Healing The Trauma from Within: How Vagus Nerve Stimulation is Revolutionizing PTSD Treatment

by Robair Sedarous

Post-Traumatic Stress Disorder (PTSD) affects millions around the world, from combat veterans to civilian survivors of traumatic events that happen every day (VA 2018). PTSD symptoms often include, but are not limited to, intense fear responses, flashbacks, and heightened “vigilance.” PTSD disrupts the lives of those affected greatly. The most common PTSD treatments have been limited to Cognitive Behavioral Therapy (CBT) and pharmacological drugs, which have provided relief, but clinical results have been either not long-term or have not had a significant effect. Research has been on the hunt ever since, and new neuroscience studies point to Vagus Nerve Stimulation (VNS) as a promising solution.

What is PTSD?

PTSD is caused after exposure to an intense traumatic event or stimulus, which leads to significant psychological distress which tends to manifest as constant flashbacks, nightmares, avoidance of trauma-related stimuli even if said stimuli isn’t inherently traumatic(ex: avoiding being in a car after being in a car accident), and heightened fight or flight responses (IFM 2024). PTSD causes large structural and functional changes in the brain, such as reduced volumes in critical regions like the hippocampus and prefrontal cortex, alongside hyperactivation/hypersensitivity of the amygdala (Bremner 2021). There is a direct link between PTSD to high cortisol levels, which is also known as the stress hormone. PTSD patients also show inflated emotional memory reinforcement, creating a positive feedback loop where memories of fear become increasingly vivid and distressing. A stimulus causes an emotional response, the emotional response reinforces the memory, which causes an even larger emotional response for future triggering stimuli. These memories become deeply ingrained in PTSD patients because of strong emotional consolidation, caused by the increased amygdala activity. When treating PTSD, it is important to consider these heightened changes.

Relationship between PTSD and Fear

Fear conditioning is a natural survival mechanism built into all animals, including humans, which enables animals to learn and remember potential threats. The amygdala, hippocampus, and medial prefrontal cortex (mPFC) play key roles in this conditioning process. The amygdala integrates emotional stimuli at first, allowing for the “encoding” of fear memories. The hippocampus then contextualizes these memories, helping animals distinguish safe environments from dangerous ones (Noble 2017). The mPFC assists in the expression of fear conditioning and is partially responsible for the activation of the amygdala. Fear extinction happens when consistent exposure to the feared stimulus occurs without actual harmful outcomes, gradually diminishing the overall fear response. Extinction involves inhibitory signals from the mPFC to the amygdala, which send “safety” signals and decrease the fear responses(MØLLER 2019). However, extinction memories are very fragile compared to fear memories. They require constant reinforcement and are easily susceptible to disruption by stress. PTSD is very closely linked to impaired fear extinction. The PTSD patients tend to struggle with removing their fear responses even though they are in a safe context. For PTSD patients, impaired extinction causes worsened symptoms, making treatments, like CBT and pharmacological drugs, that reinforce extinction memories, all the more important.

VNS: The Final Solution?

The vagus nerve, a key player in the parasympathetic nervous system, has highly extensive connections linking the brain to various internal organs. It has significant effects on emotional regulation and stress responses. The activation of this nerve through stimulation (VNS) has shown impressive effects on modulating brain function, showing great relevance for PTSD (Bremner 2019). When VNS activates the parasympathetic nervous system, it counters the sympathetic nervous system’s stress response. This activation causes a calming state throughout the body, significantly beneficial for anxiety-related conditions, like PTSD. The VNS enhances fear extinction by activating the locus coeruleus, a brainstem region releasing norepinephrine, a hormone essential for attention and alertness. This activation helps modulate neural plasticity, making extinction memories more distinct and resistant to relapse (Gurel 2020).

Clinical Evidence of VNS

Clinical trials researching VNS as the main method or as a “co-therapy” with CBT, pharmacological drugs, or other types of therapies for PTSD patients have shown promising outcomes. In some of these studies, patients receive VNS concurrently with exposure therapy, having controlled exposure to trauma-associated stimuli in a safe environment. This combination significantly enhanced fear extinction effectiveness when compared to standard exposure therapy alone (Gurel 2020). A specific clinical trial that caught my attention involved patients with PTSD showed significant reductions in PTSD symptom severity when VNS was accompanied by therapeutic exposure. Subjects reported fewer nightmares, reduced anxiety, and improved daily functioning. Most importantly, these trials have also prioritized patient safety, confirming VNS as a well-tolerated therapy with minimal adverse effects (Bremner 2021). The fact that VNS has shown very minimal adverse effects is highly intriguing since research studies often show various negative side effects; however, with VNS, adverse effects are limited to a weird tingling sensation around the location of the VNS that lasts a few days. Animal models, rats, also support these human findings, consistently showing enhanced extinction memory formation following VNS. All of these findings suggest that VNS could dramatically improve PTSD treatment outcomes by strengthening the neurological basis of fear extinction (Noble 2017).

