The bidirectional associations between cognition and depression in mid‐life and older adults in the CLSA

Abstract

AbstractBackgroundExisting evidence suggests that depression may be a risk factor for subsequent cognitive impairment and dementia. Concurrently, other evidence suggests that cognitive impairment may precede depression symptoms. We investigated the relationship between depression symptoms and memory performance over a three‐year time period in a sample of mid‐life (45 ‐ 64 years) and older adults (65 ‐ 85 years).MethodData were drawn from the Canadian Longitudinal Study on Aging (CLSA), a large longitudinal study of health and aging. Depression symptoms were assessed with the Centre for Epidemiological Studies Depression Scale (CESD‐10) and memory was captured using the Rey Auditory Verbal Learning Test (RAVLT). Two time points were analyzed: baseline (completed in 2015) and first follow‐up (completed in 2018). We used multigroup cross‐lagged structural equation modelling (SEM) to estimate the bidirectional relationships between depression and cognition over time, based on age group: participants aged 45‐64 years (n = 26,605) and 65 years and above (n = 17,986). Sex, education, ethnicity, sexual orientation, and general health were controlled for at baseline.ResultThe results confirmed a bidirectional association between depression symptoms and memory over time, a relationship that was moderated by age group (difference test: p = .02). Results showed that the association between depression at baseline and memory at follow‐up was stronger for the younger cohort (r = ‐.039, p<.001) compared to the older cohort (r = ‐.015, p = .026).ConclusionThe results confirm the bidirectional relationship between depression symptoms and memory. This work also highlights the role of age group as a moderator of this relationship, insofar as depression is a stronger correlate of memory for mid‐aged adults in comparison to older adults.