Dreams are normal occurrences for everyone, and most people report having occasional nightmares. However, the frequency of your nightmares, and how old you are when you experience them, might reveal information about your risk for dementia.
Research shows that experiencing frequent distressing dreams and nightmares ― meaning, specifically, frightening dreams that cause you to wake up ― may be linked with a higher risk of cognitive decline and dementia.
A 2023 analysis in the American Journal of Preventive Medicine concluded that sleep disturbances should be considered when evaluating someone at risk for dementia. Previous research has discovered a possible link between distressing dreams and a higher risk of dementia in people with Parkinson’s disease. And a 2022 study published in The Lancet’s eClinicalMedicine found that some associations may also exist in the general population.
The 2022 study, authored by Dr. Abidemi Otaiku, a clinical research fellow at Imperial College London, evaluated 605 middle-aged adults at a cognitively normal baseline over a maximum of 13 years. Researchers also examined 2,600 older adults, with a mean age of 83, at a dementia-free baseline for a maximum of seven years.
The data suggested that the group of middle-aged adults who reported a higher frequency of nightmares ― classified as once a week or more ― were associated with having a higher risk of cognitive decline. Likewise, for the older adults, the study found that more nightmares were linked to higher risks of “all-cause dementia,” meaning the syndrome can be caused by a number of different diseases.
Middle-aged adults who reported having weekly nightmares, compared to those who reported having none, were 4 times as likely to be at risk for experiencing cognitive decline. Older adults with frequent distressing dreams were about twice as likely to be at risk for dementia.
The cognitive function of the middle-aged participants was determined by using five cognitive tests. The older participants were evaluated for dementia by a doctor.
But there were some limitations of the study, such as the lack of racial diversity among the participants, who were mostly white, and a possible underestimation of associations between nightmares and dementia among the female participants. The associations in the findings between distressing dreams and risks of cognitive decline and dementia were only significant among the men who were evaluated, not the women.
Furthermore, the questionnaire given to participants didn’t clearly distinguish between “bad dreams” and “nightmares,” which may have affected the responses. “Bad dreams” don’t cause you to awaken, whereas nightmares can jolt you out of sleep.
In an article published at The Conversation, Otaiku wrote that the results of the study could lead to two theories: one, that frequent nightmares may be one of the earliest signs of dementia, especially in men; and two, that regular nightmares might be a cause of dementia themselves.
“Given the nature of this study, it is not possible to be certain which of these theories is correct (though I suspect it is the former),” Otaiku wrote. He added that the research could, nonetheless, provide new opportunities for earlier diagnoses and “possibly earlier interventions.”
More than 55 million people around the world have dementia. With so many ongoing conversations about sleep health and dementia diagnoses, it’s important to be aware of any new information about early detection, and things you can do to lower your risk.
