Association of Loneliness with Cognitive Functions.

Introduction: Observational studies suggest psychosocial factors such as social support and loneliness are associated with vulnerability for cognitive decline in older adults. However, because of racial/ethnic homogeneity in prior studies focused on identifying these associations in predominantly White cohorts, less is known about the generalizability of these putative psychosocial mechanisms in a diverse population. Thus, we evaluated whether lower levels of loneliness were associated with better cognitive performance in our sample.

Methods: We conducted a cross-sectional study using 541 participants from (Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa) Dementia Cohort. Participants' self-reported loneliness as exposure. Cognitive performance is measured using a neuropsychological battery as the outcome. Raw scores were converted into Z scores, and global cognitive function was created. Generalized estimated equation and robust regression analysis).

Results: Better global cognitive function is associated with a lower level of loneliness at (β = -0.0131, 95 % CI -0.1990, -0.0071) after adjustment for age, gender, and education. Lower levels of loneliness were associated with varying cognitive domains after adjustment for age, gender, and education; and persisted after additional adjustments of vascular risk factors.

Conclusions: Self-reported lower loneliness was associated with higher levels of cognitive performance in a rural South African cohort of Black older adults. Although these findings and the potential of reverse causality need to be further validated, our results suggest that an intervention study may be merited to assess whether reducing loneliness lessens vulnerability to cognitive decline.