Generalized anxiety disorder (GAD) is characterized by excessive anxiety and worry about everyday concerns such as work, family, relationships, finances, health, and safety. The worry is difficult to control; it lasts months and years rather than hours or days, and is accompanied by a variety of additional symptoms including restlessness, irritability, fatigue, muscle tension, and difficulties concentrating and sleeping. The worry and anxiety in GAD is distressing and disabling. People who worry in a maladaptive way benefit from good, proactive treatment. That is the focus of this book. It begins by tracing the history of GAD. It then looks at the effectiveness of pharmacological and psychological treatments, favoring the latter. In Chapter 4, contemporary models of GAD are listed and new developments in cognitive behavior therapy (CBT) are explored. This chapter may be particularly applicable to the difficult-to-get-better patient. A clinician’s guide to treatment is then presented which covers assessment, formulation, and the beneficial and problematic steps in CBT. Finally, there is a patient treatment manual that can be used as a curriculum for individual or group therapy, or it can be copied and provided to patients to work though on their own.