[Positive and negative symptoms of schizophrenia].

Aim of the present study is to draw conclusions from published research regarding the positive-negative schizophrenia concept, and to try to present the opinion of supporters and critics of the concept in a balanced way. The historical background of the concept, from Reynolds and Jackson during the last century until today, is reviewed. After giving the definitions and presenting various instruments of evaluation, the question is discussed, how stable "negative" und "positive" psychopathological constellations are. Consideration of the results of research on the long-term time course of schizophrenia, as well as in genetics, biology und psychopharmacology, leads one to conclude, on the one hand that the positive-negative concept is relevant for clinical practice and research, but on the other hand that many of the present studies were not able to confirm a clear cut positive-negative dichotomy.