Late-Life Mood Disorders May Represent Prodromal States of Dementia: Daily Dose

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On June 13, 2025, we reported on a study published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association that was designed to examine the involvement of Alzheimer disease (AD) and non-AD tau pathologies in participants with late-life mood disorders (LLMDs).

The study

Researchers examined 52 participants with LLMDs and 47 healthy controls using positron emission tomography (PET) imaging with 2 commonly used tracers. The study team also analyzed brain tissue samples from 208 autopsy cases to validate their neuroimaging findings.

The findings

The PET imaging revealed that 28.8% of LLMD participants showed detectable amyloid deposits versus only 2% of controls. When stratified by condition, 60% of participants with late-life depression and 40.5% of those with late-life bipolar disorder demonstrated tau accumulation. For amyloid beta (Aβ) pathology, 36% of participants with depression and 22% of those with bipolar disorder showed positive findings. Autopsy analysis corroborated these results, demonstrating a higher prevalence of diverse tau protein-related pathologies in individuals who had experienced late-life mania or depression.

Authors' comments

"This research highlights the contribution of AD and non-AD tau pathologies to LLMDs. Future studies should focus on longitudinal imaging and pathological correlations to refine diagnostic and therapeutic approaches for LLMD patients."

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