Although it is generally believed that depression, retained insight, and preserved personality occur more frequently in vascular dementia than in Alzheimer's disease, there is little empiric evidence for this presumption. Most studies on this subject have been carried out with severely demented inpatients, and confounding factors such as age, sex, and severity of dementia have not been sufficiently taken into account. We compared 48 patients with relatively mild vascular dementia with 48 patients with Alzheimer's disease, matched for age, sex, and stage of dementia, to investigate if depression, lack of insight, and personality changes were related to the cause of dementia. The two groups did not differ regarding the incidence of major depression, the mean depression score, the awareness score, or the sum of scores on the items of the Blessed Dementia Scale concerning personality changes. We conclude that depression, lack of insight, and personality changes do not favor an etiology of vascular dementia over that of Alzheimer's disease. The present findings underscore the notion that the severity of the dementia should be considered in studies on the differences between vascular dementia and Alzheimer's disease.