DENVER – Depressive symptoms were not associated with decreased hippocampal volume or reduced white matter intensity in a large, population-based study conducted in the elderly.
The study involved 1,161 cognitively normal participants in the population-based Mayo Clinic Study of Aging conducted in Olmsted County, Minn. Subjects averaged 79 years of age, and 49% were women. All underwent rigorous neurologic and cognitive evaluations as part of the study, and all had at least one brain MRI within 120 days of assessment for depression using the Beck Depression Inventory, Dr. Yingying Kumar said the meeting.
Considerable research effort has been devoted to correlating major depression with structural change in the hippocampus. The hippocampus is an attractive investigative focus because it has extensive connections with brain structures related to emotional behavior.
Prior brain MRI studies, however, yielded conflicting results. Most of the studies that have found a reduced hippocampal volume in association with depressive symptoms were relatively small – fewer than 100 subjects – and took place in clinical settings where participation was likely to be skewed toward a population with relatively severe depression, noted Dr. Kumar of the Mayo Clinic, Rochester, Minn.
The median Beck Depression Inventory (BDI) score in the Mayo Clinic study was 4, although individuals scored as high as 33. After adjusting for age, gender, and education, no correlation was found between BDI and total hippocampal volume, right or left hippocampal volume, or white matter intensity. There was, however, a nonsignificant trend for reduced whole brain volume with higher BDI scores (P = 0.06).
Dr. Kumar declared having no financial conflicts.