Every night, when we go to sleep, we spend a few hours in a virtual world that creates our brain, in which we are the protagonists of a story that we do not create consciously. In other words, we dream.
For most people, dreams are mostly pleasant, sometimes negative, often bizarre, but rarely frightening. Then we remember them.
However, for about 5% of people, quite unforgettable and frightening nightmares (the ones that wake you up) happen every week or even every night.
Recent studies show that patients with Parkinson’s disease are more likely to have nightmares and bad dreams than people without the disease.
Research shows that between 17% and 78% of people with Parkinson’s disease experience nightmares on a weekly basis.
A study I conducted in 2021 found that newly diagnosed patients with Parkinson’s disease who have recurrent dreams with “aggressive or action-filled” content experience faster disease progression in the years after diagnosis, compared to those who do not have aggressive dreams.
In this way, my study, as well as similar research, strongly suggests that the dreams of people with Parkinson’s disease can predict future health outcomes.
I wondered if the dreams of people without Parkinson’s disease could also predict future health outcomes. My latest study, published in The Lancet eClinicalMedicine, shows that I can.
In particular, it has shown that the development of frequent nightmares or bad dreams in old age can be an early warning sign of impending Parkinson’s disease in otherwise healthy people.
I analyzed data from a large American study that contained data collected over 12 years from 3,818 older men living alone.
At the beginning of the study, they filled out a series of questionnaires – one of which included a question about nightmares.
Participants who reported having nightmares at least once a week were followed at the end of the study for an average of seven years to determine if they were more likely to be diagnosed with Parkinson’s disease.
During this period, 91 people became ill.
Those who reported having frequent nightmares were initially twice as likely to develop Parkinson’s disease compared to those who had less than once a week.
Interestingly, a significant proportion of diagnoses occurred during the first five years of the study.
During this period, 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 to have nightmares and bad dreams for several years before developing characteristic symptoms of the disease, such as trembling, stiffness, and slowness of movement.
The study also shows that our dreams can reveal important information about the structure and function of our brain and that they could prove to be an important target for neuroscientific research.
However, it is important to note that only 16 of 368 men with frequent nightmares in this study developed Parkinson’s disease.
Since Parkinson’s disease is a relatively rare condition, it is unlikely that most people who have frequent nightmares will develop this condition.
However, for those who have other known risk factors for Parkinson’s disease, such as excessive sleepiness or constipation, the findings could be important: be aware that bad dreams and frequent nightmares (especially when they start suddenly in adulthood) may be indicative of Parkinson’s diseases. the disease can lead to early diagnosis and treatment.
One day, doctors may even be able to intervene to stop the 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 disease.
This could help us identify treatments that can simultaneously treat nightmares and also delay or prevent the onset of Parkinson’s disease in people at risk of developing the disease.