Longitudinal impact of transition to caregiving on cognitive functioning: a matched case-control study

Chronic stress has a strong theoretical link to poorer cognitive aging outcomes. Stress from caregiving, especially dementia caregiving, is associated with worse cognition; however, most prior studies have serious methodological limitations. We examined the longitudinal impact of caregiving transitions (including dementia caregiving) on cognition, compared to carefully matched non-caregiver controls, and the possible mediating role of depressive symptoms and perceived stress.

Participants in the Caregiving Transition Study who transitioned into caregiving (n = 251) were compared to sociodemographically and health-matched non-caregiving controls (n = 251). Data included 14 years of repeated assessments, including timepoints before and after transitions on global cognition (six-item screener), episodic memory (word-list learning, delayed word recall), and verbal fluency (letter and animal fluency).

Compared to non-caregiving, negative associations between caregiving transitions, episodic memory, and global cognition were significant during transitions, but these associations were small (Cohen's d approximately 0.2 SD units). Compared to non-caregivers, transitioned caregivers showed less decline in word list learning and global cognition during post-transitions. In adjusted subgroup analyses, dementia caregivers performed worse after transitions than non-dementia caregivers in delayed word recall but better on animal fluency. Increases in depressive symptoms mediated caregiving transitions and episodic memory but not global cognition. Perceived stress did not have a mediating role.

Significant associations were found between caregiving transitions and cognition, but effects were domain-specific for memory and global cognition, and short-lived. Dementia caregiving also had differential effects on cognition. Future studies should examine whether these small, temporary declines in caregiver cognition improve with caregiver interventions.