This paper revises the medical and psychoanalytical studies approaching the relationship between physical and psychiatric symptoms in the psychotic patient, with special attention to P. Marty, A. Andréoli and C. Dejours works. The authors report two patients suffering from mood disorders whose psychiatric symptoms disappeared when a pneumonia appeared. They also present two psychotic patients who has been treated for several years with description of the oscillation between psychiatric and physical symptoms. Psychiatric symptoms in psychosis permit a discharge way of the psychic excitement that provides a protective effect against somatic disorders. The effectiveness of ancient or modern psychiatric therapeutics is partially based on their body effect (like hypoglicemics in Sakel therapy, seizures in E.C.T., fever in malaria therapy, iatrogenic parkinsonism in neuroleptic treatment). Human physical illness allows body cathexis and reorganization of the psychic life.