Social network size and cognitive decline in older adults experiencing depressive symptoms and loneliness

This paper evaluates the association between social network size and cognitive decline in older adults, approximately 61 years and older, with or without depressive symptoms and/or loneliness. This study is a secondary data analysis of the Chicago Health and Aging Project (CHAP), which is a population-based cohort study. Data collection occurred in three-year cycles from 1993 to 2012, consisting of a maximum of up to six cycles, including baseline. Mixed effects regression models were conducted to evaluate the relationship between social network size and cognitive decline. The study sample is comprised of 10,569 participants. Among participants experiencing baseline loneliness, having a social network size of nine or more individuals at baseline was associated with a slower annual rate of global cognitive decline (β = 0.016 (SE = 0.007), p = 0.019) than participants with a network size below nine at baseline. Participants experiencing moderate to severe depressive symptoms at baseline and a network size of nine or more at baseline also had a slower rate of global cognitive decline (β = 0.014 (SE = 0.006), p = 0.014) compared to participants with a network size below nine at baseline. Developing approaches for maintaining and improving social network size in individuals experiencing loneliness and depression may reduce Alzheimer's disease risk.