When Theories Change (And Why That’s Not a Crisis)
There’s been some debate — and yes, a little noise — in the world of trauma and nervous system regulation lately.
If you follow nervous system–focused practitioners, you may have heard some of it.
A theory that many practitioners have relied on for years is being questioned. Experts are debating. Articles are being written. Opinions are being shared.
And when something like this happens, it can create some confusion in us, and maybe even a feeling of instability.
If the professionals can’t agree… what does that mean for the rest of us?
Before your mind runs too far with that, let’s pause.
Take a breath.
Scientific debate is not a sign that everything we thought we understood is collapsing. It’s just a reminder that we are still learning.
Mental health science has always evolved. It has always refined itself. It has always revised its explanations as new data emerges.
And here’s the part that matters most: Healing does not disappear just because theories shift.
People are still getting better. Nervous systems are still regulating. Trauma is still healing. Bodies are still responding to safety.
The conversation happening right now isn’t a crisis.
It’s part of the natural rhythm of science.
I want to walk you through that rhythm, because understanding the past helps us interpret the present with steadiness instead of fear.
We’ve Always Been Learning
Our understanding of mental health has never been static.
In the late 1800s and early 1900s, much of psychology centered around the unconscious mind. Sigmund Freud proposed that unresolved childhood conflicts and repressed desires shaped adult behavior. His work introduced the idea that what we experience internally matters — that symptoms often have deeper roots.
Shortly after, Carl Jung expanded the conversation. He explored archetypes, symbolism, and the collective unconscious, suggesting that our inner world is influenced not only by personal experience, but by shared human patterns.
Then came behaviorism. In the early-to-mid 20th century, many psychologists shifted away from inner experience entirely and focused only on observable behavior. Thoughts and emotions were considered too subjective to measure, so they were largely set aside.
Each of these movements contributed something valuable. And each eventually revealed its limitations.
For much of modern history, trauma itself was poorly understood. It wasn’t until post-war research on PTSD, advances in neuroscience, and a deeper exploration of attachment that we began to see how profoundly the body stores and responds to stress. Books like Unbroken by Mary Catherine McDonald beautifully document how often suffering was misunderstood before we had language for it.
What becomes clear when you zoom out is this: Every generation believes it has finally figured it out. And every generation refines what came before.
Not because earlier thinkers were foolish, but because science builds in layers.
That is the scientific process working. We don’t replace understanding all at once. We expand it.
And that expansion is a sign of growth.
The Rise of Nervous System Language
In the last couple of decades, one framework in particular gained a lot of traction in the trauma world: Polyvagal Theory.
Developed by neuroscientist Stephen Porges, the theory offered a compelling explanation for why our nervous systems move between different states — like fight, flight, shutdown, and social connection.
For many practitioners and clients, this framework felt like a breakthrough.
It gave language to experiences people were already having:
Why do I shut down under stress?
Why does connection feel easier some days than others?
Why does my body react before my mind catches up?
It helped shift the conversation away from “What’s wrong with you?” to “What is your nervous system trying to do to protect you?”
That shift alone was powerful.
Recently, however, some researchers — including physiologist Paul Grossman and colleagues — have challenged parts of the theory’s biological foundations. In a published critique, they argued that certain anatomical and evolutionary claims within Polyvagal Theory aren’t well supported by current comparative physiology and autonomic research.
That has sparked a lot of debate.
Some clinicians agree with the critique.
Others defend the framework.
And many are somewhere in between — acknowledging both its clinical usefulness and the need for scientific precision.
Here’s what’s important: The debate isn’t about whether the nervous system influences emotion and behavior. That is well established.
It’s about how accurately we describe the underlying mechanisms.
And that distinction matters.
Because questioning a model isn’t the same as discarding everything we’ve learned about stress physiology. It’s part of how science refines itself.
The language that helped many people understand their bodies doesn’t suddenly vanish.
It simply gets examined, clarified, and — if necessary — adjusted.
The Bigger Shift: Beyond Any One Theory
I want to share something personal here.
