The symptomatic return of repressed childhood sexual trauma. The two main forms of hysteria are 1) conversion hysteria, in which the symptoms are manifested on the body (eg. psychosomatic illness); and 2) anxiety hysteria, in which one feels excessive anxiety because of an external object (eg. phobias).
A form of neurosis for which no physical diagnosis can be found and in which the symptoms presented are expressive of an unconscious conflict. In conversion hysteria, the symptoms usually take a somatic form (hysterical paralysis, irritation of the throat, coughs); in anxiety hysteria or phobia, the cause of the anxiety is a particular external object. Hysteria has been explained in many different ways over the centuries; the most influential aetiology or causal explanation to have been put forward in the twentieth century is that supplied by Freud's psychoanalysis.
Freud's initial thesis (1896) was the so-called seduction theory which held that hysteria and other neuroses originate in an experience of actual sexual abuse that has been repressed, but which can be recovered. Freud initially used hypnosis to recover these memories, but abandoned it in favor of what Anna O. so felicitously termed the talking cure. Freud subsequently revised his original seduction theory in the course of a long correspondence with his collaborator Fliess and argued that hysteria stemmed from unconscious fantasies about incest that were bound up with oedipus complex, though he never denied either the existence or the pathogenic effects of real abuse.