PDA… the story so far


The following is a summary of Phil Christie's talk “PDA... the story so far” at the PDA Society Conference in Birmingham on 18th April 2018

Personal journey

Phil first paid tribute to Professor Elizabeth Newson’s pioneering work around PDA, saying “possibly without Elizabeth we wouldn’t be gathered here today”.
Phil reflected on his personal journey with PDA - a former student of Elizabeth Newson, he has continued to gain his views, knowledge and insight around PDA from seeing children with PDA in widely different contexts through his work at the Diagnostic Assessment Service at the Elizabeth Newson Centre, from being responsible for a non-maintained specialist education provision for children and undertaking research including a very early home-based intervention programme. He now provides consultancy and training for schools and organisations.
Phil said that he has a very strong tradition of working closely with families having been taught that parents are part of the assessment team. He said that parents have the knowledge about their child and, as a professional it’s your responsibility to ask the right questions to unlock that knowledge, knowledge which sometimes parents don’t even realise they have. He also explained that his talk primarily focussed on children, as that was where his main experience lies, but that of course we must also be inclusive of adults with a PDA profile.


Looking at the PDA Society's timeline which documents some key dates in the history of PDA, Phil noted that the first peer reviewed paper on PDA was only 15 years ago in 2003. He pointed out that, by comparison, the first peer reviewed paper on autism was in 1943 and our understanding of autism 15 years on from then, in 1958, was very different to what it is today. So we’re still on that journey in terms of understanding and learning about PDA. He felt everyone, particularly professionals, should enter that journey with an open mind and with an open minded debate.
Phil felt that a particularly pleasing milestone was the acceptance of the article 'The Distinctive Clinical and Educational Needs of Children with Pathological Demand Avoidance Syndrome: Guidelines for Good Practice' as part of the National Autism Standards guidance in 2012 and mentioned other notable milestones including the establishment of the PDA Society and the creation of the EDAQ in 2014.

He reported that a more recent step forward had been in the interest from professional bodies in the UK and overseas and that he had recently submitted evidence to the first set of guidelines for the diagnosis of Autism Spectrum Disorders in Australia where PDA is expected to be briefly mentioned.

Key drivers

Phil explained that two of the main factors which have driven, and continue to drive, his work around PDA are:

  • The fact that there is such a strong recognition factor - again and again parents recognise their child in written accounts of PDA (the light-bulb moment, when you’re racking your brains searching for an explanation for your child’s behaviour and you come across information about PDA which describes your child).
  • The appreciation that a different emphasis is needed in an education and support approach.

Diagnosis and classification

Referring to Elizabeth Newson’s ‘The "Family" of Pervasive Developmental Disorders’ diagram which she originally created in 1999 and published in 2003, Phil explained that the circles were used to represent clusters of symptoms within the umbrella term Pervasive Developmental Disorder. He went on to say that Elizabeth Newson had conceptualised PDA as a separate sub-group within Pervasive Developmental Disorders, related to but separate from Autism or Asperger's syndrome, although acknowledged that sometimes those circles overlap and can move with time as a child develops.

At that time clinicians who used the ICD (World Health Organisation International Classification of Diseases) described children who they felt had a Pervasive Developmental Disorder that didn’t fit the conventional categories (Autism or Asperger's Syndrome) as having “Atypical Autism”. Clinicians using the DSM (American Diagnosis and Statistical Manual) described these children as having “Pervasive Developmental Disorder - Not Otherwise Specified”. Many children with PDA might have fitted those descriptions.

By 2011 clinicians were using the umbrella term 'Autism Spectrum Disorder' instead of Pervasive Developmental Disorder so the title of the diagram can affectively be changed to ‘The "Family" of Autism Spectrum Disorders or Conditions’. This reflects the shift in thinking today that PDA is best understood as part of the autism spectrum or one of the autism spectrum conditions.
The most important factor here is that the main point of a diagnosis is to help us understand and make sense of the person.