I’ve referenced portions of Polyvagal Theory in my work over the years. The language around nervous system states — fight, flight, shutdown, connection — can be incredibly helpful. It gives people a way to understand their experience without shame.
But I’ve never fully built my teachings on that framework alone.
By the time I read Stephen Porges’s book and studied his theory, I had already spent nearly two decades working hands-on with hundreds of nervous systems — through massage therapy, craniosacral therapy, and nervous system retraining. I had seen patterns. I had felt the way stress lived in tissue. I had watched how safety changed posture, breath, tone, and presence.
And while I appreciated much of what he brought to the field, I also found that parts of the theory felt… overly simplified.
The nervous system is layered. It’s dynamic. It’s constantly communicating with every other system in the body.
In my experience, no single map fully captures that complexity.
There are aspects of Polyvagal Theory that I don’t personally subscribe to, particularly some of its broader evolutionary framing. But that doesn’t mean I dismiss its contributions. It gave clinicians and clients a shared language. It helped move trauma out of the realm of “character flaw” and into physiology.
That matters a lot.
At the same time, I believe we are entering a broader shift — one that goes beyond debating one theory or another.
We are moving away from searching for a single explanatory model, and toward understanding the body as an interconnected system.
The nervous system does not operate in isolation.
It is influenced by metabolism.
By inflammation.
By immune signaling.
By hormones.
By gut health.
By tissue tension.
By lived experience.
When we zoom out, the conversation becomes less about defending one framework and more about asking a bigger question:
How do all of these systems interact to shape how we feel, think, and respond?
That, to me, is the more important update that is happening in science right now.
Where I See Mental Health Science Heading Next
For decades, we’ve searched for singular causes — a chemical imbalance, a trauma response, a faulty thought pattern, a genetic mutation.
But the body doesn’t work in straight lines.
It works in networks.
Here are a few areas I’m watching closely where science is widening the lens of understanding around mental health and the nervous system— together, these are expanding how we understand human health.
Cellular Stress & the Cell Danger Response
Researcher Robert Naviaux has explored the idea that when cells perceive ongoing threat — whether from infection, toxins, injury, or chronic stress — they shift into a defensive mode.
In this state, the body prioritizes protection over growth and repair.
When that protective state doesn’t resolve, it may contribute to persistent fatigue, mood changes, or inflammatory conditions.
That reframes symptoms not as dysfunction — but as adaptation.
This Cell Danger Response completely changes our understanding on how we respond to threat at the cellular level, and what is at the center of it.
Metabolism & Brain Energy
In recent years, psychiatrists like Christopher Palmer have explored how mitochondrial function and metabolic health influence mood and cognition.
The brain is one of the most energy-demanding organs in the body.
If energy production is compromised — by inflammation, insulin resistance, nutrient deficiencies, or chronic stress — mental clarity and emotional regulation can suffer.
Research is showing that supporting metabolism is part of supporting mental health.
The Microbiome & Immune Signaling
We now know the gut and brain communicate constantly.
Gut bacteria influence neurotransmitter production.
Immune molecules influence motivation and mood.
Inflammation can alter how we experience energy and connection.
The gut is not separate from the nervous system story. It’s part of it.
Immune System & Mood
Emerging research continues to show that inflammatory cytokines can directly affect behavior.
Low motivation, social withdrawal, and fatigue — what we often label as depression — overlap significantly with what researchers call “sickness behavior.”
The immune system and nervous system are in constant dialogue.
When one shifts, the other responds.
Growing research exploring connections between trauma history and autoimmune conditions continues to expand this body–mind conversation.
Fascia & Sensory Signaling
After more than two decades working hands-on with the body, I’ve long believed we underestimate how structural tension influences our internal state.
Fascia is richly innervated. It senses pressure, stretch, and movement. Chronic tension patterns can reinforce protective postures and shallow breathing — both of which influence nervous system tone.
The body is not simply responding to the brain.
The body is communicating with it.
This is part of why somatic movements can be a huge part of rewiring the nervous system.
Epigenetics
We also understand now that genes are not a fixed destiny.
Lifestyle, stress exposure, nutrition, sleep, and even relational safety can influence which genes are expressed.
