Sensory overload may drive PDA

Sensory Overload May Drive Demand Avoidance in PDA

Pathological Demand Avoidance (PDA) is often described as a profile of autism characterized by an extreme avoidance of everyday demands. Traditionally, the focus has been on the demand itself.

However, a 2026 study suggests that the picture may be more complex. After accounting for anxiety and autistic traits, the researchers found that sensory over-reactivity was the only factor that uniquely distinguished autistic children and adolescents with PDA from autistic participants without PDA.

About the study

Researchers analyzed data from 795 children and adolescents aged 4–17 years, including autistic participants with PDA, autistic participants without PDA, and neurotypical controls. Parents completed questionnaires measuring demand avoidance, autistic traits, anxiety, intolerance of uncertainty, and sensory processing. The researchers wanted to understand which factors best explained demand avoidance behaviours.

What did the researchers find?

1. Anxiety was associated with demand avoidance

Across all three groups, higher levels of anxiety were associated with greater demand avoidance.

This supports previous research suggesting that anxiety plays an important role in demand avoidance behaviours, regardless of whether someone has PDA.

2. Autistic traits were also associated with demand avoidance

Participants with more autistic characteristics also showed higher levels of demand avoidance.

Autistic traits and anxiety both remained significant predictors across the groups, suggesting that demand avoidance cannot be explained by a single factor alone.

3. Sensory reactivity uniquely distinguished the PDA group

The most surprising finding came after the researchers statistically accounted for anxiety and autistic traits.

Only one factor uniquely distinguished the autistic participants with PDA:

Sensory reactivity.

Specifically, the strongest sensory predictors were:

• tactile sensitivity
• sensory seeking

These sensory characteristics were not unique predictors in the autistic group without PDA.

4. Demands may trigger sensory overload

The researchers suggest that, for some autistic people with PDA, everyday demands may become difficult because of what those demands do to the nervous system.

Rather than thinking:

Demand → Avoidance

it may sometimes be more accurate to think:

Demand → Sensory overload → Anxiety → Demand avoidance

This perspective suggests that avoiding demands may function as a way of coping with overwhelming sensory experiences rather than simply avoiding the demand itself.

5. This could change how we support PDA

If sensory processing contributes to demand avoidance, reducing demands alone may not always address the underlying difficulty.

The authors suggest that recognizing sensory needs and modifying sensory environments may be an important part of supporting autistic people with PDA.

Examples include:

• reducing sensory overload
• providing quieter environments
• allowing sensory regulation strategies
• adapting environments to individual sensory needs

Why does this matter?

PDA is increasingly recognized as a lifelong autistic profile, yet there is still considerable debate about why demand avoidance occurs.

This study suggests that, for at least some autistic people with PDA, demand avoidance may be closely linked to sensory processing differences rather than simply unwillingness to comply.

That shift in perspective encourages us to ask a different question:

What sensory demands is this person trying to cope with?

Limitations

This study included children and adolescents aged 4–17 years, so we cannot assume the findings apply directly to autistic adults. The researchers also relied on parent-report questionnaires rather than direct clinical assessments, and PDA itself is not currently recognized as a formal diagnostic category.

The takeaway

This study suggests that anxiety and autistic traits both contribute to demand avoidance, but sensory over-reactivity may uniquely distinguish autistic people with PDA.

Rather than viewing demand avoidance simply as resistance to demands, it may sometimes reflect an attempt to prevent sensory overload and regulate an overwhelmed nervous system.

Understanding sensory processing may therefore be an important part of understanding PDA itself.

Research Paper

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