The group of European Medical Research Councils (EMRC) was formed in 1971 and became a Standing Committee of the European Science Foundation (ESF) in 1975. EMRC is an association of medical research councils or equivalent organizations in Western Europe. The National Institutes of Health, the Israel Academy of Sciences and the European Office of WHO are associated with EMRC and take an active part in EMRC activities. The main aims of EMRC are to exchange information on the research policies pursued by its member organizations and to initiate and stimulate international cooperation in biomedical research. Since biomedical research is highly international in itself, EMRC concentrates its activities on furthering international collaboration in those fields where it can play a significant role as a complement to existing channels. Mental illness research has been judged by EMRC to fulfill these criteria. After a survey of the activities of the member organizations in mental illness research, EMRC decided in 1978 to set up a study group to look for areas within this field to which EMRC could contribute. As a result of the work of the study group, four work shops have been arranged to define present knowledge in some specific areas and to delineate research needs. The present volume contains the proceedings of the fourth workshop, held in 1985 and dealing with the course and outcome of depressive illness. EMRC hopes that this volume will stimulate intensified research and research cooperation on mental illnesses.