A recent study suggests vagus nerve stimulation paired with exposure therapy may produce lasting relief for people with treatment-resistant PTSD — here’s what the research found.
What Did the 2025 Vagus Nerve Stimulation Study Find About PTSD?
A 2025 study published in Brain Stimulation found that all nine participants with moderate to severe treatment-resistant PTSD lost their PTSD diagnosis after completing vagus nerve stimulation (VNS) therapy combined with prolonged exposure therapy. The benefits persisted six months after treatment ended.
Participants received a standard 12-session course of prolonged exposure therapy paired with VNS. Researchers assessed them before treatment, one week after and again at one, three and six months following the completion of therapy.
According to the study, “VNS therapy resulted in significant, clinically-meaningful improvements in multiple metrics of PTSD symptoms and severity compared to baseline (CAPS-5, PCL-5, and HADS all p < 0.001 after therapy). These benefits persisted at 6 months after the cessation of therapy, suggesting lasting improvements.”
No serious or unexpected device-related adverse events were observed during the trial, the researchers reported.
How Does Vagus Nerve Stimulation Work to Treat PTSD?
Vagus nerve stimulation works by delivering brief bursts of electrical stimulation to the vagus nerve at precisely timed moments during exposure therapy, rather than continuously altering brain chemistry the way medications do. The targeted approach is designed to strengthen extinction learning — the process through which the brain learns that previously threatening cues are no longer dangerous.
In the study, researchers used a next-generation miniaturized stimulation system. An implantable pulse generator was placed within a silicone cuff and implanted on the left cervical vagus nerve. During therapy sessions, an external power and communication module sat over the device in a soft cloth collar, eliminating the need for an implanted battery. A smartphone controlled stimulation during sessions and recorded audio for homework exercises.
Stimulation was triggered to coincide with imaginal exposure exercises, during which participants revisited traumatic memories, and in vivo exposure exercises, which involved confronting real-world situations tied to trauma-related fear.
Scientists believe the treatment engages neuromodulatory systems in the brain, particularly pathways involving norepinephrine and acetylcholine — neurotransmitters known to play important roles in attention, memory consolidation and neuroplasticity. Activation of these pathways may help reinforce therapeutic learning, allowing patients to form new emotional associations with traumatic memories rather than continuing to experience them as immediate threats.
What Are the Limitations of the VNS Research for PTSD?
The study’s authors flagged two major limitations: the single-arm design and the open-label implementation of VNS therapy, both of which increase the potential for bias — particularly the lack of a sham stimulation control.
“Given the lack of previous data regarding the safety of VNS therapy in PTSD, we elected to employ this open-label design to maximize the number of participants that received active stimulation in a small sample size and ensure careful monitoring of any adverse events,” the study reads.
The researchers noted that although the functional outcomes used have been extensively validated as gold-standard measures, they consist mostly of self- and clinician-administered surveys, which are open to bias. Prolonged exposure therapy itself is known to be effective in some individuals, and while the majority of participants had received prior cognitive behavioral therapy, the authors said they “cannot conclusively ascribe benefits to the addition of VNS.”
They recommended that the findings be evaluated in a more rigorous double-blinded, placebo-controlled crossover study that directly compares active and sham stimulation with prolonged exposure therapy.
For context, VNS therapy has been FDA approved for major depressive disorder since 2005, and thousands of individuals have undergone implantation of a conventional VNS system for MDD.
Are Other Vagus Nerve Devices Being Studied for PTSD and Stress?
Yes — researchers are also studying non-implanted wearable devices that aim to influence the body’s stress-response systems. A separate clinical study involving 63 veterans with a history of PTSD investigated the Apollo Wearable System, a device that delivers gentle vibroacoustic stimulation through vibrations applied to the body.
Researchers examined whether regular use of the wearable could influence physiological measures associated with stress regulation, including heart rate variability, a marker of autonomic nervous system function. The wearable operates differently from implanted vagus nerve stimulation and was not designed to directly treat PTSD symptoms in the same way as the Brain Stimulation study’s device.
Together, these efforts reflect a growing recognition among researchers that PTSD affects not only psychological processes but also the biological systems involved in stress, arousal and emotional regulation.
What’s Next for Vagus Nerve Stimulation as a PTSD Treatment?
The study’s authors said future research should expand the sample size to capture more variation in participants and provide a stronger basis to determine effects in particular subgroups. They also pointed to the potential value of biomarker-based identification of nerve activation or therapy response, which could be used to individualize stimulation parameters.
“The present study outlines a fundamentally new neuromodulation-based approach to treat PTSD,” the researchers wrote. “Our first-in-human study shows that VNS therapy is safe, feasible to deliver, and provides initial evidence of robust, long-lasting improvements across a range of PTSD metrics among a treatment resistant population. These findings merit investigation in a larger, randomized controlled trial.”
