The Myth of Overdiagnosis

It’s become increasingly common to hear concern that Autism and ADHD are being “overdiagnosed.” It is claimed by critics that too many people—especially adults—are rushing to identify as different, that it’s somehow trendy, or that diagnostic labels are being handed out too easily. But this idea misses something critical: for decades, these conditions were severely underdiagnosed. What we’re seeing now is not overdiagnosis—it’s a correction which is leading to increased visibility.

Whenever a minority group begins to gain visibility, there’s often a backlash: "It’s too much." "Everyone’s claiming it now." "It wasn’t like this in my day." And now, ADHD and Autism have become the latest targets in the cycle of moral panic.

We’ve Been Here Before

Take dyslexia. Formal research began in the early 20th century, and by the time of the Isle of Wight studies in the 1970s, its prevalence among children of average intelligence was recorded at around 3.7%. Today? It’s estimated between 10–17%. And yet—no moral panic.  No one’s wringing their hands about the "dyslexia epidemic." Why not? Because we’ve largely accepted it as a legitimate condition, not a threat to the social order. No one’s accusing kids of faking it or "playing the dyslexia card" for special treatment. So why the outrage when Autism and ADHD diagnoses increase?

In the early 20th century, less than 5% of people identified as left-handed. Today, it's closer to 12%. Why? Because we stopped punishing children for using their left hand. The rise was caused by cultural changes – not biological ones. People didn’t suddenly become left-handed; they were finally allowed to be.

This isn't a new phenomenon. Homosexuality remained illegal in Ireland until 1993. Since its decriminalisation, there has been a marked increase in the number of individuals identifying as LGBT+. This raises the question: does this reflect a genuine rise in the proportion of LGBT+ individuals within the population, or is it more indicative of a cultural shift that has enabled more people to openly express their identities?

The same dynamic applies to neurodivergence. As stigma lowers and diagnostic tools improve, more people are being recognised—not created. Visibility always feels like a surge when you've been trained not to see.

Moral Panic in a teacup

Suzanne O’Sullivan (neurologist) has been on a tour of British and Irish media in recent weeks promoting her book “The Age of Diagnosis: Sickness, Health and Why Medicine has Gone Too Far”. O’Sullivan acknowledges that Autism and ADHD have previously been underdiagnosed, but she sets out her stall in a recent Brendan O’Connor Interview, her direct quotes in italics below

• “I find the concept of masking very problematic"

• Diagnoses of depression has "gone too far"

• Adjustments to autism criteria "has gone way too far" (factually incorrect, see below)

• Upon people explaining when diagnosed that they have found their tribe, she states “Thats sort of a problem isn’t it?... Where can it lead?” (I don’t know – to people having friends and being happy with themselves?!)

• “Belonging to a (neurodivergent) group is predicated on your inability to do things…. Being in the group requires you to have a certain set of difficulties”. (IMAGINE SAYING THIS TO A CANCER SUPPORT GROUP or any other patient/condition support group)

• “ADHD in adulthood is a really new thing… The understanding when it was first coined was that it started disappearing in adolescence as people matured. Now we’ve created ADHD in adulthood. Its very important that people know what Recovery looks like” (Per her own Guardian penned piece on this, she quotes a 40 year old journal article for this idea - I wonder if in her own area of expertise - epilepsy - she would rely on a 40 year old journal article for a similarly as important issue as to whether adults have ADHD or not)

 To be honest, this last statement alone shows that she doesn’t know anything about ADHD, Neurodivergence, the Neurodiversity Model, or modern understandings that Neurodivergence is a different brain that people are born with and live with throughout their lives. We know that people mask their differences such as hyperactivity as they get older. But I suppose if you believe "masking is a concept that has been stretched to the point of ridiculousness”, then you can’t accept the depth and breath of masking of traits.

The term “label” is often used dismissively, as Suzanne O’Sullivan does, but this overlooks the real value a diagnosis can bring. For many individuals, it offers relief from shame and negative self-talk, and creates a pathway to support—whether in school, the workplace, or daily life. It can lead to greater understanding, access to accommodations, and for those who choose it, appropriate medical treatment.

The Numbers Don't Lie—But the Panic Does

Even if you take the conservative estimate that about 3% of adults are ADHDers, a recent UK study found that only 1 in 9 of those individuals have actually been diagnosed. That means the vast majority—over 85%—are still undiagnosed. This is also supported by the evidence on misdiagnosis, particularly in women, who are often diagnosed with anxiety, depression, and even EUPD or Bipolar Disorder. I have worked with many women who have been misdiagnosed this way. So if this is an "epidemic" of overdiagnosis, it’s doing a pretty terrible job at finding the people it’s supposed to be “catching.” Instead its underdiagnosis -  a system still failing most of the people it’s meant to help.

History Has Always Pointed to Neurodiversity

Let’s be clear: divergence isn’t a new phenomenon. Grunya Sukhareva, in 1926, described children with clear autistic traits—solitary, imaginative, pattern-focused, and socially different. All were of average or above-average intelligence. Kanner in 1943 and Asperger in 1944 both echoed these descriptions, focusing on social difference and insistence on sameness.

