This book deals SPECIFICALLY with the types of obsessional or frightening thoughts that can arise as a DIRECT result of Panic Disorder.
This is not the same (although it can be similar in some regards) as obsessional thoughts that are part of OCD (Obsessive Compulsive Disorder)
Obsessional thoughts that might occur as a direct result of Panic Disorder are usually a TEMPORARY condition / experience that resolves once the panic disorder is under control.
If you experienced obsessional thoughts long BEFORE you suffered from panic attacks then you may want to explore the area of OCD in more depth. Talk to your doctor or a qualified therapist.
If the thoughts only appeared AFTER you experienced panic attacks then the information in this book along with the 4 main workbooks should be enough to help you deal with the problem.