This therapy is grounded in a theory of psychology that at the root of emotional troubles are distorted thinking. Untwist the thinking, the rest follows. I think there's a lot of truth in this take on psychology. All of us run "scripts" in our heads. Naturally if you put yourself down, keep saying in your mind that a situation is hopeless, the emotions will follow. At the same time this isn't a book of trite affirmations where you chant, "I am awesome." But it does point out that while you can't always control your situation, particularly other people--you can to some extent control what you think about it, and thus how you feel about it. To that end he identifies unhealthy habits of mind such as All-or-Nothing Thinking, Overgeneralization, Mental Filter (negativism), Disqualifying the Positive, Jumping to Conclusions, The Fortune Teller Error, Magnification and Minimization, Emotional Reasoning (Feelings are not facts), Should Statements ("I should ____"), Labeling and Mislabeling, Personalization ("It's my fault!"). The rest is elaborations, explanations and exercises, but that's it in a nutshell. And no, you're not going to end depression just by reading it--you have to put it into practice. Just as you don't gain muscles by just reading a book about weight training. And some people may need more--therapy, medication. But I do find learning about the common distortions in thinking and more rational responses does help.