This book covers the idea proposed by Engel of a Biopshicossocial model for mental health. Its a good source for a quick review of the main thoughts in the Biological, social and posychological models of mind. Each chapter is well written, with up to date references (although it's almost impossible to keep track of all the developments on each field.) The flagrant exception is when it comes to object relations theory (psychoanalysis). Bion is one of the most influential thinkers of this theory today but he isn't even mentioned.
But the big let down is the author's use and understanding of Engel's model. What Dilts basically say is that depending on the patient's problem, you can shift though theories. If X suffers from anxiety, you use psychoanalytical thinking or CBT. If hes unemployed, you think of X using a social theory, etc. In my mind, what Engel proposed is not this at all, he proposed a theory based on the general theory of the systems which means you have to use the 3 perspectives at the same time. Nothing is just biological or social or in the mind. It's all a system that work together. And so, you can't just pick the bits you like and forget the rest. To me, this is the big let down of this book. If you want to know more about the integration aspects and mind-body-environment you have to think "psychossomatic medicine", "alexithimia" and "auto-regulation" and read the work of authors like Schore, Derryberry and Rothbart, Kramer, etc.
We really need a new paradigm in medicine and psychology, but shifting though the existing ones isn't going to help to make that leap. So 4 stars for the nice review of theories in the 3 fields, but fails Engel's point by miles.