Mental Health and Polyvagal Theory and the Sympathetic & Parasympathetic Nervous Systems

Note: I am not a medical professional. I'm trying to make this "close enough" but not technically 100% correct.

Note: First draft posted 12/13/2020. May come back to edit further and/or build this article out.

Note: This article is not meant to endorse or criticize the study of polyvagal theory or its use is modern pyschotherapy.

Response to a request for simpler language about the terms polyvagal theory and parasympathetic nervous systems...

You have a nervous system. Nerves control communication in the body.

There are multiple subsystems within the nervous system. Sort of like divisions at a company (HR, sales, ect.). Different sub-systems have different roles/jobs. All of these jobs are about communication of one kind or another.

One set of jobs is the body telling your organs what to do. Things like heart rate, breathing rate (lungs), ect. The nerves responsible for this are called...

- The sympathetic nervous system

- The parasympathetic nervous system

The sympathetic nervous system tells the body when to be on alert. Be hyper. Be aware. Be vigilant.

The parasympathetic system tells the body what to do when at rest. Less awareness. Focus on things like digestion. Not over-expend un-needed energy. Be restful.

All of this came into the therapy world as theories developed around poor mental health linking to an overly active sympathetic systems (on alert all the time) and an underutilized parasympathetic system (never at rest).

One idea that gained popularity was a concept to sort of manually trigger and train a person's parasympathetic system to be used more.

The term "polyvagal theory" relates to these studies. The vagus nerve is a main nerve within the parasympathetic (relax) nervous system. Polyvagal theory, in part, relates to studying this system's relation with such concepts as stress and emotional health. Polyvagal theory techniques might, for example, include learning to train oneself on new breathing patterns. Which would serve to (in theory) activate different nervous system responses with a goal of ultimately (again, in theory) resulting in differing overall emotional responses. 

To learn more...

1) Aspects of this are covered in chapter 5 (Body-Brain Connections) of the book The Body Keeps Score by Bessel van der Kolk.

2) Here is an article I liked about polyvagal therapy being used as a therapy tool: Polyvagal Theory in Practice