By PDA Insiders (Sally Cat and Brook Madera)

SallyCat's article here: http://www.sallycatpda.co.uk/2025/06/is-pda-autism-rethinking-diagnostic.html

Introduction

Pathological Demand Avoidance (PDA) remains one of the most contentious and confusing neurodivergent profiles. At the heart of this debate is one persistent question: should PDA be recognised as a subtype of autism—or does it demand a category of its own?

To understand this, we need to trace the evolution of diagnostic systems and how PDA people became diagnostic refugees.

From PDD to the Autism Spectrum: The Collapse of Diagnostic Diversity

Under the DSM-IV, conditions such as autistic disorder, Asperger's syndrome, and pervasive developmental disorder not otherwise specified (PDD-NOS) existed as separate but related diagnoses. 

PDA was first noted, and named by, Professor Elizabeth Newson who identified the profile in children referred to her during the 1980s who puzzled clinicians by seeming autistic in someways, but with marked differences. This classed PDA as slotting under the PDD-NOS category—an intentionally broad classification for individuals showing some features of autism but not meeting full criteria.(you can read more here)

However, when it was published in 2012, the DSM-5 collapsed these subcategories into a single diagnosis: autism spectrum disorder (ASD). The intention was to simplify and standardise diagnosis. But in doing so, all differences between neurodevelopmental conditions were flattened.

PDD-NOS vanished. So did the diagnostic space where PDA had unofficially resided.Since this time, the evolving use of terminology has continued to generate confusion. Although ASD is an umbrella term which PDA can be argued to fit, there has been a growing tendency to use ‘autism’ as the overarching term. In this sense, the correct term for PDA is ASD, not autism.

PDA Under DSM-5: A Square Peg in a Round Hole

Post-DSM-5, the only remaining diagnostic route for PDA is autism spectrum disorder. But the fit is tenuous. PDA’s hallmark features—obsessive demand avoidance, surface-level social fluency, and intense emotional volatility—do not map neatly onto ASD criteria.To make a PDA diagnosis under DSM-5, clinicians must argue that PDA traits (like extreme demand avoidance and a fixation on social control) count as manifestations of rigid thinking—a core ASD feature. But for many PDA people, this feels like misrepresentation. They may not experience the kind of "rigidity" seen in classic autism; their behaviour is often highly adaptive and socially strategic—just not in neurotypical ways.

The result? Many PDA people struggle to obtain an autism diagnosis at all.

Writing for the British Psychological Society in 2015, Rebecca McElroy noted:

"Autistic children display rigidity through rules, routine and predictability; in PDA their rigidity is in their need to avoid demands and control situations, which can often lead to the child appearing extremely impulsive in their emotions and behaviour".

Erica Evans, who has coordinated support groups for PDA North America, believes perseveration (the tendency to repeat an action, thought, or behavior, even when no longer appropriate) is a form of rigidity that’s universal to PDA: "I have yet to meet a PDA person who doesn’t experience perseveration, but when the fixation might be socially driven it easily flies under most assessors’ radars."

Diagnostic Access vs. Support Reality

Here lies the paradox: an autism diagnosis opens access to crucial services and legal protections. But the supports those services provide are usually designed for classical autism, especially for individuals with social withdrawal, repetition, and sensory overwhelm.

For PDA people, traditional autism strategies—like visual schedules, structured routines, or reward-based compliance systems—can backfire, often escalating distress and avoidance. The approach is not just ineffective; it can be harmful.

It is important to note that PDA people may clash even with approaches designed to affirm autistic identities. This distinction is crucial, as such differences are sometimes overlooked with statements like, "Well, autistic people don’t like that either." However, there are well-recognized preferences and strategies associated with classic autism that can be profoundly triggering for PDA people, highlighting the need for more nuanced understanding and support.

In summary, this diagnostic catch-22 leaves many PDA people under-supported, misunderstood, and vulnerable in schools, workplaces, and healthcare systems.

Brook reflects: 
"I’m pretty sure I masked autistically to be diagnosed properly. I think there’s nuance to why and how that was for me, like I’m constantly trying to feel understood by mirroring people and things."

