When Suffering Becomes Pathology: Part I - The Origins of Defence

Predictive processing, boundary maintenance, and the ancient logic of self-protection.

There is a tension at the heart of psychiatry that we have not yet resolved.

Mental disorder is real. Anyone who has worked in mental health, lived through severe psychological distress, or loved someone who has, knows this. People can become profoundly dysregulated, terrified, despairing, impaired and even dangerous to themselves or others. The suffering is real, the dysfunction is real and compassionate intervention is necessary.

Yet the categories we use to describe this reality are incomplete. Diagnostic manuals such as the DSM and ICD organise clusters of symptoms and behaviours that often appear together. This serves a purpose. It has allowed patterns to be studied and treatments to be tested. It has allowed us to communicate clearly about what we believe to be occurring. But lived experience rarely fits cleanly into one box. People often meet criteria for several diagnoses at once. Their presentations change over time and diagnoses can accumulate accordingly. The core limitation is that no label, however useful, captures the whole person sitting in front of us.

Where do we draw the line between ordinary human suffering and pathological suffering? Grief, fear, sadness, shame, hypervigilance and avoidance are all part of the richness of human experience. They are also, to some extent, adaptive and serve a purpose. Yet in the context of certain vulnerabilities and stressors, these same processes can become maladaptive and lead to profound distress and dysfunction.

This essay is part one of an attempt to explore that threshold between ordinary human experience and what we call mental disorder.

I believe a deeper understanding lies in viewing the mind as an embodied, dynamic and adaptive process. The predictive processing account of brain functioning offers one such way of understanding mental health, not as a set of discrete disorders, but as a continuum of self-world organising processes. From this view, suffering becomes pathology when protective patterns of prediction, resistance, and defence become too rigid, dysregulated, or costly for the person to remain in a flexible, dynamic relationship with the world.

This does not mean diagnosis is irrelevant. It certainly does not discount the need to intervene where necessary. Diagnosis is not the person. It cannot ever capture the entirety of a lived experience and to reduce it in this way is not only morally questionable, but clinically limiting. The big question that remains is how ordinary suffering, in conjunction with vulnerability and circumstance, crosses a threshold into dysregulation, dysfunction, and disorder.

There is a middle way between reductive biomedical psychiatry and anti-psychiatric dismissal of disorder. Mental disorder is real, but it is not a broken brain or just a chemical imbalance. It is suffering and attempted self-protection caught in patterns that impair the relationship between a person and the world they are trying to inhabit. This is not a simple dichotomy between normal suffering and mental disorder. It is a continuous process, which in some cases, depending on certain conditions, leads to pathology.

Biological, psychological, relational and environmental processes are different levels of the same living system. They meet in the person, in the body, in the nervous system, in the self-world model, and in the field of relationships through which that model is formed.

Process is not pathology

Let us consider physical health for a moment.

Atherosclerosis is a process by which plaques form within arterial walls through a combination of mechanical stress, lipid accumulation, inflammatory processes and other factors. Atherosclerotic processes occur, to some degree, in all of us over the lifespan. They are not, in themselves, identical with disease. Yet they are pathophysiological processes. They can become pathological when they disrupt function.

If a plaque ruptures in a coronary artery, a clot may form and block blood flow to part of the heart. The heart muscle then loses the oxygen it needs to function, leading to damage, dysfunction and, in some cases, heart failure. The process itself is not the whole of pathology. It becomes pathological when it impairs the functioning of the organ and the wider bodily system.

Mutant cells arise within bodies all the time, but under certain conditions they can proliferate into cancer. Inflammation is a normal and adaptive bodily process, but it can become excessive in the case of autoimmune disease. Pain is a protective signal that guards injured tissues, yet sometimes it can persist long after it has served its protective purpose.

The same is true of mental suffering and disorder. We all suffer. We all create additional suffering through resistance around what we do not want or believe we need. We defend internal models of self and world, shaped by our hopes and fears, even when reality begins to conflict with them.

These processes are not pathological in themselves. They are part of how organisms preserve coherence, avoid danger, protect attachment and remain oriented within the world. But under some conditions, they can become rigid, excessive and self-reinforcing. They become increasingly maladaptive, creating disequilibrium between internal models and the reality they are attempting to represent. Pushed far enough, this disequilibrium can impair a person’s ability to function within a shared world.

Pathology is not simply the presence of a process. Pathology begins when a process becomes dysregulated enough that it impairs the body-mind system and its ability to function, relate and exist within the world.

Suffering involves resistance, but resistance is protective

I have argued previously that the predictive processing account of mind offers a mechanistic account of how suffering arises.

By suffering, I do not just mean the presence of pain, stress, loss, or uncertainty. These are all inherent to life. I am referring to the additional layer of suffering that arises when resistance forms around experience. Change is unavoidable, and there is pain inherent to encountering what we did not want, expect, or feel equipped to tolerate. But there is a further cost, separable from the first. The cost of the system’s resistance to updating in response. Modifiable suffering lives here. When we refuse to update our internal models in relation to what has happened, or attempt to insist that the world affirm our preferences, we suffer.

In the predictive processing account, we do not passively receive the world. We actively construct our experience of it, based on past learning. This past learning forms what are known as priors. From these priors, the brain predicts what it expects to be happening at any given moment. These predictions shape the generative model through which we perceive and enact the world.

But the brain does not just ignore incoming information. When there is a mismatch between what is expected and what is encountered, a prediction error arises. This signal suggests that the model may need to update. Whether it does so depends partly on how much confidence the system places in its existing model compared with the incoming evidence. This balance of confidence is known as precision-weighting.

