The research objective was to identify the differences in neurocognitive functioning and social cognition (emotional processing) in the presence of anorexia nervosa and schizophrenia, which will eventually help in developing methodological approaches and improving differential and diagnostic parameters to assess anorexia syndrome associated with these disorders. Materials and methods. We studied neuropsychological and anthropometric characteristics of the respondents whose clinical pattern had evidence of anorexia syndrome (129 people): (1) female patients suffering from anorexia nervosa without changed clinical diagnosis (40 patients), (2) female patients suffering from anorexia nervosa whose clinical diagnosis was changed to bulimia nervosa within a 5-year follow-up (20 patients), (3) female patients with anorexia nervosa whose clinical diagnosis was changed to schizophrenic spectrum disorders within a 5-year follow-up (15 patients), (4) female patients suffering from a paranoid form of schizophrenia lasting for up to 5 years with a history of deviant eating behavior in the clinical pattern (23 patients), (5) girls and young women who did not have mental and behavioral disorders at the time of their participation in the study, but with preclinical signs of eating disorders (ED) (31 patients). The survey included a set of anamnestic, anthropometric, and psychometric methods, as well as psychometric techniques. The statistical processing of the obtained results was carried out with the help of the Statistica 10.0 and SPSS 22.0 software packs. Results. We established qualitative and quantitative differences in the parameters of neuropsychological and anthropometric profiles in the presence of concomitant ED symptoms in the clinical pattern. Moreover, great difficulties in the implementation of executive functioning were identified in patients with anorexia nervosa whose 5-year follow-up was changed to a diagnosis from the list of schizophrenic spectrum disorders, and in patients suffering from schizophrenia with a history of deviant eating behavior. Discriminant analysis based on the identified set of neuropsychological and anthropometric parameters enabledus to correctly classify the compared subgroups with an accuracy of 99.2%. Conclusion. Assessment of neurocognitive (in terms of executive functions) and anthropometric indicators enables determining the exact nosological affiliation of anorexia syndrome in the manifestation of mental and behavioral disorders, as well as establishing a correct clinical diagnosis, which will help to provide adequate treatment and rehabilitation in the future, along with timely prevention of severe complications of eating disorders. It is necessary to consider the fact that failures to diagnose the anorexia syndrome in such patients lead to difficulties in their treatment and worsen their social and medical prognosis.