For people tormented by recurring nightmares, sleeping without problems would be a dream come true. Now, in a small experiment, neuroscientists have demonstrated a technique that, for some, can chase away bad dreams.
Improving standard treatment for nightmare disorder with a memory-boosting technique reduced the average number of weekly nightmares among a few dozen people from three to almost zeroresearchers report online Oct. 27 at current biology.
“The fact that they can actually make a big difference in the frequency of those nightmares is huge,” says Gina Poe, a neuroscientist at UCLA who was not involved in the study.
People with nightmare disorder fear the night not because of the monsters under the bed, but because of the monsters in their dreams. Frequent and frightening dreams disturb sleep and even affect well-being in waking life. The gold standard treatment for nightmare disorder is imagery rehearsal therapy, or IRT. In this treatment, patients reimagine nightmares with a positive spin, mentally rehearsing the new story while awake. Reduces nightmares for most, but fails for nearly a third of people.
To increase the power of IRT, neuroscientist Sophie Schwartz of the University of Geneva and her colleagues harnessed a learning technique called directed memory reactivation, or TMR. In this technique, a person focuses on learning something while a sound is playing, and that same signal is played again during sleep. Experiencing the signal during sleep, which is important for memory storagecan reactivate and strengthen associated memory (Serial number: 3/10/19).
In the new study, researchers trained 36 people with nightmare disorders on IRT and randomly assigned half of them to rehearse their revised nightmares in silence. The other half rehearsed while playing a short piano chord, the TMR cue, every 10 seconds for five minutes.
For two weeks, the participants practiced IRT daily and kept a dream diary. While they slept, a sensor-equipped headband recorded the electrical activity of their brains and tracked their sleep stages. The piano chord served as the soundtrack to the dreams, with the headband playing every 10 seconds during rapid eye movement, the sleep stage associated with dreams. The headband played the sound for all participants, but only half had come to associate the sound with their new setting during IRT training.
For those trained in the chord, TMR nearly beat the nightmares, lowering the weekly average from three to 0.2, and even encouraged happier dreams. The IRT-only group also improved, but still averaged a weekly nightmare.
The TMR-IRT combination also had more staying power after three months, with the average for that group increasing only slightly from about 0.2 to 0.3 nightmares a week, while the IRT-only group increased to 1.5 .
Larger studies will be needed to test how generalizable this combination of treatments is. This study involved a small number of people, all young adults aged 20 to 35 who had nightmare disorder and no other psychiatric conditions. The study also did not compare IRT and TMR to any treatment, although the researchers write that previous studies have already shown how effective IRT can be.
If a TMR-IRT combo proves to be that strong in future research, it still has a ways to go before it becomes widely accessible. Commercially available sleep trackers in watches and rings have yet to distinguish between sleep stages as accurately as brain-monitoring tools.
Even with these caveats, the results are encouraging, says Poe. She suggests that future studies could test whether the TMR-IRT combination can help people with post-traumatic stress disordero PTSD, where nightmares repeat traumatic events (serial number 9/12/14).
That’s something Schwartz wants to test. “I’m not sure we’ll be successful with these particular patients,” she says. “But if we do, it would be a very important addition to the methods we have to treat PTSD.”