A number of examples have suggested that new treatment modalities are cost-effective. These disorders usually have less severe and debilitating symptoms than other (for example, psychotic) mental disorders, and this chapter deliberately excludes more severe cases of mental disorders, including the more severe cases of common disorders such as depression and anxiety. Severity of the disorder is determined by the number of and severity of symptoms, the degree of functional impairment, and the duration of symptoms. Mild-to-moderate disorders impede the health, daily functioning, and quality of life of affected individuals, and require appropriate diagnosis, treatment and care.