What Ramani did is this book was a basic expansion of where she started in her last one. She also did a fantastic job of "dumbing down" or "spoon feeding" the psychologist terminology into the much easier to understand "Toxic". Using this, you dont get caught up in what said person is to be properly labeled. Instead, she focuses on the behavior and methods to deal with such people.
What I really appreciate in this book is her extensive talk on strategies for dealing with certain kinds of people. She also speaks at length on how to prevent raising children that become narcissistic. There are several chapters in this book that i will read to the point of near memorization.
Her previous book should be required reading for anyone thinking of marriage. This book should be required reading for all adults.