He is a master, but I think Lars Von Trier has more psychological problems than any other director I can think of.
When I went to film school our principle had to do an interview with him at one point, and he said that it was basically impossible because he was so drugged up, his self was gone. He was basically a puppet and just was yes, no or "I don't know". He hates everything outside of the few. He has an incredible amounts of phobias.
But for all his faults, he can make incredible films. Antichrist was really a masterpiece, but not one I will ever want to see again. In fact, there is no Lars Von Trier film I want to see again except for the Kingdom.