This article first appeared on 28 July 2026 in #NDChat, my newsletter on LinkedIn.

The letter was written and ready to send. A referral request for an adult autism assessment, ready to send to my GP. I’d drafted it the way I draft most things — carefully, with examples, anticipating the questions a clinician might ask. And then, before I sent it, I stopped.

I asked myself a question I don’t think I’d properly asked myself before: what was I actually hoping this would achieve?

🟠 Two children in one house, one label that already fits

I have ADHD. I’ve had it confirmed in two assessments, and if I’m honest, nobody who knows me was remotely surprised. It explained something. It gave a name to a pattern that had been visible — to me and to everyone around me — for years.

My son has an autism diagnosis. Watching him, and watching how that diagnosis changed the support he received and the way people understood him, I started to notice something. Some of what I saw in him, I recognised in myself. Not identically — but enough that I began quietly comparing our traits. How we each process a room full of people. How we each handle a change of plan. How sensory input lands differently for us both.

By the time I sat down to write that referral letter, I was fairly confident I’d land close to the threshold for an autism diagnosis. Close enough that a clinician would likely find something there.

And then I asked myself: so what?

🟠 What a diagnosis is actually for

A diagnosis isn’t just a description. It’s meant to DO something — explain an otherwise unexplained pattern, unlock support that wasn’t available before, or change how you understand and manage your own life.

My ADHD diagnosis did all three. It explained things people had noticed about me for decades. It changed how I approached work, relationships, and my own expectations of myself. It wasn’t a surprise to anyone — which, paradoxically, is exactly what made it useful. It confirmed something everyone could already see and gave it a framework.

An autism diagnosis, for me, wouldn’t do any of that. It wouldn’t explain something currently unexplained — I already understand why I find certain environments difficult, because I’ve lived with ADHD long enough to have already built an account of myself that covers most of that ground. It wouldn’t change how anyone around me sees me, because nothing about how I function would look different the day after sending the letter than it would have the day before.

What it would give me is a second label. And I found, sitting with that letter, that adding “and I have autism” to “I have ADHD” would feel less like understanding myself better and more like collecting something. That’s not a criticism of anyone who does pursue that diagnosis and finds it genuinely clarifying — for my son, it clearly was. It’s simply that, for me, the test I applied — “does this explain something currently unexplained, or change what I do next?” — came back negative.

🟠 Where this collides with what’s trending

This reflection happened alongside a lot of reading I’ve been doing on how ADHD and autism are discussed online, and I noticed my own thinking pulling against the grain of most of that content.

“AuDHD” — the unofficial term for having both ADHD and autism — is having a real cultural moment. And there is genuine, solid evidence behind the idea that the two conditions overlap far more than clinicians assumed for decades.

Until the DSM-5 was published in 2013, a clinician literally couldn’t diagnose both in the same person — one excluded the other. That rule change alone accounts for a lot of the apparent “sudden rise” in dual diagnoses; recognition caught up with reality.

But here’s where I think the online conversation blurs something important: research shows an enormous range for how often the two conditions actually co-occur — anywhere from roughly 20% to 80%, depending on the study. That’s not scientific indecision so much as different studies measuring different things.

Clinical samples (people already flagged as struggling with one condition) show much higher overlap than general-population samples. And crucially, several studies show a large gap between people who “show traits” of the other condition and people who “meet full diagnostic criteria” for it.

One well-designed study found that while parents and teachers reported symptom overlap in a few percent of children, the rate of children who actually met diagnostic criteria for both was well under 1%.

That gap — between traits and diagnosis — is exactly the gap I found myself standing in. It’s also, I noticed, the same gap some senior autism researchers have started raising publicly. The Atlantic reported in July 2026 that researchers including Catherine Lord and Uta Frith have voiced concern that “mild autism” diagnoses are increasingly being given to people whose difficulties may be better explained by anxiety, depression, or simply the ordinary discomfort of feeling different — without that meaning autism itself is being overdiagnosed everywhere.

It’s a genuinely contested question; other researchers argue the more pressing problem, especially for women and late-diagnosed adults, is still under-diagnosis. I raise it not to settle that debate, but because the pattern those researchers describe — someone searching for an explanation, finding a description that resonates, and wondering if it’s the answer — was uncomfortably close to home.

It’s entirely plausible, even likely, that having ADHD makes autistic traits more noticeable in yourself, and vice versa. The two conditions share underlying features: difficulty regulating attention, sensory sensitivity, differences in social processing.

Some of what looks like “autism” in an ADHD brain might be a genuinely separate condition running alongside it. Some of it might be ADHD wearing a similar coat. Untangling the two, from the inside, is genuinely hard — which is exactly why “I relate to a description of autistic traits” isn’t the same thing as “I meet diagnostic criteria for autism,” any more than resonating with a rejection-sensitivity video is the same as having a formal condition.

🟠 The question I’d ask before you write your own letter

I’m not writing this to talk anyone out of seeking an assessment. If a diagnosis would explain something in your life that currently doesn’t have an explanation, or would open a door to support you need, that’s exactly what assessment pathways are for — and I’d encourage you to pursue it.

But I’d gently suggest asking yourself the question I ended up asking myself: what would this diagnosis actually change? Would it explain something currently unexplained? Would it alter what support you receive, or how you understand and manage your own life? Or would it mostly just be a second label sitting alongside a first one that already does most of that explanatory work?

There’s no wrong answer to that question. But it’s worth asking honestly, before the letter goes in the post — because the answer tells you something a symptom checklist never will.

I’ve come to think the most useful thing any of us can offer someone — a child, a pupil, ourselves — is a better understanding of who they are. That’s the actual goal.

A diagnosis, when it fits, can be a genuinely powerful route toward that understanding. But it’s a route, not the destination. The question worth sitting with isn’t “will I get the diagnosis” — it’s “how will this help me understand my own traits and patterns better than I do today?”

Autism, ADHD, something else entirely, or no label at all: each of those is simply a starting point for that process of understanding, not the end of it.

Measured against that question, my unsent letter wasn’t a door I closed. It was me realising I’d already found what I was looking for down a different road.

🟠 I work with schools, families and individuals, providing training, consultancy and speaking to develop awareness and understanding of neurodivergence and to help schools and families ensure that neurodivergent children thrive and fulfil their potential.

chris@headfirstconsulting.com

Schools Training Modules