Researchers found that older adults with depression had a smaller volume in a specific part of the hippocampus—a brain region essential for learning and memory—even though they had no signs of cognitive impairment. Published in Translational Psychiatry, the study analyzed high-resolution brain scans from 2,009 cognitively healthy adults aged 50 to 90 years. This suggests depression may affect brain structure through biological pathways that are at least partly separate from those linked to Alzheimer's disease. Instead, they highlight a vulnerable memory-related brain region and reinforce the importance of recognizing and treating depression as part of healthy brain aging. Depression and hippocampal subfield volume in older adults.