Each of the adult anxiety disorders (panic disorder, generalized anxiety disorder, social anxiety disorder, specific phobias, obsessive-compulsive disorder and posttraumatic stress disorder) is presented in a separate chapter of this volume. As the rich description of each disorder is a prerequisite for their recognition, understanding and diagnosis, the book focuses on clinical features, psychopathology and the corresponding conceptual issues. There is also an emphasis of etiological factors, pathogenic processes, and pharmacological and psychological treatments of each anxiety disorder, as adequate treatment depends crucially on the clinician's understanding of the origins of these conditions and the processes involved in their occurrence. The volume is guided by a practical need to present the anxiety disorders as they occur and as they are treated in the "real world." As such, this work is intended to be a state-of-the-art reference for clinical practice, aiming to balance and integrate what is currently known about anxiety disorders and their treatment. It contains descriptions of the relevant diagnostic and therapeutic procedures, practical tips, and treatment recommendations for the commonly encountered clinical situations.