Where I live sadly the idea is that the patient should not know their diagnosis. I once went to a group thing and all the others did not think they had a diagnosis but I knew it was required for the group. I had asked about mine and they had to tell me. So they thought I was the only "sick" person in the group. Weird...

I also especially when it comes to therapists, not doctors, they think your treatment will be messed up if you know, and also they don't want to think in terms of labels. If I say something about a diagnosis they ask me why it is so important to have a label. Sigh.