I think it's probably true that creative people are touched by melancholy more than the average person, and to the extent that delving into that shadow world produces good work, I'm all for it. But I think you have to be able to step back from the work, and say, "Look how miserable I felt. Look how beautifully I wrote about it. Now I'm going to get an iced coffee and chat with a friend." Writing should be a way out of despair.