Background: to examine associations between social resources and cognitive ageing over 30 years.
Methods: participants in the Glostrup 1914 Cohort, a year of birth sample, completed a standardarised battery of cognitive ability tests every 10 years from age 50 to 80, summarised as general cognitive ability. Participants also provided information concerning a range of social resources, including marital status and living arrangements from age 50, and from age 70, details regarding social support, social contact and loneliness.
Results: across the follow-up, participants were less likely to be married, falling from 85.0 to 40.4% between ages 50 and 80, while the proportion of those living alone increased from 13.1 to 54.2%. In separate growth curve models, being married, living with others and not feeling lonely were all associated with higher cognitive ability level, while more telephone contact had a negative association. Marital status (at ages 50 and 60) and loneliness at age 70 were the only social resources associated with cognitive change; married individuals and those not feeling lonely experienced less cognitive decline. When the social resources showing significant associations were considered together (and accounting for sex, education and social class), loneliness was associated with lower cognitive ability level and greater cognitive decline, while married individuals experienced less decline.
Conclusions: in a relatively large cohort followed for up to 30 years, marital status and loneliness were associated with cognitive ability or change. Interventions designed to reduce loneliness in older adults might be supported as one avenue to reduce cognitive ageing.