Citation

Marawi T, Zhukovsky P, Rashidi-Ranjbar N, Bowie CR, Brooks H, Fischer CE, Flint AJ, Herrmann N, Mah L, Pollock BG, Rajji TK, Tartaglia MC, Voineskos AN, Mulsant BH. Biol. Psychiatry 2023; ePub(ePub): ePub.

Copyright

(Copyright © 2023, Elsevier Publishing)

DOI

10.1016/j.biopsych.2023.05.018

PMID

37271418

Abstract

BACKGROUND: Almost one-half of older patients with major depressive disorder (MDD) present with cognitive impairment, and one-third meet diagnostic criteria for mild cognitive impairment (MCI). However, mechanisms linking MDD and MCI remain unclear. We investigated the multivariate associations between brain structural alterations and cognition in three groups of older patients at risk for dementia - remitted MDD (rMDD), MCI, or rMDD+MCI and non-psychiatric controls (HC).

METHODS: We analyzed magnetic resonance imaging data and cognitive domain scores in participants from the PACt-MD study. Following quality control, we measured cortical thickness and subcortical volumes of selected regions from 283 T1-weighted scans, and fractional anisotropy of white matter tracts from 226 diffusion-weighted scans. We assessed brain-cognition associations using partial least squares regressions in the whole sample and in each subgroup.

RESULTS: In the entire sample, atrophy in the medial temporal lobe and subregions of the motor and prefrontal cortex was associated with deficits in verbal and visuospatial memory, language, and, to a lesser extent, processing speed (p<0.0001, multivariate r=0.30, 0.34, 0.26, and 0.18, respectively). Widespread reduced white matter integrity was associated with deficits in executive function, working memory, and processing speed (p=0.008, multivariate r=0.21, 0.26, 0.35 respectively). Overall, associations remained significant in the MCI and rMDD+MCI but not in the rMDD or HC groups.

CONCLUSION: We confirm findings of brain-cognition associations previously reported in MCI and extend them to rMDD+MCI, but do not support similar associations in rMDD. Early-onset and treated MDD might not contribute to structural alterations associated with cognitive impairment.

Language: en

Keywords

Depression; cognition; geriatric; magnetic resonance imaging; mild cognitive impairment; neuroimaging