneliness, and Cognitive Decline Among Black Americans: The Moderating Role of Neighborhood Context.

BACKGROUND: Our study examined how social disconnection, neighborhood contexts, and cognitive function trajectories are jointly and interactively associated among middle-aged and older Black adults. METHODS: Data came from non-Hispanic Black participants aged 51 and older (n = 1,791) from the Health and Retirement Study. Cognitive health was measured by a global cognitive function summary score. Social disconnectedness was measured by three types of social isolation (from extended family, adult children, and friends) and loneliness (UCLA 3-item Loneliness Scale). Neighborhood contextual factors included neighborhood social cohesion and physical disadvantage. Covariables included age, sex, education, marital status, and living arrangements. We used group-based trajectory modeling to test the study objectives. RESULTS: We identified four global cognitive function trajectories: low and declining (14% of sample), moderate and declining (29%), moderate and stable (40%), and high and stable (17%). Multivariable models indicated that neighborhood physical disadvantage (RRR=.61, 95%CI[0.40, 0.92]) and social cohesion (RRR=.42, 95%CI[0.23, .77]) moderated the association between social isolation from extended family and global cognitive function trajectory membership. CONCLUSIONS: Our study is among the first to examine cognitive function trajectories with linkages to social disconnectedness and neighborhood contexts among middle-aged and older Black adults. Overall, the results suggest that neighborhood contexts condition how social isolation relates to cognitive trajectories. These findings underscore the importance of considering both social disconnectedness and neighborhood context in explaining heterogeneity in cognitive aging among middle-aged and older Black adults.