The Mediating Effect of Functional Social Support in the Pathway between Memory and Depressive Symptoms: A Longitudinal Mediation Analysis of the Canadian Longitudinal Study on Aging

Abstract

Background: Cognitive function and emotional wellbeing are essential for healthy aging. Cognitive impairment and depressive symptoms can lead to severe morbidity and mortality in aging adults. Strong, positive associations exist between memory impairment – memory is a subdomain of cognition – and depressive symptoms. Evidence also suggests one’s perceived level of functional social support (FSS) may affect the emergence of depressive symptoms in aging adults with memory impairment. However, few studies have explored whether FSS mediates the association between memory and depressive symptoms. Methods: This research utilized an analytical sample drawn from 21,241 participants between the ages of 45 and 85 years who were enrolled in the Tracking Cohort of the Canadian Longitudinal Study on Aging (CLSA) at baseline. The thesis examined three aims: the association between memory and depressive symptoms across three time points of data (baseline, three-year follow-up, and six-year follow-up), controlling for health, lifestyle, and sociodemographic covariates; the potential mediation effect of FSS on this association; and whether moderated mediation was present by age group and sex. Results: Overall, memory function was inversely associated with depressive symptoms (β ̂ = -0.08; 95% confidence interval [CI]: -0.11, -0.04). The indirect (mediated) effect of memory on depressive symptoms through FSS was statistically significant, though minimal (β ̂ = -0.02; 95% CI: -0.02, -0.01), and most of the effect was direct (β ̂ = -0.07; 95% CI: -0.10, -0.04). No evidence existed for statistically significant moderated mediation by age group or sex. Contribution: This novel research suggested that functional social support may mediate the association between memory and depressive symptoms. Further research is required to advise health practitioners who deal with memory-impaired individuals as to whether interventions promoting functional social support (e.g., social prescribing) can help minimize symptoms of depression.