Sensory Reactivity and PDA: What the Latest Research Means for Clinical Practice

A study published in Research in Autism in January 2026 offers robust, peer-reviewed data on the specific role of sensory reactivity in demand avoidance behaviours. Rai, Rishworth, Gutierrez, and Ludlow examined 795 children aged 4–17 across three groups:

• autistic children with PDA (n=475),
• autistic children without PDA (n=171)
• neurotypical controls (n=94).

The findings are clinically significant for every paediatric OT working with this population.

This blog will walk through what the study found, what it means for our understanding of PDA, and how it translates into practice.

PDA (Pathological Demand Avoidance) describes a profile most commonly identified within the autism spectrum, characterised by an extreme, anxiety-driven need to avoid everyday demands and expectations.

The research literature also refers to this as Extreme Demand Avoidance, or EDA, which is the term used throughout the 2026 study (For those who prefer a different lens please read PDA according to your preference).

It is worth acknowledging that PDA has been a confusing area for many OTs. Questions about how it sits within the autism diagnostic framework, how reliably it can be identified, and what evidence-based intervention looks like have left many OTs uncertain about how to proceed.

Why This Research Matters

Until now, the sensory profile of children with PDA has not been differentiated from that of autistic children more broadly. Clinicians have been working largely from observation, reading whatever information they can get from other professional sources and this includes social media. 

For the first time, peer-reviewed data illustrates that sensory reactivity uniquely characterises demand avoidance in children identifying with autism and PDA in a way that is not seen in autistic children without PDA. That distinction has direct implications for assessment, goal-setting, and intervention planning.

The Three Key Findings

Finding One: Anxiety and Autistic Traits Predicted EDA (PDA) Across All Three Groups

 The study found that higher levels of anxiety and more pronounced autistic traits corresponded with higher levels of demand avoidance across all three participant groups. This held true whether the child had PDA, autism without PDA, or was neurotypical.

For clinicians, this confirms that anxiety is a core driving factor for demand avoidance. Any approach to intervention that does not address or accommodate the underlying anxiety profile is likely to have limited impact, and at worst, be traumatising for the child. 

Finding Two: Sensory Reactivity (Both Sensitivity and Seeking) Uniquely Characterised the Autism + PDA Group

This is the most clinically significant finding of the study.

When the researchers examined what differentiated the autism + PDA group from the autism-only group, sensory reactivity emerged as the distinguishing variable. Specifically, both sensory sensitivity and sensory seeking. Neither of these patterns was significantly associated with PDA in the autism-only group. In the PDA group, both were.

This means that across the full neurological threshold to sensory input (hyper-reactivity at one end, sensory seeking at the other ), elevated sensory reactivity was a meaningful predictor of demand avoidance in children with PDA. The child who withdraws from sensory input and the child who actively seeks it may both be presenting a sensory signal that is directly relevant to their demand avoidance profile.

This reminds us as OTs, that what we see is an external expression of the child's internal world, and to look more closely at the task, environment, relationship and culture of the childs world.

THERAPY NUGGET

When assessing a child with suspected PDA, ensure your sensory assessment captures both sensory sensitivity and sensory seeking patterns. This study found both to be significant predictors of demand avoidance in the PDA group. A seeking presentation should not be interpreted as high threshold requiring more input. It may reflect a dysregulated nervous system attempting to organise under threat. A comprehensive sensory assessment of both modulation and discrimination patterns is essential before determining therapy plan and handling principles. 

Finding Three: Intolerance of Uncertainty Was Not a Significant Predictor for the Autism + PDA Group

The relationship between intolerance of uncertainty (IU) and demand avoidance has been a prominent feature of the clinical picture around PDA in the past. In this study, IU was a significant predictor of EDA in the neurotypical control group. It was not, however, a significant predictor for the autism + PDA group! This is where sensory reactivity was the differentiating factor.

Uncertainty remains a very relevant factor; however, it now points us towards a more comprehensive picture. This includes understanding the child’s nervous system, sensory profile and environment as a primary consideration.

For OTs in particular, this finding supports placing sensory assessment and sensory-based intervention at the forefront of the clinical approach.

THERAPY NUGGET

Consider whether the sensory environment, task and child have been adequately assessed and sensory considerations addressed. According to this research, sensory reactivity and not intolerance of uncertainty was the variable that differentiated the PDA profile. Sensory considerations should precede and inform cognitive or behavioural intervention planning.

What This Means for Clinical Thinking

Taken together, these findings point to a clear clinical implication: sensory reactivity is a central, differentiating characteristic of PDA, and is directly associated with the ‘demand avoidance behaviours’.