Sally notes:
"When I gained my adult autism diagnosis, I thought I’d finally found my kin group and had a passport to the support I’d always needed.
But I wasn’t on the same wavelength as people in autistic forums I joined. As an example, they viewed the social communication skills I longed to learn as an evil thing non-autistic people tried to force them to do.
As for my support needs being met, this proved a mixed bag. My autism diagnosis was pivotal in winning my disability benefit entitlement tribunal. But practical support offered didn’t fit my needs, and was sometimes detrimental. For example, airport staff increased my anxiety by corralling me into boarding a plane last, then forced me to stay onboard until everyone else left, triggering my aversion to confinement."

PDA and the Identity Politics of Autism

Beyond clinical debates, the classification of PDA has ignited ideological tensions—especially within the autistic community.

 The DSM-5’s unified spectrum was intended to reflect a core truth: that autism is not a series of distinct boxes but a continuum of traits. To argue that PDA is a “distinct type of autism” seems, to some autistic academics, a betrayal of this principle.

Scholars like Damian Milton have publicly critiqued PDA as simply being misunderstood autistic agency, a position that's made it vulnerable to professionals assuming PDA is a pseudo-condition--one invented or exaggerated by clinicians seeking diagnostic niches or by parents resistant to seeing their child as "truly autistic." Others, such as outspoken UK student, R Woods, have dismissed PDA as a myth, contending that its unique presentation is simply a variation within autism, not a separate entity.

From their standpoint, the notion that PDA is "different" undermines the unity and solidarity of autistic identity, whilst simultaneously leaving PDA open to assumptions of being rooted in racism because autistic BIPOC people are far more like to receive diagnoses of oppositional defiance disorder (ODD) than the less common diagnosis of PDA.

After discussing this with communications researcher and autism advocate Kaligirwa, PDA advocate Kristy Forbes told us she had realized:

"With the DSM-5, PDD-NOS as the umbrella for various ‘subtypes’ (for lack of a better word) was eliminated and so PDA, previously considered a PDD-NOS was no longer as such. 

I haven't found anything that evidences that PDA is an autistic profile. I'm thinking it was just continued and presumed to be one, even though the PDD-NOS no longer exists. 

I think it's important to unpack, particularly as Newson said, ‘PDA is a pervasive developmental disorder but not an autistic spectrum disorder: to describe it as such would be like describing every person in a family by the name of one of its members.

 I dunno, for me, I am who I am. Autistic, PDA, ADHD, all the things. Still me."

With regard to differences between PDA and "general" autism, Libby Hill, a multi-award winning speech and language therapist specialising in PDA, says:

"PDA children often have no readily identified language difficulties. Indeed, they use language creatively to avoid demands, while autistic children often struggle to navigate language itself."

Institutional Harm: The Case of the National Autistic Society

The consequences of this disagreement are not abstract. In the UK, when the National Autistic Society (NAS) revised its webpage on PDA—stating that PDA was not a separate condition but just one way autistic people may express avoidance—the effects were immediate.

Schools and local authorities used this shift as justification to withdraw support plans for PDA children. Without a distinct identity, PDA people are invisible within autism services, but unqualified for alternative support pathways.

This policy decision, informed by conceptual debates, had real-world consequences for some of the most vulnerable children and families.

Brook comments:
"When you add to it that diagnosticians struggle to see beyond personal bias, or sexism, or [fill in the blank] and they hold power in deciding what someone is, or is not, it makes it even more triggering.
We don’t get to speak to who and what we are without that external validation."

Sally adds:
"Worse, some PDA people may lack the requisite rigidity of thought/behaviour to qualify them for autism diagnosis. This means that, under the current diagnostic system, a percentage of the PDA population is totally excluded."

Polar Views of Autism in the PDA Community

As we’ve seen, PDA’s relationship to autism is complex. Even the word ‘autism’ has shades of meaning, with a majority of people––including the autism community itself––viewing it as common ground between the former diagnostic categories of autism disorder and Asperger’s disorder. In fact, it was for this reason that the DSM-5 replaced individual pervasive developmental disorder diagnoses with the unified autism spectrum. But doing so made PDA a diagnostic refugee.