RFK has recently called Autism an epidemic. He says that “these are kids that will never pay taxes, they’ll never hold a job, never play baseball, never write a poem, they’ll never go out on a date, many of them will never us a toilet unassisted”. What is unfortunate is sometimes the most ignorant have the biggest microphone.  Donald Triplett, considered the first formally diagnosed autistic person, in 1943, was institutionalised at age 3 and monosyllabic until age 10, but when on to live a full life—college graduate, 60-year banking career, golf enthusiast.

Likewise, Asperger* noticed that some of the children he identified as being autistic in the 1940s, used their special talents in adulthood and had successful careers: one became a professor of astronomy and solved an error in Newton's work,  and another was Austrian writer and Nobel Prize in Literature laureate, Elfriede Jelinek

So despite what Suzanne O’Sullivan says, this is very like the people being diagnosed today, who might appear to have more subtle traits, but have deep traits that make them different.

Diagnsosis Creep Claims

Accusations of “diagnosis creep” around ADHD often come from outside the field. While many conditions have seen expanded criteria over time, that’s actually less true for Autism and ADHD. Yet somehow, these are the ones that attract the most criticism.

For example, consider the changes between the DSM-IV-TR (2000) and DSM-5 (2013). In the DSM-IV-TR, criteria required that "some hyperactive-impulsive or inattentive symptoms that caused impairment were present before age 7." In the DSM-5, this was revised to: "several inattentive or hyperactive-impulsive symptoms present prior to age 12 that interfere with functioning or development." The trait is basically the same, the key difference here is a change in the age threshold, which has allowed for better recognition of ADHD in a wider range of presentation.

In overstretched underfunded school and healthcare settings, it’s often the most visibly hyperactive boys who get noticed early. However, those with predominantly inattentive symptoms—or who are less overtly hyperactive—may not be identified until academic and social demands increase in secondary school or third level. The symptoms weren’t new at that point; they were simply manifesting as demands increase over time.

We’re also seeing more diagnoses in people in their 20s, 30s and 40s—often those with combined-type ADHD or even AuDHD—who were overlooked in childhood due to various factors, including cultural differences, gender bias, inattentive presentation, or lack of access to healthcare. Additionally, there’s now a growing group of adults in their 50s to 70s seeking assessment, as their own children or grandchildren are assessed and diagnosed, revealing a hereditary pattern.

What’s actually happening?

If today’s neurodivergent adults don’t match the outdated stereotypes of "real Autism," or “real ADHD” that says more about the limits of those stereotypes than about today’s diagnoses. The diagnostic criteria have evolved, yes—but the core traits haven’t changed. What’s changed is that people who were once invisible are finally being heard.

What we’re seeing now isn’t a flood of false positives—it’s the beginning of a long-overdue correction. And the panic is not about science or precision; it’s about who’s allowed to be seen and understood.

The rise in diagnosis has triggered what feels like a familiar pattern: a public anxiety not about the conditions themselves, but about who is allowed to name their experiences. We've seen this before as I said with left-handedness, and even numbers in the LGBT+ community. The numbers rose not because of a sudden increase in left-handedness, or same sex attraction, but because people were finally allowed to be themselves.

The same is happening now with neurodivergence. People are finding language to describe lifelong struggles— differences in attention, executive function, sensory sensitivity, social processing—and are often only now realising those aren't just personal failings. They're features of a different neurotype. For many, a diagnosis is not a trend but a lifeline.

And yet, the public conversation remains sceptical. Adults seeking late diagnoses are often dismissed as hypochondriacs, trend-chasers, or just “too online.” Self-diagnosis, especially among minority communities, is mocked or pathologized, despite being a valid response to barriers in healthcare and a common first step toward professional support. Self identification is valid, especially with continuing financial and cultural barriers in our society. It's as if there's only one acceptable narrative: that neurodivergence is real, but only when someone else decides it is.

This moral panic, however subtle, is rooted in discomfort. When more people are identified as neurodivergent, it disrupts the idea of what’s normal. It forces us to reconsider how workplaces, schools, and healthcare systems are built—and who they were not built for.  And still not built for. It questions whether the problem lies with individuals or with expectations that were never designed to accommodate different minds in the first place.

This moral panic isn’t about scientific rigor or protecting resources. It’s about control. The status quo relies on a clear line between the “normal” and the “abnormal.” If too many people step out of the norm—if they stop masking, stop pretending—then society might have to change to accommodate them. That sounds expensive. Uncomfortable. Inconvenient.

It's the same logic behind resistance to disability access, racial justice, or LGBTQ+ rights. If 80% of the population doesn’t need it, they don’t see why they should pay for it. And so the remaining 20% are left out, again and again—until they finally speak loudly enough to be heard. And then they’re accused of being “too loud.”

That kind of reflection can be unsettling. It's easier to frame rising diagnosis rates as a problem of excess. But the numbers don’t support that narrative. What they show, instead, is decades of unmet need and a slow process of cultural unlearning.

We have not yet reached the point of “too much” diagnosis. We’re still playing catch-up. Still trying to reach the people who grew up thinking they were broken, lazy, or failing—when in reality, they were simply misunderstood. That’s not a cause for panic. That’s a reason to keep going.

*https://www.healthline.com/health/autism/why-is-the-term-aspergers-no-longer-used