Combining Trauma Script Exposure With rTMS to Reduce Symptoms of Post-Traumatic Stress Disorder: Randomized Controlled Trial

The effect of transcranial direct current and magnetic stimulation on fear extinction and return of fear: A meta-analysis and systematic review

BACKGROUND

We conducted a meta-analysis and qualitative review on the randomized controlled trials investigating the effects of transcranial direct current stimulation and transcranial magnetic stimulation on fear extinction and the return of fear in non-primate animals and humans.

METHODS

The meta-analysis was conducted by searching PubMed, Web of science, PsycINFO, and Cochrane Library and extracting fear response in the active and sham groups in the randomized controlled trials. The pooled effect size was quantified by Hedges' g using a three-level meta-analytic model in R.

RESULTS

We identified 18 articles on the tDCS effect and 5 articles on the TMS effect, with 466 animal subjects and 621 human subjects. Our findings show that tDCS of the prefrontal cortex significantly inhibit fear retrieval in animal models (Hedges' g = -0.50). In human studies, TMS targeting the dorsolateral/ventromedial prefrontal cortex has an inhibiting effect on the return of fear (Hedges' g = -0.24).

LIMITATIONS

The limited number of studies and the heterogeneous designs of the selected studies made cross-study and cross-species comparison difficult.

CONCLUSIONS

Our findings shed light on the optimal non-invasive brain stimulation protocols for targeting the neural circuitry of threat extinction in humans.

Efficacy and acceptability of noninvasive brain stimulation for treating posttraumatic stress disorder symptoms: A network meta-analysis of randomized controlled trials

INTRODUCTION

Despite its high lifetime prevalence rate and the elevated disability caused by posttraumatic stress disorder (PTSD), treatments exhibit modest efficacy. In consideration of the abnormal connectivity between the dorsolateral prefrontal cortex (DLPFC) and amygdala in PTSD, several randomized controlled trials (RCTs) addressing the efficacy of different noninvasive brain stimulation (NIBS) modalities for PTSD management have been undertaken. However, previous RCTs have reported inconsistent results. The current network meta-analysis (NMA) aimed to compare the efficacy and acceptability of various NIBS protocols in PTSD management.

METHODS

We systematically searched ClinicalKey, Cochrane Central Register of Controlled Trials, Embase, ProQuest, PubMed, ScienceDirect, Web of Science, and ClinicalTrials.gov to identify relevant RCTs. The targeted RCTs was those comparing the efficacy of NIBS interventions, such as transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation (rTMS), and transcutaneous cervical vagal nerve stimulation, in patients with PTSD. The NMA was conducted using a frequentist model. The primary outcomes were changes in the overall severity of PTSD and acceptability (to be specific, rates of dropouts for any reason).

RESULTS

We identified 14 RCTs that enrolled 686 participants. The NMA demonstrated that among the investigated NIBS types, high-frequency rTMS over bilateral DLPFCs was associated with the greatest reduction in overall PTSD severity. Further, in comparison with the sham controls, excitatory stimulation over the right DLPFC with/without excitatory stimulation over left DLPFC were associated with significant reductions in PTSD-related symptoms, including depression and anxiety symptoms, and overall PTSD severity.

CONCLUSIONS

This NMA demonstrated that excitatory stimulation over the right DLPFC with or without excitatory stimulation over left DLPFC were associated with significant reductions in PTSD-related symptoms.

TRIAL REGISTRATION

PROSPERO CRD42023391562.

Enhancing Agency in Posttraumatic Stress Disorder Therapies Through Sensorimotor Technologies

Posttraumatic stress disorder (PTSD) is a significant public health concern, with only a third of patients recovering within a year of treatment. While PTSD often disrupts the sense of body ownership and sense of agency (SA), attention to the SA in trauma has been lacking. This perspective paper explores the loss of the SA in PTSD and its relevance in the development of symptoms. Trauma is viewed as a breakdown of the SA, related to a freeze response, with peritraumatic dissociation increasing the risk of PTSD. Drawing from embodied cognition, we propose an enactive perspective of PTSD, suggesting therapies that restore the SA through direct engagement with the body and environment. We discuss the potential of agency-based therapies and innovative technologies such as gesture sonification, which translates body movements into sounds to enhance the SA. Gesture sonification offers a screen-free, noninvasive approach that could complement existing trauma-focused therapies. We emphasize the need for interdisciplinary collaboration and clinical research to further explore these approaches in preventing and treating PTSD.

