Cognitive behavioral therapy (CBT) is a form of psychological treatment that has been demonstrated to be effective for a range of problems including depression, anxiety disorders, alcohol and drug use problems, marital problems, eating disorders, and severe mental illness. Aaron Beck`s cognitive theory considers the subjective symptoms such as a negative view of self, world, and future defining features of depression. The model assumes that psychopathological states represent extreme or excessive forms of normal cognitive, emotional, and behavioral functioning. Additionally, the cognitive theory posits that anxiety and depression can be distinguished by their cognitive content, with thoughts of personal loss and failure specific to depression and cognitive content involving physical or psychological threat and danger specific to anxiety.