Cognitive Behavioral Therapy (CBT) is a form of relatively brief psychotherapy which emphasizes the importance of thoughts in affecting a person’s emotions and behaviors. A key idea in CBT is that if a person changes their thoughts they can improve their psychological state, even if they cannot change their external situation. CBT is highly structured and directive, and often involves the use of workbooks and homework assignments. CBT has been used to treat a very wide range of psychiatric and psychological disorders.