Our environment and experience leave biological fingerprints.
Healing, in many cases, may involve changing the signals the body receives.
None of these fields contain the answer.
And that’s the point.
What excites me isn’t a new singular theory. It’s the growing recognition that nothing in the body works in isolation.
The nervous system doesn’t operate separately from metabolism.
Metabolism doesn’t operate separately from immune signaling.
Immune signaling doesn’t operate separately from the microbiome.
The microbiome doesn’t operate separately from stress.
Everything is in conversation.
When we zoom out far enough, we begin to see that mental and physical health are not separate categories.They are expressions of how well our systems are communicating — and how safe the body perceives itself to be.
The Unifying Thread: Safety
When I zoom out and look at all of these systems — cellular stress, metabolism, immune signaling, gut health, fascia, gene expression — I don’t see separate stories.
I see one repeating question.
Am I safe?
At every level, safety influences whether the body prioritizes growth or protection.
Different systems.
Different languages.
Same organizing principle.
When safety is present, systems communicate fluidly.
When safety is absent, systems narrow toward protection.
And protection is not pathology.
It is adaptation.
What we often label as anxiety, depression, fatigue, or irritability is most often the body doing exactly what it was designed to do under conditions it perceives as unsafe.
The question isn’t which framework wins.
The question is:
What signals of safety or threat is this body receiving — and how can we influence them?
Why I Teach Through the SAFE Framework
This is exactly why I teach through the SAFE Framework.
I developed this framework not to replace other theories or even to explain everything.
I intentionally designed it to allow for complexity.
SAFE stands for:
S – Systems
We look at the whole picture.
Nervous system patterns, yes — but also metabolism, inflammation, gut health, hormones, sleep, tissue tension, and lifestyle stressors. Nothing works in isolation, so we don’t treat it that way.
A – Awareness
We learn to recognize patterns without shame.
What state does your body default to? What triggers activation? What cues help you soften? Awareness creates choice.
F – Foundations
We build safety in practical, repeatable ways.
Breath, rhythm, nourishment, movement, light exposure, relational repair — small signals that tell the body it can shift out of protection.
E – Expansion
As safety increases, capacity increases.
More resilience. More flexibility. More room for connection, creativity, and clarity.
The SAFE framework isn’t built on one research paper or one theoretical model.
It’s grounded in lived experience — both my own and the hundreds of nervous systems I’ve worked with over the last two decades. It reflects what I’ve consistently seen help people move from survival mode toward steadiness.
And it’s designed to be refined as our understanding refines.
If there’s one thing that has remained true in my years of studying the body, it’s this: we are always still learning. Asking better questions. Seeing wider patterns.
My SAFE Framework doesn’t depend on a single explanation of the nervous system. It depends on observing how human systems actually respond to safety.
And it’s in that steady observation — not rigid certainty — that we continually discover what works.
Regulated, Not Reactive
If there’s one thing I hope you take from this conversation, it’s this: Scientific refinement is not a threat to your healing.
It’s evidence that we’re still asking questions. Still clarifying. Still deepening our understanding.
Yes, experts will debate.
Yes, models will be questioned.
Yes, new research will continue to expand — and sometimes challenge — what we thought we knew.
That’s not instability.
That’s actually progress.
It’s science doing what science is supposed to do.
The body has always been more complex than any single framework can capture. And yet, despite our incomplete maps, people continue to heal. Nervous systems continue to regulate. Trauma continues to soften. Patterns continue to shift.
It all still works because living systems are designed to move toward balance when given the right conditions.
Curiosity will always serve us better than rigidity.
Humility will always serve us better than certainty.
Integration will always serve us better than isolation.
So if you ever find yourself feeling unsettled by debates in the wellness or mental health space, come back to something simple:
Your body is not broken.
Your healing is not dependent on one theory.
And safety — in whatever ways we cultivate it — still matters.
Science will continue to refine.
Our understanding will continue to expand.
And while the models adjust, the principles remain:
Safety supports regulation.
Regulation supports healing.
And that is steady ground.
