Every night, when we go to sleep, we spend a few hours in a virtual world created by our brains, in which we are the main protagonist of an unfolding story that we did not consciously create. In other words, we dream.
For most people, dreams are mostly pleasant, sometimes negative, often bizarre, but rarely terrifying. That is, if they are remembered. However, for about 5% of people, highly memorable and terrifying nightmares (bad dreams that make you wake up) happen weekly or even every night.
Recent studies have shown that people with Parkinson’s disease have nightmares and nightmares more often than people without the disease. Studies suggest that between 17% and 78% of people with Parkinson’s have nightmares on a weekly basis.
A study I conducted in 2021 found that people newly diagnosed with Parkinson’s who have recurring dreams with “aggressive or action-packed” content have faster disease progression in the years following diagnosis, compared to those without aggressive dreams. As such, my study, along with similar studies, strongly suggests that dreams of people with Parkinson’s can predict future health outcomes.
It got me wondering if the dreams of people who don’t have Parkinson’s can also predict future health outcomes? My latest study, published in The Lancet’s eClinicalMedicine journal, shows that they can. Specifically, it showed that the development of nightmares or frequent nightmares in old age could be an early warning sign of impending Parkinson’s disease in healthy people.
I analyzed data from a large American study that contained data over 12 years from 3,818 older men who lived independently. At the start of the study, the men filled out a series of questionnaires, one of which included a question about nightmares.
Participants who reported nightmares at least once a week were followed at the end of the study for an average of seven years to see if they were more likely to be diagnosed with Parkinson’s.
In that period, 91 people were diagnosed with Parkinson’s. Those who reported having frequent nightmares at baseline were twice as likely to develop Parkinson’s compared to those who had them less than once a week.
Interestingly, a significant proportion of diagnoses occurred during the first five years of the study. During that time, participants with frequent nightmares were three times more likely to develop Parkinson’s disease.
These results suggest that older adults who will one day be diagnosed with Parkinson’s disease may begin having nightmares and nightmares a few years before they develop the disease’s characteristic symptoms, including tremors, stiffness and slowness of movement.
The study also shows that our dreams can reveal important information about our brain structure and function and could prove to be an important target for neuroscience research.
However, it is important to note that only 16 of the 368 men with frequent nightmares in this study developed Parkinson’s. Because Parkinson’s is a relatively rare condition, most people who have frequent nightmares are unlikely to have the condition.
Still, for those who have other known Parkinson’s risk factors, such as excessive daytime sleepiness or constipation, the finding could be important. Being aware that frequent nightmares and nightmares (especially when they start suddenly in adulthood) can be an early indicator of Parkinson’s, can lead to early diagnosis and treatment. One day, doctors may even intervene to stop Parkinson’s disease from developing.
My team now plans to use electroencephalography (a technique for measuring brain waves) to analyze the biological reasons for changes in dreams in people with Parkinson’s. This could help us identify treatments that can simultaneously treat nightmares and also delay or prevent the onset of Parkinson’s in people at risk of developing the disease.
This article is republished from The Conversation under a Creative Commons license. Read the original article.