'Processing traumatic memories in sleep may change brain to improve PTSD symptoms

Currently, the first-choice treatment for PTSD is exposure-based psychotherapy, where therapists help rewire the emotions associated with the traumatic memory in the patient's brain, shifting from fear and arousal to a more neutral response. However, up to 50% of patients fail to respond well to this treatment. In a new study published on August 7 in the Cell Press journal Current Biology, scientists showed for the first time that reactivating therapeutically-altered memories during sleep leads to more brain activity related to memory processing, which is associated with a reduction in PTSD symptoms.

"Our goal is to unlock sleep as a new treatment window for PTSD," says Hein van Marle, one of the paper's senior authors and the study's principal investigator at Amsterdam University Medical Center. "This is the first proof of concept for potentially enhancing daytime treatment effects during sleep."

PTSD is a mental health disorder that can occur after experiencing or witnessing a traumatic event. People with PTSD may experience flashbacks, nightmares, heightened vigilance, hyperarousal, and mood and sleep problems. Currently available treatments for PTSD include eye movement desensitization and reprocessing (EMDR), where therapists guide patients through their traumatic memories while using a moving light or clicking sounds to distract them.

EMDR has shown positive results, but Van Marle says that success is low and dropping out from the treatment program is common among patients because revisiting traumatic memories is emotionally demanding.

So Van Marle and his collaborators, including first author Christa van der Heijden at Amsterdam University Medical Center and Lucia Talamini at the University of Amsterdam, set out to investigate how to boost the effect of EMDR treatment and make it long-lasting.

Sleep provides a unique opportunity to enhance the memory of newly formed emotional reactions to traumatic events. During sleep, the brain focuses on consolidating memories and storing information for the long term.

Previous research has shown that if someone forms a new memory in the presence of an experimentally administered sound or scent, exposing them to the sound or scent while they sleep can improve their ability to recall that memory after waking up. This memory-enhancement technique is called targeted memory reactivation (TMR).

During Van Marle's experiment, the team first performed an EMDR session with a standard clicking sound in the background for 33 PTSD patients in the evening. At night, the researchers recorded these patients' brain waves while they slept in the laboratory. For 17 of the patients, the team conducted TMR by playing the clicking sound used during the earlier EMDR session again when they were asleep, aiming to boost the storage of the EMDR treatment memory and alleviate PTSD symptoms.

They found that patients who received the sound during sleep showed higher levels of brain wave activities associated with memory processing and consolidation compared with participants who received no clicking sounds during sleep.

Journal Reference:

1. Anna C. van der Heijden, Ysbrand D. van der Werf, Odile A. van den Heuvel, Lucia M. Talamini, Hein J.F. van Marle. Targeted memory reactivation to augment treatment in post-traumatic stress disorder. Current Biology, 2024; DOI: 10.1016/j.cub.2024.07.019

https://www.sciencedaily.com/releases/2024/08/240807122724.htm