Anorexia Nervosa is an enigmatic and, too commonly, an extremely challenging disorder. Its core clinical features have been recognized for centuries, and the label anorexia nervosa was coined in the 19th century. Over the many ensuing years, the disorder has been examined from a wide variety of perspectives, ranging from psychoanalytic to genetic. While potential risk factors have been identified, features clarified and complications appreciated, a full understanding and universally effective methods of treatment remain elusive. The current volume does not attempt to review the long history of research on anorexia nervosa. Rather, leaders in the field describe fresh approaches and new directions. This volume is a very forward-looking examination of novel ideas and new approaches to the understanding of an old, extremely persistent and enigmatic mental disorder. The approaches described will hopefully form a foundation for significant advances in the years ahead.