Relieving nightmares: Manipulating emotions in dreams

Nightmares, those terrifying memories that resurface in dreams, can become regular occurrences, visiting people multiple times per week for months on end.

Dreamers may be coached in therapy to rehearse positive versions of their most frequent nightmares. Still, researchers in Switzerland take this a step further in a study of such patients published in the journal Current Biology.

They discovered that playing a sound associated with a positive daytime experience through a wireless headband during sleep may reduce the frequency of nightmares.

"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."

Epidemiological studies have found that up to 4 percent of adults have chronic nightmares at any given time, a condition frequently associated with waking up during the night and poor sleep quality. Patients are frequently prescribed imagery rehearsal therapy, which requires them to rewrite the negative dream scenario and rehearse it during the day. While effective, some cases do not respond.

Perogamvros and his colleagues examined 36 patients who were all receiving imagery rehearsal therapy to see if sound exposure during sleep could improve success. The other half of the group was required to create an association between a positive version of their nightmare and a sound during an imagination exercise, which they needed to practice daily and to wear a headband that could send them the sound during REM sleep for two weeks. This is the stage of sleep where most nightmares occur.

"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 in 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."

Both groups saw a decrease in nightmares per week, but the half who received the combination therapy had fewer nightmares both during the intervention and three months later. They also had more joy in their dreams. The findings support the idea that such combined therapy should be tested on a larger scale and with a variety of populations to determine the extent and generalizability of its efficacy.