Dementia is a neurodegenerative disease characterised by irreversible and rapid cognitive decline. Patients are generally robbed of their memory before other cognitive functions start to hinder, leading to a complete loss of independence. Fortunately, some risk factors can be avoided. New scientific findings suggest nightmares may precede memory loss by decades, substantially increasing the risk of brain decline in men and women.
Doctor Abidemi Otaiku, of the University of Birmingham’s Centre for Human Brain Health, said: “We’ve demonstrated for the first time that distressing dreams or nightmares can be linked to dementia risk and cognitive decline among healthy adults in the general population.
“This is important because there are very few risk indicators for dementia that can be identified as early as middle age.
“While more work needs to be done to confirm these links, we believe bad dreams could be a useful way to identify individuals at high risk of developing dementia and put in place strategies to slow down the onset of disease.”
The study, published in the Lancet journal eClinicalMedicine, suggests nightmares may become more prevalent several years or even decades before memory problems set in.
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Researchers made the discovery after analysing data from more than 600 adult men and women aged between 35 and 64, and 2,600 adults aged 79 and older.
None of the participants had dementia at the outset of the study, which was carried out between 2002 and 2012.
Self-reported data allowed researchers to gauge the frequency of bad dreams, and assess whether these tendencies were linked to dementia in any way.
According to the results, middle-aged people who experienced bad dreams on a weekly basis are four times more likely to experience cognitive decline over the following decade.
Older people, on the other hand, appear to be twice as likely to be diagnosed with dementia.
Interestingly, the association appears to be stronger for men than they were for women in the study.
For instance, men who experienced nightmares on a weekly basis were five times more likely to have dementia compared to those who didn’t report bad dreams.
In women, on the other hand, the increase in risk was only 41 percent.
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During the day, the brain accumulates beta-amyloid proteins which are one of the hallmarks of dementia.
After falling asleep, however, the brain cells and their connections shrink, allowing more space for these toxic proteins to be flushed away.
Alternatively, the association could be explained by genetic factors underpinning frequent nightmares and dementia.
The researchers believe, however, that in individuals who already have the underlying disease, bad dreams and nightmares might be “one of the earliest signs”.