Kraepelinian dichotomy

Emil Kraepelin (1856-1926)

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,^[1][2] and manic-depressive psychosis, which has now been reconceived as bipolar disorder.^[3] This division was formally introduced in the sixth edition of Emil Kraepelin's psychiatric textbook Psychiatrie. Ein Lehrbuch für Studirende und Aertze, published in 1899.^[3] 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.^[4] However, there is also a diagnosis of schizoaffective disorder to cover cases that seem to show symptoms of both.

History

Karl Ludwig Kahlbaum (1828-1899)

The Kraepelinian system and the modern classification of psychoses are ultimately derived from the insights of the Karl Kahlbaum.^[5] In 1863 the Prussian psychiatrist published his Habilitation which was entitled, Die Gruppirung der psychischen Krankheiten (The Classification of Psychiatric Diseases).^[6] In this text he reviewed the then heterogeneous state of medical taxonomies of mental illness and enumerated the existence of some thirty such nosologies from the early seventeenth-century until the mid-nineteenth-century.^[7] The major contribution of his published dissertation, which is still the foundation of modern psychiatric nosology,^[7] was to first formulate the clinical method for the classification of psychosis by symptom, course and outcome.^[8]

Kahlbaum also differentiated between two major groups of mental illnesses which he termed vecordia and vesania.^[7]

Emil Kraepelin first introduced his proposed dichotomy between the endogenous psychoses of manic-depressive illness and dementia praecox during a public lecture in Heidelberg, Germany on 27 November 1898.^[9]

Notes

Bibliography