The Section of Research Psychiatry at Sloan-Kettering Institute and the Neuropsychiatric Service at Memorial Hospital have conducted studies of patients who have undergone abdominoperineal resection,9radical mastectomy,2total gastrectomy, or hysterectomy,5to identify the psychological problems associated with cancer and specific surgical procedures. The major purposes of these investigations were to determine the measures which could be employed (1) to reduce the incidence and severity of postoperative hypochondriasis with associated curtailment of activity, and (2) to provide a rationale for the establishment of a rehabilitation program for patients with cancer. During the course of research with the above objectives the development of major psychiatric disorders other than hypochondriacal reactions has been observed. Depressive and paranoid reactions have been observed where there was no evidence of their prior occurrence in such form. This development does not imply, however, that the potential for psychopathology was not present, or even