This book comprises the conferences and discussions presented at the 4th sym­ posium on the SEARCH FOR THE CAUSES OF SCHIZOPHRENIA, which took place in Guaruja, Brazil, November 1998. This series of symposia started in 1986, on the occasion of the 600th anniversary of the University of Heidelberg, followed by two others in 1989 and 1993. From these meeting resulted three volumes that have been widely used as a reference for comprehensive reviews on the state of the art in schizophrenia research. They reflect the progresses result­ ing from the most relevant studies on the etiology of the disease. The spirit of the 4th "Search for the Causes" remains the same: again we gathered some of the most prominent researchers on schizophrenia to contrib­ ute not only with their own data, but also summing up the state of the art and the perspectives in their areas of work. The topics covered in 6 parts are Epide­ miology, Risk factors and antecedents, Genetics, Neuropathology and neuro­ chemistry, Brain imaging and function, and Treatment and rehabilitation. In this 4th volume were introduced in each topic a chapter on the "Balance of the Cen­ tury", to summarize what did we learn (and what we did not) in the last 100 years of schizophrenia research. We hope that this volume can help us to see how far we are in the Search for the Causes of Schizophrenia and how much further we still have to go before our problem can be solved.