Suicide in mental hospitals has been studied by tabulation of various factors as well as by analysis of individual case histories in 18 patients who committed suicide at the Eloise Hospital from 1929 through 1941.The statistical approach, although of limited value because of the small number of cases, indicates the need for considering schizophrenics, particularly catatonics and paranoids, as potential suicides, as well as the more generally recognized manic-depressive and involutional patients.Suicide in a mental hospital is found to maintain the same age distribution and seasonal incidence as suicide in the general population. The suicidal attempt is more likely to be successful when it occurs in the early morning hours.Far more fruitful is a study of the individual case histories. A large majority of these patients revealed definite warning signals of the suicidal act, either by a previous attempt or through their overt behavior or verbal productions in the form of irritability, combativeness, death wishes, hypochondriacal trends or feelings of guilt. It is felt that these could have been recognized as such if full awareness of their significance had existed. Sudden, unexplained improvement in agitated patients is also to be looked upon with suspicion. Apparently trivial frustrations may also precipitate the suicidal attempt.The physical setting of the suicidal act was reviewed and several factors of importance from the point of view of hospital planning, management and routine were considered. These included the questions of window guards, surface projections, locking of mop rooms, toilet rooms and other utility rooms, as well as the prevention of plunging from heights.Specific problems in the management of suicidal patients were discussed in the light of clinical experience. The importance of ward and occupational activities designed to meet the psychological needs of the patient was emphasized. The value of convulsive shock therapy as one means of meeting the sense of need for punishment was mentioned as a possible explanation for the improvement it produces in depressed patients.Abstract Teaser