A neuropathological study of vascular factors in late-life depression

Objectives-Depression is a common psychiatric disorder in late life and it may be associated with vascular disease processes. Although there are clini cal and neuroimaging studies lending support to such a "vascular depression " hypothesis there have been no neuropathological studies to directly test this. Postmortem tissue was investigated to determine whether late life dep ression was associated with atheromatous change in large and medium vessels and microvascular disease in the brain. Methods-Postmortem tissue wae obtained from 20 patients with a history of a t least one episode of DSM-IV major depression and 20 control subjects. Sta ndard procedures were carried out to analyze and quantify Alzheimer type pa thology (plaques, tangles, Braak staging) and cortical Lewy bodies. Coronar y arteries, cerebral vessels, and aorta were rated for atheromatous disease on a 0-3 scale and the four neocortical areas were rated for microvascular disease. Results-The two groups showed no significant differences in age, sex, or po stmortem delay. There was a significant increase in atheromatous disease in the depressed group (p=0.023). No differences were found for microvascular disease, either in the brain generally or locally in the frontal lobes. No subject had any significant Alzheimer type or Lewy body pathology. Conclusions-Neuropathological evidence was found for an excess of atheromat ous disease, related to the aortic and cerebral vessels, in late life depre ssion. However, there was no evidence of an increase in microvascular disea se. The findings broadly support the vascular depression hypothesis.