Mastering the literature on anxiety disorders is a truly Herculean endeavor, thanks to the explosive growth of the field since the 1980s. Few scholars possess the intellectual range to tackle such a task. David Barlow is one of them. A clinical psychologist who has made important contributions to descriptive psychopathology, experimental psychopathology, and the development and evaluation of cognitive-behavioral treatments of anxiety disorders, Barlow is unusually qualified—perhaps uniquely qualified—to write the definitive book on this topic.

The second edition of Anxiety and Its Disorders is not merely an updating of the original edition, published in 1988; it is an entirely new book. It consists of two main parts. The first comprises eight chapters that present Barlow’s theoretical views on fear, panic, and anxiety, cast within the context of emotion theory. The second part comprises seven chapters, each co-written with another author, usually one of Barlow’s Boston University colleagues. In addition to a chapter on diagnostic classification, each covers one of the anxiety disorders. Theoretical themes developed in the first part are continued in the second part, and Barlow’s "voice" is evident throughout. The influence of co-authors is most apparent in the issues emphasized. For example, the chapter on posttraumatic stress disorder concentrates on assessment, the specialty of coauthor Terence M. Keane.

Barlow was wise to invite others to join him in writing the second part of this book. Had he undertaken the entire project alone, it would have taken him so many years merely to finish a first draft that he would have had to start all over again on completing it. Such is the ever-changing nature of our vast and complex field.

The strength of the book is attributable to Barlow’s breadth of vision and his latitudinarian intellectual style. He is refreshingly free of the parochial guild biases that so often cramp theorizing in psychology and psychiatry. He draws on an astonishing range of disciplines. His thinking is informed by research in not only clinical psychology but also cognitive psychology, neuroscience, psychiatric anthropology, psychophysiology, genetics, psychopharmacology, and ethology.

Occasionally, however, I experienced difficulty grasping some of his conceptual points. For example, I am not sure what he means when he characterizes anxiety "as a unique, coherent cognitive-affective structure" (p. 64), or when he says that stressful life events "trigger specific emotional action tendencies stored deep in memory" if they "present a sufficient number of response, stimulus, and meaning propositions" (p. 232). Otherwise, Barlow’s prose is seldom obscure.

Anxiety and Its Disorders is a magisterial work of scrupulous scholarship. A lucidly written, learned treatise of panoramic scope, it is the most comprehensive book ever written on the topic of anxiety disorders. It will be essential reading for students, researchers, and clinicians in the field of mental health for many years to come.