By Dr Michelle S Garnett & Prof Tony Attwood
PDA officially stands for Pathological Demand Avoidance, a term coined by Professor Elizabeth Newson in Nottingham, UK, in the 1980s to describe a group of children who seemed autistic but who were ‘atypical.’ Language around autism has evolved in recent years, and it is now widely referred to as ‘PDA, a profile of autism’. Both clinicians and researchers have found that the profile is a useful one to discover because the parenting and therapeutic strategies to assist an autistic PDA-er differ from those strategies used for an autistic person who does not have a PDA profile and is also different from the strategies used for a non-autistic child who is experiencing problems. Applying strategies for PDA across home and school settings gives the child the best chance of a good outcome. Continuing to misunderstand the profile as typical autism or oppositional defiance risks increasing the child’s suffering and can worsen the symptoms.
Lastly, demand avoidance is common and can be seen in many individuals, For e.g. it is common for children and adolescents to avoid the demands of authority figures in their quest for independence. People suffering clinical levels of anxiety and/or depression can find themselves unable to face or complete everyday demands of life that others do not think about, such as getting out of bed, leaving the house, or brushing their teeth. It is important to be able to accurately diagnose PDA to ensure that it is not over-diagnosed. Over diagnosing PDA would lead to applying PDA strategies that are unsuitable for other groups, such as those with an anxiety disorder, depression, or a behavioural disorder such as Oppositional Defiance Disorder.
Historically there have been, and there still are, many questions around the PDA profile including:
- the name itself,
- whether PDA is a separate condition or syndrome,
- whether PDA may one day appear in the international diagnostic texts,
- if PDA is a subtype of autism or if it co-occurs with other neurotypes,
In this article, we consider the research to inform our current understanding of the above largely historical questions, and then we look at where more research is needed to inform how we support and assist. Almost all the research to date focuses on children and adolescents. In later articles that will be published within the next couple of months we will discuss ways to understand PDA and suggestions for what to do as a clinician if you are referred someone who is seeking or has a diagnosis of PDA, based on our own clinical experience, consultation with experts and review of the current research.
What’s in a name?
It is probably clear to see why people have taken exception to the name, Pathological Demand Avoidance. It certainly does not sound like a condition one would wish to have or identify with. The National Autistic Society, specifically Judith Gould, suggested using the term Extreme Demand Avoidance syndrome (EDA) instead and this term has been adopted by some researchers (Gillberg, 2014; O’Nions et al, 2014). A term that has gained popularity within some social media groups is Pervasive or Persistent Drive for Autonomy. The PDA Society in the UK uses the term, PDA, without the full wording, c.f. their Practice Guidance document (referenced below). Our own view is that we need to use a term that provides a clear signpost to all, that leans into and benefits from the legacy of previous research, otherwise an already complex and unclear area becomes even more complex and unclear.
Is PDA a separate syndrome?
Currently, there is consensus amongst researchers that there has not yet been the detailed clinically based research needed to support the inclusion of PDA within the international diagnostic textbooks, either as a subtype of autism or as a separate condition or syndrome. A syndrome is defined as “a recognizable complex of symptoms and physical findings which indicate a specific condition for which a direct cause is not necessarily understood” (p. 802, Calvo et al, 2003). One of the first steps for determining if a syndrome exists is to design an instrument that reliably measures it across multiple populations.
Elizabeth O’Nion’s and colleagues (2014, 2016) developed a questionnaire called the Extreme Demand Avoidance Questionnaire (EDA-Q) to screen for PDA in 5–17-year-olds. The resulting 26-item, parent-report questionnaire has good psychometric properties, (Stuart et al, 2020) including internal consistency, content validity, sensitivity (ability to identify true positives), and specificity (ability to identify true negatives). Ten out of thirteen subsequent studies of PDA reviewed by Kildahl and colleagues (2021) utilised the EDA-Q or parts of the EDA-Q to contribute to the verification of the diagnosis of PDA.
