Cognitive Behavior Therapy (CBT) is a form of psychotherapy that was developed about 50 years ago as a highly effective treatment for depression. Since then, because of CBT's success in treating depression, a problem that had previously been difficult to address, it has been adapted to be used with other problems as well. CBT focuses on identifying the thoughts that lead to problem feelings and actions. Through countless research studies, sometimes referred to as clinical trials, CBT has been shown to be highly effective in the treatment of a wide range of problems. Some of these include struggles with depression and sadness, eating, excessive worry, obsessive compulsive disorders, panic, anger, social anxiety, procrastination, perfectionism, substance use, fears, and self-injury. The American Psychological Association's website provides a table summarizing the types of problems for which CBT has been found to be an effective treatment. CBT, because of its' problem-focused approach, can easily be used alone or in combination with medication or other types of "talk" therapies.