Frequent Distressing Dreams Tied to More Than Double Parkinson’s Risk
Men who have distressing dreams more than once a week are at more than two times higher risk of being diagnosed with Parkinson’s disease, a new study suggests.
“This study provides evidence for the first time that frequent distressing dreams in community-dwelling older adults, may be associated with an increased risk for developing” Parkinson’s, wrote study author Abidemi Otaiku, a researcher at the University of Birmingham.
The study, “Distressing dreams and risk of Parkinson’s disease: A population-based cohort study,” was published in eClinicalMedicine.
People with Parkinson’s commonly report having dreams that are unusually vivid or negative, and negative dreams have been linked with cognitive decline in Parkinson’s patients. Also, “people with [Parkinson’s disease] are approximately four times more likely than adults in the general population, to experience nightmares sufficiently frequent to be considered a clinical disorder,” the researchers wrote.
However, it’s not been clear whether frequent distressing dreams are associated with an increased risk of Parkinson’s in the general population.
To learn more, Otaiku analyzed data from the Osteoporotic Fractures in Men Study (MrOS), an observational study that tracked health outcomes for thousands of men older than 65 at several sites in the U.S.
“This is the first study to investigate the association between dream content in community-dwelling older adults and the subsequent development of” Parkinson’s, Otaiku wrote.
Otaiku analyzed data collected from 2000 to 2016 on 3,818 men (average age 77) who were followed for more than seven years on average. In the follow-up, 91 of the men were diagnosed with Parkinson’s. Compared to those who didn’t develop the disease, at the study’s start, these men were more likely to experience depression, but less likely to report difficulties sleeping through the night.
At the beginning of the study, 368 of the men reported having distressing dreams at least once per week. They were more likely to have less formal education, drank less alcohol, were less physically active, and tended to score worse on measures of cognitive function and physical and mental health. They also were more likely to use medications that can affect dreaming.
Otaiku tested whether Parkinson’s risk was increased in those who reported frequent distressing dreams, making mathematical adjustments to account for race, education, smoking status, alcohol intake, depression, sleeping difficulties, diabetes, high blood pressure, physical activity levels, self-rated health, and medication use.
Results showed the risk of Parkinson’s was increased significantly, by slightly more than twofold, in those who reported distressing dreams at the start of the study.
“In this large prospective study of community-dwelling older men without PD [Parkinson’s disease] from the USA, frequent distressing dreams were found to be associated with an increased risk for incident PD during a 12-year follow-up, accounting for a wide range of possible confounders,” Otaiku concluded.
The risk of Parkinson’s was increased more than threefold for those with frequent distressing dreams in the first five years of follow-up, analyses showed. However, no significant connection between distressing dreams and Parkinson’s risk was found at later follow-ups.
According to Otaiku, this likely means that distressing dreams associated with Parkinson’s are not a lifelong phenomenon among people predisposed to the disease, but more likely are a very early (“prodromal”) symptom that appears before the disease begins in earnest.
“Frequent distressing dreams may be a prodromal symptom of PD. As such, screening for late onset distressing dreams in the general population, may help to identify individuals at increased risk of developing” Parkinson’s, Otaiku wrote.
Otaiku noted that, given the established connection between frequent bad dreams and faster cognitive decline among Parkinson’s patients, screening for distressing dreams may be especially helpful for identifying those with more aggressive disease who are likely to benefit from early interventions.
The study noted as limitations that small number of people diagnosed with Parkinson’s were analyzed, and since MrOS only enrolled men ages 65 and older, it’s not clear whether these findings are applicable for women or younger people.