Excessive sleep is a symptom of dementia, but not the cause of dementia, researchers have found. The new study also found that people who sleep for over 9 hours every day increase their risks of developing dementia two fold within 10 years. And then, MRI scans of the brain reveal that people who sleep in excess of 9 hours daily have smaller brain volumes compared with those who sleep less.
This study was published in the journal Neurology by a team of international researchers. The study was titled "Prolonged sleep duration as a marker of early neurodegeneration predicting incident dementia." The authors of the study disclosed that most dementia patients suffer from inexplicable sleep disturbances, and sleep duration plays a role in their mental stability.
2,457 participants took part in this study as part of the Framingham Heart Study
About 2,457 participants enrolled for this study via the Framingham Heart Study in Massachusetts. The participants recorded how long they sleep per night and they were monitored over a 10-year period. Within the 10 years of monitoring the study participants, the researchers found that 234 of them developed dementia, and some of these developed this condition as a fallout of Alzheimer's disease.
People who habitually sleep for over 9 hours since their childhood were not seen to be at risk of developing dementia. People who changed their sleeping pattern and started to sleep for over 9 hours in the recent past were found to be at risk of dementia, said Dr. Mathew Pase of the Department of Neurology, Boston University School of Medicine. He also added that people who possess no high school degree but habitually sleep very long have their risks of dementia increase six-fold, Medical Research reports.
More research is still needed on medical consequences of excessive sleep
The authors of the study noted that long before the onset of dementia, excessive sleep causes changes in the brain. These brain changes serve as a biomarker of dementia even though they are not the cause, Tech Times writes. They therefore added that reducing the amount of sleep will not necessarily reduce the risks of dementia. However, it is quite possible that dementia and cognitive impairments could be detected much earlier by analyzing sleep patterns and associated problems.
The researchers state that more studies are needed to establish the medical consequences of excessive sleep on the brain. They revealed that prolonged sleep affects various parts and functions of the brain. They are therefore currently in the process of using polysomnography to investigate how onset of dementia could be influenced by changes in sleep patterns.