Electroconvulsive therapy for post-traumatic stress disorder: efficacy, mechanisms and a hypothesis for new directions

The Role of Electroconvulsive Therapy in Posttraumatic Stress Disorder: A Systematic Review

ABSTRACT

Posttraumatic stress disorder (PTSD) is associated with a high burden of disability and mortality. Despite standard treatments with antidepressants and/or psychotherapy, remission is often difficult to achieve. Electroconvulsive therapy (ECT) is an effective treatment for mood disorders but is currently not recognized as a treatment modality for PTSD. The literature about its potential role in the management of PTSD is growing. Thus, we aim to systematically review the available evidence for the role of ECT in PTSD.Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 guidelines, we performed a systematic literature search from 1958 to December 2023 using PubMed, Embase, Web of Science, Cochrane Central Register of Controlled trials databases, and the Clinicaltrials.gov-registry.Eighteen studies met our inclusion criteria: 1 meta-analysis, 2 randomized control trials, 2 prospective, 4 retrospective studies, 8 case reports, and 2 reviews.Accumulating evidence suggests that ECT might have a beneficial effect on the core symptoms of PTSD with comorbid conditions, such as depression or schizophrenia. Although in some studies, the effect on core PTSD symptoms was not related to an antidepressant effect of ECT, these findings need further replication. Nevertheless, in severe and intractable cases, ECT can be considered, especially in the presence of comorbid depression. Further research in patients without comorbidity is warranted.

Evaluating the effect of electroconvulsive therapy (ECT) on post-traumatic stress disorder (PTSD): A systematic review and meta-analysis of five studies

ECT has been proposed as a potential treatment for PTSD. There is a small number of clinical studies to date, but no quantitative review of the efficacy has been conducted. We performed a systematic review and meta-analysis to evaluate the effect of ECT in reducing PTSD symptoms. We followed the PICO and the PRISMA guidelines and searched PubMed, MEDLINE (Ovid), EMBASE (Ovid), Web of Science, and the Cochrane Central Register of Controlled Trials (PROSPERO No: CRD42022356780). A random effects model meta-analysis was conducted with the pooled standard mean difference, applying Hedge's adjustment for small sample sizes. Five within-subject studies met the inclusion criteria, containing 110 patients with PTSD symptoms receiving ECT (mean age 44.13 ± 15.35; 43.4% female). ECT had a small but significant pooled effect on reducing PTSD symptoms (Hedges' g = -0.374), reducing intrusion (Hedges' g = -0.330), avoidance (Hedges' g = -0.215) and hyperarousal (Hedges' g = -0.171) symptoms. Limitations include the small number of studies and subjects and the heterogeneity of study designs. These results provide preliminary quantitative support for the use of ECT in the treatment of PTSD.

Cathodal transcranial direct current stimulation on the prefrontal cortex applied after reactivation attenuates fear memories and prevent reinstatement after extinction

BACKGROUND

In the last decade, pharmacological strategies targeting reconsolidation after memory retrieval have shown promising efforts to attenuate persistent memories and overcome fear recovery. However, most reconsolidation inhibiting agents have not been approved for human testing. While non-invasive neuromodulation can be considered an alternative approach to pharmacological treatments, there is a lack of evidence about the efficacy of these technologies when modifying memory traces via reactivation/reconsolidation mechanism.

OBJECTIVE

In this study, we evaluate the effect of cathodal (c-tDCS) and anodal (a-DCS) transcranial direct current stimulation applied after memory reactivation and extinction in rats.

METHODS

Male Wistar rats were randomly assigned into three groups: one sham group, one anodal tDCS group, and one cathodal tDCS group (500 μA, 20 min). Reconsolidation and extinction of fear memories were evaluated using a contextual fear conditioning.

RESULTS

Our results showed that c-tDCS and a-tDCS after memory reactivation can attenuate mild fear memories. However, only c-tDCS stimulation prevented both fear expression under strong fear learning and fear recovery after a reinstatement protocol without modification of learning rate or extinction retrieval. Nevertheless, the remote memories were resistant to modification through this type of neuromodulation. Our results are discussed considering the interaction between intrinsic excitability promoted by learning and memory retrieval and the electric field applied during tDCS.