 When we understand the neuroscience, the ways in which the child interacts in the world become considerably easier to interpret.

‘Demands’ are events that challenge a nervous system that may already be operating under significant sensory load.

State first. Strategy second.

 Translating the Research into Practice

 The authors of this study recommend a strengths-based approach to intervention for children with PDA that specifically addresses environmental sensory demands. The following three practice areas reflect that recommendation and are grounded directly in the research findings.

1. Observe and Understand

 Understand and map the child’s contexts/ environments, including the home, the school, the waiting room, the transition between settings. Every environment presents its own unique sensory challenges and its often the shift or change in sensory demand of the environment that carries the biggest impact on the nervous system.

The cumulative effect of sensory input on a child, as well as unexpected changes within the sensory environment, has direct bearing on how the child responds. Demands that would otherwise be manageable may exceed the child’s capacity entirely, and this may vary day by day or situation to situation. 

Relevant considerations include: ambient noise levels, visual complexity, predictability of transitions, tactile demands from clothing or physical contact, proprioceptive and vestibular input, and the degree of social or sensory unpredictability in the environment.

Therapy Nugget

Being child-led and providing choice at the start of a session signals safety to the child’s nervous system.

Observe whether the child presents as seeking or avoiding on arrival, and adjust the session plan accordingly. The sensory state the child arrives in informs what the nervous system can manage in that session.

A session that begins with co-regulation and attunement is more likely to support meaningful therapeutic engagement than one that begins with task demands. 

2. Reassess the Demand Hierarchy Through a Sensory Lens

When sensory load is elevated, the threshold for demand tolerance is reduced.

The attuned therapist observes the child’s capacity through this lens and adjusts accordingly during the session.

For children with PDA, the sequence of intervention matters as much as the content. Sensory regulation must precede demand introduction. Where you see avoidance increase, review yourself as a therapeutic tool as well as your environment and the demands.

Practically, this means reviewing each therapeutic goal and asking:

• What is the inherent demand embedded in this goal, and
• Has that demand been assessed and modified as needed

A communication goal, a self-care goal, or a social participation goal may each carry a significant sensory load. OT’s excel at activity analysis, so use it!

That load may be the primary barrier to progress.

THERAPY NUGGET

Analyse each goal on the child's intervention plan for the inherent sensory demands on the child.

For each goal, identify: what sensory inputs does achieving this goal require the child to manage simultaneously?

Where that sensory demand is high, consider whether it needs to be addressed as a prerequisite before the goal itself is targeted.

The gap between what a child is capable of and what they are currently able to demonstrate is seldom a motivational or compliance gap.

3. Provide Families with Evidence-Based Explanatory Language

A significant component of effective intervention for PDA children is equipping families with accurate, accessible information about the neurological basis of demand avoidance. When caregivers understand that a child's refusal behaviour may be primarily driven by sensory reactivity and nervous system threat responses, it changes how they respond and how they support their child across settings.

OTs are well-placed to translate the research for families. An explanation grounded in neuroscience: that the child's nervous system is interpreting demands as unsafe, that sensory load from the transition or task is central to the degree of demand avoidance observed, and that environmental modification is a legitimate and evidence-supported intervention. This gives families a framework they can apply consistently at home, at school, and in community settings.

Most importantly our understanding and support for PDAers is about ensuring that the neurological conditions for meeting expectations are in place before those expectations are introduced.

THERAPY NUGGET

Where families have an accurate understanding of their child's sensory profile, they are better equipped to advocate for their child across educational and therapeutic settings and more likely to implement the strategies that have been shown to be effective in session.

In summary

 The 2026 Rai et al. study makes a meaningful contribution to the evidence base for paediatric OT practice with PDA populations. It provides the first peer-reviewed data to demonstrate that sensory reactivity uniquely characterises demand avoidance in autistic children with PDA, distinct from autistic children without PDA.

For clinicians, this finding affirms the centrality of sensory assessment and sensory-informed intervention in this area of practice.

As developmental OTs, we are obliged to understand all facets of development, including the nervous system and sensory processing. This research gives us important new grounds on which to do exactly that.

 Reference: Rai, A.J., Rishworth, B., Gutierrez, R., & Ludlow, A.K. (2026). Sensory reactivity and intolerance to uncertainty: What characterises demand avoidance behaviours in children and adolescents with pathological demand avoidance? Research in Autism, 131, 202816. https://doi.org/10.1016/j.reia.2026.202816