The polyvagal theory was introduced in 1994 by Stephen Porges, and popularised by authors such as Deb Dana who made the dense scientific writing by Porges more accessible. Prior to this, the main way of understanding the autonomic nervous system was that it consisted of two parts: the sympathetic nervous system, which is activating and is linked to the fight/flight reaction and the parasympathetic nervous system, which is linked to relaxation (‘rest and digest’). Porges suggested the parasympathetic nervous system consisted of two branches of the vagal nerve: the “ventral vagal system” which is linked to social connection and the “dorsal vagal system” which supports immobilisation as well as rest and digest. The existence of these three vagal branches has been scientifically questioned, but as the polyvagal theory is such an important part of trauma theory right now, I briefly summarise it here.

The beautiful landscape where I live to counter the density of the text a bit

Some core principles of the theory:
​​1. Hierarchy: The autonomic nervous system reacts in three different types of reactions that are activated in a specific order.
2. Neuroception: In contrast to perception, it is a cognition without awareness, triggered by a stimulus such as danger.
3. Co-regulation: Our need to feel safe enough to allow ourselves to be in relationship, which can be difficult for traumatized people.

The physiological explanation:
The sympathetic branch is found in the middle part of the spinal cord, and is the part of the autonomic nervous system that prepares us for action. The release of adrenaline is triggered in response to stress, which activates the fight or flight response.

According to the polyvagal theory, the parasympathetic branch of the autonomic nervous system consists of two pathways within the Vagus nerve: the ventral vagal pathway and the dorsal vagal pathway. The ventral pathway responds to cues of safety and supports feelings of being safely engaged and socially connected. The dorsal vagal pathway responds to cues of danger, it takes us out of connection, out of awareness and into a protective state of collapse.

These are thought to respond in a hierarchy based on the evolution of the nervous system, the collapse of the dorsal vagal pathway being the oldest, followed by mobilisation of the sympathetic branch followed by the social connection of the ventral vagal pathway. We are believed to move along this hierarchy throughout the day, adapting to our surroundings and we need the capacity for activation, inhibition and flexibility of response. We should experience well-being when all three parts of the system work together.

Another important concept in polyvagal theory is that of the Vagal brake which takes place when, when activated through social engagement, the parasympathetic nervous system stimulates the vagus nerve, overrides the stress hormones, slows the heart rate, slows the breathing rate, and relaxes the gut. A person can train their mind to activate the parasympathetic nervous system, and put on the vagal brake as soon as they feel alarmed.

The polyvagal theory has gained massive attention the last few years in relation to trauma and psychotherapy, but it seems that the world has overlooked the fact that it is a ‘theory’, and one that lacks scientific data to back it up. It has been debunked in the same year the theory was published and by many research articles since. There is quite a lot of critique by the scientific community about inconsistencies and lack of evidence for some aspects of the theory. The problem with these types of theories about these types of topics, is that they are quickly taken on like a dogma. Even in this article about being trauma informed, the fact that you have to know about polyvagal theory is considered ‘useful’, while for example attachment theory, for which the foundational work has been documented in the 1950’s, is not mentioned.

Specifically Dr. Paul Grossman from the University hospital of Basel has expressed (and published) criticism of the theory, with the worry that patients who have undergone therapy under this dogma might be left feeling confused, unvalidated etc… when they understand that the theory is debunked. There have been several articles published to debunk the main point of polyvagal theory, namely that there is an extra vagal pathway, the theorie’s physiological basis and evolutionary assumptions, but the public has not caught up on this. The train of the polyvagal theory seems to be going and has not/cannot be stopped, and I am convinced social media has a big part in this. I highly recommend reading through this conversation on Research Gate where Dr Grossman shares several published articles that indicate the theory has no scientific basis.

A Quote from Grossman: ‘Providing fictional narratives to therapeutic processes can be damaging for the credibility of a therapy (that may, nonetheless, be effective for very different reasons) and may turn out to be very harmful for clients or patients once they discover that the physiological explanations of the therapeutic process are wrong.’

And I really appreciate Grossman’s input here:
‘Physiological explanations can sometimes be helpful for clients in psychotherapy, even when such explanations are simplified. However, they can and should be plausible and based upon real state-of-the–art evidence. The parasympathetic nervous system (i.e. the vagus) has been clearly implicated in behaviour and psychological responses for greater than a century (the sympathetic system as well): for instance, increases in cardiac vagal activity slow down heart rate, whereas decreases speed heart rate up; gut vagal responses contribute to digestive processes; bronchial vagal activity will constrict the bronchial making it more difficult to breath, etc.). These are well known and established phenomena that can be built into narratives of physiological activation related to behavioural reactions to psychological changes. However fanciful stories contradicted by existing evidence (e.g. about “dorsal vagal shutdown” or reptilian vs. mammalian vagal responses) are not helpful because they simply don’t tell the truth. It’s like wilfully importing fake news into how our own mind/bodies function. That can only throw patients off and make them wonder about the effectiveness of their possibly very beneficial therapy when they discover that the physiological explanation offered by their clinician is highly controversial or even plain wrong. So I would always go with physiological simplifications that have real hands and feet and not try to explain (in this case) why there is a ”poly” in the polyvagal speculations (which genuinely seems to be a misnomer). Just talk about how the vagus has been known to work for at least 150 years and maybe add in a few sympathetic ingredients, which have also been long established as absolutely vital in the psychophysiological literature. (And to the neurotransmitter issue in depression, it’s also probably better to say we don’t really understand how depression is expressed in the brain, but neurotransmitter substances are likely to contribute: modesty may be the best policy when one doesn’t have the answer).’

A comment in the conversation on Polyvagal theory by Kate McLaren that I can relate with: ‘The trauma healing community seems to be a troubled one. Bessel Van der Kolk was an unapologetic supporter of the recovered memory debacle. Peter Levine teaches the triune brain theory, which has been known to be wrong for decades (no, you don’t have a lizard brain!). Gabor Mate is making concrete assumptions about the trauma history of addicts that doesn’t track with more responsible (and less melodramatic) approaches to addiction (see the work of Lance Dodes for a more functional approach).
And as we’ve seen, Porges has become so wrapped up and inseparable from his theory that he cannot see his way through. The trauma healing community is in deep philosophical and ethical trouble, and that would be sad if it wasn’t tragic, because vulnerable people are being drawn in, and their heads are being filled with nonsense that does not lead to healing. But it makes them perfect prey for more workshops.’

Can I also bring to the attention that the Safe Sound Protocol that Porges developed is offered in a dubious marketing scheme, where you as a therapist are offered a concrete business plan of what you will earn while offering it to clients, and the numbers are HIGH. You pay for the training and then you pay to be able to offer the treatment, the more clients you have, the more money it costs. I think the use of marketing practices like this for trauma support should definitely be approached with a lot of caution and I do not understand why there is not more critique on it. There is no way to benefit from the SSP program other than going through the money mill Porges set up on the website I feel it is paramount to think about ethics in the world of trauma healing and to me, this is not it.

In recent months there have been more and more articles popping up that are critical of the ployvagal theory. Here are some that I found very useful:

And to conclude, obviously some of the techniques and practices used in the polyvagal theory as a framework are bringing people relief in their struggles with the aftermath of trauma. And I have worked with and found benefit in those techniques as well. The vagus nerve is super cool and it’s definitely worthwhile knowing about and working with. However, engaging in those techniques and practices doesn’t require you to know about what polyvagal theory wrongly claims is happening in your body. As Max Pearl writes (here): We don’t always need (and will not always find) neuroscientific evidence for why certain therapies or embodiment practices work. Sometimes things just work and feel good, and that’s ok.