This document provides an overview of cognitive behavioral therapy (CBT). It explains that CBT was developed in the 1960s by Aaron Beck and is based on the theory that thoughts, feelings, and behaviors are interconnected, and that by modifying dysfunctional thoughts people can experience improvements in their emotional state and behaviors. The document outlines the basic principles of CBT, including that it is a semi-structured, time-limited, collaborative approach focused on skill development and cognitive change through techniques like identifying and modifying thoughts and beliefs. Research evidence demonstrates CBT is an effective treatment for a wide range of mental health and medical conditions.