Results from a UK study suggest that experiencing bad dreams or nightmares as an older person may be an early sign of Parkinson’s disease.
The University of Birmingham study, which is published in eClinicalMedicine, analysed a cohort of nearly 4,000 men, finding that individuals who frequently experienced bad dreams were twice as likely to be later diagnosed with Parkinson’s disease than those who did not.
Although earlier research has demonstrated that Parkinson’s disease patients experience bad dreams or nightmares more regularly than adults in the general population, this study is the first to identify that nightmares may be an early sign of Parkinson’s disease. This novel discovery may enhance our understanding of the neurodegenerative disease’s risk indicators.
Dr Abidemi Otaiku, the lead author of the study from the University’s Centre for Human Brain Health, said: “Although it can be really beneficial to diagnose Parkinson’s disease early, there are very few risk indicators, and many of these require expensive hospital tests or are very common and non-specific, such as diabetes.
“While we need to carry out further research in this area, identifying the significance of bad dreams and nightmares could indicate that individuals who experience changes to their dreams in older age – without any obvious trigger – should seek medical advice.”
Investigating early warning signs of Parkinson’s disease
For their investigation, the team employed data from a large cohort study that included 3,818 men in the US who were living independently. The participants were monitored over a 12-year period, and at the study’s inception, the men completed several questionnaires, one of which included a question about sleep quality.
Individuals who reported having a bad dream at least once per week were then followed up at the end of the study to analyse is they were more likely to be diagnosed with Parkinson’s disease. The researchers identified 91 cases of Parkinson’s disease during the follow-up period.
The results illuminated that nightmares may be an early sign of Parkinson’s disease, as the participants who experienced bad dreams most frequently were twice as likely to develop the condition compared to those who did not. The majority of diagnoses occurred within the first five years of the study. Participants who had regular bad dreams during this period were three times more likely to develop Parkinson’s.
The investigation indicates that before Parkinson’s disease patients start to display characteristic symptoms of the condition, such as slowness of movement, tremors, and stiffness, they are likely to start experiencing frequent nightmares several years before a diagnosis.
The team noted that the research has not only identified a new early sign of Parkinson’s disease but has also discovered that our dreams can reveal crucial information about our brain structure and function that may be instrumental in future neuroscience research.
The researchers are now aiming to utilise electroencephalography (EEG) to examine the biological reasons for dream changes. They are also looking to replicate the findings in a more extensive and diverse cohort and investigate potential links between dreams and other neurodegenerative diseases, including Alzheimer’s.