Long-term followup studies of schizophrenia: editors' introduction.

What are the major long-term followup studies of schizophrenia from around the world? What have we learned about schizophrenia and its vicissitudes over a lifetime? Does the lifelong vantage point help us to identify the primary psychopathologic components of schizophrenia and to distinguish it from other forms of mental illness? What are the implications of the longitudinal perspective for reducting heterogeneity, for transcultural comparisons, and for updating nosology? Is it time to emphasize hypothesis testing in longitudinal studies? These and other questions about schizophrenia are addressed in the Bulletin issue which focuses upon the long-term followup study, its productivity, and its promise.