Examining Hippocampal Volume in Older Adults With Depression

A study published in the Journal of Psychiatric Research probed volume differences in the hippocampus (HC) in a general population sample of French older adults, comparing currently depressed individuals, persons with a previous major depressive episode (MDE), and healthy controls, reports Science Trends . Subjects 65 years and older were randomly chosen from the 15 electoral rolls of the Montpellier district between March 1999 and February 2001, and they received clinical, biological, and neuroimaging assessment. Magnetic resonance imaging determined a left posterior HC volume reduction in currently depressed participants versus controls with a manual HC measurement technique. When individuals with a history of past, but not current, MDE were compared to controls, no HC volume reduction was observed. The main result remained consistent even with slight modification of sub-group inclusion criteria. Brain volume changes due to depression in older adults may be altered by confounding factors like depression severity, antidepressant use, or cardiovascular risk associated with the metabolic syndrome. Theoretically, previously depressed individuals may have recovered in terms of brain atrophy, with such recovery possibly involving a restoration of the original basal rate of neurogenesis.