I have read the book, although it was ten years ago and I don't remember the details. I just remember it made me very, very angry, especially at his treatment of Obsessive-Compulsive Disorder. I seem to recall he felt we could help ourselves? But at any rate, what I think doesn't matter. If it's helping you then I say go for it, and happy reading! Depression is so hard to conquer, use whatever means you have at your disposal that make sense to you and for you. I wish you strength.
P.S. If you ever want to read a book that's purely fun and very funny, try anything by Dave Barry. His books have absolutely nothing to do with depression (in fact, they don't have much to do with anything) but I find them hilarious, and that helps sometimes, too.