Lilo Süllwold (*1930) was the first psychologist in the German Federal Republic to acquire habilitation for Clinical Psychology at a Medical Faculty. However, she had already been appointed professor for Clinical Psychology following to a new University Act implementing the recommendations of the National Council of Science and Humanities. Her habilitation treatise to justify the initial professorship appointment centered on a self-made questionnaire as a diagnostic tool for beginning schizophrenia. The manner how the questionnaire together with the politico-scientific structural changes at the German Federal universities endowed the young psychologist with a carrier in psychiatry, is an illuminating example of psychology's way into psychiatry: the institutionalization and professionalization of Clinical Psychology in psychiatry since the end of the 1950s up to the end of the 1970s. In a comparative perspective on the developments of Clinical Psychology in the German Democratic Republic, the example demonstrates not only the role of new psychological theories und methods in research and clinic in enabling the entry of the new profession into psychiatry, but also the importance of initial socio-economic and socio-politic frame conditions and decisions. The negotiation of the scope or limits of competences between doctors and psychologists created more than a professional niche inside the clinic; it changed psychiatry and psychology as academic branches in their structures due to the establishment of new Clinical Psychology departments. The role of the psychologist turned from a doctor's "assistant" into a colleague at "eye level".