CONCLUSION

These results point out some of the boundary conditions influencing the efficacy of tDCS in fear attenuation and open new ways for the development of noninvasive interventions aimed to control fear-related disorders via reconsolidation.

Electroconvulsive Therapy for Trauma-Related Nightmares: A Case Report and Commentary

Trauma-related nightmares (TRN), one of the most reported symptoms of posttraumatic stress disorder (PTSD), may not always respond to current pharmacologic and therapeutic treatments. Validity of electroconvulsive therapy (ECT), which is used worldwide in clinical treatment for a broad range of neuropsychiatric conditions, is investigated as a potential therapeutic option for TRN in this report. A case of a 39-year-old male with a history of severe combat-related PTSD, major depressive disorder, history of traumatic brain injury, suicidal ideations, and persistent TRN is discussed here. Successful treatment outcome of this case with six sessions of right unilateral ECT is presented. On initial presentation, the patient had a Patient Health Questionnaire-9 (PHQ-9) score of 27 and a Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5) score of 77. After six sessions of ECT, the patient had a PHQ-9 score of 3 and a PCL-5 score of 45. Furthermore, the rationale and potential mechanisms of action underlying the ECT treatment for treatment-resistant PTSD and TRN are also reviewed in this report.

Electroconvulsive therapy with a memory reactivation intervention for post-traumatic stress disorder: A randomized controlled trial

BACKGROUND

Post-traumatic Stress Disorder (PTSD) often does not respond to available treatments. Memories are vulnerable to disruption during reconsolidation, and electroconvulsive therapy (ECT) has amnestic effects OBJECTIVE/HYPOTHESIS: To test the use of ECT to disrupt the reconsolidation of traumatic memories as a potential treatment for PTSD METHODS: Participants were adults from the civilian population and were referred for ECT treatment for severe depression with comorbid PTSD symptoms. Twenty-eight participants were randomly assigned to reactivation of a traumatic or non-traumatic memory using audio script driven imagery prior to each ECT treatment. Primary outcomes were change in scores on the Modified PTSD Symptom Scale - Self Report (MPSS-SR) and the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5). Secondary outcomes included a comparison of the change in heart rate while listening to the script RESULTS: Twenty-five female patients who completed a post-ECT assessment were included in the analysis. No significant group differences were found in the MPSS-SR or CAPS-5 scores from pre-ECT to post-ECT or 3-month follow-ups. However, both groups improved at post-ECT and 3-month follow up. Partial eta squared estimates of effect size showed large effect sizes for all outcomes (η² > 0.13). Changes in heart rate were not significantly different between groups or over time CONCLUSIONS: ECT paired with pre-treatment traumatic memory reactivation was not more effective for treating PTSD symptoms than ECT with non-traumatic memory reactivation. While our primary hypothesis was not supported, our data provides further support for the efficacy of ECT for improving symptoms of PTSD with comorbid depression. ClinicalTrials.gov. https://clinicaltrials.gov/ct2/show/NCT04027452.

IDENTIFIER

NCT04027452.

Treating Posttraumatic Stress Disorder Symptoms With Low Amplitude Seizure Therapy (LAP-ST) Compared With Standard Right Unilateral Electroconvulsive Therapy: A Pilot Double-Blinded Randomized Clinical Trial

OBJECTIVES

An important barrier to further studying electroconvulsive therapy (ECT) in posttraumatic stress disorder (PTSD) is the cognitive adverse effects. However, recent data suggest that low amplitude seizure therapy (LAP-ST) has no or minimal cognitive adverse effects. The aims of this report were to examine the efficacy of LAP-ST in PTSD and to compare LAP-ST with standard right unilateral (RUL) ECT using a pilot randomized clinical trial.

METHODS

Patients were randomized to LAP-ST or RUL ECT. Posttraumatic stress disorder was assessed using clinical interview based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, and symptom severity with PTSD Checklist (PCL). The scores pertaining to PCL were analyzed using descriptive analysis for this pilot study.

