treatment for serious mental disorders in which prolonged periods of coma are induced by heavy doses of insulin.The technique was developed by the Austrian psychiatrist, Manfred Sakel, after he had observed that insulin relieved the manic symptoms of morphine patients during the withdrawal period. He then tried the treatment with excited schizophrenics and discovered that the best results could be obtained when the dosage was large enough to induce a deep coma.Sakel’s original method is still occasionally used today. It is based on the fact that the principal fuel of the brain is a carbohydrate, glucose, and not fat or protein—and insulin reduces the glucose content of the blood, thus depriving the brain of needed fuel. When the doses are large enough, brain cell oxidation decreases to a point where coma takes place.Sakel discovered that the higher brain centers are affected by hypoglycemia (low blood sugar) before the lower centers. He used this knowledge to establish five stages of insulin coma, and regulated the doses accordingly. The technique, however, requires an exhaustive series of psychiatric, physical, and neurological examinations before it can be undertaken, and, constant medical supervision and vigilant nursing are necessary during the treatment and for twenty-four hours afterward in order to avoid “after-shock.” It is contraindicated where there is active infection, diabetes, serious heart, liver, or kidney disease, and in ages below sixteen and above forty-five.Various techniques have been developed for administering insulin, and specialists differ about the optimum depth,length, and frequency of comas. In general, insulin is injected intramuscularly in the morning before food is taken, and several hours later the patient becomes increasingly weak, hungry, and drowsy. As somnolence deepens he goes into a typical shock state with muscular spasms, body tremors, heavy breathing, and mumbling. This is followed by a deep coma. Some therapists use a variation known as “subshock,” in which small amounts of insulin are injected and the reaction stops short of coma. This technique is used particularly to quiet anxious or excitable patients, but not for schizophrenia. In severe cases, convulsions are sometimes induced, although extra precautions must be taken. Methods of terminating the coma also vary, but in all cases glucose is used and usually has a rapid effect. The patient is then given a meal rich in carbohydrates. With most patients the treatment is administered five or six times a week for a total of thirty to fifty coma hours.Insulin shock is limited to cases of schizophrenia and shows best results during the first year of the illness. The prognosis is most favorable when the patient is in his twenties and has shown a relatively stable pre-illness personality, and when the onset of the illness was sudden and acute. It is least favorable in cases of meager personality resources, ingrained schizoid personality, and insidious onset below the age of fifteen or above the age of forty. Paranoid and catatonic patients, and those with affective (emotional) overtones respond considerably better than simple and hebephrenic types. However, the remission rate is rarely higher than 40 to 50 per cent, and often less, and the rate of recurrence tends to be high (Kalinowsky and Hoch, 1961).Insulin shock therapy has been almost completely replaced by psychoactive drugs and electroshock therapy, since they produce a higher rate of improvement and more lasting results, are less time-consuming, and involve far less danger to the patient. Some psychiatrists, however, resort to it when drug or electroshock treatments fail. It may also be used in combination with electroshock for schizophrenic patients who do not improve or who show insufficient improvement under insulin or electroshock alone, and for patients who are overactive, assaultive, aggressive, suicidal, or in a stuporous state. The two methods may also be alternated. English and Finch (1964) sum up the present status of insulin therapy in these words: “While great results were expected from its use, it gradually became evident that this type of treatment did not produce any lasting beneficial results and its use has been almost entirely discontinued.”