Recent investigations on carbohydrate metabolism for use in diagnosis of endocrinopathies1 have provoked interest in their possible application to the problem of schizophrenia. Horvath and Friedman2 reported that after the intravenous administration of insulin schizophrenic patients showed a delay in the hypoglycemic effect and the subsequent recovery as compared with normal subjects. Meduna, Gerty and Urse3 found an anti-insulin factor to be present in the blood of schizophrenic patients which was specific for that psychosis. Gellhorn, Feldman and Allen4 using the hypophysectomized-adrenomedullated rat as an assay object, obtained results somewhat contrary to those noted by these authors. The latter stated that there was no difference in the insulin content of the blood of normal and of psychotic subjects, in a quiet state. Under the stress of excitement, however, the blood insulin of psychotic (including schizophrenic) patients so increased as to have a hypoglycemic effect, a phenomenon