Sunday, 15 May 2016

The difference between Pathological Demand Avoidance (PDA) and Oppositional Defiant Disorder (ODD)

Our daughter was diagnosed by a paediatrician at the young age of two and a half. Her actual diagnosis is written as: 
1. Autistic Spectrum Disorder and 
2. Oppositional behaviours/pathological demand avoidance behaviours.

After a few months of searching for general information on autism, we experienced our 'lightbulb moment' when we stumbled across Pathological Demand Avoidance (PDA). We could tick almost all of the diagnostic criteria for our girl; the language delay with catch-up was just one point which seemed particularly relevant for us.

She was passive, resisted demands, led by a need to control, sociable and comfortable with role-play. The last two characteristics are not often associated with classic autism or Aspergers, and that is where we saw the most difference to other autistic children we knew.

photo of a rainbow over grass with purple border and white text as per post title
Pathological Demand Avoidance is an Autism Spectrum Condition. Oppositional Defiant Disorder is not an Autism Spectrum Condition.

Our daughter was lucky, I feel, to escape the suggestion of Oppositional Defiant Disorder as a diagnosis. It wouldn't have been right, but it would have been an obvious choice given that the word oppositional was being used when she was first assessed. When training now, I am often asked 'what is the difference between PDA and ODD?'

Oppositional our girl may have been, but she definitely wasn't defiant. She also wasn't naughty. When she was younger, there may not have seemed to be an obvious reason for her refusal to do the most basic of tasks, but we soon learned that there was. She didn't refuse to wear socks just because she wanted to be awkward, or just because we'd asked her to; it was a sensory issue. She didn't get irrationally distressed when we walked a different way to nursery just to annoy us; her fear of not being in control and not knowing what was happening was the cause of that.

In fact, we've come to learn that several of her refusals are sensory led. Others are anxiety driven; going to new places or the fear of being sick in the car prevent us from getting her out as much as we'd like. Of course many children have these worries, but those children are not autistic. The difference we see in our younger daughter (we have one older daughter who is not autistic) is the extreme distress which it causes her, and the long-lasting knock-on effects if we choose to force the issue.

So back to my original question: what is the difference between ODD (Oppositional Defiant Disorder) and PDA (Pathological Demand Avoidance)?

This diagram below, made by the PDA Society (, shows that PDA falls within the circle of Autistic Spectrum Disorders, whereas ODD does not. There are other commonly found co-morbid conditions shown in the green circle; these are also not classed as part of the autism spectrum.

Circles diagram showing autism conditions in the middle circle and related, co-morbid, non-autistic conditions in outer circle
With thanks to the PDA Society for creating this slide and allowing me to share
A child (or adult) can be given an ODD diagnosis without an autism diagnosis; however every child/adult diagnosed with PDA is autistic. There are various tests for Autistic Spectrum Disorder/Condition which can be found elsewhere online; the National Autistic Society is the best place to start looking for information on those.

Children with ODD are often described as having 'emotional and behavioural difficulties', or 'conduct problems'. They may have experienced difficult social environments and use behaviour as a means of attention, an outpouring for their anger or to hide their lack of self-worth. One difference often quoted between those with ODD or PDA is that children with ODD are less keen on embarrassing themselves in front of their peers; they are keen to fit in and can socialise in a typical way. Children with PDA on the other hand, are more likely to have unpredictable outbursts, even in front of their peers, and they tend to try and control all social interaction without understanding why their peers do not like it and then shun them.

It may be possible to be autistic (whether that's Asperger Syndrome or Classic Autism) and have a co-morbid diagnosis of ODD. It is probably true to say that demand avoidance is there for most children with autism, especially when they are resistant to changes in routine. Children with PDA may enjoy some routine as it can lessen anxiety, but they are also keen to have control of their environment and so can be largely unpredictable. 'Jekyll and Hyde' personality is often mentioned in conjunction with PDA.

The diagram below shows the family of pervasive development disorders specifically, in a different way:
venn diagram showing the family of pervasive development disorders
ODD is not mentioned above as this diagram is purely information on autistic spectrum disorders, which we have established ODD is not (ODD may be present in children/adults without ASD). There is crossover possible between most of these diagnoses however; you could for example, have a child diagnosed with Asperger Syndrome who shows PDA traits. It would be unlikely I feel (though maybe not impossible), to have a child diagnosed with PDA and ODD.

It is possible that some children are given a diagnosis of ODD and ASD because Pathological Demand Avoidance is not yet recognised everywhere. The trouble with using ODD when PDA would be a better fit for a child is that there is a huge difference in the strategies which are proven successful for either diagnosis.
My post Strategies for PDA gives a starting point, and I'd also suggest you check out strategies listed on the PDA Society page, or Behavioural Strategies produced by Autism West Midlands.

For ODD, take a look at Contact A Family's page. There is a fantastic Facebook page called the Autism Discussion Page where many different strategies are suggested for varying situations, and there is also a good summary of ODD over on the Good Schools Guide website.

The term 'can't help won't' is often used to describe PDA, meaning that a child can't help the fact that they won't do something. Traditional parenting methods, such as rewards and consequences, are not generally effective over a sustained period. They may work once or twice if all other conditions are favourable, but not when the need to avoid demands is strong. If strategies for ODD have been tried with a child and are not working, it would be worth taking a look at the PDA ones, or vice versa.

This is a topic which is likely to continue to draw much further discussion over the coming years as it is not a clear cut area. Remember that parents are experts, and no-one knows their own child as well as a parent. Go with your gut instinct and what works for your child and your family. The diagnosis DOES matter as it can back up your choice of strategies and a diagnosis will help educate others, but what is immediately more important is making sure that all those around your child are using helpful and consistent strategies.

pinnable image of rainbow with text the difference between pathological demand avoidance and oppositional defiant disorder

For more information about PDA, please read the book shown below: 
(this is an affiliate link and I may receive a small commission if you visit a link and go on to buy anything. It won't cost you any extra)

Book cover for Understanding pathological demand avoidance syndrome in children, by Phil christie, margaret duncan, zara healy and ruth fidler

(Other PDA books can be found in my 

To find out more about our experiences, please check out our 'About Us' page or the summary of our experience in Our PDA Story Week 35. If you are looking for more online reading about Pathological Demand Avoidance, the posts below may help.

What is PDA (Pathological Demand Avoidance)?

Ten things you need to know about Pathological Demand Avoidance

Does my child have Pathological Demand Avoidance?

The difference between PDA and ODD

Strategies for PDA (Pathological Demand Avoidance)

Pathological Demand Avoidance: Strategies for Schools

Challenging Behaviour and PDA

Is Pathological Demand Avoidance real?

Autism with demand avoidance or Pathological Demand Avoidance?

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