THE 100-YEAR EPIDEMIOLOGY OF SCHIZOPHRENIA

Since Kraepelin delineated dementia praecox as a disease entity constr uct, epidemiological studies conducted since the beginning of the cent ury have produced remarkably consistent estimates of its prevalence, i ncidence and lifetime risk across various populations and geographic a reas. A similar pattern emerged from the WHO ten-country study on firs t-contact incidence of schizophrenia. The diagnostic concept of dement ia praecox originally used by Kraepelin and that of schizophrenia empl oyed in the WHO studies were found to overlap extensively, indicating continuity over time. However, the findings of a similar incidence of schizophrenia in diverse populations and across time periods are unusu al for a multifactorial disease and are compatible with at least two a lternative interpretations that have different implications for the se arch for genetic and environmental causes of the disorder. (C) 1997 El sevier Science B.V.