Are you enjoying being treated like you treat others?
I didn't treat anybody like this. I simply said, he was in his rights to ask.
Had I made your post and he made the request to me, I'd have said, "Jaime, I'm not a medical doctor, if it matters to you but I've worked with many mentally ill patients and any idiot can read the DSM".
When people have asked me about mine, I've also been pretty honest about them. They are not particularly impressive.
Sometimes credentials matter and other times they don't. It depends on the question asked.