A diagnosis is a map, not a name for you: what the ICD says and what it does not

“I have an anxiety disorder.” I hear that sentence often, and every time I am curious about the same thing: what has the person just told me about themselves. Sometimes it means “a doctor said so”. Sometimes “I read it online and it fits”. Often it means something else entirely — this is simply how I am made.

The difference between those meanings decides what will happen over the next year. A diagnosis as a description of a state is a useful tool. A diagnosis as a name for you is something that can lock you in.

In this piece I explain what a diagnosis actually is, where it comes from, what it tells you and what it does not — and why we handle it differently in a therapy room than in a clinic. Not because it is wrong, but because it was built for a different purpose.

Where a diagnosis comes from

Mental health conditions are not diagnosed by test result. There is no blood panel that shows depression and no scan that confirms an anxiety disorder. A diagnosis is made when a professional compares your description and their observation with a description in a classification manual.

There are two manuals. In Europe, and here, the ICD applies — the World Health Organization’s International Classification of Diseases, in its eleventh edition since 2022. In research and in American practice the DSM of the American Psychiatric Association dominates, now in its fifth edition.

Both work on the same principle: they list criteria and set a threshold. A depressive episode, for instance, requires a certain number of symptoms, lasting a certain period, with a significant effect on functioning. Have enough for long enough and you are inside. Have one fewer and you are outside.

That alone tells you something essential: the boundary is an agreement, not a natural dividing line. Someone with one symptom fewer does not suffer meaningfully less than someone with one more.

What a diagnosis does well

Since there will be some criticism in this piece, let us start where a diagnosis is useful — and it often is, considerably.

It opens doors. Without a diagnosis there is no referral in the health system, no sick leave, no cover, no right to adjustments at school or work. That is not a small thing; for many people a diagnosis is the only way to get help at all.

It guides treatment. Treatment guidelines are tied to diagnoses. If you know this is obsessive-compulsive disorder rather than generalised anxiety, you know which method has the strongest research support. The wrong label means the wrong first choice.

It names things. This should not be underestimated. Someone who has spent ten years believing they are lazy, incapable and weak often experiences relief at diagnosis for the first time: this has a name, other people have it, there is research about it. Naming distress reduces it to its actual size.

It lets professions talk to each other. When a psychiatrist, a doctor and a therapist discuss the same person, they need a shared language. The diagnosis is that language.

What a diagnosis does not tell you

Now the other side, rarely said aloud in a clinic because there is no time for it.

It does not give a cause. This is the biggest misunderstanding. A diagnosis is a description, not an explanation. “You have a depressive episode” means “your symptoms match this description”, not “now we know why”. In medicine we are used to a diagnosis explaining — a fracture explains the pain. With mental states that step is missing.

It does not tell the story. Two people with the same diagnosis can have completely different roads to it. One has been burning out for four years, another has just lost their mother, a third carries a childhood they have never spoken about. The diagnosis is identical for all three. The work is different for all three.

It does not tell you what will help you. Guidelines say what works on average for a group. You are not the average of a group.

It does not say who you are. The difference between “I have depression” and “I am depressive” sounds like a grammatical detail and is not. The first is a state that can change. The second is an identity.

What happens when a diagnosis becomes a name

Naming has a bright side and a dark one, and the research on this is fairly consistent.

The bright side is relief from blame: if this is an illness, I am not lazy. The dark side shows up elsewhere. Studies on the effect of biological explanations of mental disorders show that the account “this is a brain disease” does reduce blame, while at the same time increasing pessimism about recovery — both in the people themselves and in the clinicians treating them. What is explained as broken biology also seems less changeable.

In practice it looks like this. Someone who says “I have social anxiety” often stops asking when exactly it appears and when it does not. The answer is already there. And with it disappears exactly the observation that would move them forward: that it never appears among old friends, and appears every single time at work with their manager.

So in the therapy room I treat a diagnosis as a starting point, not a conclusion. I do not deny it and I do not pretend it is unimportant. But I always ask the same thing: when does this happen and when does it not?

Why the boundaries move

Something that often surprises people: diagnostic categories change, and not because of new discoveries about the brain but because of professional agreement.

Homosexuality was in the DSM until 1973. Asperger’s syndrome existed as a separate diagnosis until the fifth edition folded it into the autism spectrum. The criterion that prevented grief after a death from being diagnosed as depression was removed in the same edition — prompting a public debate about whether we were declaring mourning an illness.

None of these changes followed a new test result. All were decisions by committees. That does not make them arbitrary — they came out of data and debate. But it does mean a diagnosis is not a natural object we discover; it is a tool we build. And a tool is judged by whether it helps.

How we handle a diagnosis in therapy

Practically: what happens if you bring a report to an introductory session.

I read it and take it seriously. The fact that someone identified a depressive episode or panic disorder is useful information. It tells me where the person has already been treated, what was prescribed and what happened next.

Then I set it aside for a while. I ask for your description: what your day looks like, when it is worst, what was different a year ago. That description is often richer than the label and leads somewhere else.

I look for exceptions. When is this absent? Around which people is it milder? In which part of the week? In systemic work, exceptions are the most telling information there is, and a diagnosis erases them by its nature — it describes a state, not its fluctuations.

I do not make diagnoses. That is not within my remit. If something emerges in our work that needs medical assessment, I say so and point you onwards. I have written separately about who is who among psychotherapists, psychologists and psychiatrists.

When you do need a diagnosis

So there is no wrong impression: there are situations where diagnostic assessment is the first step rather than an option.

When symptoms are so strong that daily life stops working. When bipolar disorder, a psychotic state or a serious eating disorder is suspected. When there are thoughts of suicide. When physical symptoms require ruling out a physical cause — thyroid problems, anaemia, vitamin deficiency and some medications can mimic depression closely enough to be mistaken for it. And when you need sick leave or cover.

In all these cases, a therapist who steers you away from a doctor is not acting in your interest. I write about the signs that make a psychiatrist the first address in a separate piece.

What to remember

A diagnosis is a map, not a name for you. It says roughly where you are and helps choose a direction. It does not say how you got here, who you are, or where you are going.

Use it as a starting point: as a reason to find the right treatment, and as evidence that you are neither lazy nor weak. But do not let it become the answer to the question of who you are — because that question stays open even when the symptoms are gone.