Cognitive Behavioral Therapy (CBT) is now being applied not only to depression and anxiety disorders but also to a wide range of psychiatric disorders. In Japan, in 2010, cognitive therapy and cognitive behavioral therapy, which are implemented by skilled physicians based on manuals for mood disorders, became eligible for medical reimbursement. Furthermore, in 2016, the scope was expanded to include anxiety disorders such as obsessive–compulsive disorder, social anxiety disorder, panic disorder, and post-traumatic stress disorder. In the United States, psychotherapy became mandatory during resident training in 2001, and subsequent revisions identified three specific types of psychotherapy: supportive psychotherapy, psychodynamic psychotherapy, and cognitive behavioral therapy. Today, CBT is not just a therapeutic approach one should be familiar with; it has become a practice that requires the ability to implement or appropriately refer alongside pharmacotherapy.