Commentary on
Vagus nerve stimulation therapy for treatment-resistant PTSD;
Mark B Powers et al., Brain Stimul. 2025; 18(3):665-675.
The first-in-human prospective open-label early feasibility study, published in the journal Brain Stimulation, generated considerable interest in the field of trauma therapeutics by showing the therapeutic potential of vagus nerve stimulation (VNS) as a treatment for posttraumatic stress disorder (PTSD).
The study by Mark B Powers et al. outlines a fundamentally new neuromodulation-based approach to treat PTSD. This is based on a combinatorial approach on coupling prolonged exposure therapy (PE), a gold-standard cognitive behavioural therapy, with short bursts of VNS. All participants with moderate to severe treatment-resistant PTSD were implanted with a VNS device and underwent a 12-session course of PE with concurrent stimulation.
The authors report that the VNS therapy resulted in significant, clinically-meaningful improvements in multiple metrics of PTSD, persisting 6 months after the cessation of therapy. Of note, all participants showed loss of PTSD diagnosis after completing treatment.
This first-in-human study represents a major advancement in neuromodulation-based psychiatric interventions. Offering hope for patients who have exhausted all other conventional treatment options and pointing to a new era of precision neurostimulation therapies for trauma-related disorders.
The recent study by Powers and colleagues represents the largest clinical trial to date using an implanted device for PTSD treatment. In this open-label study, nine individuals with moderate to severe treatment-resistant PTSD underwent a novel therapeutic protocol combining traditional prolonged exposure therapy with timed vagus nerve stimulation. The results showed that all participants lost their PTSD diagnosis following treatment completion, with benefits throughout a six-month follow-up period.
The clinical improvements were substantial across multiple validated metrics. Participants showed significant reductions in CAPS-5 scores (the gold-standard assessment for PTSD symptoms), PCL-5 scores, and Hospital Anxiety and Depression Scale scores. These improvements extended across all PTSD categories, including intrusion, avoidance, cognition and mood, and hyperarousal symptoms.
The therapeutic mechanism underlying VNS-enhanced PTSD treatment appears to involve synaptic neuromodulation during fear extinction learning. Preclinical research revealed that VNS promotes synaptic plasticity through multiple molecular pathways, including activation of brain-derived neurotrophic factor (BDNF), Arc protein expression, and phosphorylation of TrkB receptors. These molecular changes with VNS-paired extinction training translate into consolidating better fear extinction, producing more robust and lasting reductions in conditioned fear responses compared to extinction training alone
The timing of VNS delivery appears critical for therapeutic efficacy. Experimental research in rats showed that stimulation must occur in temporal proximity to extinction learning events to maximize benefits. In the clinical study, VNS was delivered every 6 seconds during therapy sessions, ensuring that stimulation coincided with relevant therapeutic content. This precise timing protocol is based on optimization studies showing that VNS delivered during or immediately after fear extinction trials produces superior outcomes compared to stimulation delivered at other time points.
The neuroanatomical basis for VNS effects involves the activation of ascending noradrenergic pathways from the locus coeruleus, which modulate synaptic plasticity in fear-related brain circuits including the amygdala and prefrontal cortex. Interestingly, recent research suggests that while VNS increases norepinephrine levels, the therapeutic effects may involve complex interactions between different noradrenergic subsystems, with some evidence indicating that locus coeruleus activity may actually interfere with extinction learning under certain conditions.
The clinical significance of these findings extends beyond its efficacy data. Traditional PTSD treatments have limitations. For example, evidence-based cognitive-behavioral therapies like prolonged exposure therapy help many patients but leave a significant proportion without adequate symptom relief. Pharmacological interventions similarly show mixed results and can be associated with intolerable side effects or limited durability. The development of a neuromodulation-based therapy that increases the clinical efficacy of existing psychological interventions represents a paradigm shift in treatment approach
Previous work with transcutaneous VNS has provided supporting evidence for the therapeutic potential of vagal stimulation in PTSD. Studies showed that non-invasive cervical VNS reduced sympathetic responses to traumatic reminders and blocked immune responses associated with stress reactivity. These effects on autonomic regulation and immunity provided additional mechanistic support for VNS as a PTSD intervention by addressing both the psychological and physiological dimensions of the disorder.
The safety profile of the VNS therapy is encouraging. No serious device-related adverse events were reported, and side effects such as incision pain and skin irritation resolved spontaneously. This safety profile is comparable to or better than other VNS applications, suggesting that the miniaturized device system may offer advantages over larger conventional VNS implants.
