Regional distribution of amyloid deposition and grey matter atrophy in late‐life depression

• Published in: Alzheimer's & dementia Vol. 16
• Main Authors: Takamiya, Akihiro, Casteele, Thomas Vande, Koole, Michel, De Winter, François‐Laurent, Bouckaert, Filip, Van den Stock, Jan, Van Laere, Koen, Emsell, Louise, Vandenbulcke, Mathieu
• Format: Journal Article
• Language: English
• Published: 01.12.2020
• ISSN: 1552-5260; 1552-5279
• DOI: 10.1002/alz.041564

Background Depression is associated with a risk of developing dementia and is hypothesized to enhance (pathological) brain aging. Previously we reported that amyloid burden in late‐life depression (LLD) did not differ from healthy controls in cortical regions typically associated with Alzheimer’s disease (AD) [1]. Here we extend our analysis beyond hippocampal volume and AD‐specific volumes‐of‐interest, to the whole brain. Method Forty‐eight individuals with LLD (age 74.1±7.5 years, 33 female) and 52 healthy controls (72.4±6.4 years, 37 female) underwent static amyloid PET imaging with [18]F‐flutemetamol and 3D T1‐weighted structural MRI. Amyloid deposition was quantified using the standardized uptake value ratio (SUVR) relative to the cerebellar grey matter (GM). Whole‐brain voxel‐wise comparisons of amyloid PET SUVR and GM volume (GMV) between LLD and controls were performed using SPM12, with age as covariate. Total intracranial volume was included as an additional covariate in the GMV analysis. The significance threshold was set to a family‐wise error (FWE) corrected p <0.05 at cluster‐level with an individual voxel height threshold p = 0.001. Result There were no statistically significant group differences in amyloid deposition. In contrast, compared to controls, individuals with LLD showed widespread significant GMV reductions, predominantly in the left temporo‐parietal and the right occipital regions (Figure). Conclusion Late‐life depression is associated with lower GMV in regions also implicated in AD, but is not associated with increased amyloid burden. Future analysis investigating correlations with neuropsychological measures of mood and cognition, and accounting for the potential effects of regional atrophy and white matter pathology on amyloid quantification, may further extend our knowledge about differences in the underlying neurobiology of LLD and AD.