THE REALITY OF MISDIAGNOSIS: WHAT HAVING THE RIGHT (OR WRONG) LABEL DOES
Recently, I sat in my zoom appointment and heard “generalised anxiety disorder” after years of being told it was obsessive-compulsive disorder (OCD). Same intrusive thoughts, completely different explanation for why they wouldn’t leave me alone. It changed so much about how I understood myself, and it’s part of the reason I can’t stop thinking about how many people are walking around with the wrong map for their own brain.
Here’s one way I like to think about it. If there’s a storm outside, we call it a storm. Not “grey sky phenomenon with intermittent aggressive water droplets and a side of wind.” We call it a storm because that one word does three jobs at once:
it tells other people what’s going on without a fifteen-point description;
it tells you what to grab on your way out the door; and
it tells you roughly what to expect for the rest of the day. Get the label wrong, call a storm a light drizzle, and you walk out in a t-shirt, confused about why you’re drenched and cold and nobody warned you.
Diagnoses work the same way. A good one is a fast, accurate weather report for a human experience or brain wiring. A wrong one sends you outside completely unprepared, then blames you for getting wet.
THE PATTERN SO MANY LATE-DIAGNOSED ADULTS KNOW TOO WELL
Ask any late-diagnosed autistic or attention-deficit/hyperactivity disorder (ADHD) adult about their diagnostic history and you’ll usually get a list, not a single label. Anxiety. Depression. Maybe an eating disorder. Sometimes several personality disorder mentions along the way. Each one wasn’t necessarily wrong in the sense of “there was nothing there,” there was often real distress, real anxiety, real relational chaos. But each one was a clinician looking at a cluster of symptoms and reaching for the label that explained the most visible slice of the picture, without stepping back far enough to see the whole weather system.
Take OCD and generalised anxiety disorder (GAD). On the surface they can look similar: intrusive thoughts, distress, a compulsion to do something about it. But the treatment implications are opposite. If it’s OCD and we treat it like GAD, we might be encouraging exactly the compulsions that are feeding the obsessive cycle, without either of us realising that’s what’s keeping it alive. If it’s GAD and we treat it like OCD, we might be pushing someone through exposure work when actually, in this case, a bit of reassurance is a completely reasonable and valid response. Same visible behaviour, opposite mechanism, opposite treatment. This is why the label isn’t pedantry. It’s the difference between a plan that works and a plan that quietly makes things worse.
THE BPD-SHAPED ELEPHANT IN THE ROOM
I want to say this as gently and as directly as I can: borderline personality disorder (BPD) has become one of the most common “landing spots” for autistic people, particularly female-identifying folks, who present in crisis. Recent qualitative research interviewing autistic adults who had previously been diagnosed with BPD found a striking common thread: unnoticed autistic traits going back to childhood, and a BPD diagnosis that came with real weight and stigma attached, often without anyone stopping to ask whether autism explained the picture more accurately (Brighton and Sussex Medical School, 2024). It’s not that autism and BPD can’t coexist, they can, and do. But BPD is also widely reported as the single most common perceived misdiagnosis among autistic people themselves, precisely because undiagnosed autism can so easily be mistaken for BPD by clinicians without training in how the two can overlap (Neurodivergent Insights, n.d.).
When someone is in crisis, in front of a clinician who has fifteen minutes and a risk assessment to complete, “personality disorder” can become a catch-all for “this person’s distress doesn’t fit neatly into a mood or anxiety box.” It’s rarely malicious. It’s usually a system that’s overstretched and under-trained, looking at surface behaviour rather than the internal experience driving it. But the consequences for the person on the receiving end are not small.
WHAT THE RIGHT LABEL ACTUALLY DOES
Here’s the bit that doesn’t get said enough: finding out you’re autistic or ADHD as an adult is rarely a clean, tidy relief. It’s more like a rollercoaster with a very specific order of carriages. First there’s relief: oh, there’s a reason. Then, often faster than people expect, there’s grief, for the years spent thinking you were lazy, dramatic, too much, broken. Then a strange, quiet fear: does this change who I am? And eventually, if you’re lucky and supported, something closer to gratitude and self-acceptance.
But compare that whole messy, worthwhile process to the alternative: not knowing at all. Not having a rollercoaster, just an open question mark, indefinitely. Just “why am I like this,” on a loop, with no scaffolding to hang the answer on.
There’s a saying that’s done the rounds in neurodivergent communities for a while now, and I still think it’s one of the most useful reframes in the whole conversation: finding out you’re autistic isn’t finding out you’re a broken horse. It’s finding out you’re a zebra. You were never a badly-performing version of the “normal” thing. You were a different thing all along, and the instructions you were given were for the wrong species.
And yes, this applies to kids too.
I hear the hesitation from parents a lot: I don’t want to label my child. I understand the instinct. But here’s the uncomfortable truth: kids get labelled either way. If we don’t offer “you have ADHD” or “you’re autistic,” the world will hand them labels anyway: weird, awkward, too much, too sensitive, dramatic, difficult. Those labels come with zero context and zero community attached. A clinical label, offered well, comes with the other half of the sentence: you’re wired differently, there are other people like you, and you will find your people. That’s not a life sentence. That’s a map.
SO WHAT DO WE DO WITH ALL OF THIS?
Get curious before you get certain, as clinicians, and as people trying to understand ourselves. A diagnosis is genuinely useful when it changes what you do next: what support you seek, what you stop blaming yourself for, what treatment actually fits the mechanism underneath the experience. It’s genuinely harmful when it’s handed out because it’s the most familiar shape in the room, not because it’s the most accurate one.
The weather report only helps if it’s the right one. Get it wrong, and you’re not just uninformed, you’re standing in the rain in a t-shirt, wondering what’s wrong with you, when the truth was you just needed a very different coat.
IF YOU OR SOMEONE YOU KNOW IS STRUGGLING
If something in this post has brought up difficult feelings for you, or you’re concerned about someone you know, support is available.
For immediate support, you can contact Lifeline on 13 11 14 or Kids Helpline on 1800 55 1800.
If you or someone else is in immediate danger, please call 000.
Please note that Brianna Thomas Psychology is not a crisis service and enquiries are not monitored 24/7.
References
Brighton and Sussex Medical School. (2024). Study reveals harrowing experiences of misdiagnosis of borderline personality disorder in autistic adults. BSMS News.
Neurodivergent Insights. (n.d.). Borderline Personality Disorder vs. Autism.
