_Manic-Depressive_ psychosis is a relatively common condition in most large mental hospitals. It is so called because the same patient may have periods of excitement or depression separated by phases of apparent well-being. The stage of excitement begins with arrogance, assurance, exuberance and energy, and may superficially resemble the pleasantly boisterous drunk seen at a national convention. The patient talks rapidly, histrionically, and with a play on words called “flight of ideas” because each new phrase suggests new ideas on which the patient will embark, leaving the main thought-stream. This excitement may continue to the point where the fatigueless drive is remarkably great. This may or may not be followed by an opposite reaction. In the depressive phase patients may feel gloomy, speak slowly, and look worried. A feeling of inadequacy may lead to self-punishment and suicidal intent. The symptoms may progress to the complete inactivity known as stupor. The first manifestation of this disease is usually manic with the first depressive state years later. Attacks last about six months or longer and although they usually recur at a future date, may not. In the time between attacks the patient may appear quite normal and return to his previous activities. In the manic phase, sedatives are frequently administered. Stimulating music would only tend to increase the disturbance. If the physician prescribes music it should be of the restful type, preferably a selection which will attract the patient’s attention by its familiarity. In the depressive phase, patients should not hear cheerful and gay music. Entertainment often deepens the depressive state because of the contrast, and the awareness of their own problem, which prevents enjoyment. _Schizophrenia_ literally means splitting of the mind. It is a group of conditions in which the usual harmonious blending of emotions, intellect, and drive are disorganized into a seeming inactivity and resultant apathy. In the _simple_ type the patient becomes uninterested in his environment and responsibilities. This result is seen in the vagrant and the delinquent. In the type known as _catatonic_ there are phases of excitement or stupor. In the stuporous state the attitude of the patient resembles that of an automaton. In this state it is difficult to make any contact with the patient who refuses to co-operate or even move. Catatonic excitement sometimes follows the stupor and is evidenced by the same purposeless absence of emotion, but may include unexpected acts of destructiveness. There is another type called _paranoid_ in which the patient develops false beliefs of persecution, and a hebephrenic type in which the patient becomes even more inaccessible and inattentive. Schizophrenia, once thought incurable, is now considered amenable to treatment and about one fourth of the stricken recover completely after the first attack.