Out of the concept of neurasthenia, the main non-psychotic diagnosis of nineteenth-century psychiatry besides hysteria, and on the basis of psychophysiological problems of his own, self-diagnosed as neurasthenia, Freud developed the notion of ‘actual neurosis’, a ‘contentless psychic state’ manifested by various somatic symptoms and a depressive mood, which he attributed to a chemical factor associated with aberrant sexual practices and in particular masturbation. Rejected by post-Freudian analysts as such along with the diagnosis of neurasthenia, the concept of ‘actual neurosis’ has survived under various theoretical schemes that seek to explain psychosomatic illness and somatisation, in general, with its concomitant poverty of affects and dearth of fantasy life. In more recent years, the concept of ‘actual neurosis’ has resurfaced under the label of chronic fatigue syndrome, a medical entity thought to be an immunological deficiency, while in psychoanalysis Freud's idea of a contentless mental state has been replaced by that of unconscious fantasy and symbolisation at a pre-genital or pre-verbal level.