RESULTS

Eleven patients consented to be enrolled. Seven were randomly allocated to LAP-ST or RUL ECT. Five completed the study and had completed PCL before and after the course. In both groups, PTSD symptoms showed fast improvement. The effect size of improvement seems promising. The mean baseline PCL score for patients in the LAP-ST group was 42.5 (SD = 16.26) and the mean end point PCL score after treatment was 31 (SD = 15.56). The mean baseline PCL score for patients in the standard RUL ECT group was 64.7 (SD = 1.15) and the mean end point was 41 (SD = 15.62).

CONCLUSIONS

Both LAP-ST and standard RUL ECT showed reduction in PTSD symptoms with fast improvement. This first PTSD LAP-ST study adds support to the prior LAP-ST proof-of-concept clinical trial that LAP-ST can produce effective therapeutic outcomes. Replication of this trial is warranted in larger clinical trials (ClinicalTrials.gov ID: NCT02583490).

Efficacy of donepezil for the attenuation of memory deficits associated with electroconvulsive therapy

We sought to confirm and extend the findings of studies that reported that acetylcholinesterase inhibitor drugs protect against electroconvulsive therapy (ECT)-induced cognitive impairment. We randomized 30 patients with depression (n=24) or schizophrenia (n=6) to receive either donepezil (10 mg/day; n=15) or placebo (n=15) during a fixed course of 6 thrice-weekly, modified, bifrontotemporal sine wave ECT, and for 30 days subsequently. We assessed memory using the Postgraduate Institute Memory Scale (PGI-MS) at baseline, and again at days 2, 7, and 30 after the ECT course. At baseline, memory functioning was comparable in the 2 groups. At 2 days post-ECT, memory functioning was impaired on almost all 10 subtests and on the total scale. At 30 days post-ECT, memory functioning improved to (numerically) above baseline levels on almost all subtests and on the total scale, with the bulk of the improvement evident by day 7, itself. There was no significant difference between groups in the primary outcome, improvement in PGI-MS scores between Days 2 and 30 post-ECT. On almost all subtests, also, there was no significant difference between groups. In summary, we found that donepezil (10 mg/day) did not improve memory outcomes after ECT.

Neuromodulatory treatments for post-traumatic stress disorder (PTSD)

Electroconvulsive therapy has been used successfully in some individuals with posttraumatic stress disorder (PTSD) whose symptoms have not improved with other treatments. But there are only a few reports. Meanwhile, an array of new neuromodulation strategies, including repetitive transcranial magnetic stimulation, transcranial direct current stimulation, vagus nerve stimulation, trigeminal nerve stimulation, and deep brain stimulation have been developed and applied experimentally in the treatment of other psychiatric disorders. This article will review the clinical evidence and mechanistic basis for their use in PTSD.

Electroconvulsive therapy regulates emotional memory bias of depressed patients

Emotional memory bias is considered to be an important base of the etiology of depression and can be reversed by antidepressants via enhancing the memory for positive stimuli. Another antidepressant treatment, electroconvulsive therapy (ECT), has rapid antidepressant effect and frequently causes short-term memory impairment. However, it is unclear about the short-term effect of ECT on memory bias. In this study, the incidental memory task with emotional pictures were applied to evaluate the emotional memory of twenty depressed patients at pre- and post-ECT (three days after ECT) compared to twenty healthy controls. The depressive symptoms were evaluated using the Hamilton rating scale of depression (HRSD). Before ECT, patients showed decreased recognition memory for positive pictures compared to controls and remembered negative pictures more easily than positive pictures in the recognition task. In patients, the main effect of session (pre-ECT and post-ECT) was significant for both recognition and recall memory with reduced memory performance. The interaction between valence (positive, neutral and negative) and session was significant for recognition memory, indicating that negative memory was impaired more severely than positive memory. Our study indicates that ECT relieves depressive symptoms and regulates emotional memory through more severe impairment on memory for negative stimuli.