Answer by taking a quote from the following article:

Wilhelm Stekel (German: ['Ste:k@l]; 18 March 1868 - 25 June 1940) was an Austrian physician and psychologist, who became one of Sigmund Freud's earliest followers, and was once described as "Freud's most distinguished pupil". According to Ernest Jones, "Stekel may be accorded the honour, together with Freud, of having founded the first psycho-analytic society"; while he also described him as "a naturally gifted psychologist with an unusual flair for detecting repressed material." He later had a falling-out with Freud, who announced in November 1912 that "Stekel is going his own way". His works are translated and published in many languages.

Stekel made significant contributions to symbolism in dreams, "as successive editions of The Interpretation of Dreams attest, with their explicit acknowledgement of Freud's debt to Stekel": "the works of Wilhelm Stekel and others...since taught me to form a truer estimate of the extent and importance of symbolism in dreams".  Considering obsessional doubts, Stekel said,  In anxiety the libido is transformed into organic and somatic symptoms; in doubt, the libido is transformed into intellectual symptoms. The more intellectual someone is, the greater will be the doubt component of the transformed forces. Doubt becomes pleasure sublimated as intellectual achievement.  Stekel wrote one of a set of three early "Psychoanalytic studies of psychical impotence" referred to approvingly by Freud: "Freud had written a preface to Stekel's book". Related to this may be Stekel's "elaboration of the idea that everyone, and in particular neurotics, has a peculiar form of sexual gratification which is alone adequate".  Freud credited Stekel as a potential forerunner when pondering the possibility that (for obsessional neurotics) "in the order of development hate is the precursor of love. This is perhaps the meaning of an assertion by Stekel (1911 [Die Sprache des Traumes], 536), which at the time I found incomprehensible, to the effect that hate and not love is the primary emotional relation between men". The same work is credited by Otto Fenichel as establishing 'the symbolic significance of right and left...right meaning correct and left meaning wrong '. Less flatteringly, Fenichel also associated it with "a comparatively large school of pseudo analysis which held that the patient should be 'bombarded' with 'deep interpretations,'" a backhanded tribute to the extent of Stekel's early following in the wake of his break with Freud.

When was the theory of neurosis developed?
Stekel wrote one of a set of three early "Psychoanalytic studies of psychical impotence" referred to approvingly by Freud: "Freud had written a preface to Stekel's book