David Lynch, Catching The Big Fish:

“It’s good for the artist to understand conflict and stress. Those things can give you ideas. But I guarantee you, if you have enough stress, you won’t be able to create. And if you have enough conflict, it will get in the way of your creativity. You can understand conflict, but you don’t have to live in it.
In stories, in the worlds that we can go into, there’s suffering, confusion, darkness, tension and anger. There are murders; there’s all kinds of stuff. But the filmmaker doesn’t have to be suffering to show suffering. You can show it, show the human condition, show conflicts and contrasts, but you don’t have to go through that yourself. You are the orchestrator of it, but you’re not in it. Let your characters do the suffering. It’s common sense: The more the artist is suffering, the less creative he is going to be. It’s less likely that he is going to enjoy his work and less likely that he will be able to do really good work.
…some artists believe that anger, depression, or these negative things give them an edge. they think they need to hold on to that anger and fear so they can put it in their work. and they don’t like the idea of getting happy— it makes them want to puke. they think it would make them lose their edge or power.
but you won’t lose your edge if you meditate. you will not lose your creativity. and you will not lose your power. in fact, the more you meditate and transcend, the more those things will grow, and you’ll know it. you will gain far more understanding of all aspects of life when you dive within. in that way, understanding grows, appreciation grows, the bigger picture forms, and the human condition becomes more and more visible
If you’re an artist, you’ve got to know about anger without being restricted by it. In order to create, you’ve got to have energy; you’ve got to have clarity. you’ve got to be able to catch ideas. you’ve got to be strong enough to fight unbelievable pressure…”