Can I just insert a word of caution here about this now outdated book?
My daughter has severe ME and was so bothered by the lack of medical knowledge and the mis-truths published about the illness, that she made a study of it all, which you can see at her website.
http://www.hfme.org/goodbooksbut.htm#421133432

While there are some good bits in this book, there is more that is not, and it is now outdated.
This is her review:

"CFS, Fibromyalgia and other invisible chronic illnesses, by Katrina Berne, Ph.D.

Like her first book, this book does not distinguish adequately, or at all, between fatiguing illnesses and M.E. or 'CFS.' Ridiculous and unscientific claims are also made about Fibromyalgia being basically the same as 'CFS.' This book also very clearly means well, but is not a good source of reliable medical information.

The poor quality information in this book was a real lost opportunity to do some good.

This type of misinformation and lack of political awareness is a big part of why we have made so very little progress over the last 20 years. I don't understand why some patients still recommend this book to fellow M.E. patients. It's hugely problematic.

Anyone who can't see the huge difference betwen FM and M.E. and between teh definitions of 'CFS' and M.E. - clearly does not understand even the most basic facts about M.E."