Separating the Effects of Transitions Into and Out of Social Isolation and Loneliness on Cognitive Function in Later Life

Objectives This study investigates the effects of social isolation and loneliness on cognitive function, distinguishing between the effects of transitioning into and out of these states. Methods This study analyzed data from 6,663 adults aged 65 or older collected over the course of 7 waves (12 years) of the Korean Longitudinal Study of Aging from 2006 to 2018. A novel asymmetric fixed effects model was utilized to separately estimate the effects of transitions into and out of social isolation or loneliness. Results The association of transitions into social isolation due to a lack of informal social contact or loneliness with cognitive function (b = -1.387, p < .001 and b = -0.601, p < .001, respectively) was stronger than the association of transitions out of these states (b = 0.345, p < .05 and b = 0.353, p < .001, respectively). The magnitude of the negative and positive coefficients was statistically different (F-statistic = 45.29, p < .001 and F-statistic = 5.12, p < .05, respectively). In contrast, no such asymmetric effects were observed for social isolation due to a lack of formal activity (F-statistic = 0.06, p = .800). Discussion The detrimental effects of transitioning into social isolation due to a lack of informal social contact (but not formal activity) or loneliness on cognitive function outweigh the beneficial effects of transitioning out of these states. Preventing the onset of social disconnection should be prioritized as an intervention to improve the cognitive function of older adults.