Technical Innovation and Delivery
The study employed a novel miniaturized VNS system that represents a significant technological advancement over traditional implanted stimulators. The device consists of a small glass-encapsulated pulse generator (13 mm x 7.5 mm x 3 mm) that is wirelessly powered during therapy sessions, eliminating the need for an implanted battery. This design allows for a minimally invasive surgical procedure with same-day discharge and reduces long-term device maintenance requirements.
The integration of VNS with prolonged exposure therapy required careful coordination between technological and therapeutic elements. A smartphone-based control system recorded therapy sessions and triggered stimulation at predetermined intervals, ensuring consistent delivery of the combined intervention. This integrated approach represents a model for how neuromodulation technologies can be seamlessly incorporated into existing evidence-based psychotherapies.
Limitations and Future Directions
Despite the promising results, we need to take into account several limitations. The open-label design and small sample size limit the generalizability of findings and raise questions about placebo effects. The absence of a control group receiving prolonged exposure therapy alone makes it difficult to characterize the specific contribution of VNS to the outcomes. Furthermore, the studied population was relatively homogeneous, and future research will determine VNS efficacy across diverse demographic groups and trauma types.
The durability of treatment effects (six months) requires longer-term follow-up for sustained remission rates. Previous research with other neuromodulation interventions showed that initial benefits may diminish over time, making extended observation periods essential for evaluating true therapeutic durability.
Conclusion
Vagus nerve stimulation improved prolonged exposure therapy to the point of eliminating PTSD diagnoses and represents a remarkable moment in psychiatric neurostimulation. These findings challenge existing assumptions about the impossibility of treatment-resistant PTSD and suggest that targeted neuromodulation can reshape the trajectory of trauma-related disorders. While larger controlled trials are needed to confirm these initial results, the study revealed precision neurostimulation as a potential therapy for patients resistant to conventional treatment options.
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Commentary on
Vagus nerve stimulation therapy for treatment-resistant PTSD;
Mark B Powers et al., Brain Stimul. 2025; 18(3):665-675.
The first-in-human prospective open-label early feasibility study, published in the journal Brain Stimulation, generated considerable interest in the field of trauma therapeutics by showing the therapeutic potential of vagus nerve stimulation (VNS) as a treatment for posttraumatic stress disorder (PTSD).
The study by Mark B Powers et al. outlines a fundamentally new neuromodulation-based approach to treat PTSD. This is based on a combinatorial approach on coupling prolonged exposure therapy (PE), a gold-standard cognitive behavioural therapy, with short bursts of VNS. All participants with moderate to severe treatment-resistant PTSD were implanted with a VNS device and underwent a 12-session course of PE with concurrent stimulation.
The authors report that the VNS therapy resulted in significant, clinically-meaningful improvements in multiple metrics of PTSD, persisting 6 months after the cessation of therapy. Of note, all participants showed loss of PTSD diagnosis after completing treatment.
This first-in-human study represents a major advancement in neuromodulation-based psychiatric interventions. Offering hope for patients who have exhausted all other conventional treatment options and pointing to a new era of precision neurostimulation therapies for trauma-related disorders.
The recent study by Powers and colleagues represents the largest clinical trial to date using an implanted device for PTSD treatment. In this open-label study, nine individuals with moderate to severe treatment-resistant PTSD underwent a novel therapeutic protocol combining traditional prolonged exposure therapy with timed vagus nerve stimulation. The results showed that all participants lost their PTSD diagnosis following treatment completion, with benefits throughout a six-month follow-up period.
The clinical improvements were substantial across multiple validated metrics. Participants showed significant reductions in CAPS-5 scores (the gold-standard assessment for PTSD symptoms), PCL-5 scores, and Hospital Anxiety and Depression Scale scores. These improvements extended across all PTSD categories, including intrusion, avoidance, cognition and mood, and hyperarousal symptoms.
The therapeutic mechanism underlying VNS-enhanced PTSD treatment appears to involve synaptic neuromodulation during fear extinction learning. Preclinical research revealed that VNS promotes synaptic plasticity through multiple molecular pathways, including activation of brain-derived neurotrophic factor (BDNF), Arc protein expression, and phosphorylation of TrkB receptors. These molecular changes with VNS-paired extinction training translate into consolidating better fear extinction, producing more robust and lasting reductions in conditioned fear responses compared to extinction training alone
The timing of VNS delivery appears critical for therapeutic efficacy. Experimental research in rats showed that stimulation must occur in temporal proximity to extinction learning events to maximize benefits. In the clinical study, VNS was delivered every 6 seconds during therapy sessions, ensuring that stimulation coincided with relevant therapeutic content. This precise timing protocol is based on optimization studies showing that VNS delivered during or immediately after fear extinction trials produces superior outcomes compared to stimulation delivered at other time points.
