Altered Brain Volume in Older Adults With Recent and Chronic Depression

Recent or chronic depression in older adults is associated with measurable differences in brain structure, according to study results published in the Journal of Geriatric Psychiatry and Neurology.

Researchers analyzed structural magnetic resonance imaging (MRI) data from the National Alzheimer’s Coordinating Center uniform data set to evaluate how different patterns of depression relate to brain volumes across multiple regions.

The cross-sectional analysis included 1551 participants categorized into 4 groups: recent depression (n=173), depression more than 2 years prior (n=101), chronic depression (n=183), and no depression (n=1094). Women made up 58% of the total population, with a higher proportion in each depression subgroup (65% to 73%). The majority of participants were White (85%). The mean age varied significantly between groups, ranging from 67.72 years in the chronic depression group to 72.770 years among those without depression (P <.01). Overall, 41% of participants were carriers of the APOE ε4 allele, while cognitive status distribution showed that individuals with recent depression were more likely to present with mild cognitive impairment or dementia compared with other groups (P <.001).

After adjusting for covariates including age, sex, education, and intracranial volume, significant structural differences emerged. Individuals with recent depression had smaller total cerebrum cranial volumes and reduced left frontal lobe cortical gray matter volumes compared with those without depression (P =.03 for both). Chronic depression was associated with larger right lateral ventricle volume (P =.01). In contrast, individuals with a history of depression more than 2 years ago did not show significant structural changes after correction.

Moderation analyses indicated that APOE ε4 status did not significantly influence the associations between depression and brain structure, nor did depression status alter the relationships between cognitive impairment and volumetric measures.

Study limitations include reliance on a convenience sample from AD Research Centers, variability in MRI acquisition protocols, and a cross-sectional design, which limits causal inference.

“The accumulation of harmonized or comparable regional brain volume data is essential to inform the development of interventions to treat late-life depression, reduce the risk for, and ultimately, prevent AD and its devastating consequences,” the study authors concluded.

Disclosures: This research was supported by the Florida Department of Health, Ed and Ethel Moore Alzheimer’s Disease Research Program, National Institutes of Health/ National Institute on Aging, National Institutes of Health/National Institute on Aging, & the National Science Foundation.