Hippocampal volume in geriatric depression

Background: There is a growing literature on the importance of hippocampal volume in geriatric depression. Methods: We examined hippocampal volume in a group of elderly depressed pat ients and a group of elderly control subjects (N = 66 geriatric depressed p atients and 18 elderly nondepressed control subjects) recruited through Duk e's Mental Health Clinical Research Center for the Study of Depression in t he Elderly. The subjects received a standardized evaluation, including a ma gnetic resonance imaging scan of the brain. patients had unipolar major dep ression and were free of comorbid major psychiatric illness and neurologic illness, Differences populations of were assessed using t tests and linear regression modeling. Results: Accounting for the effects of age, gender, and total brain volume, depressed patients tended to have smaller right hippocampal volume (p = .0 14) and left hippocampal volume (p = .073). Among depressed patients, age o f onset was negatively but not significantly related to right hippocampal v olume (p = .052) and to left hippocampal volume (p = .062). We noted that a mong subjects with either right or left hippocampal volume of 3 mt or less, the vast majority were patients rather than control subjects. Conclusions: These results support a role for hippocampal dysfunction in de pression, particularly in late-age onset depression. Longitudinal studies e xamining both depressive and cognitive outcomes are needed to clarify the r elationships between the hippocampus, depression, and dementia, (C) 2000 So ciety of Biological Psychiatry.