Cognitive therapy is a system of psychotherapy with a powerful theoretical infrastructure, which has received extensive empirical support, and a large body of research attesting to its efficacy for a wide range of psychiatric and medical problems. This article provides a brief overview of the conceptual and practical components of cognitive therapy and highlights some of the empirical evidence regarding its efficacy. Cognitive therapy (often labeled generically as cognitive behavior therapy) is efficacious either alone or as an adjunct to medication and provides a prophylaxis against relapse and recurrence.