ASSOCIATED with the Massachusetts Department of Mental Health is an ' agency designated to investigate certain deaths occurring in psychiatric hospitals. In the last 11 years eight deaths incident to insulin coma or subcoma therapy have been reviewed: four in state hospitals, two in private institutions, one in a veterans hospital, and one following treatment in a patient's home.Numerous fatal insulin reactions have been reported.1 Most of the clinical papers have been concerned with the events of the final coma. Little attention has been paid to factors, other than overt organic diseases, which give warning of an untoward reaction. Certain clinical features and aberrant physiological responses occurring prior to the fatal reaction, and of possible value in prognosticating it, are presented in this report.Case 1.\p=m-\Awhite man aged 47, with a diagnosis of schizophrenia, paranoid type, was treated with insulin coma. On the 63d treatment, 28th coma, he had an apparently normal coma, with a dose of 360 units of insulin. Five minutes before termination ivas scheduled, he suddenly became pulseless and apneic and died immediately.The patient had had influenza in 1918 and otitis media in 1944, with permanent bilateral hearing loss. The psychiatric history revealed neurotic and schizoid traits from early childhood.The psychosis developed insidiously in 1947. In January, 1948, he was admitted to a psychi¬ atric hospital, where a diagnosis of schizophrenia, paranoid type, was made. The patient was well nourished and presented no abnormalities on physical examination. A cardiologist reported no heart disease, and the blood pressure, pulse, and electrocardiogram were recorded as normal.Shortly after his admission, electroshock therapy was instituted, and tubocurarine was used. During the fifth shock, with 3.5 cc. of tubocurarine chloride, he had dyspnea, cyanosis, and then respiratory arrest. When artificial respiration and oxygen were administered, respiration and color improved. For the next hour he showed generalized tremor, signs of atelectasis at the base of the right lung, and a shaking chill. An hour later he had apparently recovered. Electroshock therapy was continued without curare for a total of 22 treatments. No other unfavorable reactions occurred.Senior Physician,