As @reddragonfly says I think it depends of the person. Art is something very personal. So everyone have their own answer.
In the game production field though, we can strive being in pain, tormented etc and putting most of those feelings aside sometimes, (no good if you are a depressed artist good at painting depressed ghosts and working on a comedy movie or game), but not under alcohol or drugs influence. I think that altering mind states can be good on the short term to have a quick release of .... production ?
But this will not show your true skills and the real 'you'. I am talking in an amateurish level, I guess shamans and people doing that regularly and with control can definitely do good, but the usual John might get to driven and lost in his own mindstate.
Yeah, sorry (I try to learn how to write little by little, I'm better at painting haha) I think that to truly be able to connect with an audience you must empathize with them through that language and alcohol and some other drugs...well... at some point you can't speak or walk properly so doing art..
Cheers !