Enhancing imagery rehearsal therapy for nightmares with targeted memory reactivation.

Pairing a sound with imagery rehearsal therapy during REM sleep reduces nightmare frequency and increases positive dream emotions more than therapy alone. Thirty-six patients with nightmare disorder performed one initial therapy session where half heard a sound while generating a positive nightmare outcome; the other half did not. All patients then practiced therapy nightly at home for two weeks while a wireless headband played the sound during REM sleep. After two weeks, the group that heard the sound reported fewer nightmares and more positive dream emotions, and the reduction in nightmares persisted at three months. The results indicate that targeted memory reactivation during REM sleep can strengthen therapy effects and modulate dream emotions.

Study at a glance

Abstract

Nightmare disorder (ND) is characterized by dreams with strong negative emotions occurring during rapid eye movement (REM) sleep. ND is mainly treated by imagery rehearsal therapy (IRT), where the patients are asked to change the negative story line of their nightmare to a more positive one. We here used targeted memory reactivation (TMR) during REM sleep to strengthen IRT-related memories and accelerate remission of ND. Thirty-six patients with ND were asked to perform an initial IRT session and, while they generated a positive outcome of their nightmare, half of the patients were exposed to a sound (TMR group), while no such pairing took place for the other half (control group). During the next 2 weeks, all patients performed IRT every evening at home and were exposed to the sound during REM sleep with a wireless headband, which automatically detected sleep stages. The frequency of nightmares per week at 2 weeks was used as the primary outcome measure. We found that the TMR group had less frequent nightmares and more positive dream emotions than the control group after 2 weeks of IRT and a sustained decrease of nightmares after 3 months. By demonstrating the effectiveness of TMR during sleep to potentiate therapy, these results have clinical implications for the management of ND, with relevance to other psychiatric disorders too. Additionally, these findings show that TMR applied during REM sleep can modulate emotions in dreams.