1. A mental and behavioral disorder causing gross distortion or the disorganization of a person's mental capacity, affective response, and capacity to recognize reality, communicate, and relate to others to the degree of interfering with the person's capacity to cope with the ordinary demands of everyday life.

• Those associated with organic brain syndromes; such as, Korsakoff's syndrome.
• Those less strictly organic and having some functional component(s); for example, the schizophrenias, and bipolar disorders.

2. Generic term for any of the so-called insanities, the most common forms being the schizophrenias: "Melvin's doctor determined that he had a psychosis that consisted of a mental disorder in which he has a loss of contact with reality as well as personality disintegrations or the disorganizations of his psychic and behavioral mental processes."
3. A severe emotional and behavioral disorder: "The doctor told Derek's wife that her husband had a psychosis that includes a loss of reality contact, unlike a neurotic disorder in which reality contact is retained."

A term sometimes used to describe an acute episode or gross stress reaction in a hysterical personality, usually manifested by sudden, bizarre, histrionic, violent, and volatile behavior.

Mental disorders which may be associated with becoming old: The psychoses of senility often involves the inability to deal with social situations or consists of behavioral disorders.

More severe psychosis of senilities may include confusion, memory failure, disorientation, restlessness, and speech disturbances.

A psychiatric disorder that may affect women in the first two weeks after giving birth. It may be depressive or schizophrenic and may involve false ideas concerning the baby.