The truth is that many PDA people embrace being autistic. Eloquent arguments are made for PDA traits––such as perseveration––qualifying as rigid thinking, or behavior that meets the diagnostic threshold.
However, others identify as being PDA without diagnosable autism.

Each side of the PDA camp may view the other as deluded. For example, advocates for PDA being "autism" may be accused of shallow understanding. 

Conversely, Brook notes:
"I know that one mistake made in the PDA advocacy corner is assuming that those who are PDA who don’t view themselves as autistic are suffering from ‘autistic-phobia’." 

The truth may be that rigidity varies across the PDA population. This could explain the split between those who do, and don’t, identify as autistic. It might also explain the impermeable barrier some PDA folk run into when trying to gain autism spectrum diagnoses.

Sally recalls:
When I first suggested that PDA might be a standalone condition––this was back in 2016––some members of the PDA community were so angry that I tailspun into muteness, panic and overwhelm.
I didn’t drop the idea because other PDA adults were convincingly sure they weren’t autistic, and their exile from diagnostic recognition had triggered my social justice drive.
But, back then, having people shout that I was wrong made me freeze, and scrambled my thoughts.  
We were all learning about PDA as best we could, but there was precious little information, and nothing at all about adult PDA. 
Lots of people were strongly attached to the idea that PDA was autism. I continued to hold space for PDA existing without autism, but didn’t broadcast it from the metaphorical rooftops.
It’s taken this long for me to make sense of the conundrum in my own head; to distinguish the autism spectrum from autism; and the purpose behind the autism spectrum from technical arguments about whether PDA fits it.

The Ethics of Calling PDA "Autism"

Despite eloquent arguments, is it actually ethical to insist that PDA is autism? After all, the autism community fought long and hard to gain the autism spectrum as a unified home. 

Arguing that all rigidity qualifies as autism disrespects the autism spectrum’s purpose of rehousing people who fitted the DSM-IV classifications of autism disorder and Asperger’s disorder. In this light, the term "autism" might most appropriately be used for people matching the common consensus of what autism is. 

Following the same logic, arguing that PDA "is autism" equates to invading the autism community’s hard won homeland.

Would a Needs Based Approach be Better?

While we acknowledge that it's not our place to criticise fellow PDA folk’s self-identities, we argue that the priority should be meeting support needs.
The fact is that, no matter how passionately PDA is argued to fit the autism spectrum, doing so causes inappropriate, and even harmful support measures to be put in place.

Brook provides an analogy:
"If you have two kinds of badgers that need very different environments to live in, what’s most important? The fact that they are both badgers, or what they need to survive?"

In other words, although PDA can be argued to fit the autism spectrum, doing so causes inappropriate support to be offered.

Might it be better to rename the autism spectrum for a neutral word that describes PDA and "general" autism’s commonality. 

Using Brook’s badger example, autism-badgers and PDA-badgers would slot into the family of neurodevelopmental badger disorders. 

A Case for Bringing Back PDD-NOS

One solution to PDA’s diagnostic crisis could be bringing back the category of PDD-NOS (pervasive development disorder not otherwise specified) to sit alongside the autism spectrum. 

Reclassifying PDA in this way would silence arguments that autism can’t be split into distinct profiles, and allow people to consider what PDA is in its own light.  

Is It Time for a New Neurodevelopmental Spectrum?

What’s becoming increasingly clear is that the autism spectrum may be too narrow a container for all neurodevelopmental realities. Perhaps the solution lies not in trying to wedge PDA into ASD, but in reframing the entire landscape.

Imagine a neurodevelopmental spectrum, a broader diagnostic and conceptual umbrella under which autism, PDA, ADHD, Tourette’s syndrome, and other neurodevelopmental conditions could sit as neighbours rather than subsets. This model would:

• Allow PDA to stand on its own without disqualifying it from support
• Acknowledge similarities between conditions without collapsing their differences
• Offer more accurate diagnostic labels that reflect real lived experience
• Avoid the gatekeeping and tribalism that currently define the autism discourse

On social media, James the Autistic Photographer states:
Autism is often a reflection of ADHD and vice versa. I truly believe these conditions are part of the same alternative neurotype which presents differently in different people. 

Conclusion: Toward Inclusion Without Erasure

PDA may overlap with autism, but its differences are not trivial, delusional, or invented. Diagnostic structures that fail to accommodate these distinctions don’t just distort science—they harm people.

