This chapter examines Cognitive Behavioral Therapy (CBT) in the treatment of depression. Psychotherapy has an important place in the treatment of depression, and the most commonly used therapy school is CBT. For people with mild or moderate depression, CBT may be recommended as a first-line treatment. Patients with severe depression may benefit from a combination of CBT and pharmacotherapy. CBT provides patients with skills such as identifying distorted thoughts, changing beliefs, establishing new relationships with the environment, and changing behavior, which they can use to solve their problems throughout their lives.