Why health is never caused by one thing
Families often arrive looking for the single cause. Is it sensory? Anxiety? Parenting? Something neurological? They are fair questions — but a child's regulation, participation and wellbeing almost never come from one cause. They emerge from a web of conditions, interacting across many systems at once.
Health is never caused by one thing
When a child is struggling — with behaviour, regulation, eating, sleep, school or simply being in the world — the search for one clear cause feels urgent. It is a completely human place to start. But practice keeps showing the same thing: human functioning doesn't come from causes acting alone.
It comes from many conditions interacting at once — the child's biology and nervous system, the family and the relationships around them, the physical and sensory environment, the shape of their daily occupations, the school day, and the wider social and structural world they live inside. And these conditions don't simply add up. They feed each other. Sleep affects regulation. Regulation affects eating. Eating affects energy. Energy affects play. Play affects confidence. Confidence affects how a child joins in. How they join in affects mood. Mood affects learning. Learning affects family stress. And family stress settles back into the nervous system of everyone in the house.
Seeing that web isn't paralysing — it is the useful part. If a difficulty is held in place by many conditions, then there are many places where change becomes possible, not just one. The work is to find which of those conditions are most worth moving, for this child and this family, right now.
In real life, causes rarely sit in neat boxes.
Six domains shape a child's regulation and participation, and each one pulls on the others. Tap a domain to see how a change there reaches the rest.
Because the conditions move together, a single-factor explanation is almost always too small. Each of these can be one real contributing condition — and none of them, on its own, is usually the whole answer.
Swap “it's just …” for “this may be one condition within a larger, interacting pattern,” and the question opens up — without dismissing anything the family has noticed.
The body matters — and it lives in a context
Biology is foundational, and this model takes it seriously. Genetics, neurodevelopmental profile, disability, sensory processing, pain, illness, fatigue, hormones, sleep physiology, gut function, medication — all of it shapes a child's capacity to regulate and take part. None of that is minimised or explained away.
But the body doesn't work in a vacuum. It is continuously shaped by what surrounds it: the quality of sleep, the food on offer, the sensory load of the rooms a child spends their day in, the stress hormones in the air at home, how much movement is available, and the steadiness of the people nearby. So even where a biological difference is significant and fixed — a diagnosis, a sensory profile — how it shows up in daily life still depends on the conditions around it. Two children with the same diagnosis can look very different depending on what is surrounding them.
The nervous system mediates everyday functioning
Beneath awareness, the nervous system is constantly reading the room — and the people in it — for cues of safety or threat. That reading shapes a child's state, and the state shapes what is possible moment to moment: learning, play, flexible thinking, tolerating a transition, joining in.
When enough safety has been detected, there is capacity — room for curiosity, problem-solving, connection, and the ordinary tolerance most of a day asks for. When the system is running on chronic stress, sensory threat, relational disruption or plain depletion — too little sleep, hunger, illness — it shifts into protective states. These aren't choices. Some children mobilise into fight or flight and look defiant, impulsive or always-moving; others drop into shutdown and look flat, withdrawn or “lazy.” Many swing between the two, which is why the same child can look so different from one hour to the next.
The same child can move between all three, depending on the conditions present.
Mobilised for protection
Sympathetic activation. Aggression, meltdowns, refusal, running, impulsivity, arguing, constant movement, rigid control.
Social engagement on
Ventral vagal. Flexible, curious, cooperative — able to learn and play, tolerate frustration, recover from difficulty, connect with others.
Conserving resources
Dorsal vagal. Flatness, withdrawal, “I don't care,” school refusal, not responding, hiding — easily misread as laziness or defiance.
Dysregulation rarely comes from one trigger. It comes when the load built up across a day finally exceeds what's left to hold it.
Behaviour isn't ignored. It's read in the context of the state it's coming from.
Family systems and relational conditions
Regulation grows through relationship. Co-regulation — a calm adult nervous system steadying a child's — is the mechanism through which self-regulation slowly comes online. So a child's regulatory capacity isn't only an individual trait. It's also a relational and environmental product.
That makes the relationships around a child a major set of conditions. The obvious ones: whether there is safe, warm, consistent caregiving from adults who can stay steady in the face of distress. And the less visible ones: financial stress, caregiver sleep, strain between caregivers, a parent's own mental health, cultural obligations, whether there's extended family or community nearby, and the general predictability and warmth of home.
Parents aren't outside the system trying to fix the child. They're part of the same living system — often carrying enormous pressure of their own.
