This book was recommended to me as part of my treatment for panic disorder. I wouldn't have guessed that it was possible to completely cure panic disorder, but between this workbook and my therapist, it's been over a year since my last panic attack. I'm sure that it is a good idea to use this workbook under the guidance of a good therapist, but it gave me my life back. There aren't enough stars for that.
This is a therapy with good, solid science behind it. It doesn't ask you to ever do anything outrageous or dangerous. It is simple and reasonable, and worth every penny.