I did try leaving it up to the GP's judgement (cos hey i'm no professional) but some are not particularly experienced in this field so it didn't go well. It's easier to just ask for one instead. (4/14)
Remember, these psychiatric appointments will be expensive. But for a lifetime diagnosis, it's worth it. It was for me at least. It took several sessions to get a proper diagnosis. During the sessions, the psychiatrist asked a LOT of questions. (5/14)
He also asked for blood test and drug test results. Had to get those from another clinic. (6/14)