We asked David A. Clark to send us a description of the excellent, state-of-the-art new book on anxiety he co-authored with Aaron Beck, along with some behind-the-scenes history. Here’s what he wrote: Cognitive Therapy of Anxiety Disorders: Science and Practice (Clark & Beck, 2010, from Guilford Press, pp. 628) represents the outgrowth of my 26 year journey of inquiry, discovery and acquired knowledge on the cognitive basis of the emotional disorders. It has been an honor and privilege to collaborate with Aaron T. Beck on many different projects over the years. He has been the mentor who contributed enormously to what I know about psychological problems like anxiety and depression, and who taught me most about the importance of adopting an integrative, scientific perspective in which theory, research and practice are mutually informed by each other. There is, however, an ironic twist to Cognitive Therapy of Anxiety Disorders. My introduction to Dr. Beck occurred in 1983 while I was a doctoral student at the Institute of Psychiatry, London, England. I gave my first conference paper at the annual meeting of the British Association of Behavioural and Cognitive Psychotherapy in Hull, England. It was on the two hour train ride escorting Dr. Beck back to London that I had my first private conversation with the founder of cognitive therapy. Coincidentally during that train ride Dr. Beck spent much of his time writing in a notebook on what later turned out to be an innovative extension of cognitive therapy to the anxiety disorders. This work subsequently appeared in Anxiety Disorders and Phobias: A Cognitive Perspective (Beck & Emery, 1985; Basic Books). Never in my wildest dreams could I have imagined that 26 years later we would collaborate on a major refinement and reformulation of the very work that was taking shape as we whizzed through the English countryside so many years ago. Cognitive Therapy of Anxiety Disorders is the result of four years of a painstaking review, evaluation and synthesis of the enormous research and clinical literature on the cognitive basis of anxiety. There has been a paradigmatic shift in how we understand and treat the anxiety disorders since the original formulation of the cognitive model in 1985. We felt it was timely to update and refine Beck’s cognitive model in light of substantial advances that have been made on the cognitive basis of anxiety over the last two decades. Thus the first four chapters lay out a reformulated cognitive model of anxiety and critically review empirical support for 12 key hypotheses of the model. Hundreds of research studies are included in this review and future directions for cognitive research are identified. Consistent with past major publications on cognitive therapy, Cognitive Therapy of Anxiety Disorders presents the treatment as a theory-driven, empirically based system of psychotherapy. Consequently the second part of the book provides a detailed explanation of cognitive assessment, case formulation, and intervention strategies that are based on the reformulated cognitive model outlined in the first part of the book. A step-by-step description of the cognitive approach is provided along with dozens of clinical resources such as rating scales, checklists, structured diaries, etc. Our intention was to provide a thorough, systematic, and practical description of cognitive assessment, formulation and treatment strategies for anxiety that could be utilized by even a novice to cognitive therapy. The final five chapters are really mini treatment manuals for the five most prominent anxiety disorders; panic disorder, social phobia, GAD, OCD, and PTSD. Each chapter focuses on a specific disorder and begins with a brief review of diagnostic features and phenomenological research. This is followed by presentation of a disorder-specific application of the reformulated cognitive model to each disorder as well as a review of the key hypotheses derived from this model. The second half of each chapter presents a step-by-step explanation of a disorder-specific cognitive assessment and treatment protocol for the anxiety disorder discussed in that chapter. Each chapter ends with a brief review of the efficacy of cognitive therapy and suggestions for future directions. The enormous advances made in the last 26 years on the cognitive basis of anxiety are the result of many brilliant and talented researchers from around the world. Cognitive Therapy of Anxiety Disorders is our attempt to provide a comprehensive, in-depth evaluation, synthesis and integration of this work from the vantage point of Beck’s original insights into the problem of anxiety. It is hoped that this publication will provide a framework for future theory and research on anxiety as well as providing practitioners with the latest clinical tools that will enhance cognitive treatment of anxiety disorders.