My sister...wow, she was hard to grow up with because of her bipolar disorder. Because of the disorder, she is hard to tell she's wrong. Its really hard in fact. So when I got this book, I thought I might find some easy ways to let her know what I feel without being preachy. Without telling her I had a book as my guide I walked her through all 4 steps of the disorder and I have to say she is much better today and she can see when things change and how she feels, but those are 2 breakthroughs I have to credit to Dr. Fast. Really I think this book is a breakthrough and you really don't have to have the disorder to benefit from this book. Everyone around my sister notices a change, and my sister credits me for that.