In the eight years since the publication of the second edition of this Guide, psycho phannacotherapy has made many advances not only through the discovery of new medications but by the effective directing of their use to an ever-increasing variety of clinical disorders. These welcome developments are reflected in the concurrent growth and development of the Guide itself, which now enters adulthood with renewed vigor. Under the thoughtful and scholarly leadership of Dr. Alan Gelenberg, the third edition has undergone a significant transformation designed to meet the needs of the modem clinician. The panel of contributors is nearly double that of the former edition with the addition of nine new authors, who have helped in the major revision and rewriting of the text and in a broadening of the topics included. As a conse quence, the reader is assured of a thorough and thoroughly up-to-date coverage of current psychopharmacology that is both accurate and aimed at clinical utility. Having reached maturity, the third edition, while maintaining the lineaments of its earlier versions, is a considerably expanded and strengthened guide to treatment. Although now more encyclopedic in content, the new Practitioner' s Guide to Psy choactive Drugs retains the virtues of a clinical vade mecum that informed its predecessors and have eamed it a place by the patient's bedside for weIl over a decade. One may confidently anticipate its long and flourishing career in the years ahead. John C. Nemiah, M.D.