Hi there. Welcome.
I think you may do better posting on the Parent Emeritus board because she is an adult child and you really have no legal way to force her to do anything anymore. You can't make her go to therapy. Many of us have dealt with adult problem children over there.
Does she have a job? Does she help pay for continuing to live with you? Is she in college?
Regardless of what her problems are, she is the one, at her age, who will have to initiate treatment and she will have to want the help to get better.
The best way to try to guess what is wrong with her is to look at both sides of her genetic family tree--if there are any psychiatric illnesses, substance abuse, or autism that would be significant. However even professionals get it wrong, as you have seen. It is hard to diagnose.
Sorry you had to come here. I wish you well.
