Social Connectivity is Related to Mild Cognitive Impairment and Dementia

Background: Evidence supports a relationship between loneliness, social isolation, and dementia, but less is known about whether social connections confer protection against cognitive decline in disadvantaged neighborhoods. Objective: This longitudinal population-based study examines the relationship between social connectivity and cognitive impairment in a multi-ethnic cohort with low socioeconomic status and high vascular disease risk. Methods: Northern Manhattan Study participants self-reported frequency of social visits, phone calls, satisfaction with social visits, number of friends, and loneliness at baseline, and were followed prospectively with a series of neuropsychological assessments. Social connectivity was examined in relation to incident mild cognitive impairment (MCI)/dementia using logistic regression adjusting for demographics and vascular risk factors. Results: Among 952 participants (mean age at first neuropsychological assessment = 69±8 years, 62%women, 17%Black, 13%white, 68%Hispanic), 24%developed MCI/dementia. Participants who had phone contact with friends/family 2 + times/week (91%) had a lower odds of MCI/dementia (OR = 0.52, 95%CI = 0.31–0.89), with no association for frequency of in-person visits. Compared to those who were neither socially isolated (≥3 friends) nor lonely (reference, 73%), those who were socially isolated and lonely (3%) had an increased odds of MCI/dementia (OR = 2.89, 95%CI = 1.19–7.02), but differences were not observed for those who were socially isolated but not lonely (10%, OR = 1.05, 95%CI = 0.60–1.84), nor those who were lonely but not isolated (11%, OR = 1.58, 95%CI = 0.97–2.59). Conclusion: This study raises the possibility that social connections confer some protection for cognitive health in the face of adversity and supports potential opportunities for community social interventions for improving cognition in disadvantaged populations.