Previous studies have shown that people with Parkinson’s disease experience distressing dreams more frequently than the general population, but nightmares had not been considered as a risk indicator for Parkinson’s disease.
In this study[1], researchers analyzed data from a large cohort study in the United States, which included 3,818 community-dwelling older men over a 12-year period. At the beginning of the study, these participants completed a series of questionnaires, including questions about sleep quality.
At the end of the study, participants who reported having nightmares at least once per week were followed up to analyze whether they were more likely to have been diagnosed with Parkinson’s disease.
Overall, 91 cases of Parkinson’s disease were diagnosed during the follow-up period.
The study found that people who frequently had nightmares were twice as likely to later be diagnosed with Parkinson’s disease as those who did not. However, most diagnoses occurred within the first five years of the study, during which frequent nightmare sufferers were more than three times as likely to develop Parkinson’s disease.
[1]Distressing dreams and risk of Parkinson’s disease：A population-based cohort study