Vagus means "wandering" in Latin. The vagus nerve is known as the "wandering nerve" because it has multiple branches that diverge from the brainstem and wander to the lowest viscera of your abdomen touching your heart and most major organs along the way. The vagus nerve is tied to the calming parasympathetic nervous system (PNS). The PNS regulates inhibitory “rest-and-digest” responses and slows down our psychophysiology. On the flip side, the excitatory sympathetic nervous system (SNS) drives “fight-or-flight” stress responses and revs us up. Hyperactivity of the HPA axis is fueled by the SNS and marked by weaker vagal tone (VT). When the vagus nerve is strong, VT is higher and someone can cope with stress more effectively.
In 2013, I stumbled on some landmark vagus nerve research by Barbara L. Fredrickson et al. and wrote a Psychology Today blog post, “The Neurobiology of Grace Under Pressure,” which offers eight ways to improve vagus nerve function and stay calm, cool, and collected in distressing times. Much to my surprise, this seemingly esoteric blog post went viral.
Since then, I’ve kept my antennae up for any news about the vagus nerve and have written extensively on this topic. For example, in May 2017, I wrote a nine-part series for Psychology Today, “Vagus Nerve Survival Guide to Combat Fight-or-Flight Urges.” This series offers lots of gadget-free ways to boost parasympathetic vagus function ranging from diaphragmatic breathing to talking to yourself using non-first person pronouns or your own name to create self-distancing, narrative expressive journaling, seeking moments of awe to reduce egocentric bias, and many others.
I’ve also strived to keep Psychology Today readers updated about the growing list of benefits from vagus nerve stimulation (VNS) via an implanted device in situations where pharmaceuticals and other treatment options fail to help patients. Vagus nerve stimulation is part of a burgeoning field called “bioelectronics” or “electroceuticals” that uses clinically-tested devices to “hack” into the body’s nervous system to improve psychological and physical well-being.
In 1997, the FDA approved implanted vagus nerve stimulation devices as an adjunctive therapy for reducing the frequency and severity of epileptic seizures in pharmaco-resistant epilepsy patients who did not respond to medications. VNS therapy sends mild pulses to the vagus nerve at regular intervals throughout the day at a personalized dosage level of frequency and amplitude depending on the patient's specific needs.
A few years after vagus nerve stimulation had been FDA approved, doctors began noticing a surprising range of unexpected positive side effects of VNS therapy such as fewer depressive symptoms, less systemic inflammation, lower incidence of irritable bowel syndrome (IBS), and a reduction in severe headaches.
Kevin J. Tracey is a pioneer and thought leader in the field of vagus nerve stimulation. Most notably, Tracey is world-renowned for his 2002 discovery of “The Inflammatory Reflex,” which is rooted in the PNS and vagus nerve. In July 2016, Tracey and colleagues published a groundbreaking study, "Vagus Nerve Stimulation Inhibits Cytokine Production and Attenuates Disease Severity in Rheumatoid Arthritis," in Proceedings of the National Academy of Sciences.
Historically, vagus nerve stimulation therapy has required a minimally invasive outpatient surgical procedure (which takes about an hour) to implant a silver-dollar-sized pacemaker-like VNS device under the skin below the collarbone that attaches to the vagus nerve.
Earlier this year, the FDA approved a first-of-its-kind noninvasive vagus nerve stimulator called “gammaCore” for the acute treatment of the pain associated with episodic cluster headaches. The gammaCore is a hand-held device that is gently pressed against the neck by a patient who self-administers a prescriptive dose of VNS therapy through the skin to stimulate his or her vagus nerve.
In September 2017, researchers orally presented a new paper, "Non-invasive Vagus Nerve Stimulation (nVNS) for the Acute Treatment of Migraine: A Randomized Controlled Trial," at the 18th Congress of the International Headache Society in Vancouver. This clinical study on the benefits non-invasive vagus nerve stimulation was a multicenter, double-blind, randomized, sham-controlled trial that evaluated the efficacy, safety, and tolerability of nVNS using the gammaCore device in 243 patients with episodic migraines.
The researchers concluded that non-invasive vagus nerve stimulation was a rapidly effective, well tolerated, and practical treatment for episodic migraine headaches. However, gammaCore has not yet been approved by the FDA for treatment of migraines. (I reported on these findings in a Psychology Today blog post "Non-Invasive Vagus Nerve Stimulation May Relieve Migraines.")
As part of this timeline: In June 2017, a UK-based company, BioSelf Technology, unveiled another non-invasive vagus nerve stimulation gadget called “Sensate.” This palm-sized gizmo is worn or placed close to the sternum and uses sub-audible sound waves to stimulate the vagus nerve. The makers claim that Sensate triggers the "relaxation response" and lowers fight-or-flight stress responses in the autonomic nervous system.
