[Psychasthenia: history and evolution of the P. Janet concept].

Description of psychasthenia by P. Janet (1903) sets up at the end of a double reflection, with on the one hand a theorization of asthenia, the notion of which already occupied the medical concepts of the 18th and 19th centuries, and on the other hand a progressive attribution of neurosis to the psychiatric field. Its clinical characteristics (feelings of non-fulfillment in action and emotion, experiences of oddness and depersonalization, obsessions, phobias...) makes psychasthenia a fully-fledged illness, the psychopathological organization of which results from a decrease of psychological tension and from a loss of reality function. Since P. Janet, the term of psychasthenia has not ceased to be used, although its etiopathological references blurred behind the psychoanalytic work, and it is usually synonymous with obsessional neurosis, even with obsessional personality. Description of psychasthenia appears in these rubrics of the DSM III, even though the term itself is ignored.