It’s time to move past the binary question of whether PDA "is" or "isn’t" autism. A better question might be: how can we build a diagnostic system that reflects the full richness of neurodiversity?

Until then, PDA remains a condition caught between categories—too autistic for some, not autistic enough for others—stranded in the no-man’s land of diagnostic ambiguity.

Want to Join the Conversation?

If you’re interested in reforming how we understand neurodiversity, share this article and help bring visibility to PDA people. Recognition matters. So does being seen for who you truly are.

Below are a section of email interactions with Richard Woods on his understanding of Pathological Demand Avoidance (PDA) compared with my own.

About these emails:

Richard Woods is a Ph.D social sciences student at London Bank University. He is a pupil of autistic researcher and writer Damian Milton, both of whom have voiced concerns about PDA. You can read more about Woods here and on his blog Rational Demand Avoidance here.

My intent in sharing these interactions is to make his reasoning more accessible to the general public. As a prolific researcher Woods has had a heavy influence on PDA research.

Woods objects to my publishing these emails and I do not have his consent. Since we do not share a private or privileged relationship, and since the topic is on PDA and it pertains to his influence as a public figure, I am publishing them. Any details referencing his personal life are redacted but otherwise the emails are wholly intact.

Brook Madera <nopressurepda@gmail.com>

One issue at a time, but to highlight:

If you can explain your demand avoidance with rational needs, that is different than PDA which we experience (among other things) as irrational. That would mean we are talking about two different internal experiences. The differences would explain how you have tried to explain how PDA works, where it comes from, so on, then clashes with how the PDA community experiences their demand avoidances and triggers.

If you can’t accept this as a possible premise then we’ll end up talking in circles because any response I provide will be explained by a similar experience you have that may or may not fit what I and others actually experience. This would be why your explanations are received with hostility because it is felt as very disrespectful because your internal experience is validated, ours is not.

This above is I think the root of the ongoing conflict between you and anyone in the PDA community. 

Richard Woods <richardwoodsautism@gmail.com>

Hi Brook.

Thank you for the clarification, it is much appreciated.

Where does it say PDA’s demand-avoidance must be irrational?

I am not going to explain how I have PDA. The PDA community does not know me as a person, has not seen my medical records, and it discounts my own understanding of how categories, like autism, are attributed by clinicians to people. The Autistic PDA community is simply not in a position to make claims about if I have PDA or not. I should not explain this. There is also the added point that the point Autistic PDA community is unlikely to treat others who identify with PDA as it is presently treating me, i.e., it tends to recognise that having a PDA “diagnosis” is privilege, so it would accept it when someone has PDA. I simply should not need to defend if I have PDA, or not to the Autistic PDA community. I have it in writing and the PDA Society accepts me as having PDA. Likewise, I have just had a highly respected journal accept a piece of mine calling for further research to evaluate PDA’s risks; i.e., my expertise is being respected by neutral parties. If the Autistic PDA community cannot, or will not respect the fact I have PDA, it says a lot more about the Autistic PDA community than it does me! I suppose you will claim Damian Milton does not have PDA, as they also advocate for the “Rational Demand-Avoidance” term?

This matters, as it is reflective of a broader pattern of attacks and behaviour against those it views as a threat. I would be well within my rights to sue those making apparent defamatory attacks against me/ report it to the police. I have been advised by my support network to take those actions against the likes of Sally Cat. I have tried to engage with Sally Cat, and they seem not interested, or unable to substantiate their likely defamatory attacks against me. It is not a good look Sally Cat seems to have no evidence to back up their claims. When I asked them for it.

Will you (and hopefully the rest of the Autistic PDA) stop attacking me and making apparently spurious comments about me?

May your stimming activities be many, and your flow states long.

Richard.

