Apolipoprotein E epsilon4 allele affects the relationship between stress and depression in caregivers of patients with Alzheimer's disease.

We examined the effect of the apolipoprotein E (apo E) epsilon4 allele on the relationship between self-reported stress and mood in caregivers of patients with Alzheimer's disease. Eighty-six female subjects between the ages of 28 and 82 years who were community-dwelling AD patient caregivers participated in the study. A cross-sectional analysis of stress and mood was performed using the Revised Memory and Behavior Problem Checklist and the Geriatric Depression Scale. All subjects were evaluated for normal cognitive function (Mini-Mental Status Examination) and apo E genotype. The results indicated that increased levels of stress were associated with increased levels of depressive symptoms in nondemented caregivers with the epsilon4 allele. This relationship was not observed in caregivers without the epsilon4 allele. These results suggest that carriers of the epsilon4 allele may respond differently to psychological stress than do individuals without the epsilon4 allele.