Longitudinal Associations Between Friendship and Cognitive Function Among Older Chinese Adults: Will Gender Make a Difference?

This study aims to understand the influence of friendship ties on the cognitive function in older Chinese population aged 60+ and the moderating role of gender. Three waves of the Chinese Longitudinal Aging Social Survey (CLASS) (2014, 2016, and 2018) data were adopted (<i>n</i> = 2145). A latent class growth modelling (LCGM) was conducted to examine friendship trajectories from 2014 to 2018. Four friendship trajectories were identified: (1) stable and strong, (2) steady decline, (3) recovery after decline, and (4) decline after growth. After controlling the cognitive function at baseline, compared to the "stable and strong" group, the "steady decline" group reported significantly lower cognitive function in 2018 (B = -0.79, β = -0.27, 95% CI [-0.42, -0.11]). Recovering friendship ties after decline is associated with a higher increase in cognitive function among males than females. This study highlights the protective effects of friendship on later-life cognitive function.