This volume reports the proceedings of a NATO Advanced Workshop held in Castelvecchio Pas coli, Italy, from August 28 - September 1, 1989. An important inspiration for this Workshop came from our studies in Helsinki and Denmark, which have found that exposure to an influenza epidemic during the second trimester of fetal development increases the risk of adult schizophrenia. This finding has stimulated an important new hypothesis in the study of the etiology of schizophrenia. It has suggested the possiblity that disturbances of brain development during gestation may contribute to the risk of...