Brook Madera <nopressurepda@gmail.com>

It nowhere states explicitly that PDA style avoidance as irrational, but PDA is described as being distinct from rational demand avoidance via PDA Society:

"When demand avoidance is more significant there can be many possible reasons for this – it could be situational; relate to physical or mental health; or relate to a developmental or personality condition. It is sometimes difficult to distinguish underlying causes, but a PDA profile isn’t necessarily always the best explanation for extreme demand avoidance. It’s also important to remember that marked demand avoidance is the most significant, but not the only, trait in a PDA profile. For a detailed exploration of other explanations for marked demand avoidance, please see Identifying & Assessing a PDA Profile – Practice Guidance."
https://www.pdasociety.org.uk/what-is-pda-menu/what-is-demand-avoidance/

Myself and SallyCat propose that defining PDA as an irrational style of avoidance is a way to help bring understanding between those that feel like the PDA label is helpful, and those like yourself who feel it is harmful.

We suggest that it be called irrational in that our demand avoidance often compels us to behave in ways that run contrary to our own desires, our own will, and/or our own best interest. While it has some predictable elements, it also can be "predictably unpredictable" in that we can't always navigate our needs with certainty based on the past. In fact, it isn't uncommon within the PDA community that we can say there are things we can't do, and then we are suddenly able to do them simply by virtue of articulating that we cannot. It is for this reason that it is best understood as a personal experience around perceived demands and not only on objective traits or environmental triggers.

PDA (as the PDA community we know experiences it) requires a unique set of supports not outlined in the Low Arousal Approach or on autistic best practice, even when that best practice is informed by actual autistics like yourself. PDA needs often contradict non-PDA autistic needs, such as how we react to language (indirect often being preferred to direct, reading into tone of voice and inflection and the need to "tone police" to a certain degree so as to not trigger a traumatic reaction) and the reaction to structure (being easily triggered by routines that even we establish for ourselves), and that these needs are present from their developmentally appropriate ages and run through families much like any other distinct neurodivergent experience, and not due to additional trauma.

If you experience your demand avoidance due to rational reasons, then you would be experiencing something different than the above. Extreme Demand Avoidance is also debilitating but requires the kind of support you have identified as being helpful for you and others who share your view. 

If you take what I have explained (and other PDA advocates agree to these similarities and differences) and redefine it based on your own rational reasons, you are excluding a lot of humans who do not identify with you, nor are they best supported by what you prescribe. Redefining others/ experience to fit your own is (it has been argued) doing what Milton points out with his Double Empathy problem in that two people can experience similar yet fundamentally things, be attempting to communicate based on those similarities, but misunderstand each other because of their innate differences.

When you second guess our own interpretation of our experiences then you are speaking over our voices, which is what generates offense and hostility. 

In summary: The "rational demand avoidance" description, definition, and prescription leave myself, SallyCat, and others like us without a voice.

The PDA label as it stands makes room for our existence, and also the existence of rational demand avoidance, making it the more accurate and inclusive option.

Until this is resolved, the tensions will remain. I'm working on an article right now trying to parse apart some of the confusion in understanding PDA and I will be mentioning your research, and I will attempt to be accurate in representing your views.

Hope this helps,
Brook

Richard Woods <richardwoodsautism@gmail.com>

Hi Brook.

Thank you for the response, it is greatly appreciated.

You hit it on the head, the PDA Society… Which is not an arbiter of clinical practice. It did produce what I consider to be a highly biased research report claiming to provide clinical guidance on the topic. That document is based on the views of 12 clinicians the PDA Society invited to contribute to the report. That document also ignores anything it views to be potentially awkward, like Goodson (2018) which indicates PDA behaviours are caused by executive dysfunction issues to claim PDA’s demand avoidance is not caused by EF issues. There are good grounds to question the reputability of that document and the PDA Society. If you do not believe me, look at how “Profound Autism” advocates are attempting to create a stable definition for that proposed category; trying to completely redefine “profound autism” based on adaptive functioning, instead of co-occurring Intellectual Disability and/ or Language Impairment. Additionally, “profound autism” advocates are conducting a Delphi Method study:

https://www.thetransmitter.org/spectrum/pinning-down-profound-autism-for-reliable-research-qa-with-matthew-siegel/

Advocates of “rational demand avoidance”, like myself and Damian Milton do not agree with the arbitrary split between PDA and RDA, that the likes of PDA Society has done. It is using the RDA term in my view! Restating it, would you claim Damian Milton does not have PDA, due to their suggestion of the “Rational Demand Avoidance” term (it originated in Milton’s 2017 book)?

