Dreams can be, well, just weird sometimes. But the worst are recurring nightmares when the same dreadful dream pops up time and time again regularly. Being chased, finding yourself naked in a public place or in the middle of a natural disaster, losing your teeth, or forgetting to go to class for an entire semester are some of the most common recurring nightmares people have.

It’s not entirely clear at all why people have recurring nightmares. Some scientists go as far as saying they mean absolutely nothing beyond exposing potential areas of stress in one’s life, while others claim that recurring negative dreams are a hallmark of unresolved personal conflict.

Regardless of what causes them, having repeating nightmares night after night can be draining, often causing people to wake up in the middle of the night, affecting the quality of sleep. Up to 4% of adults will experience chronic nightmares at any given time.

Therapists often coach patients to reframe their nightmares and turn them into positive, pleasant versions. In a new study, researchers in Switzerland have gone a step further, fitting patients with a wireless headband during sleep that plays a sound associated with a positive daytime experience to pull the patient out of the nightmare and guide the dream toward more positive territory.

“There is a relationship between the types of emotions experienced in dreams and our emotional well-being,” says senior author Lampros Perogamvros, a psychiatrist at the Sleep Laboratory of the Geneva University Hospitals and the University of Geneva. “Based on this observation, we had the idea that we could help people by manipulating emotions in their dreams. In this study, we show that we can reduce the number of emotionally very strong and very negative dreams in patients suffering from nightmares.”

Perogamvros and colleagues recruited 36 patients who reported chronic nightmares and separated them into two groups: half received no intervention whatsoever, while the other half went through a daily trial in which they learned to associate a positive version of their nightmare with a certain sound.

Patients in the intervention group had to wear a headband that played the sound at regular intervals during REM sleep — the stage of sleep associated with dreaming and memory consolidation — for two weeks.

Although both groups experienced a reduction in the intensity and frequency of recurrent nightmares, the patients who wore the headband had fewer nightmares even three months post-intervention. They also reported more joyful dreams.

“We were positively surprised by how well the participants respected and tolerated the study procedures, for example performing imagery rehearsal therapy every day and wearing the sleep headband during the night,” says Perogamvros.

“We observed a fast decrease of nightmares, together with dreams becoming emotionally more positive. For us, researchers and clinicians, these findings are very promising both for the study of emotional processing during sleep and for the development of new therapies.” 

The findings appeared in the journal Current Biology.