Critically Assessing the Unanswered Questions of How, Where, and When to Induce Plasticity in the Posttraumatic Stress Disorder Network With Transcranial Magnetic Stimulation

Extinction of traumatic memory, a primary treatment approach (termed exposure therapy) in posttraumatic stress disorder (PTSD), occurs through relearning and may be subserved at the molecular level by long-term potentiation of relevant circuits. In parallel, repetitive transcranial magnetic stimulation (TMS) is thought to work through long-term potentiation-like mechanisms and may provide a novel, safe, and effective treatment for PTSD. In a recent failed randomized controlled trial we emphasized the necessity of correctly identifying cortical targets, the directionality of TMS protocols, and the role of memory activation. Here, we provide a systematic review of TMS for PTSD to further identify how, where, and when TMS treatment should be delivered to alleviate PTSD symptoms. We conducted a systematic review of the literature by searching for repetitive TMS clinical trials involving patients with PTSD and outcomes. We searched MEDLINE through October 25, 2023, for "TMS and PTSD" and "transcranial magnetic stimulation and posttraumatic stress disorder." Thirty-one publications met our inclusion criteria (k = 17 randomized controlled trials, k = 14 open label). Randomized controlled trial protocols were varied in terms of TMS protocols, cortical TMS targets, and memory activation protocols. There was no clear superiority of low-frequency (k = 5) versus high-frequency (k = 6) protocols or by stimulation location. Memory provocation or exposure protocols (k = 7) appear to enhance response. Overall, TMS appears to be effective in treating PTSD symptoms across a variety of TMS frequencies, hemispheric target differences, and exposure protocols. Disparate protocols may be conceptually harmonized when viewed as potentiating proposed anxiolytic networks or suppressing anxiogenic networks.

Explore the durability of repetitive transcranial magnetic stimulation in treating post-traumatic stress disorder: An updated systematic review and meta-analysis

The objective was to synthesize results from studies that assessed symptom relief after repetitive transcranial magnetic stimulation (rTMS) treatment for post-traumatic stress disorder (PTSD) and investigate the long-term effectiveness of rTMS for treating PTSD. We searched multiple databases for relevant randomized controlled trials of rTMS for PTSD treatment up to 1 January 2023. Two researchers evaluated the studies and focused on the CAPS and PCL as outcome indicators. We used STATA17 SE software for the data analysis. Eight articles involving 309 PTSD patients were analysed in a meta-analysis, which found that rTMS had a significant and large effect on reducing core post-traumatic symptoms [Hedges'g = 1.75, 95% CI (1.18, 2.33)]. Both low and high-frequency rTMS also significantly reduced symptoms, with the latter having a greater effect. rTMS was shown to have a long-term effect on PTSD, with all three subgroup analyses demonstrating significant results. Interestingly, no significant difference in symptom relief was found between the follow-up and completion of treatments [Hedges'g = 0.01, 95% CI (-0.30, 0.33)], suggesting that the treatment effect of rTMS is stable. The meta-analysis provides strong evidence that rTMS is effective in reducing the severity and symptoms of PTSD in patients, and follow-up studies confirm its long-term stability.

Disentangling the Link Between Mindfulness and Dissociation in PTSD: The Mediating Role of Attention and Emotional Acceptance

INTRODUCTION

A number of studies have investigated the relationship between mindfulness and dissociation and suggested that mindfulness-based interventions could be effective in the treatment of dissociative symptoms. A recent study in healthy volunteers found that attention and emotional acceptance mediates this relationship. However, no study has yet been performed among a clinical sample to assess this association.

METHOD

We recruited 90 patients (76 women) suffering from Posttraumatic Stress Disorder (PTSD). They completed self-report questionnaires to measure PTSD, dissociation, emotion regulation difficulties, childhood trauma, mindfulness abilities and cognitive abilities.

RESULTS

We found that mindfulness abilities, emotional difficulties, dissociation and attention-concentration were all related to each other. Using a step-by-step approach and bootstrapping techniques, we found a significant indirect effect of mindfulness abilities on dissociation through non-acceptance (confidence interval 95%=-.14 to -.01) and attentional difficulties (confidence interval 95%=-.23 to -.05).

CONCLUSION

Patients with higher levels of dissociative symptoms have less capacity for mindfulness. Our results support Bishop et al.'s model proposing that attention and emotional acceptance are the two active components of mindfulness. To extend our findings, clinical trials are required to evaluate a causal relationship and the effectiveness of mindfulness-based interventions for patients suffering from dissociation.

A transdiagnostic meta-analysis of acute augmentations to psychological therapy

At least half of all patients with mental health disorders do not respond adequately to psychological therapy. Acutely enhancing particular biological or psychological processes during psychological therapy may improve treatment outcomes. However, previous studies are confined to specific augmentation approaches, typically assessed within single diagnostic categories. Our objective was to assess to what degree acute augmentations of psychological therapy reduce psychiatric symptoms and estimate effect sizes of augmentation types (for example, brain stimulation or psychedelics). We searched Medline, PsycINFO and Embase for controlled studies published between database inception and 25 May 2022. We conducted a preregistered random-effects meta-analysis (PROSPERO CRD42021236403). We identified 108 studies (N = 5,889). Acute augmentation significantly reduced the severity of mental health problems (Hedges' g = -0.27, 95% CI: [-0.36, -0.18]; P < 0.0001), particularly for the transdiagnostic dimensions 'Fear' and 'Distress'. This result survived a trim-and-fill analysis to account for publication bias. Subgroup analyses revealed that pharmacological, psychological and somatic augmentations were effective, but to varying degrees. Acute augmentation approaches are a promising route to improve outcomes from psychological therapy.

