This informal diagnosing issue can't be under-estimated, I've found. It can get quite bizarre.

I was once communicating with a national governmental mental health organisation, and they suddenly provided documents relating to a different diagnostic category than the one I was asking them about. I asked them why and got no answer, they literally didn't reply.

I eventually guessed my friend, who had a long-term different diagnosis himself, said something to them, because he'd been contacting them at the same time. And when I mentioned what had happened, he didn't deny it. He started referring to that diagnostic category, as if he thought it was the one (and only one) that applied to me. He'd never mentioned this to me before. He had no training or qualifications in mental health or psychology or anything (unlike me), though he was experienced in the service user/survivor movement. If he'd just discussed his idea with me, I'd have been fine to discuss it, because I'm interested in all that stuff, and I take the current diagnostic system with a big pinch of salt scientifically anyway.

But apart from him who had his own issues, isn't that so bizarre a government agency just hears randomly from someone with no qualifications about an alleged diagnostic category of someone else, and just assumes it's true, like totally and utterly assume it's true (presumably it triggered some prejudice about people lacking insight or fearing stigma), but doesn't tell me anything and just ignores my own actual communication, even when I'm asking what's going on.

In this case it didn't matter much, but it's dreadful to think how this sort of stupid mess can play out in more controlling situations in mental health care. Actually it seems like government may have a culture of seeing psychiatric categories as just something to make up, because the very agency tasked with checking psychiatric facilities for safety etc, when one of their inspectors kept complaining about flaws in this assessment processes, they got their HR doctor to falsely diagnose her with schizophrenia when in fact her diagnosis was depression (totally non-psychotic). I'm not joking.