Continuing The Conversation On PDA

The science behind the PDA controversy - Part 5

This is the final installment in a series investigating the science behind Pathological Demand Avoidance (PDA). In part 1, I talked about the controversy behind PDA. In part 2, I went into detail about the origins of PDA and investigated whether it is even a real phenomenon. In part 3, I looked at whether PDA could be attributable to autism alone. In part 4, I investigated what conditions (other than autism) might be underlying PDA symptoms, and what research backs those connections. 

If you haven't read parts 1, 2, 3 and 4 yet, I definitely recommend going back to them first.

In part 5, I am offering my own thoughts on how to understand PDA given the current research. 

My Thoughts on PDA

After reading through the most relevant research on PDA, I find that I still don’t have solid answers about what PDA is, or what causes it. None of us really do, because the research still isn’t there yet. 

Still, I am going to share what my view is on PDA, based on what we currently know. I want to say first that science is a constantly moving process and new information will often shift our understanding. Given the under-developed state of research on PDA, it’s likely that our views on PDA will continue to evolve. So what follows is my current opinion and, while based on evidence, it is not meant to be taken as the only possible interpretation of the evidence. 

PDA Is Probably Not Just Autism

First, given PDA’s presence in non-autistic populations, it is likely that PDA represents something more than autism alone. As we saw in parts 2 and 3, we don’t have strong evidence to say PDA is a “profile of autism” because the traits don’t seem to cluster in statistically significant ways within autistic populations. Similarly, saying that PDA is “just autism” makes little sense when non-autistic people meet the PDA criteria, and studies suggest PDA is better predicted by factors like anxiety and ADHD than it is by autism. There are definitely a lot of PDArs who are autistic. But, unless more research comes out suggesting otherwise, I think we should stop using language that implies that anyone who identifies with PDA is also autistic - or that being autistic entirely explains the PDA experience. It is simply not what the evidence suggests.

Of course, there very well may be cases where someone identifies with PDA and all their symptoms do come directly from their autism. Researchers have shared ways that autistic traits can explain PDA traits. But the stronger statistical ties to other conditions, and the circularity issues that come from studying PDA primarily in the context of autism, make it seem very unlikely that autism is the full story here. 

I do, however, think that the evidence supports PDA as a common comorbidity of autism, or a condition that could emerge out of autism in combination with other conditions, environmental factors or genetics that add heightened anxiety to the picture. 

PDA Is Likely Related to Anxiety

In my view, the best supported theory presented in the literature is that PDA is a manifestation of anxiety and intolerance to uncertainty. And that this could arise in a variety of contexts. 

The current evidence supports the idea that PDA symptoms involve an intense anxiety around demands. This is also supported by the descriptions from many adults with PDA, who describe an intense threat response to demands and to situations that impinge on their autonomy. 

To add to this, nothing in the literature seems to conflict with the theory. While it is far from proven at this point, I think it is the most consistent and supported possibility. For me, it also fits best with my own experience of PDA symptoms. 

Still, so much research needs to be done to actually work out these questions. And even if it is true that an intolerance of uncertainty is a key aspect of PDA, it’s still unclear why it manifests. 

We Don’t Understand PDA’s Causes

Given all this, it’s far too early to make definitive statements about the mechanisms underlying PDA. We have very little evidence on what actually causes PDA and its heightened anxiety response. Does it emerge for autistic people, as well as people with other conditions like ADHD, when everyday demands pose more intense challenges and opportunities to be misunderstood? Or is it an innate response due to differences in the brain? Either option is consistent with the research. 

I find both of these possibilities more likely than a sort of patchwork theory I’ve seen people lean into online, where PDA symptoms are just a random cluster of symptoms from a variety of conditions being seen as one thing. For example, some symptoms are from autism, and some from ADHD and some from trauma. 

Why? Honestly, just because my own PDA feels like a very consistent experience across its manifestations. It feels like one consistent thing that arises in a variety of contexts. While other factors may certainly play into what demands feel more demanding, I think the instinct towards demand avoidance and need to maintain autonomy is something beyond this. Even if it may have originally been triggered by my patchwork of neurodivergent challenges, my PDA feels like one consistent force– and I’ve heard many others online echo this feeling. Of course, this point is unrelated to the scientific research – it's just my personal feeling. It’s totally possible and consistent with the literature that PDA is just a patchwork of symptoms attributable to other conditions. But it’s also too early to claim that we know this is the case – we don’t. 

We also don’t have enough evidence to say that PDA is a unique neurotype. I’ve seen literally no hard evidence on how PDA relates to differences in our brain, other than the statistical associations and similarities to other neurodivergent conditions like autism, anxiety disorders and ADHD. That doesn’t mean it’s not a unique neurotype… just that we don’t have the evidence to show that it is. 

