Influence of social network characteristics on cognition and functional status with aging

OBJECTIVE: To determine whether more frequent engagement in larger social networks, and more emotional support protect against cognitive and functional decline with aging. METHODS: We examined the influence of social networks on cognition and instrumental activities of daily living (IADLs) over a median interval of 10.9 years. Data were from the Baltimore follow-up of the Epidemiologic Catchment Area (ECA) study, a community-based sample of adults in eastern Baltimore. Eight hundred and seventy-four participants completed cognitive testing at both the third and fourth study waves (1993-1996 and 2003-2004) on the Mini-Mental State Examination (MMSE) and a delayed word recall task. Functional status at both waves was self-reported on the Lawton-Brody IADL scale. Social network characteristics, assessed at the third study wave, included network size, frequency of contact, and emotional support. RESULTS: In cross-sectional analyses at wave 3, larger networks were associated with higher MMSE and better delayed recall scores. This association persisted after adjustment for covariates. More emotional support was associated with better functional status, before and after adjustment. By contrast, social networks were not longitudinally associated with cognitive change, with two counter-intuitive exceptions: more frequent contact and more emotional support were associated with worse delayed recall and IADL scores after adjustment. CONCLUSIONS: There was no evidence of a longitudinal association between social networks and cognition or IADLs, although a clear cross-sectional association exists. Together, these findings suggest the emergence of social isolation in individuals declining in cognition and functioning, rather than a protective effect of social networks.