[Neurasthenia, yesterday and today].

Neurasthenia was described and explained in very mechanistic terms, at the end of the 19th century, by G.M. Beard to account for physical and mental exhaustion and for varied somatic troubles imputed to failure of too much solicited nervous resources. This concept was then universally adopted and gave rise to diverse interpretations, among which was the Freud's one. Later, in Occident, came a deterioration, the diagnostic of neurasthenia giving way to those of anxious or affective disorders. In the same time, at least for ideological and cultural reasons, the concept remained lively in Russia and in Asia. During the last decade the western psychiatry has been led to accept that there are clinical situations focussed on fatigue and fatigability, even if it coined for them new terminologies (post-infectious fatigue, chronic fatigue syndrome, etc.) and while DSMs keep on ignoring neurasthenia, the ICD 10 gives it an important place.