Caregivers' depressive symptom trajectories and risk of cognitive impairment among older adults with functional limitations: A prospective cohort study.

Abstract

Caregiver (CG)'s depression is common and its prevalence is rising. The relationship of CG depression with care recipients (CR)'s subsequent cognitive impairment remains unclear. This study examines the association of CG depressive symptoms trajectories with 6-year cognitive impairment risk among care recipients (CR) who are older adults with functional limitations. Retrospective analysis of prospectively collected data cohorts from 2010 to 2016. The sample included 810 community-dwelling older adults aged ≥75years, dementia free at baseline, with their primary caregiver dyads. CG's depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. The main outcomes were incident mild, moderate, and severe cognitive impairment of CRs measured using Short Portable Mental Status Questionnaire. Group-based trajectory modeling identified three CG depressive symptom trajectory groups. Competing risks regression analysis modeled the hazards as a function of CG depressive symptom trajectories. Of 810 CRs, 3% developed severe cognitive impairment, 21% had moderate cognitive impairment, and 37% had mild cognitive impairment. Only CG's "Increasing" trajectory group predicted increased risk of CR's mild and moderate cognitive impairment relative to "persistently low" group (subhazard ratio [SHR]=1.52, 95% confidence interval [CI], p<0.05; SHR=1.87, 95% CI, p<0.05, respectively). Finding highlight the intricate and non-linear association between CG depressive trajectory and CR cognitive impairment. This evidence can be used to enlighten policymakers and health providers about the need for risk stratification screening for CG mental health and early treatment for CG depression to prevent or delay CR's cognitive impairment.