The neuroanatomical basis for VNS effects involves the activation of ascending noradrenergic pathways from the locus coeruleus, which modulate synaptic plasticity in fear-related brain circuits including the amygdala and prefrontal cortex. Interestingly, recent research suggests that while VNS increases norepinephrine levels, the therapeutic effects may involve complex interactions between different noradrenergic subsystems, with some evidence indicating that locus coeruleus activity may actually interfere with extinction learning under certain conditions.
The clinical significance of these findings extends beyond its efficacy data. Traditional PTSD treatments have limitations. For example, evidence-based cognitive-behavioral therapies like prolonged exposure therapy help many patients but leave a significant proportion without adequate symptom relief. Pharmacological interventions similarly show mixed results and can be associated with intolerable side effects or limited durability. The development of a neuromodulation-based therapy that increases the clinical efficacy of existing psychological interventions represents a paradigm shift in treatment approach
Previous work with transcutaneous VNS has provided supporting evidence for the therapeutic potential of vagal stimulation in PTSD. Studies showed that non-invasive cervical VNS reduced sympathetic responses to traumatic reminders and blocked immune responses associated with stress reactivity. These effects on autonomic regulation and immunity provided additional mechanistic support for VNS as a PTSD intervention by addressing both the psychological and physiological dimensions of the disorder.
The safety profile of the VNS therapy is encouraging. No serious device-related adverse events were reported, and side effects such as incision pain and skin irritation resolved spontaneously. This safety profile is comparable to or better than other VNS applications, suggesting that the miniaturized device system may offer advantages over larger conventional VNS implants.
Technical Innovation and Delivery
The study employed a novel miniaturized VNS system that represents a significant technological advancement over traditional implanted stimulators. The device consists of a small glass-encapsulated pulse generator (13 mm x 7.5 mm x 3 mm) that is wirelessly powered during therapy sessions, eliminating the need for an implanted battery. This design allows for a minimally invasive surgical procedure with same-day discharge and reduces long-term device maintenance requirements.
The integration of VNS with prolonged exposure therapy required careful coordination between technological and therapeutic elements. A smartphone-based control system recorded therapy sessions and triggered stimulation at predetermined intervals, ensuring consistent delivery of the combined intervention. This integrated approach represents a model for how neuromodulation technologies can be seamlessly incorporated into existing evidence-based psychotherapies.
Limitations and Future Directions
Despite the promising results, we need to take into account several limitations. The open-label design and small sample size limit the generalizability of findings and raise questions about placebo effects. The absence of a control group receiving prolonged exposure therapy alone makes it difficult to characterize the specific contribution of VNS to the outcomes. Furthermore, the studied population was relatively homogeneous, and future research will determine VNS efficacy across diverse demographic groups and trauma types.
The durability of treatment effects (six months) requires longer-term follow-up for sustained remission rates. Previous research with other neuromodulation interventions showed that initial benefits may diminish over time, making extended observation periods essential for evaluating true therapeutic durability.
Conclusion
Vagus nerve stimulation improved prolonged exposure therapy to the point of eliminating PTSD diagnoses and represents a remarkable moment in psychiatric neurostimulation. These findings challenge existing assumptions about the impossibility of treatment-resistant PTSD and suggest that targeted neuromodulation can reshape the trajectory of trauma-related disorders. While larger controlled trials are needed to confirm these initial results, the study revealed precision neurostimulation as a potential therapy for patients resistant to conventional treatment options.
Related stories you may like:
Vagus Nerve Stimulation Ameliorates Disease Activity in a Rodent Model of Rheumatoid Arthritis
Afferent Vagus Nerve Stimulation Activates Brain Locus Coeruleus and Improves Experimental Joint Inflammation
Central Inflammatory Reflex: Afferent Vagal and Central Brain Stimulations Control Experimental Arthritis
Role of the Vagus Nerve at the Neural-Immune Interface
A PTSD Mouse Model Links Stress with Acute Heart Injury
Biomarkers, Hippocampal Volume Loss and Post-Traumatic Stress Disorder
The Stress Continuum of Chronic Disease Development