This page provides an overview of the research into Pathological Demand Avoidance (PDA) and related forms of demand avoidance, highlighting key milestones and developments that have shaped our current understanding.

While this research has been pivotal in defining PDA, it represents just the beginning of understanding a highly complex subject. More research is urgently needed to enable professionals to offer effective support and ensure the needs of people with PDA are met.

As this is a history of PDA research, some of the language used reflects the terms and perspectives at the time research was published.

In the 1980s, Professor Elizabeth Newson OBE, a developmental psychologist at the University of Nottingham, began working with children who displayed a distinct behavioural profile. These children shared traits with autism, but they also showed an “obsessional avoidance of the ordinary demands of everyday life” and an intense need to maintain control.

Newson described how this demand avoidance was unique because it extended beyond explicit instructions. It could include:

• Indirect and social expectations, such as being asked casually to join an activity.
• Internal demands, like getting out of bed or eating when hungry.

These children used social strategies to avoid demands, such as distraction, negotiation, or excuses—behaviours that initially seemed unusually social when compared to how autism was understood at the time. These observations prompted Newson to propose PDA as a distinct profile, though she also emphasised there was an overlap with autistic traits.

In the 1990s, Newson published a series of articles and delivered lectures that further defined PDA. Her work described children with:

• A resistance to demands, not necessarily through meltdowns but often through socially strategic behaviours.
• Intense need for control, which was linked to high anxiety.
• A tendency for these behaviours to persist into adulthood.

Newson’s detailed observations laid the groundwork for identifying PDA in clinical settings and for understanding how it could manifest across the lifespan.

In 1997, a group of parents with PDA children came together to form the PDA Contact Group. This group focused on:

• Supporting families.
• Sharing research and information.
• Raising awareness of PDA within professional and educational settings.

Over time, the PDA Contact Group evolved into the PDA Society, we’ve been a registered charity since 2016. We continue to advocate for PDA recognition, provide resources for families and professionals, and support further research.

In 2003, Newson and colleagues published the first peer-reviewed paper on PDA. This paper introduced the “Family of Pervasive Developmental Disorders” diagram, which mapped how PDA related to other conditions within the PDD umbrella, such as autism and PDD-NOS (Pervasive Developmental Disorder-Not Otherwise Specified).

Newson emphasized the fluidity of these traits, a concept particularly important for clinicians, as it highlighted that children’s needs and behaviours could evolve, requiring ongoing assessment and tailored support.

In 2013, the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders) replaced PDDs with Autism Spectrum Disorder (ASD) to reflect advances in our understanding autism.

This change prompted researchers to explore whether PDA should be understood as a profile within autism, rather than a separate condition. Studies found significant overlap, with nearly all individuals identified as having PDA also meeting diagnostic criteria for what is now called ‘autism’.

The Extreme Demand Avoidance Questionnaire (EDA-Q)

In 2013, Dr. Liz O’Nions and colleagues built on Newson’s work to develop the EDA-Q, a questionnaire that measures caregiver-reported behaviours in children and young people aged 5–17.

Although not a diagnostic tool, the EDA-Q helps researchers consistently identify extreme demand avoidance traits for study purposes. Psychiatrist Professor Christopher Gillberg suggested renaming PDA to Extreme Demand Avoidance (EDA) to better capture its characteristics, though opinions on terminology remain divided.

In 2021, researchers refined the EDA-Q into the EDA-8, an eight-item questionnaire designed to focus on core PDA traits. This shorter tool ensures greater consistency across age, gender, and ability.

The Diagnostic Interview for Social and Communication Disorders (DISCO)

The DISCO assessment, originally designed to identify autism, has been used in research to pinpoint traits specific to PDA. Studies have found that individuals with PDA often score highly on specific PDA-related items, suggesting that DISCO could be adapted for assessing PDA in clinical settings.

Differentiating PDA from autism and attachment difficulties

In 2017, Charlotte Flackhill and colleagues developed the Coventry Grid Interview to help clinicians distinguish between autism and attachment difficulties. This tool was later adapted by Dr Judy Eaton to include PDA traits, helping professionals identify overlapping but distinct patterns of behaviour.

In 2019, researchers explored how intolerance of uncertainty (difficulty coping with unknown outcomes) contributes to PDA behaviours. They found that:

• High levels of uncertainty directly correlated with controlling or avoidant behaviours.
• Understanding this relationship could help develop better strategies to support individuals with PDA.

In a small 2015 study, Professor Christopher Gillberg and colleagues examined PDA prevalence in the Faroe Islands, finding that:

• Around 1 in 5 autistic children showed significant demand avoidance traits.
• This dropped to 1 in 50 during adolescence, suggesting that demand avoidance traits may become less pronounced with age or present differently in adults.

Studies, including those by Clare Truman, highlight the overwhelmingly negative experiences of PDA children in education. These include:

• High rates of exclusion and absence
• A lack of understanding from educators.

This underscores the importance of flexible, individualized approaches to education.

In 2022, PDA Society consulted the community to identify key research priorities, including:

• Exploring the relationship between PDA, autism, and co-occurring conditions like ADHD and anxiety.
• Developing effective support strategies for PDA individuals across different life stages.
• Ensuring that research reflects the diversity of the PDA community, including gender, race, and socio-economic backgrounds.

The principle of “nothing about us without us” is central to the future PDA research. By involving the PDA community at every stage—from study design to sharing results—researchers can ensure their work leads to meaningful, impactful outcomes.