Suffering arises in the gap between reality and the model we are trying to preserve. A painful or stressful event may violate what we expected, wanted, feared, or believed ourselves able to tolerate. The world no longer fits the self-world model. At this point, the system can update, or it can resist updating. It is in this resistance that much unnecessary and modifiable suffering appears.

This innate resistance is not some kind of moral failure. It is not stupidity or weakness. It’s protective and sometimes adaptive. The organism is trying to preserve its integrity when reality threatens its dissolution.

So the question is no longer, why do we resist? It becomes: what is this resistance protecting? Are we protecting something real and resolvable, like moving our hand away from a flame? Or are we defending against something inevitable, imagined, symbolic, remembered, or ultimately outside of our control?

To understand what the system is protecting, we need to go further than developmental or even evolutionary psychology. We need to understand what it means to be an organism maintaining its coherence in a world that is always, to some degree, threatening to dissolve it.

Before psychology, there is boundary maintenance

To be a living organism at all is to maintain some distinction between inside and outside. Primordial life depended on the existence of a boundary to prevent the dissolution of the organism. Its initial form was the cell membrane. This membrane served to maintain coherence within its boundary. The primordial organism used this boundary to take in what sustains it and keep out or expel that which threatens it. The attempt to defend this boundary is our most primitive instinct. It is our survival reflex. In computational neuroscience, this boundary is described as a Markov blanket: a statistical boundary separating the internal states of a system from the external states of the world. The boundary is not sealed, a cell membrane is not impenetrable. It is semi-permeable. This allows the organism to exchange with its environment, whilst keeping it stable enough to maintain internal coherence.

The human mind is a vastly more complex expression of this same principle. We are not only defending bodily integrity. We are defending the narrative of who we take ourselves to be and our place within the world. We protect our identity, meaning, relational attachments and social status. These are not immediate threats, like a flame or a noxious chemical. They are abstract, symbolic and exist not as material reality, but as constructed models within our mind. The internal self-world model is not a literal physical membrane, but serves a similar purpose. It helps organise what is me, what is not-me, safe and unsafe, possible and impossible, tolerable and intolerable.

An abstract and symbolic threat can therefore be felt with the force of an immediate physical threat to our survival. Letting go of our identity can feel like we are literally dying, when we take that identity to be the entirety of who we are. When these conceptual boundaries are threatened, the system defends, as if it were a threat to our physical integrity. The autonomic nervous system activates. Interoceptive signals are interpreted through meaning and emotions such as fear, anger, shame or grief arise. The mind searches for resolution. We ruminate on the past and rehearse the future. We deploy psychological defence mechanisms: denial, dissociation, repression or intellectualisation.

Sometimes this is adaptive. Sometimes defence is coherent with reality and helps us respond to a real threat, or at least defer what cannot yet be metabolised. The problem is when our defences attempt to protect against threats that cannot be resolved through resistance. When we attempt to fight or run from uncertainty, loss, ageing, rejection, mortality, or a reality that no longer fits the model we were trying to preserve.

This is why mental resistance feels so urgent and real. Yet, we cannot run away from a serious diagnosis. We cannot fight the bank demanding an overdue mortgage payment. We cannot physically remove uncertainty, ageing, loss or the possibility of rejection.

In those cases, the only eventual way through is not more defence, but updating. The system has to find some way to accept what has happened, reorganise around it, restore coherence and develop a new relation to reality.

The defence, however maladaptive it appears, is always doing something. Understanding what it is doing is the beginning of understanding how, under certain conditions, protecting it starts to cost more than it resolves.

The world teaches us what we must defend

The capacity to defend is ancient, but the way we defend is not fixed or inherent to who we are. Our defences are shaped by biology, temperament, attachment, trauma, family instability, poverty, culture, social exclusion, systemic oppression and the wider conditions of our lives. The list is endless. These conditions shape what the organism learns to expect from the world. They shape what feels safe, what feels dangerous, what can be trusted, what must be controlled, what must be hidden and what must never be allowed to happen again.

This begins to dissolve the false dichotomy between biological and environmental accounts of mental disorder. Biology is not sealed off from life. Genes, neurodevelopment, inflammation, sleep, substances, hormones, metabolic disturbance and neural circuitry are all relevant factors that must be considered. But these do not exist in a vacuum. Culture, poverty, trauma, attachment, meaning and social context are also relevant factors. The world gets under the skin. Experience shapes biology, and biology shapes how experience is perceived, metabolised and defended against.

Many defences that appear maladaptive in the present were once adaptive, or at least necessary, in the environments where they first developed. A person who avoids closeness may have learned that closeness was unsafe. A person who controls obsessively may be trying to prevent a catastrophe they have learnt to expect. A person who dissociates may have learned to leave experience because staying present was once unbearable.

The defence is not the person. It is an adaptation of the person to a world they had to survive. Sometimes, the world demands they keep defending.

This changes the clinical question. We are not only asking what symptoms are present, or which diagnostic category best describes them. We are asking what these patterns are doing. What are they protecting? What would feel threatened if they softened? What world did this defence develop in? What did the organism have to learn in order to keep going?

This does not mean the defence remains helpful forever. A pattern that once preserved coherence can, under different conditions, begin to cost more than it protects. It can become rigid, self-reinforcing, dysregulating and impairing. It can narrow life, distort perception, rupture relationships and make flexible contact with reality increasingly difficult.

That is the threshold this essay has been moving toward. Suffering is not pathology simply because it exists. Defence is not pathology simply because it arises. But under certain conditions, protective processes can become pathological.

In Part Two, I will turn to that process directly: how suffering and self-protection cross the threshold into dysregulation, dysfunction and disorder.

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