[Continuing Education Course of the Swiss Society for Psychiatry. Biological aspects of psychiatry. Introduction].

The author traces the prestigious history of the Burghölzli, cradle of Swiss psychiatry. He also describes the outstanding role played by Zurich as the city in which integration took place between the developing psychiatry, psycho-analysis, psychodynamics and biological research. The author shows how psychiatry, which had been faced with the mechanistric and philosophical dilemma of an epoch, could disengage from the dangers of a reductive approach thanks to Freud's influence, as well as the knowledge produced by biological and psychopathological discoveries. A new equilibration was, thus, found and a multidimensional model came into being. Today psychiatrists may choose to become either clinicians, or psychoanalysts, or devote themselves to research. Contract has become essential as well as the recognition of these different domains, this in order to improve the understanding of mental disorder.