The impact of caregiver's depressive symptoms on trajectories of cognitive function in older adults with functional limitations

Objectives Family caregivers are important to older adults' health, but few studies have examined how caregivers' mental health is associated with older adults' cognitive function. This study examined the trajectories of cognitive function of older adults and whether caregivers' depressive symptoms shape the pattern of cognitive function trajectories. Methods This 6-year longitudinal sample consisted 1188 older adults aged >= 75 years with deficits in activities of daily living (ADL) and their family caregivers in Shanghai, China (Rounds 1-3). Cognitive function trajectories were identified based on an enhanced group-based trajectory modeling that accounted for nonrandom attrition. Multinomial logistic regression tested the association between caregivers' depressive symptoms and older adults' cognitive function trajectory. Results Three trajectory groups were identified: a "newly onset" group (50.4%) had an increased risk of being cognitive impaired during the 6-year period; a "never" group (46.2%) remained cognitive active; and a "chronic" group was largely persistently cognitive impaired (3.4%). Caregivers' depressive symptoms increased the relative risk of having the "onset" or "chronic" versus "never" trajectory. Among the four dimensions of depressive symptoms, only somatic complaints were associated with a higher risk of the "newly onset" trajectory in 6 years. Conclusion The progression of cognitive function among older adults with deficits in ADL followed three distinct trajectories during a 6-year period. Addressing the mental health of caregivers may prevent or delay progression of cognitive impairment among older adults.