“Isn’t Polyvagal Theory” just a theory? Yes. It is. And…?

The real question people seem to be asking when they ask me this question is, “What if it’s wrong?” and the story I hear behind this question (conscious or not) is, “If I believe it, then I am wrong.”

My answer to all of this is “You might be.” Hear me out.

Defining Function

Polyvagal Theory has emerged as a theory about how our nervous system supports and hinders engagement and survival in the world. As an occupational therapist I translate this to mean how our nervous system helps or hinders our function, where function is defined as engaging with some level of ease and spontaneity, in the daily activities we need to survive or thrive. Polyvagal Theory doesn’t explain everything we need to know about function but it fits alongside a lot of information we already have and know about the brain and body and about what it takes to function in the world (motor learning, sensory processing, executive functions, even language, genetics and diagnoses like autism).

For those not familiar with Polyvagal Theory, you may find out more by searching the Polyvagal Institute Website. This theory, grounded in neuroscience is a culmination of the life’s work of Dr. Stephen Porges. I have embraced Polyvagal Theory as a foundational part of my frame of reference for an integrative model of practice. Note, as a therapist it’s my job to help clients. How I decide to do that is based on years of training, experience and staying current in research and the evidence base supporting my practice. I view evidence-based practice as an obligation. Why then you might also ask, would I choose to incorporate and embrace a reportedly “unproven” theory as a core part of how I work? Because it comes down to my core belief and training in what evidence is.

Defining Evidence

Evidence can be found in many forms and I believe we end up with better overarching evidence, when we incorporate multiple sets of data points and varied types of data to come to our conclusions. Evidence includes:

• randomized clinical controlled trials (the gold standard),
• meta-analyses and literature reviews of existing prior evidence,
• real world evidence such as case studies and testimonials and
• individual outcomes I see in my clients.

The gold standard research is complicated, time consuming and expensive to complete. One of the hurdles to completing OT related research in sensory processing is the reality that we deal with humans and no two people are 100% alike. Additionally, no two therapists practice 100% alike, so controlling for confounding variables and for obtaining inter-rater reliability becomes extremely challenging. This is especially so when attempting to measure outcomes for client-centered interventions. In many cases the client-centered intervention becomes unpredictable and distinct from session to session and across clients. This forces and strengthens the need for and my belief in use of real world evidence in addition to gold-standard evidence. I have found client specific outcomes to be the best measure of effectiveness for my client centered intervention approach.

Defining Evidence-informed Intervention

Another primary hurdle to creating an evidence-based practice and translating gold-standard knowledge into my work, is how long gold-standard research takes to complete. It can take years for large randomized clinical controlled trials to be completed, thus leaving clinicians like me without much evolving current evidence to use in day-to-day decision-making. Polyvagal Theory is grounded in decades of neuroscience research (Porges, 2011) AND is consistent with studies by others in neuroscience (Breit, 2018; Kohrt, 2020; Harvard, 2003; Neuser, 2020; Krause, 2016; Marco, 2011 to cite a few). It offers language I can use to explain the neurobiology of human function, and it offers an expanded framework for explaining not only the role of sensory processing, but other elements of functional behavior I’ve observed over the years but didn’t have words for.

Polyvagal Theory doesn’t explain everything and I’m sure future refinements of this theory are yet to come. As elements of this theory get tested as will applications using it as their foundation, I trust I will be able to refine what I do with clients even more. However, theories aren’t validated by intervention outcomes; interventions are. So I continue to feel that monitoring client outcomes is THE best way to determine if my interventions are valid and if what we’ve decided to do is right or wrong.

It comes down to measuring outcomes in different ways, frequently enough throughout the therapeutic process to course correct if and when we need to. This is something that should be inherent in all OT treatment, regardless of the frame of reference or theories we draw on for our work. I consider a strong evidence-base such as Polyvagal Theory paired with a solid and consistent process for outcomes measurement as bookends to an effective practice. I care less about proving a theory than I do about proving my work. I no longer get stuck in needing to be right before I even start with a client. The magic of therapy happens when we partner with our clients to be brave and curious and to make informed but not perfect decisions. This makes us a little (or a lot) vulnerable as OTs and as a discipline but I think it’s necessary as we embark on thinking about and taking each next “right” step with our clients.