When I bought this book (for my best friend, who was having panic attacks) I was suffering from severe depression and anxiety. I had been professionally diagnosed, was in therapy, and was on medication; this had helped markedly, but I was still moderately to severely depressed and/or anxious every day. This book helped me get better in a surprisingly short period of time because it is specific, explanatory, and practical. Rather than relying only on one technique (like _Feel Good_'s cognitive therapy approach), it has chapters on nutrition, exercise, visualization, cognitive therapy, mistaken beliefs, emotional needs, spiritual angst, and medication. A diagnostic questionaire in the first chapter helps you to determine which chapters will help you the most.
I especially liked the fact that the book was interactive AND specific. When you're depressed, it can be hard to respond to open-ended prompts like "describe some situations that make you anxious". The prompts in this book are usually "check all that apply", True-False, "rate from 1-5" etc, which is easier to do even if part of you is resistant. Also -- every chapter ended with a checklist of, well, homework. Many books on depression and anxiety left me *knowing* more (or thinking I did) but not changing anything -- just wishing things would change! This book helped me to assume responsibility for my own role in recovering, and gave me the tools (in simple steps!) to do it.
I have given this book to at least five other people suffering from panic attacks, perfectionism, social phobia, and generalized anxiety disorder, and they ALL, also, found it extremely helpful.
The book may not help everyone, but it acknowledges this -- occasionally it points readers in other possible directions (bibliographies at the end of each chapter encourage readers to learn more about anger, co-dependence, depression, etc, if indicated). Definitely a good place to start for anyone with anxiety difficulties of any kind. Also, don't rule it out if you have depression -- your depression might be (like mine) the inevitable result of too much anxiety.