It would be amazing if researchers would look into this question, comparing the brain scans of people with suspected PDA to those with the conditions associated with PDA (and the general population). Studies like that would really help clarify these questions. We just don’t have them yet. 

The research we have so far is consistent with any of these main theories for the mechanisms behind PDA - other than it being solely attributable to autism. It could be a unique neurotype, a behavioral profile arising out of anxiety and neurodivergent challenges, or a patchwork of symptoms from other conditions. It’s way too soon to double down on one of these theories. 

How Should We Talk About PDA? 

Until more research is done on the causes of PDA, I think we should really stop referring to it as a unique neurotype, a profile of autism, or a pathwork of symptoms. We simply don’t have evidence for these claims. 

I do, however, think that we have reason to continue researching and discussing PDA as a profile of behavior and experience - and using a unique label to do so. (I tend to prefer extreme demand avoidance as the label to go with, but since most of the discussions use PDA, I used that here to make sure people could find the discussion on it.)

Why continue to discuss PDA as a unique profile of behavior and experience? Because clinicians working with PDArs see it as a distinct profile and have had success in treating it that way. Individuals who identify with PDA have had success in improving their lives by following advice from others who identify with the profile. And ultimately, medical science is about finding solutions for people’s medical challenges. 

If we discard discussions on PDA now, the research on it will also likely end, and the current research suggests that people who identify with PDA see real value in that identity. 

I’m not saying that this means PDA is a statistically significant cluster, or a unique neurotype. I’m saying the evidence isn’t there to say either way. We need to understand it more, so that we can actually untangle what is going on and how to best treat it. That means carrying on with research and adjusting our understanding as we go. We can only do that by continuing to identify the profile in a unique way. 

If there was an easy alternative to labeling PDA as its own thing – we’d probably already be doing it. But it’s not clear from the research that PDA is just autism or just ADHD or just trauma… or even just a patchwork of these conditions. It’s tied to a ton of different conditions with statistical associations and overlapping symptoms. But.. so are a lot of recognized conditions.  

Clarity Is Key In PDA Discussions

That said, discussions around PDA need to be more nuanced. They need to include acknowledgements that we don’t know what causes this profile of behavior, and that research is still ongoing. They need to include references to the important ties to anxiety, autism, ADHD, ODD and other conditions in the literature – not simply describe it as a unique neurotype or profile of autism. 

We need to encourage those who identify with PDA to explore what other underlying conditions may be factoring into their PDA, and let them know that some treatments for those conditions may benefit them too. Our discussions on treatments need to include the fact that there has been almost no research published on what is actually helpful for people with this behavioral profile, and a lot of the advice comes from personal experiences. 

We should acknowledge that it is a profile of behavior that isn’t well understood, and that may have blurry boundaries. We should explain that demand avoidance or other symptoms of PDA may come without other associated symptoms of PDA. We need to start discussing and researching these individual symptoms on their own, especially how they can be treated and how they show up in other conditions. 

If we make these caveats and avoid making unfounded claims about PDA, then PDA discussions could continue to be a fruitful way to help others explore their own symptoms and find more resources. 

Revisiting the Online Controversy 

Going back to the controversy I described in Part 1, after researching more, I find myself agreeing with the points on both sides. The way PDA has been discussed online is scientifically ungrounded. There are big risks to ignoring the nuance here. But I also agree that PDA has been a useful label for many – guiding them to resources and understandings that have actually helped them. And I agree that no one knows your internal experience as well as you know it yourself. 

Scientifically speaking, the outcry from patients, clinicians and caretakers saying “there is something specific and different going on here” are not ones we should ignore. They are the first stage of scientific discovery, and we need to follow through on investigating that until we can definitively explain what’s going on. We can’t do that yet based on the current studies, but removing all talk of PDA is not the way to get those answers either. Continuing the discussion with added nuance (as I’ve seen many in online spaces start to do) is a much more scientifically grounded approach. 

There is so much we don’t know. And an absence of evidence isn’t evidence of absence. The scientific method says the solution to not knowing is always to look for more answers. Whatever those answers are, more research is the only way to uncover them. And we will never get there if we simply throw away the label and move on. 

But we will also never get there if we assume we have answers that we just don’t have, and talk about PDA as something it simply may not be. So let’s keep talking about PDA. Let’s just be real about the giant mystery hiding behind this intense disabling experience. Let’s keep looking for answers until those of us anxiously suffering have clear guidance on what can be done to help.   

That’s my view on all this, but I would love to hear yours. Feel free to join the conversation in the comments section.