Behavioral health care professionals call disorders, illnesses or diseases that have prominent emotional, behavioral, and psychological symptoms mental disorders. These include substance use disorders and disorders associated with physical changes or illnesses, many of which directly affect the brain. For most of these disorders, however, physical causes have not been demonstrated or are poorly understood, even though biological treatments (e.g. drugs) may be effective in treating them. They may be distinguished from and classified separately from the personality disorders, or the term may be used in such a way as to include personality disorders.
Terms for specific mental disorders include those officially recognized by the American Psychiatric Association as well as other more traditional terms. They are formally classified in the APA DSM IV-TR: DSM-IV-TR Diagnoses by Category.