A caregiver who is sleep-deprived, financially stretched, isolated and supporting a child with high needs will have less to give to co-regulation — not from any failing, but as the predictable result of conditions that would tax anyone. Supporting caregiver capacity isn't peripheral to paediatric OT. It's central to it.
School, learning and peer systems
For most school-aged children, school is the most sustained regulatory demand of the day: hours of sensory input, social navigation, sustained attention, transitions not of their choosing, and a behavioural standard to hold — often while managing a great deal of internal effort that nobody around them can see.
The teacher relationship, whether the room is sensorily manageable, whether there's a genuine sense of belonging and at least one secure friendship, whether the academic demand fits — these are all conditions that either support or drain what a child has to work with. It's why the same child can function so differently across classrooms, teachers and years.
A child who holds it together at school and falls apart at home isn't saving their worst for you. They're releasing six hours of effort in the only place safe enough to do it.
The same child, very different days — depending on the conditions in the room, not a fixed trait.
Daily occupations and the practice of wellbeing
Occupational therapy is set apart by its focus on occupation — what people do, how they do it, and the conditions under which taking part is supported or constrained. That's not just a scope line. It rests on a real claim: health isn't only a state inside the body. It's continuously practised, eroded or sustained through the texture of an ordinary day.
How a child sleeps, how mealtimes feel, whether there is genuine play, how much movement is available, what transitions are like, whether there is real rest alongside the demand — these are conditions, every bit as clinically relevant as biology or relationships. An OT looking at a child's regulation or participation wants to understand all of them, because that's where the difficulty is likely emerging from.
Health isn't only something that happens inside the body. It's something practised — or undermined — in the rhythms of a day.
How the day is distributed — demand against rest — directly affects nervous-system load and recovery.
Overload without recovery
Too much structured activity, too little downtime, performance pressure, few freely-chosen occupations. Risk: chronic dysregulation, burnout, shutdown.
Variety, rhythm, recovery
Demand alternating with rest, embodied play and movement, a predictable rhythm, mastery alongside challenge. Supports: regulation, participation, learning.
Too little challenge or meaning
Excess passive screen time, little embodied play, no real routine, few mastery moments. Risk: boredom-driven behaviour, reduced agency.
Modern life and regulatory pressure
It's worth naming, without blame and without romanticising the past, that several features of contemporary life press on the conditions that support regulation. This isn't about families failing. It's about the environment that nervous systems — children's and caregivers' — are currently running in.
Screens carry real value, and also offer constant, high-novelty stimulation that can crowd out the boredom and quiet from which embodied play and internal regulation tend to grow — with knock-on effects for attention and for sleep when screens come right before bed. The pace of schedules, the loss of slow shared meals, less unstructured neighbourhood play, academic pressure arriving earlier, and thinner intergenerational support are all structural conditions shaping the environment children develop in.
Food rhythm deserves its own mention. Shared, predictable, warm mealtimes support connection and safety in a way that's distinct from nutrition alone. Meals marked by pressure, conflict or distraction create conditions that can feed feeding difficulties and appetite trouble — quite apart from any single sensory or biological factor.
Social determinants and structural conditions
A complete picture reaches past the individual and the family to the structures they're embedded in. Housing instability affects sleep, predictability and a nervous system's sense of safety. Financial strain affects nutrition, caregiver stress and the time available for the relationships that support co-regulation. Limited access to care means difficulties pile up unsupported. No safe outdoor space restricts movement, sensory regulation and play.
Sometimes the most useful question isn't “what's wrong with this person?” but “what conditions are surrounding this person every day?”
NDIS access, the affordability of services, school inclusion, workplace flexibility, whether there's a peer network for families carrying additional needs — all of it shapes what's genuinely possible for a family right now. Naming these conditions doesn't diminish agency; it stops us misreading structural disadvantage as personal failure, and it points toward advocacy, referral and systems navigation as real parts of the work.
Wellness also emerges from conditions
This isn't only a model of how difficulty arises. The same logic runs the other way. Wellbeing, regulatory capacity and participation are conditional too — they come from circumstances, not just from the absence of problems.
When a child has steady access to warm, regulated relationships; when sleep is adequate and fairly predictable; when meals are low-pressure and connected; when there's enough embodied play and movement; when the sensory environment is manageable; when there's at least one real friendship; when there are regular moments of mastery and agency — regulation and participation become more likely. Not guaranteed, but genuinely, measurably more probable.
Small shifts ripple. A loop can lift a child up, or hold a difficulty in place.