These results taken together indicate that there is a recognisable and measurable symptom set that we currently call PDA, but because all the measured symptoms are behavioural rather than physical, and the symptoms could be explained by other factors the research to date does not demonstrate that PDA is a separate syndrome, or that it isn’t. More research is needed.
Is PDA a subtype of autism?
Elizabeth Newson herself argued that PDA was a necessary distinction within the autism spectrum (Newson, Marechal & David, 2003). They make this argument on the basis that it had been found to be a useful clinical concept for over 20 years for parents and professionals where the diagnosis has previously been atypical autism. The concept was useful because the diagnosis of autism “made sense” for the first time once the PDA profile was described, and because the typical strategies used for typical autism (for e.g. use predictability and routine, teach social skills) did not work for PDA, where obsessive demand avoidance precluded teaching skills and these children thrived on novelty).
Newson and colleagues (2003) analysed data from 150 consecutive referrals of children and adolescents to their PDA clinic in the 25 years prior to 2000. They found that there were both clear similarities between autism and PDA, and clear differences. The main and striking differences cited were that (1) the strategies of avoidance of the ordinary demands of life were essentially socially “manipulative” (Elizabeth Newsom disliked the term for children but all in the study agreed there was no other term that fits better, many people now use ‘socially strategic’) e.g. distracting the adult with a compliment, “I love your necklace” or acknowledging demand but excusing self “I’m sorry but I can’t;” (2) that the demand avoidance itself was the obsessive behaviour; and (3) many were comfortable with role play and pretend play. All the children met all diagnostic criteria for autism.
O’Nion’s and colleagues (2016) examined features of PDA in a group of children and adolescents who scored highly for PDA with a diagnostic tool used mainly in the UK for diagnosing autism, the Diagnostic Interview for Social and Communication Disorders (DISCO; Wing, 2002). From a group of 153 assessed for possible PDA using this tool, 27 were investigated. All but one met the criteria for autism, as well as scoring highly on the DISCO for PDA. Their research confirmed the following behaviours (items on the DISCO that were most useful in distinguishing PDA from autism as it typically presents):
- Lack of co-operation.
- Use social skills to avoid demands.
- Lack of social identity.
- Socially shocking behaviour.
- Engage in fantasy.
- Unusual sociability, e.g. use affection but rapid and inexplicable changes from loving to aggression.
- Difficulties with other people.
- Repetitive acting out roles.
Another of their analyses highlighted several items in the DISCO that appeared to differentiate PDA from other autistic presentations, these including physical aggression, laughing at others’ distress, lack of awareness of psychological barriers, difficult/objectionable personal habits, needing constant supervision and demanding attention from caregivers. High levels of rigidity were found in the PDA group, at the same levels as the more typically autistic group.
There has been no study to determine the incidence of ADHD or other neurodevelopmental conditions in children or adolescents with diagnosed PDA. There has been one study, a case study (Reilly et al, 2014), where all four cases were reported to have PDA and co-occurring epilepsy and ADHD. Newson herself (2003) described “soft neurological signs” including epilepsy as part of the diagnostic criteria, but there has been no research on the co-occurrence. Other studies to date have not reported on the cooccurrence of ADHD or other neurodevelopmental disorders.
In the largest study to date of the PDA profile, Eaton and Weaver (2020), overviewed 136 children diagnosed as autistic in a specialist multidisciplinary clinic in the UK. They discerned, using a checklist from Elizabeth Newson (Newson, et al, 2003), the EDA-Q (O’Nion’s et al, 2014) and the items from the DISCO as mentioned, that 65 (47%) of this sample were both autistic and had a PDA profile. They then specifically compared the two groups, autistic and autistic with a PDA profile, on results from the Autism Diagnostic Observational Scale, Second Edition (ADOS-2; Lord et al, 2008) Module 3 to determine if there were any quantitative or qualitative differences between the groups. The study was especially useful because observations of the children themselves were being compared, rather than only parental reports. They found that the autistic PDA-profile children not only had higher overall ADOS scores compared to non-PDA autistic children, but there were also qualitative social communication differences between the two groups. For e.g., whilst the PDA children initially demonstrated ‘surface sociability,’ as the assessment progressed, their social energy seemed to wane and they became increasingly less motivated to engage, as evidenced by ignoring the assessor, attempting to distract them, refusing to participate, leaving the room, becoming dysregulated, or ‘freezing.’
