Frequent nightmares can affect the quality of sleep and cause great suffering for those affected. The standard therapy consists of those affected learning, with professional support, to think about positive versions of their nightmares and to practice them while they are awake. A study now shows that the effectiveness can be increased with a nocturnal reminder: If the patients heard a noise during practice, which was then also played during the dream phase of their sleep, their nightmares decreased more than in people receiving standard therapy. Further studies should clarify to what extent the results can be generalized.
Up to four percent of adults suffer from chronic nightmares. In doing so, they experience frightening situations and strong negative emotions in their dreams, which impair their sleep quality and often lead to waking up at night. It is often the same scenarios that torment the dreamer over and over again – partly due to previous traumatic experiences, partly for no apparent reason. So-called Imagery Rehearsal Therapy (IRT; “practicing ideas”) helps many of those affected. In doing so, they learn to transform their nightmare: under the guidance of a therapist, they think of a positive ending for the dream and rehearse the changed dream scenario during the day by imagining it as vividly as possible.
Reinterpret nightmares
“Although IRT is generally effective in treating nightmares, about 30 percent of patients do not respond to this treatment,” explains a research team led by Sophie Schwartz from the University of Geneva. “Therefore, new options for accelerating and improving the therapeutic results are needed.” Schwartz and her colleagues have now tested such an option. To do this, they randomly divided 36 people with nightmares into two groups. Both groups received the standard therapy with the practice of positive dream versions.
While one group received no further treatment, the other group also learned to associate the idea of the new end of the dream with a sound. To do this, the researchers repeatedly played a piano chord to the subjects in this group whenever they practiced the new dream version. The subjects should also hear this chord during the independent exercises at home. The idea behind it: An effect called “Targeted memory reactivation” (TMR; “targeted memory reactivation”) ensures that certain memories come back to us more easily when we experience a stimulus linked to them again. For example, if you like listening to music while learning, you can most easily retrieve the buffed content if you listen to the same piece of music again.
Acoustic reminder
Schwartz and her colleagues took advantage of this effect. They instructed all subjects to wear a headband every night for two weeks, which registered when they entered REM sleep – the sleep phase in which most dreams occur – and played the sound repeatedly during this phase. “We were pleasantly surprised at how well the participants respected and tolerated the study procedures, such as performing the imagery therapy daily and wearing the headband at night,” says Schwartz’ colleague Lampros Perogamvros. In order to rule out that the nocturnal sound exposure is responsible for a possible effect independent of the associated associations, subjects from the control group also had to wear the headband.
The result: As expected with Imagery Rehearsal Therapy, all subjects reported fewer nightmares over the course of therapy. However, in people who had formed associations with the sound, nightmares decreased even more and they reported positive emotions in their dreams more often. Even at a follow-up three months later, subjects who had received the combination therapy reported fewer nightmares. “For us as researchers and clinicians, these results are very promising, both for studying emotional processing during sleep and for developing new therapies,” says Perogamvros. In further studies, the team now wants to clarify to what extent the results can be generalized with larger numbers of test subjects and including different population groups.
Source: Sophie Schwartz (University of Geneva, Switzerland) et al., Current Biology, doi: 10.1016/j.cub.2022.09.032