There are problems with basing PDA on irrational demand avoidance, as what is “irrational” is inherently a subjective outlook. There are also times when the person expressing the demand-avoidance will not know/ perceive if the demand-avoidance is rational/ irrational!

One seems to be making a lot of assumptions about how I experience demand-avoidance. Again restarting it, you and the other members of the Autistic PDA community do not know me, or my medical records, or my life story. You are simply not in a position to claim if I have PDA, or not. Likewise, ignoring my ability to understand my own medical records, and how PDA is attributed.

Ironic, that those claiming I am do not have PDA, are talking about them being excluded, when they are the ones excluding me for reasons they have constructed between themselves. I recently peer reviewed a manuscript on those with PDA’s experiences, and I asked the authors to contextualise that research in other studies of PDA lived experience, including the “PDA by PDAers” book. The authors ignored the suggestion! I am not the one doing the excluding…

Says the ones who are not only speaking over me, but making many erroneous claims about me on inaccurate information. Especially, when I rarely publicly discuss my own Autistic, ADHD, anxiety, depression, OCD experiences, let alone how I express PDA features. You and the broader Autistic PDA community do not have the information needed to say if I have PDA, or not!

Claiming I do not have PDA equivalent to trying to diagnose with something else, it is no different attempting to diagnose historical figures. Which tends to be viewed as bad practice to attribute historical figures with autism, ADHD etc, as we lack sufficient information to reasonably make an informed decision on the topic, and not following current “best practice” diagnostic practice/ like not using relevant tools. It is inappropriate to claim someone is not Autistic, or does not have PDA when does not have suitable information to make that claim.

Another way of putting it is. Hypothetically I started publicly saying PDA advocates like, yourself do not have PDA, or not Autistic. The typical response to that scenario would be stating:

·        I am not in position to claim said person is not Autistic, or does not have PDA, as I do not have necessary information.

·        I did not conduct typical assessment practices.

·        Ignoring any formal autism/ PDA diagnoses a person has.

·        Generally, it is bad practice to claim any particular person has any neurodiversity/ category without sufficient evidence.

In the above scenario I publicly claimed any specific PDA advocate is not Autistic/ does not have PDA; said person’s response would likely be to formally challenge me, either with a complaint to my university, or police, to sue me. Do you disagree here?

Can you empathise with why I am getting frustrated with you and others making the spurious claim I do not have PDA?

It does not matter what the Autistic PDA community thinks about me having PDA, or not. It simply is not in a position to comment about me having PDA, or not. It is highly inappropriate that it is making claims about me not having PDA.

Restating it, will you (and hopefully the broader Autistic PDA community) stop making defamatory claims about me, like I do not have PDA?

Best wishes.

Richard

Brook Madera <nopressurepda@gmail.com>

Richard,

I am not saying whether or not you have PDA, only that if you can attribute your demand avoidance to rational reasons then we are experiencing different things. 

Your experience already has a label and mine does not if you are successful in redefining PDA according to your parameters.

You have decided to speak over me by stating that I must not know why my demand avoidance is happening when it happens instead of hearing me say it is unique from my other avoidances around executive functioning, or sensory struggles, or trauma, and that I approach each of my demand avoidances differently. You are having to fit me into a mold that makes sense to you and your experiences. Doing so will make it impossible for you to discover if there really is something else at work since you refuse to accept its possibility of existing. This also fundamentally limits your research efforts.

I am sorry you have been harmed in the emotionally charged discussions around PDA, but I believe that you are putting yourself in that position by sticking to your preconceptions that are actively harming an entire community. 

 I say this with confidence because when I give guidance for families that state they are PDA, I do point them toward all the supports they may need such as trauma, sensory sensitivities, EF, so on, and *additionally* address the PDA component.  I try to cover all the bases that impact the autistic person.

The advice and guidance I read from yourself and other professionals who think like you leaves out the PDA specific supports and would harm me and my family if I was forced to comply with them, or if I was not informed on them.

I have to draw a line around myself now in that I don’t engage in discussions where my personal experiences are invalidated or I’m put in the position of having to defend what’s working for me or others like me. 

Wishing you the best,
Brook