Story at a glance
- Middle-aged people between 35 and 64 who had bad dreams on a weekly basis were four times more likely to experience a decline in cognitive function over the following decade, a precursor to dementia.
- Older participants were found to be twice as likely to be diagnosed with dementia.
- The study found the associations between nightmares and future dementia was much more prevalent among men than women.
Experiencing frequent bad dreams and nightmares during middle or older age may be a marker for an increased risk of developing dementia, according to new research.
Researchers from the University of Birmingham in the United Kingdom published a study in The Lancet’s eClinicalMedicine journal suggesting persistent nightmares may be an early sign of cognitive decline and dementia that can occur several years, or even decades, before dementia symptoms begin to show themselves.
The study analyzed data from three large U.S. studies of health and aging, which included more than 600 adults between the ages of 35 and 64 and 2,600 adults 79 and older. Participants were dementia-free at the beginning of the study and were followed for an average of nine years for the middle-aged group and five years for the older-aged group. From 2002 to 2012, participants completed various questionnaires, including one that asks how often they experienced nightmares.
Researchers analyzed the data using statistical software to determine whether participants who had more nightmares were also more likely to develop dementia, and found middle-aged people between 35 and 64 who had bad dreams on a weekly basis were four times more likely to experience a decline in cognitive function over the following decade, a precursor to dementia. Older participants meanwhile were found to be twice as likely to be diagnosed with dementia.
“We’ve demonstrated for the first time that distressing dreams, or nightmares, can be linked to dementia risk and cognitive decline among healthy adults in the general population,” Abidemi Otaiku, researcher with the University of Birmingham’s Center for Human Brain Health, said in a statement.
“This is important because there are very few risk indicators for dementia that can be identified as early as middle age. While more work needs to be done to confirm these links, we believe bad dreams could be a useful way to identify individuals at high risk of developing dementia, and put in place strategies to slow down the onset of disease,” Otaiku added.
The study found the associations between nightmares and future dementia was much more prevalent among men than women. Older men who had nightmares weekly were five times more likely to develop dementia and older men who reported no bad dreams. Among women, the increase in dementia risk was just 41 percent.
Researchers plan to look at the association between nightmares and younger groups of people, as well as other dream characteristics such as vivid dreams and how well participants remember their dreams.
Alzheimer’s disease is the most common type of dementia and roughly 5.8 million people in the U.S. have Alzheimer’s and related dementias. The number of Alzheimer’s cases is estimated to increase to an estimated 14 million by 2060.