For more information, visit our dedicated Research Priorities page.

This timeline highlights how far our understanding of PDA has come, as well as the challenges that remain. By building on this foundation, we can continue advocating for greater recognition, support, and inclusion for individuals with PDA.

Elizabeth Newson and colleagues early research papers from Autism East Midlands ^[1] https://www.pdasociety.org.uk/resources/papers-from-autism-east-midlands-formerly-norsaca/

Newson E, Le Maréchal K, David C. Pathological demand avoidance syndrome: a necessary distinction within the pervasive developmental disorders 2003 ^[1] Newson E, Le Maréchal K, David C. Pathological demand avoidance syndrome: a necessary distinction within the pervasive developmental disorders. Arch Dis Child. 2003 Jul;88(7):595-600.

Judy Eaton and Kaylee Weaver 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 2020 ^[1] https://www.pdasociety.org.uk/wp-content/uploads/2021/04/Eaton-Weaver-An-explorationof-the-PDA-profile-in-children.pdf

NICE Guidelines Autism spectrum disorder in under 19s: recognition, referral and diagnosis Appendix: Features suggesting possible autism 2011 ^[1] https://www.nice.org.uk/guidance/cg128/chapter/appendix-features-suggesting-possible-autism#appendix-features-suggesting-possible-autism

Elizabeth O’Nions, Essi Viding, Corina U Greven, Angelica Ronald and F Happé Pathological Demand Avoidance: Exploring the behavioural profile 2014^[1] https://journals.sagepub.com/doi/pdf/10.1177/1362361313481861

Elizabeth O’Nions, Phil Christie, Judith Gould, Essi Viding & Francesca Happé Development of the ‘Extreme Demand Avoidance Questionnaire’ (EDA-Q): Preliminary observations on a trait measure for Pathological Demand Avoidance 2014^[1] https://discovery.ucl.ac.uk/id/eprint/1422617/1/O’Nions_EDAQ_accepted.pdf

Elizabeth O’Nions, Judith Gould, Phil Christie, Christopher Gillberg, Essi Viding, Francesca Happé Development of the ‘Extreme Demand Avoidance Questionnaire’ (EDA-Q): preliminary observations on a trait measure for Pathological Demand Avoidance 2015 ^[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4820467/

Elizabeth O’Nions, Francesca Happé, Essi Viding & Ilse Noens Extreme Demand Avoidance in Children with Autism Spectrum Disorder: Refinement of a Caregiver-Report Measure 2021^[1] https://link.springer.com/article/10.1007/s41252-021-00203-z

Judy Eaton, Kathryn Duncan and Ellen Hesketh: Modification of the Coventry Grid Interview (Flackhill et al, 2017) to include the Pathological Demand Avoidant profile 2018 ^[1] https://www.pdasociety.org.uk/wp-content/uploads/2019/07/GAP-Eaton-et-al.pdf

Christopher Gillberg, I. Carina Gillberg, Lucy Thompson, Rannvá Biskupsto & Eva Billstedt Extreme (“pathological”) demand avoidance in autism: a general population study in the Faroe Islands 2014 ^[1] https://link.springer.com/article/10.1007/s00787-014-0647-3

Prof Jonathan Green, Michael Absoud, Victoria Grahame, Osman Malik, Prof Emily Simonoff, Prof Ann Le Couteur, Prof Gillian Baird Pathological Demand Avoidance: symptoms but not a syndrome 2018 ^[1] https://www.thelancet.com/journals/lanchi/article/PIIS2352-4642(18)30044-0/abstract

PDA society Research meeting report 2019 ^[1] https://www.pdasociety.org.uk/research-meeting-report/

Lisa Stuart, Victoria Grahame, Emma Honey, Mark Freeston Intolerance of uncertainty and anxiety as explanatory frameworks for extreme demand avoidance in children and adolescents 2019
^[1] https://acamh.onlinelibrary.wiley.com/doi/abs/10.1111/camh.12336

Vincent Egan, Elinor Bull, Grace Trundle
Individual differences, ADHD, adult pathological demand avoidance, and delinquency
^[1] https://www.sciencedirect.com/science/article/abs/pii/S0891422220301633

Rhianna White, Lucy A. Livingston, Emily C. Taylor, Scarlett A. D. Close, Punit Shah & Mitchell J. Callan Understanding the Contributions of Trait Autism and Anxiety to Extreme Demand Avoidance in the Adult General Population 2022
^[1] https://link.springer.com/article/10.1007/s10803-022-05469-3

The educational experiences of autistic children with and without extreme demand avoidance behaviours Clare Truman ,Laura Crane, Patricia Howlin and Elizabeth Pellicano 2021 ^[1] https://www.tandfonline.com/doi/full/10.1080/13603116.2021.1916108

Mapping experiences of pathological demand avoidance in Ireland
Alison Doyle, Neil Kenny 2022^[1] https://nasenjournals.onlinelibrary.wiley.com/doi/10.1111/1471-3802.12579

Pathological demand avoidance in children and adolescents: A systematic review
Arvid N Kildahl, Sissel B Helverschou, Anne L Rysstad, Elisabeth Wigaard, Jane MA Hellerud, Linn B Ludvigsen, and Patricia Howlin 2021 ^[1]
https://journals.sagepub.com/doi/full/10.1177/13623613211034382