Phil signposted people to the PDA Society’s list of published articles and summary of ongoing research and pointed out that we’re at a really early stage in terms of research but the key findings so far suggest:

  • The behavioural features of PDA are dimensional across the autism spectrum. The characteristics associated with PDA may occur in others across the spectrum but the “PDA profile” represents a constellation of those symptoms at a sufficient level and sufficient intensity.
  • PDA is comparatively rare.
  • More females with ASD display PDA features than males.
  • There are parallels between features of PDA and other descriptions such as ODD (Oppositional Defiant Disorder) and CD (Conduct Disorder) but there are important differences. One of the most important differences in relation to ODD is that children and young people with PDA tend to be avoidant of more mundane everyday things whereas children with ODD are oppositional about bigger demands. Also children with ODD tend to respond well to behavioural rewards and sanctions whereas children with PDA don’t.
  • More research is needed to look at aspects of PDA and whether aspects of the PDA profile can be found in other populations other than those with autism.

He noted that the UCL (University College London) research team produced an article about PDA (which was accepted for publication in an issue of the British Psychological Society Debate in 2016) concluded that an accurate description and formulation of the child’s difficulties is the starting point for identifying management strategies and how essential it is for this help to be provided for these very vulnerable children and their families.

Phil went on to discuss the Jonathan Green et al review paper recently published in The Lancet, which suggests that PDA can be explained with an ASD diagnosis together with the use of other co-morbid diagnoses (such as Autism with ODD and OCD). He set out his view that the difficulty with this line of thinking is that you end up with a set of separate conditions with potentially separate interventions and you miss the holistic and pervasive nature of PDA. He welcomed their case for a common approach for autism spectrum assessments which is detailed, comprehensive and includes a rigorous trait description and also that parents should be listened to and believed.

He said that there is a need for more research - using the quote “not everything that can be counted counts and not everything that counts can be counted” though, he made the point that research is part of the picture but that there are all sorts of other sources to gain valuable information from – through clinical accounts, case studies, personal descriptions etc.

Implications for education

Very briefly Phil highlighted some of the key implications PDA has for education:

  • The need to work together
  • To work at negotiated solutions
  • To be flexible and accommodate to the needs of the child

He said that schools should be looking at how they can find a way that works with and for the child rather than simply saying “this is how we do it”.

Other notable points

Some other key points Phil made during his talk include:

  • In her early work, before she came up with the notion of PDA, Elizabeth Newson would describe the first group of children as being “like autism or Asperger syndrome but … “ and that one of the key ‘buts’ was a seemingly better level of social understanding. Phil said that many children with PDA are discounted for an ASD diagnosis on the basis of being too sociable (eye contact too good, seemingly better social empathy than you would expect from a child with an ASD).
  • However robust the child’s behaviour may seem, he said it is important to remember that it is underpinned by anxiety.He said we have to understand the “why” as well as the “what” when looking at behaviours.
  • Phil shared a personal story where a child explained that sometimes they can overcome demand avoidance but that at other times it’s too strong but that others don’t understand this. Phil felt that the ‘sometimes’ element was a key message and that it’s one of the things that confuses professionals the most – why does it happen sometimes and not others?

The central challenge

Phil finished his talk by saying that the central challenge for everyone going forward is to build on ongoing developments, insights from families and from individuals, the increasing recognition of PDA but at the same time maintain the integrity of the concept. He said that we needed to maintain the integrity of

  • how the profile is understood – not every child who says “no” has PDA and there’s a danger of the concept becoming so broad that it becomes diluted and that we must guard against that for those children who really do fit the profile.
  • the nature of support that is needed – when we talk about an indirect approach, reducing demands and reducing boundaries, we’re not actually saying everything goes, we are saying reduce to what you need in the moment to reduce the anxiety, choose priorities carefully and then try to build back up as the child’s anxiety decreases.