This book is from New Harbinger Publication known for its self-help books.
Most mental disorders come with emotion irregulation to some degree. So the key concept of this book is to accept your problem, do not try to find the reasons of how you became ill, namely, think less about the past,then try your best to concentrate on now.
A same idea appeared in the book"self-coaching: the powerful program to beat anxiey and depression"(中文译名：《自我训练：改变焦虑和抑郁的习惯》)。
All in all, it is helpful for those distracted by emotions.