Many DSM-5 diagnosis come into effect with the ICD-11, ICD-10 doesn't have a good deal of them, and that rollout is still fresh & ongoing.
It is kinda spooky, though, to have freshly minted doctors from a few years back whose school-knowledge will forever be "outdated and archaic" based on standards published before they were in school.
Some good advice I got: treat this as a generation shift, find younger and newer doctors who are familiar with the "modern" standards.
Oh I agree with you, it's just that I don't think LLMs are either. If you think of LLM knowledge, especially in scientific/engineering fields, as a lossy representation of the density of ideas, then you'd expect to see some weird behavior. I'm sure there is some sort of a temporal discounting and people thinking about this, but a naive NLL or Reverse-KL on medical literature would engrain some weird, wrong ideas.
This is kinda the case though. In Poland I met only one psychiatrist that knew about DSM-5. In this year. DSM-5 was a thing from 2013.
Doctors are people just as us, not every single of them is good.