The following paper is concerned with the statistical analysis of the clinical data about nearly 500 schizophrenic patients. About half of these received insulin treatment, while the others did not. The patients were followed up for periods of between 5 and 10 years, so that the material is also classifiable by good and bad outcome. A full account of this clinical material, collected and studied at the University Psychiatric Clinic at Lisbon by one of us (P.P.), has already been published in the Portuguese language (Polonio, 1950).