Targeted Memory Reactivation During REM Sleep in Patients With Social Anxiety Disorder

Abstract

BackgroundSocial anxiety disorder (SAD) is characterized by a significant amount of fear when confronted to social situations. Exposure therapy, which is based on fear extinction, does not often lead to full remission. Here, based on evidence showing that rapid eye movement (REM) sleep promotes the consolidation of extinction memory, we used targeted memory reactivation (TMR) during REM sleep to enhance extinction learning in SAD.MethodsForty-eight subjects with SAD were randomly assigned to two groups: control or TMR group. All patients had two successive exposure therapy sessions in a virtual reality (VR) environment, where they were asked to give a public talk in front of a virtual jury. At the end of each session, and only in the TMR group (N = 24), a sound was paired to the positive feedback phase of therapy (i.e., approval of their performance), which represented the memory to be strengthened during REM sleep. All participants slept at home with a wearable headband device which automatically identified sleep stages and administered the sound during REM sleep. Participants' anxiety level was assessed using measures of parasympathetic (root mean square of successive differences between normal heartbeats, RMSSD) and sympathetic (non-specific skin conductance responses, ns-SCRs) activity, and subjective measures (Subjective Units of Distress Scale, SUDS), during the preparation phase of their talks before (T1) and after (T2) one full-night's sleep and after 1 week at home (T3). Participants also filled in a dream diary.ResultsWe observed an effect of time on subjective measures of anxiety (SUDS). We did not find any difference in the anxiety levels of the two groups after 1 week of TMR at home. Importantly, the longer the total duration of REM sleep and the more stimulations the TMR group had at home, the less anxious (increased RMSSD) these participants were. Finally, fear in dreams correlated positively with ns-SCRs and SUDS at T3 in the TMR group.ConclusionTMR during REM sleep did not significantly modulate the beneficial effect of therapy on subjective anxiety. Yet, our results support that REM sleep can contribute to extinction processes and substantiate strong links between emotions in dreams and waking stress levels in these patients.

Influencing dreams through sensory stimulation: a systematic review

“…The earliest study among our selection was issued in 1958 (Dement & Wolpert, 1958) and the publication count has steadily increased ever since, with the most recent article appearing in 2022 (Borghese et al, 2022; Figure 4). The studies are characterised by a very high heterogeneity in terms of experimental protocols and methodologies, both across and within modalities.…”

“…Very recently, Borghese and colleagues reported the results of an auditory TMR procedure aimed at favouring social fear extinction in a group of subjects suffering from social anxiety (Borghese et al, 2022). They recruited 48 patients who participated in two virtual-realitybased exposure therapy sessions; for half the subjects, the positive feedback phase was paired to an auditory cue.…”

Evidence for an emotional adaptive function of dreams: a cross-cultural study

“…Data from the Global North populations were drawn from previously published studies done in Switzerland, Belgium, and Canada. The Switzerland and Belgium samples were generated between 2014 and 2022 25,26,[53][54][55] and included data from three groups: a non-patient group of young healthy participants, patients suffering from social anxiety disorder (SAD), and patients suffering from nightmare disorder. Participants in these studies all kept the same sleep and dream diary (for details see 18 ).…”

“…Dreams were also collected from patients suffering from social anxiety disorder (SAD) according to The Diagnostic and Statistical Manual of Mental Disorders (DSM5) 26,56 . SAD is characterized by a persistent amount of fear when confronted with social situations 57 .…”

An update on recent advances in targeted memory reactivation during sleep

“…More recent studies explored other aspects of memory via TMR, such as the persistence of TMR effects over longer time periods 12 , 13 , the role of interference between cues 14 , and the possibility of inducing memory forgetting 15 , 16 . What is more, some studies combined TMR with other methodologial approches such as virtual reality settings 17 , 18 , functional magnetic resonamce imaging (fMRI) and intracranial recordings to investigate specific brain areas activated during TMR 12 , 13 , 19 , 20 . Additionally, recent studies combined TMR with closed-loop stimulation to test the best time point for cue delivery in the ongoing oscillatory activity 21 , 22 .…”