Trauma affects the mind and body immensely and prevents those affected from living in the present. Van der Kolk, who has researched trauma since the 1970s, first became interested in trauma after meeting with Vietnam veterans who had a very hard time living their lives after returning from the war. They would become very angry, numb to their regular life, and unable to leave behind traumatic moments that occurred during war time. Van der Kolk was instrumental in identifying posttraumatic stress disorder (PTSD) and creating strategies to help those afflicted by it.
Van der Kolk also realized that there are millions of people affected by trauma in their everyday lives, especially children. For example, one in five Americans were molested as children, and one in four people living in the United States has an alcoholic parent. Through work with these people, van der Kolk identified another trauma based disorder, Developmental Trauma Disorder (DTD). Van der Kolk wrote this book, in part, to argue for the inclusion of DTD in the Diagnostic and Statistical Manual of Mental Disorders (DSM VI).