Treating Post-traumatic Stress Disorder with Neuromodulation Therapies: Transcranial Magnetic Stimulation, Transcranial Direct Current Stimulation, and Deep Brain Stimulation

Abstract

Post-traumatic stress disorder (PTSD) is a prevalent and debilitating illness. While standard treatment with pharmacotherapy and psychotherapy may be effective, approximately 20 to 30% of patients remain symptomatic. These individuals experience depression, anxiety, and elevated rates of suicide. For treatment-resistant patients, there is a growing interest in the use of neuromodulation therapies, including transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), and deep brain stimulation (DBS). We conducted a systematic review on the use of neuromodulation strategies for PTSD and pooled 13 randomized clinical trials (RCTs), 11 case series, and 6 case reports for analysis. Overall, most studies reported favorable outcomes in alleviating both PTSD and depressive symptoms. Although several RCTs described significant differences when active and sham stimulations were compared, others found marginal or nonsignificant differences between groups. Also positive were studies comparing PTSD symptoms before and after treatment. The side effect profile with all 3 modalities was found to be low, with mostly mild adverse events being reported. Despite these encouraging data, several aspects remain unknown. Given that PTSD is a highly heterogeneous condition that can be accompanied by distinct psychiatric diagnoses, defining a unique treatment for this patient population can be quite challenging. There has also been considerable variation across trials regarding stimulation parameters, symptomatic response, and the role of adjunctive psychotherapy. Future studies are needed to address these issues.

Dropout in Neural Networks Simulates the Paradoxical Effects of Deep Brain Stimulation on Memory

“…In this article, we suggest hypothetical mechanisms for the effects of DBS on memory. We showed that dropout of engram nodes could disrupt memory processes, which might be useful in translating DBS as a treatment for anxiety disorders like PTSD (Gouveia et al, 2020 ). We also showed that dropout of engram nodes could improve memory function and suggested that this happens through increased synaptic function.…”

Trauma-related guilt as a mediator between post-traumatic stress disorder and suicidal ideation

“…DMPFC is crucial in the DMN related to self-referential processing and episodic memory ( 41 ). More recently, non-invasive brain stimulation (NIBS) such as repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) has been shown to alleviate PTSD-associated symptoms ( 43 ). For instance, high frequency stimulation on the right DLPFC has been shown to reduce re-experiencing feelings, avoidance, hyperarousal ( 44 ), related depressive ( 44 , 45 ) and anxiety symptoms ( 44 ), and suicidal ideation ( 46 ).…”

Elevated activity in the dorsal dentate gyrus reduces expression of fear memory after fear extinction training

“…Although DBS has been used routinely to treat depression 47 and obsessivecompulsive disorder 48 and preclinical DBS studies in fear conditioning animal models have suggested its potential use for treatment-resistant PTSD, [49][50][51] very few studies have explored the clinical effect of DBS in PTSD. [52][53][54] About 20% to 30% of PTSD patients do not respond to medications and conventional psychotherapy. 49,51 A recent clinical trial showed that 6 patients with treatment-resistant PTSD experi enced a 30% decrease in clinician-administered PTSD scale scores after bilateral basolateral amygdala highfrequency stimulation.…”