Differentiation of the psychiatric diagnosis in the clinical praxis sometimes could be difficult; particulary in cases of kindred/similar diagnoses like schizophrenia, schizoaffective disorder or personality disorder cluster A (or cluster I) - paranoid, schizoid and schizotipal. Relationship between schizophrenia and personality disorder cluster I is not quite clear; according some authors, descendants of schizophrenic patients could suffer from personality disorder cluster I; which suggest on possible genetic correlation between those diagnoses.

As a case report we going to present a female single patient, 32 years of age, no kids, living with her mother, disapointed in herself after unsucessfull second year on faculty of low which she left. After that, she closed up, she also had problems with nutrition, showing signs of anorexic and bulimic behavior. After 10–12 years of living in social retraction, not working, without social contacts, she „decided to start from the beginning” after being on intensive vitamine therapy, and asked for the psychiatric therapy for the first time in her life, with motivation for working.

In conclusion, in this study we are going to present a critical view of both diagnosis traying to understand similarity and differences, as well as identify common points between them and make guidelines for practical approach to the question.