The data on 1500 patients with syndrome of anorexia and bulimia nervosa were summarised in terms of clinical-psychopathological, catamnestic and experimental-psychological investigation, This syndrome was considered as one disease which presented the variation of borderline mental pathology be the manifestation of schizophrenic process. Obsessive-phobic disorders were observed In majority of patients (95%). Such disorders were characterized by prevalence of obsessive phenomena with food content. It was noted that diagnosis ansi prognostic significance had either obsessive-phobic disturbances or obsessions with other content which occured on the initial stage of disease, before development of syndrome of anorexia and bulimia and in period of pronounced cachexia. The therapeutic resistance of obsessive disturbances in patients with anorexia and bulimia were emphasized as weal as the necessity of prolonged ambulatory treatment of such patients.