According to a new study, people who often had nightmares in childhood are more likely to develop dementia and Parkinson’s disease later in life.
Researchers collected data from nearly 7,000 UK residents over the age of 50 and learned that participants who had persistent bad dreams had an 85% increased risk of developing cognitive impairments such as dementia and chronic dementia. Alzheimer’s or Parkinson’s disease at the age of 50.
The study, published in the Lancet journal eClinicalMedicine on Sunday, analyzed data from the 1958 British Birth Cohort Study – which collected information on everyone born in Britain in a single week in March 1958 – including if they had had nightmares at 7 and 11.
Doctors then assessed individuals’ cognitive abilities at age 50 — in 2008.
They found that 267 people – or 3.8% – in the study group who underwent the assessment had developed some form of cognitive impairment or Parkinson’s disease.
Children who had distressing dreams at ages 7 and 11 were 76% more likely to develop cognitive impairment and were nearly seven times more likely to be diagnosed with Parkinson’s disease than those who did not, said the author of the study in his conclusions.
“The results were clear,” wrote author and clinical neurology researcher Abidemi Otaiku in an article about his findings. “The more regularly children had bad dreams, the more likely they were to develop cognitive impairment or be diagnosed with Parkinson’s disease.”
Otaiku noted, however, that more research needs to be done on the topic to determine if the link between nightmares and health issues is causal.
A possible explanation between the connection could be heredity. A gene known to increase the risk of regular nightmares has also been linked to an increased risk of developing Alzheimer’s disease in older people, according to the researcher.
Another potential reason could be that frequent nightmares disrupt sleep, which humans need to recharge and restore brain energy, he said.
However, if causation is proven by future studies, treating nightmares early could become a “primary prevention strategy” for dementia and Parkinson’s disease, Otaiku said.
“Being aware that bad dreams in childhood may signal a higher risk of dementia or Parkinson’s disease later in life suggests that there may be a window of opportunity to implement simple strategies to reduce these risks,” he wrote in the article.
Previous studies have suggested that middle-aged and older adults who have frequent nightmares may be more than twice as likely to develop both disorders in the future.