Allison J. Smith has this book recommendation.
I had many blocks (and signs of depression) and created paintings very slowly, less than 10 paintings a year! I found and read the book, Painting from the Source by Aviva Gold, and then followed its method of creating imagery.
I am now block-free! I freely express myself through my art. I create unabashedly, fluidly, and in 2007 created 180 paintings. And I have to say, the paintings now are of a much higher quality. Not to mention, I am no longer stressed-out and I think more clearly than I have in my entire life!