Skip to main content

Verified by Psychology Today

Vagus Nerve

Polyvagal Theory: An Approach to Understanding Trauma

This theory highlights the nervous systems importance in how we perceive trauma.

Josh Riemer/Unsplash/Creative Commons
Source: Josh Riemer/Unsplash/Creative Commons

Co-authored by Lotus Huyen Vu and Robert T. Muller, Ph.D.

In 1994, Stephen Porges introduced the polyvagal theory, based on an evolutionary, neuropsychological understanding of the vagus nerve’s role in emotion regulation, social connection, and fear response. Since then, the theory has brought a new understanding of trauma and recovery, providing for the first time a physiological explanation for trauma survivors’ experiences.

Deb Dana, a clinical social worker and therapist, recognized the need for a practical application of polyvagal theory and has adapted the theory for clinical and therapeutic purposes. Dana authored the books The Polyvagal Theory in Therapy, Clinical Applications of the Polyvagal Theory, and most recently, Polyvagal Exercises for Safety and Connection, published in 2020. Dana explained the theory and how it organizes the nervous system into three key principles: hierarchy, neuroception, and co-regulation.

Hierarchy refers to three nervous system states—ventral vagal, sympathetic, and dorsal vagal—and their activation in a particular order. Dana states that ventral vagal helps us feel safe, show up, communicate, and connect with others. She calls ventral vagal home, the place of safety where we want to be most of the time. Sympathetic is that energy of flight or fight that helps us mobilize to survive in dangerous environments. If we cannot fight or take flight, dorsal vagal has us shut down, collapse, or go numb to protect us.

Dana describes the principle of neuroception as our nervous system automatically scanning the environment for cues of danger below our awareness. She states that it listens from the inside of our body, outside in our environment, and between the interaction of two people. Neuroception determines whether we are in states of ventral vagal, sympathetic, or dorsal vagal depending on our environment.

Dana describes co-regulation as “the biological imperative to be connected with others to survive. We hope to meet others who are regulated and welcoming.” The longing to be safely connected with other people persists throughout our lifetime, even when self-regulating.

Dana explains why the polyvagal theory is essential for therapists and clients alike by saying the theory made so much sense to her when explaining the inner workings of our brain and nervous system because it’s the vehicle through which we drive through life. Dana encourages her clients to understand their nervous system so that they can navigate the more ordinary challenges in everyday life. The nervous system informs the brain; it is essential to first comprehend the processes of the nervous system before understanding the brain. Dana suggests that this is the fundamental breakthrough that the polyvagal theory proposed.

Christine* is currently undergoing the therapeutic treatment of Dana’s method of rhythm regulation, derived from the polyvagal theory. She describes her experience: “It was an eye-opener to come to understand why my nervous system reacts a certain way at times. I was constantly in a sympathetic state and often felt depleted at the end of the day. My nervous system was stuck on the hierarchy. Knowing where I was on the ladder, I started to meditate and learned deep breathing to calm down. Suddenly, my brain didn’t catastrophize as much anymore.”

The polyvagal theory also explains why some victims do not run away or resist in the presence of abuse or violence. Their nervous systems switch to the dorsal vagal response of numbing or immobilization for survival instead of the sympathetic response of fight or flight. For the trauma survivor, the nervous system has become fixed in the sympathetic or dorsal states without returning to the ventral state. In the application of polyvagal-informed therapy, it is essential for therapists to help clients establish safety by guiding them back to their ventral vagal state.

Stuck in the sympathetic state, individuals with unhealed trauma may carry a story of fear, distrust, dysregulation, and anxiety, while those stuck in the dorsal vagal state may carry one of loneliness, disconnection, and numbness. When survivors heal and reside in the ventral vagal state, they are able to let go of these stories and become more connected and attuned with others.

Although the theory shows promise in therapeutic treatment, some question the polyvagal theory as there is no clear consensus among biologists that the dorsal brainstorm or dorsal-ventral centres are responsible for parasympathetic control of heart rate during psychological dissociation. Future research may make this connection clearer.

Still, the new understanding brought by polyvagal theory relates to the critical role of the nervous system in shaping the perception and understanding of trauma.

*Name has been changed for anonymity.

Copyright Robert T. Muller, Ph.D.


Lotus Huyen Vu is a Contributing Writer at The Trauma and Mental Health Report.

More from Robert T Muller Ph.D.
More from Psychology Today