Book excerpt: Behavioral Science in Medicine introduces medical students to the science of human behavior. Organized to mirror the behavioral science/psychiatry course taught in the first two years, this text effectively teaches the major concepts of this complex subject and prepares students for board exams. The Second Edition is appropriate for courses in Behavioral Science alone but also for courses that merge Behavioral Science and Neuroscience. The increased depth of coverage of psychiatric illness, substance abuse, and pediatric psychiatry, also makes the Second Edition appropriate for use in Clinical Psychiatry courses in the third and fourth year.