H. HAFNER Schizophrenia Research Unit, Central Institute of Mental Health, Mannheim, Germany The present volume contains the lectures and invited discussions of the sympo sium on "Risk and protective factors in schizophrenia - towards a conceptual model of the disease process", which was held at the International Science Forum of the University of Heidelberg from October 25 to 27, 200l. They are supple mented by a "Summary and outlook", in which Peter Jones gives a brief overview of the results and perspectives featured in the presentations and discussions. The contributions and discussions reflect the open-minded and creative atmosphere at the meeting. The systematically structured program of the symposium continued the tradition of the Search for the Causes of Schizophrenia symposia, which were th started in 1986 on the occasion of the 600 anniversary of the University of Hei delberg and which are co-organized with Prof. Wagner Farid Gattaz/Sao Paulo. The aim of these symposia and their proceedings volumes [6,8-10] has been to reflect the state of the art in schizophrenia research at their time, and they have successfully done so. In contrast, the present symposium pursued a more lim ited objective and was of a different type. It brought together, around a large table at the International Science Forum in Heidelberg, 22 invited speakers and dis cussants and an equal number of young scientists working in the research fields in question, who were thus given an opportunity to listen and to participate.