Anxiety has proven a challenging and rewarding field of inquiry, one that begins with normal anxiety. Normal anxiety signals danger and readies the individual for action. While psychologists have explored the mechanisms of this adaptive response, philosophers and theologians have sought to give it meaning and to offer guidance for dealing with it. The biology of anxiety is complex and includes arousal with its physiological changes, learning and the acquisition of skills for dealing with dangerous situations, as well as cognitive elaborations. Recently, our understanding of the biology has been enriched by animal models that have permitted study of stress-related changes in the nervous system. Also, new pharmacological probes and imaging techniques have opened windows to the human brain.

Anxiety disorders represent deviations from the normal. Although these disorders can be explained in psychological terms, they are rooted in distinct nervous system abnormalities that distort the normal response. Thus, the exploration of psychological and biological differences between normal and pathological anxiety encompasses most areas of human knowledge.

The idea for this book on anxiety and its disorders originated with George Winokur, MD, who envisioned a series of volumes based on the medical model. For this champion of data-based psychiatry, psychiatric illnesses are like other medical conditions. They have distinctive clinical features and are separable from other disorders on the basis of characteristic epidemiological factors, biological abnormalities, family and genetic features, course and outcome, and response to treatment. This book examines the anxiety disorders within the framework of this model. Chapters dealing with individual disorders contain information about definition, epidemiology, etiology and pathogenesis, clinical picture, natural history, differential diagnosis, and treatment.