Could mood disorders after age 40 be an early sign of dementia?
- Late-life mood disorders (LLMDs) are mental health issues that first occur or recur at an older age.
- Past research shows that people with an LLMD may be at a higher risk of developing dementia.
- A new study found that people with LLMDs have larger amounts of the proteins beta-amyloid and tau in their brains than those with no late-onset mental health issues.
- Researchers also found that these abnormal brain protein levels can be detected years before traditional dementia symptoms first appear.
Late-life mood disorders (LLMDs) are mental health issues, such as depression and bipolar disorder, that first occur or recur at an older age…
These abnormal protein amounts could be detected years before traditional cognitive symptoms appeared, with mood symptoms preceding cognitive or motor symptoms by an average of 7.3 years in autopsy cases. …
At the study’s conclusion, researchers found that about 50% of participants with LLMDs had tau accumulation and 29% had amyloid deposits, versus 15% and 2%, respectively, in the control group.…
It suggests that we should consider mood disorders — especially those with late onset — as possible prodromal features of neurodegenerative dementias. This perspective has important implications for earlier diagnosis and proactive monitoring of at-risk individuals…
“This isn’t just about treating mood symptoms anymore — we’re potentially intervening in the earliest stages of neurodegeneration,” Bermudes explained. “The finding that 50% of late-life mood disorder patients showed tau pathology compared to only 15% of healthy controls means we’ve been underestimating the stakes.”…[end quote]
This discovery could make a huge difference if and when a drug is finally developed that slows the degradation of tau protein in neurons.
In current practice, a person over age 40 who presents with a mood disorder such as clinical depression or bipolar disorder would be treated with psychiatric drugs. At this point, the person would not show classical signs of dementia so they wouldn’t be evaluated.
Based on the study, the patient would receive positron emission tomography (PET) scans using two different tracers to detect the presence of beta-amyloid and tau in the brain. This is an expensive test. It’s not likely that it would be prescribed routinely unless there was a drug available to slow the progression of disease.
If there was an effective drug the benefit of starting it early in the disease process, before extensive damage, would be clear.
Recent research shows that early dementia symptoms can include loss of executive function (including financial mismanagement) and personality changes before memory loss. This research shows that mood disorders can occur even earlier.
Wendy