In this study, only children who had already been diagnosed as being autistic were included, so the study cannot be taken as evidence that PDA only exists within autism. The percentage of children diagnosed at the clinic with PDA was very high (47%), and the authors explain that the diagnostic team were known for their specialisation in PDA and so received a larger percentage of referrals for this type of profile. However, the study does add to the evidence that there is a recognisable and measurable profile within the autism spectrum that can be teased out with current assessment tools, including the ADOS-2 Module 3, i.e. via clinician’s observations, rather than only parental reports.
It is interesting to note that Elizabeth Newson discovered the profile in a group of children referred for assessment of a social communication disorder and all her PDA children were diagnosed with ‘atypical autism’ initially. PDA is not being picked up as an identifiable profile at clinics for ADHD, for e.g., although these clinics have existed for as long as clinics for autism.
In conclusion, all current research points to the conclusion that PDA is a recognisable and measurable autistic profile and is currently understood as such by clinicians and researchers in the area.
Where to from Here?
If you are interested in learning more about PDA, whether you are a parent or a professional, we have created two 3-hour courses to help:
PDA and Autism: The purpose of this training is to increase your understanding of PDA to assist you to recognise the profile your child, student or client, to increase your confidence in your role with these children and equip you with strategies to maximise positive outcomes.
PDA for Professionals: We assume the knowledge presented in the first course and go deeper to explore strategies and how to best support the PDA-er and their family or partner.
There are many resources available. These are some of our favourites:
The PDA Society in the UK has developed a library of helpful, evidence-based resources on PDA and we recommend these:
For e.g. we highly recommend their Practice Guidance Document as a start:
Dr Ross Greene, American Psychologist has developed a model of care called Collaborative & Proactive Solutions (CPS) which is based on research and practice and based on collaboration and compassion. He does not use the term PDA, but instead talks about kids for whom challenging behaviour occurs when the demands and expectations being placed on them exceed their capacity to respond adaptively. His website has excellent practical resources for parents, teachers and health professionals.
Books: Children and teenagers:
Collaborative Approaches to Learning for Pupils with PDA: Strategies for Education Professionals (2018) by Ruth Christie and Phil Fidler, published by Jessica Kingsley Publishers.
Super Shamlal – Living and Learning with Pathological Demand Avoidance (2019) by K I Al-Ghani, published by Jessica Kingsley Publishers.
Dr Ross Green (2021). The Explosive Child [Sixth Edition]: A New Approach for Understanding and Parenting Easily Frustrated, Chronically Inflexible Children. Published by Harper Collins, US.
Being Julia: A Personal Account of Living with PDA (2021). By Ruth Fidler and Julia Daunt. Published by Jessica Kingsley Publishers.
PDA by PDAers: From Anxiety to Avoidance and Masking to Meltdowns (2019). Ed. Sally Cat. Published by Jessica Kingsley Publishers.
PDA Paradox; The Highs and Lows of My Life on a Little Known Part of the Autism Spectrum. (2019). By Harry Thompson. Published by Jessica Kingsley Publishers.
There are many more wonderful books on PDA that we can recommend, as listed on this web page of the PDA Society:
Bettelheim, Bruno. The Empty Fortress: Infantile Autism and the Birth of the Self. New York: Free Press, 1967.
Calvo F, Karras BT, Phillips R, Kimball AM, Wolf F. Diagnoses, syndromes, and diseases: a knowledge representation problem. AMIA Annu Symp Proc. 2003;2003:802. PMID: 14728307; PMCID: PMC1480257.
Christie, R. & Fidler, F. (2018). Collaborative Approaches to Learning for Pupils with PDA: Strategies for Education Professionals. Jessica Kingsley Publishers, London, UK.
