The Kraepelinian dichotomy is the division of the major endogenous psychoses into the disease concepts of dementia praecox, which was reformulated as schizophrenia by Eugen Bleuler by 1908, and manic-depressive psychosis, which has now been reconceived as bipolar disorder. This division was formally introduced in the sixth edition of Emil Kraepelin's psychiatric textbook Psychiatrie. Ein Lehrbuch für Studirende und Aerzte, published in 1899. It has been highly influential on modern psychiatric classification systems, the DSM-IV-TR and ICD-10, and is reflected in the taxonomic separation of schizophrenia from affective psychosis. However, there is also a diagnosis of schizoaffective disorder to cover cases that seem to show symptoms of both.