Tokyo: New research suggests that mood disorders beginning after age 40 could be an early warning sign of dementia.
A study led by Dr. Keisuke Takahata at Japan’s National Institutes for Quantum Science and Technology found that people with late-life mood disorders (LLMDs), like depression and bipolar disorder, show significantly higher levels of beta-amyloid and tau proteins in their brains, key indicators of Alzheimer’s disease.
The findings were published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
Using PET scans and brain tissue analysis from both living participants and autopsied cases, the study compared 52 LLMD patients to 47 healthy individuals. It showed that 50% of LLMD patients had tau buildup and 29% had amyloid deposits, versus 15% and 2% in the control group.
These abnormal protein accumulations were seen an average of 7.3 years before traditional dementia symptoms appeared.
Dr. Takahata said these mood disorders might represent early symptoms of neurodegeneration. Experts like Dr. Richard Bermudes and Dr. Gary Small agreed that the study supports changing clinical approaches, emphasizing early diagnosis and aggressive treatment of mood disorders in older adults. This could offer a vital therapeutic window to slow or prevent dementia progression.
This study builds on past evidence linking late-onset depression to dementia and suggests doctors should consider dementia in older patients presenting with new mood issues. Researchers now plan long-term studies tracking brain changes in LLMD patients to identify who is truly in the early stages of dementia.
