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 its activities. The main aims of EMRC are to exchange information on the research policies pursued by its member organizations and to initiate and stimulate inter national cooperation in biomedical research. Since this 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 of 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 analyze areas where EMRC could contribute. As a result of the work of the study group, five workshops have been arranged to define present knowledge in some specific areas and to delineate research needs. The present volume contains the proceedings of the fifth workshop, held in 1987 and dealing with interactions between mental and physical illness. EMRC hopes that this volume will contribute both to intensified research and to research cooperation on mental illnesses.