People who experience frequent nightmares in their late thirties are more likely to be diagnosed with dementia later in life, according to some disturbing new research.
The study, from the University of Birmingham, suggests nightmares may be an early warning sign of dementia, with bad dreams becoming prevalent several years or even decades before the characteristic memory and thinking problems of the disease set in.
Dr 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.”
In the study, Dr Otaiku examined data from three cohorts in the US. These included more than 600 adult men and women aged between 35 and 64 (defined in the study as ‘middle aged’) 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.
Participants completed a range of questionnaires, including the Pittsburgh Sleep Quality Index, which includes a question on how often individuals experienced bad dreams.
This data was analysed using statistical software to find out whether participants with a higher frequency of nightmares were more likely to go on to experience cognitive decline and be diagnosed with dementia.
The research shows that people aged 35-64 who 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.
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%.
If you’re prone to a scary dream or two, don’t panic just yet – researchers said that more research is needed. The scientists will now investigate 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 as early warning signs.
The researchers plan to investigate the biological basis of bad dreams in both healthy people and people with dementia to gain more clarity.