"In connection with a study of behavior changes following long continued use of chlorpromazine with chronic psychotic patients, the Porteus Maze Test was applied to 13 males who were accessible to testing and whose scores showed any significance. Analysis of post-medication results for the whole group of 22 cases revealed an average Maze Test deficit of 2.06 years, affecting over 68% of patients. This evidence that chlorpromazine acts as "a pharmacologicallobotomy"is summarized by means of a review of all important psychosurgical studies in which the Porteus Maze was used, and the deficits found are compared with those now demonstrated to follow prolonged chlorpromazine medication.".