Cognitive behavioral therapy (CBT) was developed in the 1960s by Aaron Beck based on his research challenging the psychoanalytic view of depression. Beck observed that depressed clients had negative biases in interpreting events that contributed to cognitive distortions. He developed CBT which focuses on identifying and modifying dysfunctional thoughts and beliefs. The key assumptions of CBT are that cognitions influence behaviors and emotions, and that maladaptive thinking can be identified and changed. Common techniques include cognitive restructuring to challenge irrational thoughts, behavioral experiments, and homework assignments.