First published in 1999. This book contains the thirteenth volume in the nineteen-volume series: Abnormal and Clinical Psychology - part of The International Library of Psychology. This study has moved into an examination of the influence of social environmental factors upon the postoperative course of psychosurgical patients. An appendix is included giving the status of the patients included in the first project, two years after their operation. Additional, still later, material on these cases is included in the first chapter, which brings our information up-to-date at the time of going to press.