WHO Write Pathological Demand Avoidance as a Distinct ASD Subtype in ICD11 Final Version

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In 1983 Professor Elizabeth Newson, University of Nottingham, identified a pervasive developmental disorder related to autism, which she named Pathological Demand Avoidance (PDA).

The PDA Society lists multiple research articles here:


The UK's national autism charity The National Autistic Society mirrors information on the PDA Society website: http://www.autism.org.uk/about/what-is/pda.aspx and recognoses PDA as an ASD. 

PDA has been found to share many similarities to autism but has some key differences.  Some of these are that the individual has:

  • somewhat better superficial socialising skills than other ASD subtypes but still emotionally immature and lacking some empathy;
  • can be very manipulative with others;
  • obsessively avoids daily demands through behaviours such as excuses, challenging behaviour, manipulation and distraction;
  • has an overriding need for control;
  • often demonstrating role-play and mimicry and immersion in fantasy;
  • special interests and obsessions are often based on people rather than things;
  • extremely high rates of anxiety contributing to demand avoidance;
  • very moody and often described as "Jekyll and Hyde" characters;
  • may have shocking and extreme behaviours, including irrationally blaming and falsely accusing others, which in some instances involves making false police reports.

The Extreme Demand Avoidance Questionnaire (EDA-Q) has been developed to identify those with the PDA profile. Liz O'Nions provides an explanation here of how the EDA-Q was developed: https://sites.google.com/site/lizonions/EDAQ

Some research has been done on which clinical tool best identifies the PDA ASD subtype in assessments and it is likely that the DISCO is more accurate at identifying PDA:

"Identifying features of ‘pathological demand avoidance’ using the Diagnostic Interview for Social and Communication Disorders (DISCO)" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4820467/

Even with typical ASDs the DISCO is better, than the ADOS-2 with ADI-R:

"Comparisons Between the DISCO and the ADI-R and the ADOS"

"Five cases with clinical ASD were missed by the ADI-R autism algorithm, but were all picked up with DISCO-10 algorithms. When the ADI-R thresholds for the broader category of ASD (Risi et al., 2006) were applied, four of the five were identified as ‘other ASD’. Preliminary findings for the Belgian study appear to support the foregoing results. Conclusions: The DISCO algorithms show good convergent validity in comparison to ADI-R and ADOS. Advantages over the ADI-R include valuable information of the broader autism phenotype and co-existing problems, relevant to both clinical practice and research."

But most clinicians appear to use the ADOS-2 for ASD assessments, coupled with the confusion and lack of awareness and understanding of the PDA subtype among many clinicians, this is detrimental to those with PDA and there are anecdotal reports of children with PDA not receiving any diagnosis at all. This is catastrophic for the child.

Some clinicians have been recognising that the individual has ASD and diagnosing as such, with a descriptor of a demand avoidant profile, in other cases using the term pathological demand avoidance in the diagnosis itself, recognising it as a distinct subtype or profile of ASD.  Both adults and children have received diagnoses of ASD-PDA in the UK.  However, there is a lot of confusion among clinicians and some will not diagnose it, as it is not currently described in the diagnostic manual. Because clinical tools such as the ADOS-2 don't always identify the individual's ASD-PDA, this has resulted in some vulnerable individuals not receiving any diagnosis at all and therefore lacking the support they need, negatively impacting their wellbeing, family life, education and prospects.

PDA is often compared to oppositional defiance disorder (ODD), as the behaviours are very similar.  An autistic individual has a different neurology than a neurotypical one. So even in the event that PDA is the expression of ODD in an autistic child, the whole must still be recognised as a distinct profile, because the child in which it exists is on the autistic spectrum.  ODD would naturally present differently in an ASD child than it would in a neurotypical child. An autistic child with ODD would have their autistic traits in addition to the oppositional and avoidant behaviour. This means that even if PDA is ASD+ODD, it is warranted and clinically justified giving it it's own name as a compound of two conditions that makes up a distinct syndrome.

A particularly pressing reason for PDA to be formally recognised in the diagnostic manual, is that those with PDA need different support and behavioural management techniques and strategies than other ASDs and many parents and professionals report that typical ASD strategies don't work.  The Autism Education Trust developed educational guidance which is supported by the UK Department for Education:

"The Distinctive Clinical and Educational Needs of Children with Pathological Demand Avoidance Syndrome: Guidelines for Good Practice"

The UKs Department of Work and Pensions who issue disability benefit payments recognise PDA in their Guidance Document on Medical Conditions in Children for Assessors (P3):

Normal parenting strategies do not work most of the time for children with PDA, leaving families struggling and sometimes traumatised and in crisis.  Many children with PDA school refuse, even refusing to leave the home at all and fail to engage with mental health support services, who simply close their file due to lack of engagement.  When social services deem a family unable to control their child they can be taken into state care. And when professionals blame the parent for their child's difficulties, especially when the child has not received a diagnosis, parents can be falsely accused of neglect or child abuse and permanently lose their children. Adults with PDA have a higher risk of entering the criminal justice system.

The widespread ignorance and lack of recognition of PDA has resulted in not only missed diagnoses but misdiagnoses of other conditions.  These may include ADHD and worryingly, attachment disorder, due to as stated above, blaming parents for the child's behaviours and difficulties.  This can particularly occur when the child masks their difficulties in school as many on the autistic spectrum do and parents are disbelieved as to how much they are struggling and how severe the behaviours are at home. Children with PDA can be particularly violent and aggressive in their meltdowns.

NHS NICE Guidance requires that the individual's personal profile is explained in diagnostic reports, but in practice this doesn't help the child, if the NHS region denies that PDA exists, which is happening in some areas.  Typical ASD strategies that don't work for PDA, will still be recommended.  The English and Scottish Governments both formally recognise that PDA falls within the autism spectrum, in response to recent petitions.  However, as explained above, because of the distinct differences of PDA to other ASDs, the clinical overreliance on the ADOS which doesn't always identify those with PDA, the ignorance among diagnosticians that PDA is an ASD, the need for different techniques for support and the postcode lottery across the UK (https://www.zeemaps.com/map?group=1558150) - and likely other countries - as to diagnosing PDA, a clear description and diagnostic code in the International Classification of Diseases Manual is required for ASD-PDA, so that all with the condition are accurately diagnosed and receive the right support.

Therefore we ask the World Health Organisation (WHO) to formally recognise Pathological Demand Avoidance as a distinct subtype under the Autism Spectrum Disorder category in the ICD11 when it is finalised and issued.