Social connectedness and cognitive outcomes in rural middle- to older-age adults.

Social connectedness plays a vital role in cognitive health for rural adults, a population at heightened risk for Alzheimer's disease and related dementias (ADRD). We reviewed 39 primary studies examining associations between dimensions of social connectedness and cognitive function/cognitive impairment in rural adults (≥ 40 years). Most studies (56%) focused on a single dimension of social connectedness and most (82%) were cross-sectional. Sixty-seven percent examined social isolation, 44% examined social support, 23% examined social engagement, and 18% examined loneliness. Social connectedness was frequently associated with cognitive outcomes (≥ 90% of studies), with isolation and loneliness appearing detrimental and engagement and support appearing protective. Most were conducted in Asia (62%), with the remainder in North America (18%), Africa (18%), and Europe (5%). This review highlights four interrelated but distinct domains of social connectedness and underscores the need for longitudinal, multidimensional, and context-specific research to inform strategies promoting cognitive resilience in rural populations.