From 1925 until 1934, she was the Secretary of the International Psychoanalytical Association while she continued her child analysis practice and contributed to seminars and conferences on the subject. In 1935, she became director of the Vienna Psychoanalytical Training Institute and the following year she published her influential study of the "ways and means by which the ego wards off depression, displeasure and anxiety", "The Ego and the Mechanisms of Defence". It became a founding work of ego psychology and established Freud's reputation as a pioneering theoretician.