Association of depression with Alzheimer's disease and vascular dementia in an elderly Arab population of Wadi-Ara, Israel

Objectives: Because dementia and depression share common risk factors, we investigated risk factors for depression in Arab subjects with Alzheimer's disease (AD) and vascular dementia (VaD). Methods: In a cross-sectional population-based study, we conducted a door-to-door survey of all adults over age 60 in an Arab community of rural Israel. We conducted interviews, gave questionnaires, and collected DNA blood specimens for determination of ApoE genotype. Results: Of the 823 individuals in this naturalistic sample, 168 had dementia of Alzheimer's type (DAT) and 49 had VaD. Vascular risk factors, including the ApoE-ε4 allele, were more prevalent among VaD than DAT subjects. Depressive symptoms were present in 57% of DAT patients and 86% of VaD patients. Depressed DAT individuals had a greater history of ischemic cardiovascular or cerebrovascular (CV/CBV) disease than non-depressed DAT subjects, but depressed DAT subjects were less likely to have the ApoE-ε4 allele. Within the VaD group, there was no difference in the distribution of cardiovascular risk factors in individuals with and without depressive symptoms, and ApoE-ε4 was more prevalent among subjects with depressive symptoms. Conclusions: Depressive symptomatology is prevalent among subjects with dementias in this Arab community. History of CV/CBV is associated with the presence of depressive symptoms in DAT. Further studies are needed to clarify the role of ApoE in depression onset in different ethnic groups with DAT.