Sensate users can also wear headphones and listen to auditory tracks that augment the sub-audible sound waves and guide brain activity towards specific frequencies. Binaural sounds heard through headphones can activate a parasympathetic vagus nerve response.
Sensate interfaces with a smartphone app that uses an algorithm to continuously monitor stress biomarkers and fine-tunes the device for optimal therapeutic response. This non-invasive VNS device is still patent-pending and won't be available for sale in the UK until sometime in 2018.
Stefan Chmelik is the founder and CEO of BioSelf Technology. He also directs the UK’s leading integrated healthcare center. In a statement, Chmelik said, “Stress has a huge and growing impact on the daily lives of people all over the world, and we have developed Sensate to directly combat the negative effect that it is having on society.”
Although more clinical studies are needed, the makers of the Sensate device say that more than 100 volunteers have used their pioneering gadget for 10-minutes per day over a six week period. Based on changes in their heart rate variability (HRV), the researchers speculate that up to 86 percent of participants showed increased stress resiliency and parasympathetic vagus nerve activity. Of course, these findings should be viewed with pragmatic skepticism based on the limited sample size and lack of controls. More research is necessary before drawing any firm conclusions about the clinical efficacy of Sensate usage.
Anecdotally, a freelance writer for the Daily Mail, Victoria Woodhall, recently tried a prototype of the Sensate device. She gave it glowing reviews. In a November 26 article about her experience using the non-invasive VNS gizmo, Woodhall said:
“After ten minutes, I feel as rejuvenated as after a long hot bath. What I’ve just experienced is ‘vagal toning,’ a term that you’ll be hearing more and more. Looking back, 2017 was the year of gut health; 2018, however, is set to be the year that we’re all talking about the vagus nerve—the latest scientific weapon in the battle against stress.”
Earlier this year, the American Psychological Association published a “Stress in America: Coping With Change” annual report which identified the first significant uptick in anxiety levels since the survey began 10 years ago. In June 2017, the New York Times corroborated these findings in an article, “Prozac Nation Is Now the United States of Xanax,” which chronicles the epidemic of anxiety sweeping our nation.
Along this same line, in November 2017, the most recent “Stress in America: The State of Our Nation” report indicated that chronic stress is increasingly gnawing away at people’s sense of coherence. The latest APA survey found that 75 percent of Americans had experienced at least one symptom of acute stress in the month prior to the survey.
“Regular meditation is well-established as one of the most effective ways to self-manage stress, however, few people have the time to learn or practice this important skill,” Jacob Skinner, CTO of BioSelf Technology said in a statement. “Sensate provides a solution to the growing stress epidemic in a time-poor generation.”
For the record: I have no conflict of interest or affiliation with any of the aforementioned vagus nerve stimulation manufacturers. As always, I encourage people to seek gadget-free ways to improve vagal tone and vagus nerve function on a daily basis whenever possible. Nevertheless, the latest technological advances regarding implanted VNS devices and non-invasive vagus nerve stimulation gadgetry appear to have tremendous potential.
As mentioned earlier, more rigorous clinical research is needed to empirically support the stress-busting claims being made by Chmelik and Skinner. That said, based on what we know about the vagus nerve, there appears to be a very good chance that non-invasive VNS devices could be a game-changer when it comes to tackling the global stress epidemic on a psychophysiological level.
Tracey, Kevin J. "The Inflammatory Reflex." Nature (2002) DOI: 10.1038/nature01321
Koopman, Frieda A., Sangeeta S. Chavan, Sanda Miljko, Simeon Grazio, Sekib Sokolovic, P. Richard Schuurman, Ashesh D. Mehta, Yaakov A. Levineh, Michael Faltysh, Ralph Zitnikh, Kevin J. Tracey, and Paul P. Tak. "Vagus nerve stimulation inhibits cytokine production and attenuates disease severity in rheumatoid arthritis." Proceedings of the National Academy of Sciences (2016) DOI: 10.1073/pnas.1605635113
Garland, Eric L., Barbara Fredrickson, Ann M. Kring, David P. Johnson, Piper S. Meyer, and David L. Penn. "Upward spirals of positive emotions counter downward spirals of negativity: Insights from the broaden-and-build theory and affective neuroscience on the treatment of emotion dysfunctions and deficits in psychopathology." Clinical Psychology (2010) DOI: 10.1016/j.cpr.2010.03.002
Kudielka, B. M., A. Buske-Kirschbaum, D. H. Hellhammer, and C. Kirschbaum. "HPA axis responses to laboratory psychosocial stress in healthy elderly adults, younger adults, and children: impact of age and gender." Psychoneuroendocrinology (2004) DOI: 10.1016/S0306-4530(02)00146-4