Chronic and persistent pain, which is a problem for the individual who suffers and the society that has to deal with it, has become increasingly appreciated. Over the last three decades, several books and journals have been specifically devoted to the topic of pain, especially chronic and persistent pain. It has been increasingly recognized that chronic and persistent pain, unlike acute pain, involves significant psychosocial factors and requires treatment strategies that deal with these issues. All measurements and factors that affect improvement seem to be in the psychosocial area rather than the medical/ biological/physical areas. Psychosocial conveys the importance of the environmental and interpersonal factors of the patient's functioning. The writing of this book has brought together some of the leading researchers and clinicians in the area of managing the patient with chronic pain. The authors express their opinions based on experience and review of the literature available to date. Each of the chapters focuses on an important element of the assessment and/or treatment intervention utilized for the individual with chronic pain. The concluding chapter summarizes the status of the assessment and treatment strategies for those patients.