The Polyvagal Theory: How to Calm the Body

By Ashley Barnes, M.S. AMFT

What is Polyvagal Theory?

Polyvagal Theory explains the impact that our nervous system has on our experience of threat and safety. Shifts in our autonomic nervous system (which regulates involuntary physiological processes like heart rate, respiration, digestion, etc.) produces key states of being: rest-and-digest (safe), fight-or-flight (unsafe, mobilization), or shutdown (unsafe, freeze). The autonomic nervous system is composed of three divisions, two of which are the sympathetic and parasympathetic nervous systems. 

If we have unresolved trauma in our past, struggle with chronic stress, or experience anxiety and depression, we may live in a version of perpetual fight-or-flight. This is hard on the body and can lead to many adverse health outcomes, both physical and mental.

What is the Vagus Nerve?

Central to Polyvagal Theory is the vagus nerve, “is the longest cranial nerve in the body, containing both motor and sensory functions in both the afferent and efferent regards,” meaning that this nerve is responsible for signals sent from (motor/efferent) and to the brain (sensory/afferent) (National Library of Medicine, 2022). It is one of twelve cranial nerves in the human body and is responsible for many internal organ functions like digestion, heart rate, breathing, cardiovascular activity, and reflex actions (like sneezing, swallowing, vomiting, or coughing) (Healthline, 2022). 

The vagus nerve is also heavily involved in the parasympathetic nervous system which helps your body exit its fight-or-flight mode; when the parasympathetic nervous system is activated, you feel calm and serene, as our body enters rest-and-digest mode. 

The Vagus Nerve and mental health.

Researchers believe that the vagus nerve could form a connection between metabolic disease, heart disease, and depression (Howland, 2014). While researchers are still investigating the connection between the vagus nerve and impacts on mental health, some studies show promising results that suggest vagus nerve stimulation can help alleviate depression symptoms. 

One study assessed participants with treatment-resistant depression who underwent 5 years of vagus nerve stimulation (VNS) treatment; results indicated that the VNS group had a higher response rate (67.6%) compared to the treatment-as-usual group (40.9%), a significantly higher remission rate ( The registry results indicate that the adjunctive VNS group had better clinical outcomes than the treatment-as-usual group, including a significantly higher 5-year cumulative response rate (67.6% compared with 40.9%) and a significantly higher remission rate (43.3% compared with 25.7%) (Aaronson, et al., 2017). 

In simpler terms, the study found a significant decrease in treatment-resistant depression symptoms in those who received the VNS treatment and also found that the positive effects of the treatment were lasting for a significant portion of these participants. 

Ways to Calm the Body.

Thanks to Polyvagal Theory, there are many ways to stimulate the vagus nerve to prompt the parasympathetic nervous system, effectively calming the body. Here are merely some of the ways:

  • Yoga: yoga is a powerful way to stimulate the vagus nerve through mindful body movements and stretches.
  • Breathe: breathe slowly and deeply from the belly, exhale longer than you inhale, and think about expanding your abdomen and widening your rib cage when you inhale.
  • Sing: utilizing our vocal chords can stimulate the vagus nerve. If you aren’t a singer, you can also just allow simple sounds to stimulate your throat. In the “Voo Breathing Method,” you exhale very slowly while creating a “voo” sound from the back of your throat. The vibrating sound on the outbreath stimulates the vagus nerve.
  • Massage: massaging certain points on the body can stimulate the vagus nerve.

If you are looking for additional support from experienced mental health professionals, please contact us at the Mental Health Center!





Aaronson, S. T., Sears, P., Ruvuna, F., Bunker, M., Conway, C. R., Dougherty, D. D., Reimherr, F. W., Schwartz, T. L., & Zajecka, J. M. (2017). A 5-year observational study of patients with treatment-resistant depression treated with vagus nerve stimulation or treatment as usual: Comparison of response, remission, and Suicidality. American Journal of Psychiatry, 174(7), 640–648. 

Healthline.  (2023). Vagus nerve: Function, stimulation, and more. 

Howland, R.H. (2014) Vagus Nerve Stimulation. Curr Behav Neurosci Rep. 2014 Jun;1(2):64-73. doi: 10.1007/s40473-014-0010-5. PMID: 24834378; PMCID: PMC4017164.

National Library of Medicine. (2022). National Center for Biotechnology Information.