[Emil Kraepelin and bipolar disorder: invention or over-extension?].

From 1899 to 1913, Emil Kraepelin (1856-1926) creates and elaborates the nosographical group of the "manic-depressive insanity". In the 50-60s, Leonhard splits off this homogeneous group and describes unipolar psychosis, bipolar psychosis and cycloïd psychosis (anxiety-elation psychosis, motility psychosis and confusion psychosis). Recent nosographical orientations seem to announce a come-back to Kraepelin's conception of "mood disorders". This paper presents the essential of Kraepelin's "manic-depressive insanity" theory-temperamental basis, integration of mixed states, epidemiological datas- and highlights its dialectical relations with today's theory of bipolarity.