Did you know a group of brain regions only come alive when you’re daydreaming? These regions are called the Default Mode Network (DMN).
Now, in first-of-its-kind research, scientists have discovered that changes in this network can predict dementia with a high degree of accuracy up to nine years before diagnosis. Here’s what it means for you…
Key Takeaways
- The brain has its network for daydreaming called the Default Mode Network (DMN).
- Research shows the DMN is one of the first networks in the brain to experience changes related to dementia.
- Researchers at Queen Mary University studied these changes and predicted dementia up to nine years earlier than current methods.
The Default Mode Network
When did you last let your mind wander? Perhaps you were thinking of an upcoming vacation, last week’s birthday party, or the welfare of a sick relative.
At these times, you’re using the default mode network (DMN), which operates in at least three, possibly five brain regions. The network is involved with processing emotions, decision-making, and memory.
When the DMN is working as it should, these regions communicate well. But in many neurological conditions, connections in this network are disrupted. Researchers have documented this in ADHD, PTSD, schizophrenia, depression, Parkinson’s, and Alzheimer’s. In fact, the DMN is known to be especially vulnerable to dementia, being the first neural network in the brain to be affected by memory loss.
That being the case, and since neurological damage occurs many years before symptoms appear, neuroscientists at Queen Mary University, London, conducted a study to see if the DMN could predict future Alzheimer’s or other dementias.
They weren’t disappointed.
More Than 80 Percent Accurate
To detect changes in the DMN, they conducted functional MRI scans on over a thousand volunteers with an average age of 70 who are part of the UK Biobank resource, which contains detailed medical and genetic information on each participant.
Each volunteer was given a probability value of developing dementia based on the connectivity pattern. This predictive model was then compared with each person’s medical records. This showed that the model achieved an accuracy of more than 80% in forecasting who would go on to be diagnosed with dementia, and it did so with an average of 3.7 years before diagnosis. In the earliest case, it could predict Alzheimer’s nine years in advance.
These results are more accurate than memory tests or measurements of brain shrinkage, two commonly used methods currently used for diagnosing dementia.
What’s more, of the 81 undiagnosed individuals who later developed dementia, the model could predict within a two-year margin of error exactly how long it would take for that diagnosis to be made. To date, virtually no other test is scientifically proven this accurate.
In a separate analysis, researchers looked at known risk factors for dementia and whether any of these could disrupt the network. Two stood out, being strongly linked to DMN disruption. The first was a genetic predisposition to Alzheimer’s. We can’t change our genes, but we can certainly do something about the second disruptor - social isolation.
Social Isolation Triggers Memory Loss
Research consistently shows a strong association between social isolation, loneliness, and an increased risk of developing dementia. A meta-analysis published in 2020 in the Journal of Gerontology found that socially isolated individuals had a 50% increased risk of developing dementia compared to those who were socially engaged.
In addition, studies using brain imaging techniques like MRI have demonstrated that socially isolated individuals show a more rapid decline in brain volume, especially in regions like the prefrontal cortex and hippocampus, which are critical for cognitive function.
A Valuable Addition to The Existing Toolkit
Professor Charles Marshall, who led the research, said: “Although we are getting better at detecting the proteins in the brain that can cause Alzheimer’s disease, many people live for decades with these proteins in their brain without developing symptoms of dementia.
“We hope that the measure of brain function that we have developed will allow us to be much more precise about whether someone is actually going to develop dementia, and how soon, so that we can identify whether they might benefit from future treatments."
Experts described this new research as “promising” and “potentially exciting” but did point to the need for a much larger and more diverse sample of participants studied over a longer time frame to truly test daydreaming’s predictive powers. Another drawback is that while the scan only takes six minutes, it’s expensive, requires specialized staff and isn’t yet widely available.
Even so, if validated, the research team believes it will be a valuable addition to the existing toolkit of blood tests for Alzheimer’s, optical scans, checking levels of certain proteins and free radicals, scans using artificial intelligence to monitor speech patterns, and other biomarkers of Alzheimer’s disease used to identify people at future risk of dementia.
Summary:
A groundbreaking study by Queen Mary University, London, reveals that changes in the brain’s Default Mode Network (DMN) can predict dementia up to nine years before diagnosis with over 80% accuracy. Using functional MRI scans, researchers identified disruptions in the DMN, a network active during daydreaming and involved in emotions, decision-making, and memory processing. This method outperformed traditional memory tests and brain shrinkage measurements, offering a new tool for early dementia detection. While promising, experts call for further research with diverse participants and note the current limitations of cost and availability.
