A Manic Depressive Psychotic with a Persistent Forty-eight Hour Cycle

Richter (1960) reviewing knowledge about biological “clocks” in medicine and psychiatry, emphasized the incidence of 48-hour cycles of physical and mental symptoms. He considers that the mental symptoms are not specific and can be manic depressive or schizophrenic. Menninger-Lerchenthal (1960), in his book on periodicity in psychopathology, devoted a section to 48-hour rhythms and lists references to 48-hour cycles in the literature.