[Contribution of epidemiology to etiological research in psychiatry: from risk factors to risk mechanisms].

Over the last 25 years, the burgeoning of psychiatric epidemiology has generated a considerable knowledge base on the prevalence and incidence of psychiatric disorders. For most disorders, risk factor research has also led to the identification of vulnerability factors in the genetic, biological, psychological and social arenas. However, the delineation of psychopathological mechanisms requires a better understanding of the developmental connexions and sequences of intervention of the postulated risk factors. Similarly, psychopathological models should benefit from the study of protective influences and processes. The importance of longitudinal approaches to the study of causation in psychopathology is emphasized. While future research endeavors need to be theory-driven and to rely on more sophisticated measurement strategies, etiological research in psychiatry will continue to benefit from the range of research methods provided by epidemiology.