He has bipolar. One of my good friends' family member has it and when she's having a manic episode she really is like a completely different person. I'm not making excuses but I think until you've been around a 'normal' person who has it and is in an episode, it's quite a hard thing to understand. But having said that, I have read that he actively stops taking his meds when he wants to make music as he isn't creative enough on his meds, which makes him a bleep when medicated too I guess.