Paraphrenia is a psychotic disorder described by Kraepelin in 1913. He formulated this concept to define a group of patients who exhibited symptoms characteristic of dementia praecox (marked delusions with or without hallucinations), but with minimal disturbances of emotion and volition, and much less personality deterioration. after the publication of Mayer"s prognostic research in 1921 (which studied the outcomes of 78 paraphrenic patients reported by Kraepelin), the view to differentiate paraphrenia from schizophrenia was considered to be unfounded in Germany. Paraphrenia is now diagnosed relatively infrequently and is not listed in the current Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) or International Classification of Diseases (ICD-10). However, it appears that some psychiatrists recognize the illness but label it "atypical psychosis", "schizoaffective disorder," or "delusional disorder" for lack of a better diagnostic category.

Virtually no systematic research on paraphrenia has been conducted in the past 60 years. We describe a 30-year-old man affected by sistematic paraphrenia, according to the neo-Kraepelinian description of paraphrenia proposed by Ravindran et al. in 1999 (description compatible with the formats of DSM-IV and ICD-10). Using a questionnaire adapted from this description, our case of paraphrenia were distinguished from those of schizophrenia and delusional disorder. in conclusion, It is possible to define and recognize paraphrenia, because it is a viable diagnostic entity. as in the days of Kraepelin, the problems concerning paraphrenia cannot be neglected when considering the classification of psychotic disorders.