A new study has found that middle-aged people who experience frequent bad dreams are more likely to be diagnosed with dementia later in life.
The research done at the University of Birmingham and published in The Lancet journal, eClinicalMedicine, suggests nightmares may become prevalent several years or even decades before the characteristic memory and thinking problems of dementia set in.
Neurodegenerative diseases triggered by nightmares
“We have 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,” said Dr. Abidemi Otaiku of the University of Birmingham’s Centre for Human Brain Health.
“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 the disease,” he added.
The study examined data from three community-based cohorts in the US. These included more than 600 adult men and women aged between 35 and 64; and 2,600 adults aged 79 and older. All the participants were dementia-free at the start of the study and followed up for an average of nine years for the younger group and five years for the older participants.
Commenting on the study, Dr. Mustafa Seyam, Consultant Neurologist at Fakeeh University Hospital, Dubai Silicon Oasis said that some studies confirm the definite link between sleep disorders and dementia, particularly Alzheimer’s dementia.
“There is a higher risk to develop neurodegenerative diseases by sleep disorders occurring during REM sleep, but it is unlikely by non-REM since there is no proven correlation between dementia and sleep disorders occurring during non-REM sleep,” he explained.
The research shows that middle-aged people (35 to 64 years old) that experience bad dreams on a weekly basis are four times more likely to experience cognitive decline over the following decade, while older people were twice as likely to be diagnosed with dementia.
Men are at high risk of dementia episodes
Interestingly, the study found that the associations were much stronger for men than for women. For example, older men experiencing nightmares on a weekly basis were five times more likely to develop dementia than older men reporting no bad dreams. In women, however, the increase in risk was only 41 per cent.
Dr. Seyam said that physical and mental activity is considered crucial in slowing the onset of dementia. “The human brain starts developing changes 20 years before the appearance of any clinical symptoms. Early screenings are important to identify patients who may be at high risk of developing dementia in the future to begin treatment early. Aging is a risk factor for dementia, however that doesn’t make dementia a normal aspect of ageing,” he added.
Next steps for the research will include investigating whether nightmares among young people could be associated with future dementia risk and whether other dream characteristics, such as how often we remember dreams and how vivid they are, could also be used to identify dementia risk. Using electroencephalography (EEG) and magnetic resonance imaging (MRI), the researchers also plan to investigate the biological basis of bad dreams in both healthy people and people with dementia.