When this series was conceived, a book on substance abuse, including alcohol and alcoholism, was to be of the highest priority. This priority was a reflection of my view that the subject is often inadequately or insufficient ly taught in many training programs. Few clinicians have had comprehen sive didactic education in this area, despite the frequency with which these problems are encountered in practice. All too often these encounters are in situations in which accurate diagnosis and rapid treatment are of critical im portance. We wanted a book that would be concise and easily readable but also comprehensive in its presentation of the basic principles underlying clinical manifestations, diagnosis, and management. It was of particular im portance that the book also serve as an easy reference guide in emergency situations. Marc Schuckit, a man with impeccable credentials as a scholar and an experienced clinician in this field, produced just such a book with his critically acclaimed first edition. That volume rapidly became a resource of great significance for psychiatrists, psychotherapists, and physicians in general. It has been adopted as a text in medical schools and residency train ing, as well as for courses in psychology, emergency medicine, social work, and nursing. The entire volume has been revised and updated to reflect changes in knowledge and clinical practice since the publication of the first edition and in order to keep the comprehensive references current. There is a new chapter on phencyclidine and another on caffeine and nicotine.