[Depressive disorders. Development of the nosographic concepts]

Between the nosological position of Kraepelin a century ago and the present situation, there are only surface differences despite all what has been claimed. Main lines separating entities remain the same and the consensus on the value of evolution, as a key factor for nosological problems, is not questioned. However, concepts characterising subtypes have changed and, overall, the many attempts in this direction in the last 30 years have not been unanimously accepted. These concepts appear heterogeneous enough since they tackle either the notion of clinical type, or of etiology, or of prognosis. The predictive value of these various concepts is discussed.