Purpose of the study: Caregiving for a person with dementia is frequently used to model the impact of chronic stress on health, including cognitive functioning. However, the prevalence of typically healthier, self-selecting non-caregiving control groups could contribute to a picture of poorer caregiver performance and overstate the negative effects of stress. We investigated differences in cognitive performance between dementia caregivers and two groups of non-caregivers recruited using different sampling methods.
Design and methods: We compared cognitive function and psychological wellbeing among 252 spousal dementia caregivers with demographically matched non-caregiving control groups drawn from (1) a population study and (2) a self-selecting sample. Comparable cognitive measures included immediate and delayed recall, processing speed reaction time and verbal fluency.
Results: Caregiver and non-caregiver performance was comparable on most cognitive domains. However, caregivers outperformed both control groups on processing speed (p ≤ .05) and reaction time (p ≤ .05), despite having higher levels of stress and depression (ps < .001). Furthermore, caregivers had significantly better free recall than self-selecting controls (p < .001).
Implications: Our results, overall, do not support the idea that caregiving is associated with stress-induced cognitive deficits. Rather, the trend toward better caregiver performance is consistent with the healthy caregiver hypothesis.
Keywords: Alzheimer's; Cognition; caregiving; matching; sampling; stress.