Objective and Subjective Cognitive Problems among Caregivers and Matched Non-caregivers.

Purpose of the study: Caregivers (CGs) have been shown to do more poorly than non-caregivers (NCGs) on objective cognitive tests (Trails B and Digit Symbol Test, DST), but less is known about whether these groups differ in: (a) reports of subjective cognitive problems (SCPs, memory complaints, etc.) and (b) relationships of SCPs with objective cognitive tests, depression, and stress exposure. Such relationships are important because researchers/clinicians use SCPs as proxies for objective cognitive tests.

Design and methods: One hundred and twenty-two spouse CGs of persons with Alzheimer's disease and 117 demographically matched NCG spouses were compared on Trails B and DST at baseline (T1), 1 year later (T2), and 2 years later (T3) and on SCPs at T1.

Results: Trails B was slower in CGs than NCGs and DST declined in CGs relative to NCGs. CGs reported more SCPs than NCGs. Depression mediated group differences in Trails and DST and was also associated with SCPs. Trails B and DST explained variance in SCPs in NCGs, but not in CGs. Hours of care explained variance in SCPs in CGs, but not in NCGs.

Implications: When using SCPs to make inferences about CG cognitive function, researchers/clinicians should consider the possible influence of stress exposures and depression. The lack of associations of objective and subjective cognitive measures may be a reflection of poorer self-monitoring among CGs, a potential new area of CG research.