Mid to late‐life scores of depression in the cognitively healthy are associated with cognitive status and Alzheimer's disease pathology at death

Research output: Contribution to journalArticlepeer-review

  • External authors:
  • Yvonne S Davidson
  • James Minshull
  • Calvin Heal
  • Michael A Horan
  • David Ma Mann

Abstract

Objectives: Early diagnosis of Alzheimer's disease (AD) is essential for early interventions. Symptoms of depression could represent a prodromal stage of AD. Very early mood alterations may help stratify those at highest risk of late-life AD. We aim to investigate associations between baseline/longitudinal scores for depression, presence of cognitive impairment and/or AD pathology at death.

Methods/Design: Between 1991 and 2015, participants from The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age underwent 10 waves of assessment using the Geriatric Depression Scale (GDS). AD pathology at death was evaluated in 106 eligible cases. Analyses aimed to examine associations between GDS scores, cognitive status and AD pathology (as measured by Braak stage, Thal phase and CERAD).

Results: Baseline GDS scores were significantly higher for those cognitively impaired at death than those cognitively normal. Significantly higher baseline GDS scores were found for those with greater CERAD scores than those with lower CERAD scores. Similarly, significantly higher baseline GDS scores were found for those with a greater Braak stage than those with lower tau burden. These correlations remained after controlling for age at death, education and APOE ε4, but were less robust. Mean longitudinal GDS scores associated with cognition but not pathology.

Conclusions: GDS scores collected approximately 20 years before death were associated with cognitive status and AD pathology at death. We postulate that early AD-related pathological change produces raised GDS scores due to an overlapping neural basis with depression, and that this may be considered as an early diagnostic marker for AD. This article is protected by copyright. All rights reserved.

Bibliographical metadata

Original languageEnglish
JournalInternational journal of geriatric psychiatry
Early online date11 Nov 2020
DOIs
Publication statusE-pub ahead of print - 11 Nov 2020