The Clinical Handbook of Fear and Anxiety is a comprehensive guide to the understanding and treatment of clinical anxiety and related disorders. As the editors demonstrate, the clear delineations implied by DSM and ICD diagnoses are illusory when it comes to real-life clinical anxiety. This is because symptoms are shared among different diagnoses, meaning that the same patient can be diagnosed in a variety of ways--leading clinicians to recommend different treatments that can have radically different outcomes. This volume therefore offers a shift in perspective. Chapters in Part I highlight the key psychological processes (e.g., intolerance of uncertainty, threat overestimation) that maintain clinical anxiety. Then in Part II, contributors examine empirically supported mechanisms of change (e.g., exposure, cognitive restructuring, acceptance) that are effective across a range of anxiety presentations and are found in a variety of effective treatments. The editors' transdiagnostic approach helps clinicians connect theory with the practical realities of mental health treatment.