PTSD Treatment as a Future Physician

The potential of VNS goes beyond immediate PTSD treatment improvements, bringing in larger, more applicable treatments across mental health disorders founded in neuroplasticity of fear responses. As the neuroscience community continues to advance and gain a better understanding involved in emotions and memory, treatments like VNS offer a small hint into medicine that is tailored to individual neurobiological profiles. Incorporating VNS into routine clinical practice could improve the efficacy of existing therapies, increasing the chances of reducing PTSD prevalence. Also, continued research may further refine VNS usage, perfecting its efficacy, broadening its applicability, and increasing accessibility to rural and low financial income locations. In my future career as a physician and researcher, in which I plan to specialize in neuroscience, understanding treatments like VNS could impact how trauma and stress-related disorders are managed. The potential for applying VNS, alongside other therapies such as CBT, aligns with my ambition to develop innovative, neuroscience-driven interventions that improve patient outcomes. Having a background in military medicine provides me with a unique perspective on PTSD prevalence among veterans and current service members. This gives me not only a goal but a personal vendetta against PTSD, in which I plan to use VNS to serve those who served this nation. I plan to utilize the knowledge gained from my Neurobiology of Emotion class and my research in VNS in clinical settings by integrating it into comprehensive therapeutic plans for patients suffering from PTSD.

Now What?

VNS represents a groundbreaking advancement in the battle against PTSD, directly attacking the fear extinction processes in PTSD patients. Its ability to enhance therapeutic outcomes and possibly offer lasting relief to trauma survivors shows the power of research. Consistent research has brought us to this point of innovation, and as clinical studies continue to progress and embrace treatments like VNS, they pave the way for extraordinary new approaches to managing emotional and mental health conditions. It is an inspiring time in neuroscience as we take control of our bodies and our nervous systems through highly technological advancements.

References

• Bremner JD;Gurel NZ;Jiao Y;Wittbrodt MT;Levantsevych OM;Huang M;Jung H;Shandhi MH;Beckwith J;Herring I;Rapaport MH;Murrah N;Driggers E;Ko YA;Alkhalaf ML;Soudan M;Song J;Ku BS;Shallenberger L;Hankus AN;Nye JA;Park J;Vaccarino V;Shah AJ;Inan OT;Pearce BD; “Transcutaneous Vagal Nerve Stimulation Blocks Stress-Induced Activation of Interleukin-6 and Interferon-γ in Posttraumatic Stress Disorder: A Double-Blind, Randomized, Sham-Controlled Trial.” Brain, Behavior, & Immunity – Health, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/34589887/. Accessed 22 Apr. 2025.
• Understanding PTSD from a Polyvagal Perspective | The Institute for Functional Medicine, www.ifm.org/articles/understanding-ptsd-from-a-polyvagal-perspective. Accessed 23 Apr. 2025.
• Noble LJ;Gonzalez IJ;Meruva VB;Callahan KA;Belfort BD;Ramanathan KR;Meyers E;Kilgard MP;Rennaker RL;McIntyre CK; “Effects of Vagus Nerve Stimulation on Extinction of Conditioned Fear and Post-Traumatic Stress Disorder Symptoms in Rats.” Translational Psychiatry, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/28892066/. Accessed 22 Apr. 2025.
• Nil Z. Gurel a, et al. “Transcutaneous Cervical Vagal Nerve Stimulation Reduces Sympathetic Responses to Stress in Posttraumatic Stress Disorder: A Double-Blind, Randomized, Sham Controlled Trial.” Neurobiology of Stress, Elsevier, 20 Oct. 2020, www.sciencedirect.com/science/article/pii/S2352289520300540.
• Bremner JD;Wittbrodt MT;Gurel NZ;Shandhi MH;Gazi AH;Jiao Y;Levantsevych OM;Huang M;Beckwith J;Herring I;Murrah N;Driggers EG;Ko YA;Alkhalaf ML;Soudan M;Shallenberger L;Hankus AN;Nye JA;Park J;Woodbury A;Mehta PK;Rapaport MH;Vaccarino V;Shah AJ;Pearce BD;I. “Transcutaneous Cervical Vagal Nerve Stimulation in Patients with Posttraumatic Stress Disorder (PTSD): A Pilot Study of Effects on PTSD Symptoms and Interleukin-6 Response to Stress.” Journal of Affective Disorders Reports, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/34778863/. Accessed 22 Apr. 2025.
• MØLLER, AAGE. Neurobiology of Fear, Anxiety and Other Emotions. AAGE R. MOLLER, PUBLISHING, 2019.
• “Va.Gov: Veterans Affairs.” How Common Is PTSD in Adults?, 13 Sept. 2018, www.ptsd.va.gov/understand/common/common_adults.asp.