This book contains the papers from invited lecturers as well as selected contributions presented at the 6th International Meeting on Clinical Pharmacology in Psychiatry (I.M.C.P.P.) held in Geneva, Switzerland, 5-7 June 1991. At this meeting the basic theme of the previous meetings in this series (Chicago 1979, Troms0 1980, Odense 1982, Bethesda 1985, Troms0 1988) was continued, namely, to bridge the gap between experimental development and clinical reality in psychopharmacology. After more than 25 years of intensive research in biological psychiatry, basic understanding of the biological mechanisms underlying major psychiatric diseases has advanced significantly but is still far from complete. Likewise, the hypotheses underlying the development of new psychotropics have been refined and produced a wide spectrum of novel, yet designed compounds. The crucial condition for all progress in this field is reliable, informative clinical testing of new compounds. It is our hope that this book, as a continuation of the earlier publications in this series, provides further evidence of the ongoing interaction between preclinical and clinical scientists, who only together can assure progress in this exciting area of research and clinical practice.