Regular nightmares can shorten life expectancy by several years

People who experience nightmarish dreams on a weekly basis are almost three times more likely to die before reaching the age of 75 compared to those who rarely have bad dreams. This is the conclusion reached by the authors of a large-scale study recently presented at the European Academy of Neurology (EAN) Congress.

Source: Timothy Hearn, The Conversation.

The scientists combined data from four large long-term studies in the US, involving more than 4,000 people aged 26 to 74. At the beginning of the experiment, participants reported the frequency of nightmares disrupting their sleep. Over the next 18 years, the researchers recorded 227 premature deaths among the subjects.

The authors believe that frequent nightmares are a risk factor comparable in its negative effects on the body to heavy smoking. Even after common risk factors such as age, gender, mental health, smoking and overweight were taken into account, the link between nightmares and premature death remained clear.

The research team also examined the effect of nightmares on biological age using an "epigenetic clock" - special chemical tags on DNA that show the body's actual biological age. It turned out that people who had regular nightmares were biologically older than their birth certificates indicated, and this was confirmed by three independent measurement techniques (DunedinPACE, GrimAge and PhenoAge).

"Accelerated biological aging explains approximately 39% of the relationship between nightmares and premature death," the study authors emphasise. This means that the cause that triggers nightmares simultaneously pushes the body's cells towards accelerated aging.

According to scientists, frequent nightmares occurring during the REM phase of sleep are accompanied by a sharp release of adrenaline, cortisol and other stress hormones. Since the brain is very active at this time, and the muscles are paralysed, the body experiences the strongest stress, comparable to a real danger. If such stress is repeated regularly, it leads to chronic inflammation, high blood pressure and premature wear and tear of cells, which accelerates aging.

In addition, nightmares disrupt deep sleep, during which the body repairs damaged cells and cleanses itself of toxins. Thus, constant stress and lack of deep sleep form a double blow to human health, the authors said.

The link between nightmares and poor health has been seen before. It is known that adults who have frequent nightmares are more prone to develop Parkinson's disease and dementia long before the first symptoms of these diseases appear. This supports the hypothesis that nightmares may serve as an early warning of neurological diseases.

Nightmares are a more common problem than they seem: about 5 per cent of adults experience them weekly, and another 12.5 per cent experience them at least once a month. With this in mind, the authors suggest that nightmares should be given special attention and treated as an important public health issue.

There are several effective and accessible methods to reduce the frequency of nightmares, including cognitive-behavioural therapy and the visualisation method, where a person "rewrites" a bad dream scenario while awake. Simple tips such as a cool, dark room with no screens before bedtime have also proven effective.

However, the study authors urge caution about the results, as the work has limitations. In particular, most of the study participants were white Americans, and subjective reports from people about their dreams were used, which can make it difficult to objectively assess their severity. In addition, biological age was only measured once.

However, the strengths of the study, according to the researchers, are the long-term follow-up of participants and the use of official mortality data rather than participants' self-reports. If follow-up studies confirm these findings, the authors believe that doctors may start asking patients about nightmares on a regular basis, along with measuring blood pressure and cholesterol levels.

The authors are convinced that nightmare therapy could be an effective and inexpensive way to improve not only sleep but also overall health, giving people a few extra years of life.

The study was presented in the form of abstracts at the EAN 2025 conference and has not yet passed the peer-review stage.