Dreams are normal occurrences for everyone, and most people report having them occasional nightmares. However, the frequency of your nightmares, and how old you are when you experience them, can reveal information about your risk of dementia.

Research shows that often experience distressing dreams and nightmares ― which in particular means frightening dreams that wake you up — may be linked to a higher risk of cognitive decline and dementia.

An analysis from 2023 in 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 study from 2022 is 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 researcher at Imperial College London, evaluated 605 middle-aged adults at a cognitively normal baseline for a maximum of 13 years. Researchers also examined 2,600 older adults, with an average age of 83, at a dementia-free baseline for up to 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”, which means that 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 four times more likely to experience cognitive decline. Older adults with frequent distressing dreams were about twice as likely to develop dementia.

The cognitive function of the middle-aged participants was determined using five cognitive tests. The elderly participants were evaluated for dementia by a physician.

But there were some limitations to the study, such as the lack of racial diversity among the participants, who were mostly white, and a possible underestimation of the association between nightmares and dementia among the female participants. The associations in the findings between distressing dreams and risks of cognitive decline and dementia were significant only among the men evaluated, not the women.

In addition, the questionnaire to the participants did not clearly distinguish between “bad dreams” and “nightmares”, which may have influenced the responses. “Bad dreams” don’t wake you up, while nightmares can wake you up.

In an article published At The Conversation, Otaiku wrote that the results of the study may lead to two theories: one, that frequent nightmares may be one of the earliest signs of dementia, especially in men; and two, that common nightmares can be a cause of dementia in themselves.

“Given the nature of this study, it is not possible to be sure which of these theories is correct (although I suspect it is the former),” Otaiku wrote. He added that the research could still provide new opportunities for earlier diagnoses and “possibly earlier interventions.”

More than 55 million people around the world have dementia. With so many going on conversation about sleep health and dementia diagnosesis important to be aware of any new information about early detection and things you can do to reduce your risk.

Research has shown that regular exercise and physical activity, stay socialand refrain from smoking is one of the ways you can reduce the risk of dementia.

Dr Zaldy Tan, Head of Program for memory and healthy aging at Cedars-Sinai, previously told HuffPost that an important tip for improving brain health is to avoid social isolation.

“As social creatures, the human brain thrives on interacting with others … When this doesn’t happen, our memory and cognition can deteriorate over time,” Tan said. “It’s important to stay in touch with others.”

Adequate sleep is also key to reducing your risk. However, it can be challenging if you are someone who experiences nightmares or bad dreams.

If you find that you often have disturbing dreams or nightmares, talk to your doctor about your symptoms. There are no routine tests to diagnose a nightmare disorderwhich is a pattern of repeated frightening dreams that cause significant anxiety. But your doctor can investigate whether other conditions or factors are contributing to the nightmares.

According to The Sleep Foundation also allows people to seek different types of therapeutic treatment, such as psychotherapy, which can deal with nightmares.