Eaton, J. & Weaver, K. (2020). An exploration of the Pathological (or Extreme) Demand Avoidant profile in children referred for an autism diagnostic assessment using data from ADOS-2 assessments and their developmental histories. GAP, 21 (2), 33- 51
Gillberg C. (2014). Commentary: PDA – Public display of affection or pathological demand avoidance? Reflections on O’Nions et al. (2014). Journal of Child Psychology and Psychiatry, 55(7), 769–770. https://doi.org/10.1111/jcpp.12275
Gore Langton E., Frederickson N. (2018). Parents’ experiences of professionals’ involvement for children with extreme demand avoidance. International Journal of Developmental Disabilities, 64(1), 16–24. https://doi.org/10.1080/20473869.2016.1204743
Kerns C. M., Winder-Patel B., Iosif A. M., Nordahl C. W., Heath B., Solomon M., Amaral D. G. (2020). Clinically significant anxiety in children with autism spectrum disorder and varied intellectual functioning. Journal of Clinical Child & Adolescent Psychology. Advance online publication. https://doi.org/10.1080/15374416.2019.1703712
Kildahl, A. N., Helverschou, S. B., Rysstad, A. L., Wigaard, E., Hellerud, J. M., Ludvigsen, L. B., & Howlin, P. (2021). Pathological demand avoidance in children and adolescents: A systematic review. Autism, 25(8), 2162–2176. https://doi.org/10.1177/13623613211034382
Milton D. E. (2012). ‘Natures answer to over-conformity’: Deconstructing pathological demand avoidance. Autism Experts. https://kar.kent.ac.uk/62694/
Milton D. E. (2013). ‘Natures answer to over-conformity’: Deconstructing pathological demand avoidance. Autism Experts. https://kar.kent.ac.uk/62694/
Mitchell, P. (2017). Mindreading as a transactional process: Insights from autism. In V. Slaughter & M. Rosnay (Eds.), Environmental influences on ToM development, (pp. 157– 172). Hove, UKPsychology Press.
Newson E, Le Maréchal K, & David C. (2003). Pathological demand avoidance syndrome: a necessary distinction within the pervasive developmental disorders Archives of Disease in Childhood; 88:595-600.
Orm S., Løkke J. A., Løkke G. E. H. (2019). Pathological Demand Avoidance: en transaksjonell atferdsanalytisk forklaringsmodell uten patologi [Pathological demand avoidance: A transactional behaviour analytic explanatory model without pathology]. Norsk Tidsskrift for Atferdsanalyse, 46(1), 29–43. http://hdl.handle.net/11250/2619601
O’Nions E, Christie P, Gould J, Viding E, Happé F (2014) Development of the ‘Extreme Demand Avoidance Questionnaire’ (EDAQ): preliminary observations on a trait measure for pathological demand avoidance. J Child Psychol Psychiatry 55:758–768
O’Nions, E, · Gould, J, · Christie, P, · Gillberg, C. Viding E, & · Happé, F. (2016) Identifying features of ‘pathological demand avoidance’ using the Diagnostic Interview for Social and Communication Disorders (DISCO), Eur Child Adolesc Psychiatry 25:407–419 DOI 10.1007/s00787-015-0740-2
Reilly C., Atkinson P., Menlove L., Gillberg C., O’Nions E., Happe F., Neville B. G. (2014). Pathological demand avoidance in a population-based cohort of children with epilepsy: Four case studies. Research in Developmental Disabilities, 35(12), 3236–3244. https://doi.org/10.1016/j.ridd.2014.08.005
Sally Russell OBE (2023, personal communication). Chair of the PDA Society, UK.
Stuart L., Grahame V., Honey E., Freeston M. (2020). Intolerance of uncertainty and anxiety as explanatory frameworks for extreme demand avoidance in children and adolescents. Child and Adolescent Mental Health, 25(2), 59–67. https://doi.org/10.1111/camh.12336