A new study has found that mood disorders like depression, bipolar disorder, or mania after the age of 40 could be early signs of neurodegenerative diseases. These conditions, often seen as only mental health issues, may appear years before problems with memory or movement begin.
The research was carried out by scientists from the National Institutes for Quantum Science and Technology (QST) in Japan and published in the journal Alzheimer’s & Dementia.
The study involved 52 people with late-life mood disorders and 47 healthy individuals. The researchers used advanced brain scans to detect abnormal tau protein and amyloid deposits in the brain.
These proteins are linked to diseases like Alzheimer’s and other forms of dementia. They found that about 50 percent of those with mood disorders had tau buildup in their brains, compared to only 15 percent of healthy people. Around 29 percent also had amyloid deposits, while only 2 percent of the healthy group showed the same.
The team also studied brain tissue from 208 people who had passed away. The findings supported the brain scan results, showing a strong link between mood disorders in later life and the presence of harmful brain proteins. Many of these individuals had no major memory problems during life, suggesting that psychiatric symptoms could be the earliest sign of brain degeneration.
The abnormal proteins were often found in the frontal part of the brain, which is responsible for mood control and thinking skills. In many cases, mood symptoms appeared an average of 7.3 years before any memory or movement issues.
The researchers believe that identifying depression or bipolar disorder in older adults could help doctors detect brain diseases earlier and start treatment sooner.
