Reading of the main writings of Kraepelin enables us to understanding the way in which the concept of degeneration, developed by Morel and Magnan, reappears at the beginning of the modern psychiatry. In this paper, we analyze the theoretical and conceptual connections between: (a) the theory of degeneration of Morel and Magnan, and the criteria used by Kraepelin to classify the mental illnesses; and (b) the studies dedicated to the morbid heredity in the historical context of the emergence of neo-Kraepelinian psychiatry. Finally, we highlight the continuities and differences that exist between the proliferation of the syndromes resulting from the theory of the degeneration and the current multiplication of psychiatric diagnoses.
Psychiatry classification; Degeneration; DSM; Morbid heredity; Kraepelin