People will probably mock that comment,but I too believe it is to be factored in to his behavior.
The star of Passion, was interviewed after the movie, and commented that "You do not make a film about the Passion and not get some of it handed to you."
I think most of Mel's demons have been created by his own behavior.
But than aren't most.
I agree with the possible possession. Throw in bipolar and alcoholism and he was a prime candidate for it after that movie.