Post-traumatic stress disorder (PTSD) is a severe psychiatric disorder with traumatic memories at its core, resulting in flashbacks and nightmares. Post-treatment sleep may offer a unique time window to increase therapeutic efficacy through consolidation of therapeutically modified traumatic memories. Targeted memory reactivation (TMR) is a novel technique to enhance memory consolidation by presenting reminder cues (e.g., sounds associated with a memory) during sleep.
Reactivating memories during sleep
In the study, project leaders Van Marle and Van der Heijden, together with prof. Odile van den Heuvel, prof. Ysbrand van der Werf (department of Psychiatry, Amsterdam UMC) and dr. Lucia Talamini (UvA) applied TMR for the first time in PTSD patients to strengthen therapeutic memories during sleep after one treatment session with eye movement desensitization and reprocessing (EMDR). At night, while their sleep was assessed with EEG, PTSD patients received either TMR with the EMDR clicks as a reactivation cue (n = 17), or sham stimulation (n = 16).
Findings show that compared to sham stimulation, TMR led to stimulus-locked increases in slow oscillation (SO) and spindle dynamics, sleep parameters known to underlie memory consolidation. Importantly, within the TMR group, these induced changes in sleep physiology were correlated with greater reductions in PTSD symptoms.
First proof of principle
These findings thus suggest that TMR may have strengthened the consolidation of the EMDR-treatment memory. In addition, the team found that patients who received TMR were less inclined to avoid their traumatic memory when they listened to an audio clip retelling their traumatic events. No other clinical benefit of TMR vs EMDR alone was observed. Together with the fact that TMR did not disturb sleep or trigger nightmares, these findings provide the first proof of principle that TMR may be a safe and viable future treatment augmentation strategy for PTSD. A follow-up experiment is planned to start in fall 2024, in which the team plans to administer TMR after treatment for five consecutive nights. Their aim is to unlock the full clinical potential of TMR and open up sleep as a new treatment window for PTSD.
Read the publication in Current Biology: Targeted memory reactivation to augment treatment in post-traumatic stress disorder.