Effectiveness of repetitive transcranial magnetic stimulation combined with a brief exposure procedure for post-stroke posttraumatic stress disorder

The incidence of posttraumatic stress disorder (PTSD) following stroke ranges from 6.5 % to 25 %. Presently few studies have focused on its treatment. Repetitive transcranial magnetic stimulation (rTMS) is often applied as a rehabilitation method after stroke, and it also represents a novel approach to PTSD. The aim of this study was to explore the effect of rTMS (or combined with a brief stroke re-exposure) on treating post-stroke PTSD. Sixty participants with post-stroke PTSD were randomly assigned into three groups (rTMS + brief exposure group, TMS + BE; rTMS alone group, TMS; sham treatment group, ST) and received 10 sessions of treatment accordingly over two weeks. Changes in PTSD symptoms (Impact of Event Scale-Revised, IES-R) were evaluated at pre-treatment (T1), the end of the first (T2), and the end of the second treatment week (T3). At the three-month follow-up (T4), a PTSD interview and IES-R assessment were given. Results showed that from T1 to T3, IES-R (and its intrusion subscale) scores of TMS + BE group and TMS group were significantly lower than the ST group, and the effect remained at three-month follow-up. The treatment effect was comparable between TMS + BE group and TMS group at T3, however, it was better for TMS + BE group than TMS group at T2, indicating a brief exposure promotes the effect of rTMS. At follow-up, the rates of PTSD were lower in TMS + BE group and TMS group than ST group. In conclusion, rTMS can effectively treat post-stroke PTSD and the effects may be accelerated by combining a brief exposure procedure. TRIAL REGISTRATION: Chinese Clinical Trial Registry, identifier: ChiCTR2100043444.

Contemporary Approaches Toward Neuromodulation of Fear Extinction and Its Underlying Neural Circuits

Neuroscience and neuroimaging research have now identified brain nodes that are involved in the acquisition, storage, and expression of conditioned fear and its extinction. These brain regions include the ventromedial prefrontal cortex (vmPFC), dorsal anterior cingulate cortex (dACC), amygdala, insular cortex, and hippocampus. Psychiatric neuroimaging research shows that functional dysregulation of these brain regions might contribute to the etiology and symptomatology of various psychopathologies, including anxiety disorders and post traumatic stress disorder (PTSD) (Barad et al. Biol Psychiatry 60:322-328, 2006; Greco and Liberzon Neuropsychopharmacology 41:320-334, 2015; Milad et al. Biol Psychiatry 62:1191-1194, 2007a, Biol Psychiatry 62:446-454, b; Maren and Quirk Nat Rev Neurosci 5:844-852, 2004; Milad and Quirk Annu Rev Psychol 63:129, 2012; Phelps et al. Neuron 43:897-905, 2004; Shin and Liberzon Neuropsychopharmacology 35:169-191, 2009). Combined, these findings indicate that targeting the activation of these nodes and modulating their functional interactions might offer an opportunity to further our understanding of how fear and threat responses are formed and regulated in the human brain, which could lead to enhancing the efficacy of current treatments or creating novel treatments for PTSD and other psychiatric disorders (Marin et al. Depress Anxiety 31:269-278, 2014; Milad et al. Behav Res Ther 62:17-23, 2014). Device-based neuromodulation techniques provide a promising means for directly changing or regulating activity in the fear extinction network by targeting functionally connected brain regions via stimulation patterns (Raij et al. Biol Psychiatry 84:129-137, 2018; Marković et al. Front Hum Neurosci 15:138, 2021). In the past ten years, notable advancements in the precision, safety, comfort, accessibility, and control of administration have been made to the established device-based neuromodulation techniques to improve their efficacy. In this chapter we discuss ten years of progress surrounding device-based neuromodulation techniques-Electroconvulsive Therapy (ECT), Transcranial Magnetic Stimulation (TMS), Magnetic Seizure Therapy (MST), Transcranial Focused Ultrasound (TUS), Deep Brain Stimulation (DBS), Vagus Nerve Stimulation (VNS), and Transcranial Electrical Stimulation (tES)-as research and clinical tools for enhancing fear extinction and treating PTSD symptoms. Additionally, we consider the emerging research, current limitations, and possible future directions for these techniques.