Care Recipients' Cognitive Trajectories and Caregivers' Depressive Symptoms: The Mediating Role of Caregiving Burden

The heterogeneity of population-based trajectories of care recipients' (CRs) cognitive functioning and how they are associated with their caregivers' mental health is less studied in the United States. Informed by the stress process model, this study examines the relationship between care recipients' cognitive trajectories and caregivers' depressive symptoms, and the mediating role of caregiving burden.

Data were from the National Health and Aging Trends Study (2011-2020) for 1,086 care recipients and their 1,675 caregivers from the 2021 National Study of Caregiving. We applied Bayesian group-based trajectory modeling to identify distinct cognitive trajectory groups among care recipients. Hierarchical linear models were then used to examine the associations between these trajectory group memberships and caregivers' depressive symptoms. Finally, Gelbach decomposition analysis was conducted to investigate the mediating role of physical, emotional, and financial caregiving burden.

Five cognitive trajectories were identified among care recipients: "high start, stable" (11.81%), "medium-high start, slight decline" (31.83%), "medium start, slight decline" (27.72%), "medium-low start, sharp decline" (20.60%), and "low start, sharp decline" (8.04%). Worse cognitive trajectories (e.g., lower baselines and steeper slopes) were associated with increasing caregivers' depressive symptoms; financial, emotional, and physical caregiving burdens jointly explained 63.5% of this association. Emotional caregiving difficulty is the most important contributing caregiving burden, explaining 49.6% of the observed association.

When understanding caregiving experiences, it is critical to consider longitudinal cognitive course among care recipients. Interventions targeting multiple aspects of caregiving burden, especially emotional burden, should be prioritized.