The occupational therapy lens
OT assessment reaches past the presenting symptom to the whole range of conditions shaping a child's day. An OT doesn't only ask about the difficulty — they ask about daily life: routines, relationships, sensory environments, participation, meaningful occupations, barriers and supports. That isn't straying into other disciplines; it's the distinctly occupational view that function is always shaped by the conditions it happens in.
It's why an OT might ask about sleep when the concern is aggression; about mealtimes when the concern is anxiety; about school when the concern is refusal at home; about caregiver wellbeing when the concern is laid at the child's feet; about movement and outdoor time when the concern is attention. Each question is an investigation into the conditions that may be holding the pattern in place.
OT isn't about finding fault — in the child, the parent, the school or the diagnosis. It's about understanding the pattern, and finding where change is most possible.
Broader than families often expect — because the presenting concern can't be understood without the conditions around it.
Sleep & rest
Quality and duration, the settling routine, and what genuinely lets this child and family recover across a week.
Mealtimes & food
Rhythm and timing, the relational quality at the table, and the sensory and grazing patterns around appetite.
Play, movement & outdoors
Embodied versus screen-mediated play, movement and heavy work across the day, and regular moments of mastery.
School experience
What masking is costing, whether there's one adult who makes the child feel seen, and the sensory and social load of six hours.
Family & caregiver
What the caregiver is carrying, how predictable the day is, and what support the family actually has access to.
The presenting concern
The diagnosis, the behaviour, the cause the family came in with — held inside all of the above, never apart from it.
In practice this shows up everywhere. Post-school meltdowns may not be a behaviour disorder, but the predictable result of sensory overload, masking, thin nutrition across the day, fatigue, and the safe release of held load on getting home. Persistent food refusal may not be simple fussiness, but anxiety, a history of mealtime pressure, a grazing pattern, discomfort, and an environment beyond the child's current tolerance — together. A caregiver who seems “not coping” may be carrying sleep deprivation, financial strain, isolation and thin support, all at once. Each of those conditions is assessable, and many are changeable — but only if the lens is wide enough to see them.
Core propositions from Part 1
Health is multi-causal. A child's regulation, participation and wellbeing emerge from many interacting conditions at once — biology, nervous system, relationships, environment, daily occupations, school and structural conditions. No single factor accounts for it all.
Conditions interact, both ways. They don't just add up — they amplify and sustain each other. A shift in one changes the odds across many connected conditions, in the positive and the negative direction.
Biology is real but contextually expressed. Genetics, neurotype, sensory differences and disability matter — and how they show up in daily life still depends on the conditions around them.
The nervous system responds to conditions, not just triggers. Dysregulation usually reflects accumulated load, not a single event. Focusing on the trigger alone misses what made the threshold breach likely.
Caregivers are inside the same system. Caregiver capacity is itself a product of conditions. Supporting it is a legitimate, necessary part of paediatric OT — not a side note.
Daily occupations are clinical data. Sleep, meals, play, movement, transitions, rest and balance aren't background. They're the conditions a child's patterns are emerging from.
Wellness emerges from conditions too. The positive loops are as real as the negative ones. The question is where, within the web, change is most accessible and most likely to ripple outward.
Structured reflection for professional development
For critical reflection on Part 1. Record your responses in the Seeds OT Model CPD reflection log toward verified CPD hours.
- Take a child or family on your current caseload. Using the web of conditions, map the conditions across each domain that may be feeding the presenting pattern. Which domains are you assessing thoroughly — and which less rigorously, and why?
- When families offer a single-factor explanation (“it's just sensory,” “it's just behaviour”), what's your current response? Does the language here give you any extra tools for widening that conversation without dismissing their view?
- Find a family where a negative loop seems to be sustaining a difficulty. Where in that loop might a small shift have the most likely downstream effect — and what would that look like in practice?
Questions about this part
If there are so many conditions, how does a clinician know where to focus? +
Does this diminish the importance of diagnosis? +
What's the evidence base for a multi-causal, systems-oriented approach? +
Do social and structural factors fall within OT scope? +
How does this relate to PEO and MOHO? +
Human beings aren't mechanisms with one broken part. We're living systems inside other living systems — families, schools, communities, cultures — each shaping and shaped by the others, continuously.
When the lens is wide enough to take in the whole web of conditions around a child and family, the question changes. Not “what is wrong with this child?” but “what is making participation harder than it needs to be — and where, within those conditions, is meaningful change most possible?” That question is where the Seeds OT Model begins.
Not “what's wrong with this child?” — but “what conditions are making this harder than it needs to be?”