page_title: Dementia praecox
section_title: Time component
hierarchical_section_title: Dementia praecox / History / Time component
caption_attribution_description: English: Karl Ludwig Kahlbaum Polski: Karl Ludwig Kahlbaum
context_page_description: Dementia praecox is a disused psychiatric diagnosis that originally designated a chronic, deteriorating psychotic disorder characterized by rapid cognitive disintegration, usually beginning in the late teens or early adulthood. Over the years, the term "dementia praecox" was gradually replaced by "schizophrenia", which remains in current diagnostic use.
  The term "dementia praecox" was first used in 1891 by Arnold Pick, a professor of psychiatry at Charles University in Prague. His brief clinical report described the case of a person with a psychotic disorder resembling hebephrenia. German psychiatrist Emil Kraepelin popularised it in his first detailed textbook descriptions of a condition that eventually became a different disease concept and relabeled as schizophrenia. Kraepelin reduced the complex psychiatric taxonomies of the nineteenth century by dividing them into two classes: manic-depressive psychosis and dementia praecox. This division, commonly referred to as the Kraepelinian dichotomy, had a fundamental impact on twentieth-century psychiatry, though it has also been questioned.
context_section_description: Psychiatric nosology in the nineteenth-century was chaotic and characterised by a conflicting mosaic of contradictory systems. Psychiatric disease categories were based upon short-term and cross-sectional observations of patients from which were derived the putative characteristic signs and symptoms of a given disease concept. The dominant psychiatric paradigms which gave a semblance of order to this fragmentary picture were Morelian degeneration theory and the concept of "unitary psychosis" (Einheitspsychose). This latter notion, derived from the Belgian psychiatrist Joseph Guislain (1797–1860), held that the variety of symptoms attributed to mental illness were manifestations of a single underlying disease process. While these approaches had a diachronic aspect they lacked a conception of mental illness that encompassed a coherent notion of change over time in terms of the natural course of the illness and based upon an empirical observation of changing symptomatology.
  In 1863, the Danzig-based psychiatrist Karl Ludwig Kahlbaum (1828–1899) published his text on psychiatric nosology Die Gruppierung der psychischen Krankheiten (The Classification of Psychiatric Diseases). Although with the passage of time this work would prove profoundly influential, when it was published it was almost completely ignored by German academia despite the sophisticated and intelligent disease classification system which it proposed. In this book Kahlbaum categorized certain typical forms of psychosis (vesania typica) as a single coherent type based upon their shared progressive nature which betrayed, he argued, an ongoing degenerative disease process. For Kahlbaum the disease process of vesania typica was distinguished by the passage of the sufferer through clearly defined disease phases: a melancholic stage; a manic stage; a confusional stage; and finally a demented stage.
  In 1866 Kahlbaum became the director of a private psychiatric clinic in Görlitz (Prussia, today Saxony, a small town near Dresden). He was accompanied by his younger assistant, Ewald Hecker (1843–1909), and during a ten-year collaboration they conducted a series of research studies on young psychotic patients that would become a major influence on the development of modern psychiatry.
  Together Kahlbaum and Hecker were the first to describe and name such syndromes as dysthymia, cyclothymia, paranoia, catatonia, and hebephrenia. Perhaps their most lasting contribution to psychiatry was the introduction of the "clinical method" from medicine to the study of mental diseases, a method which is now known as psychopathology.
  When the element of time was added to the concept of diagnosis, a diagnosis became more than just a description of a collection of symptoms: diagnosis now also defined by prognosis (course and outcome). An additional feature of the clinical method was that the characteristic symptoms that define syndromes should be described without any prior assumption of brain pathology (although such links would be made later as scientific knowledge progressed). Karl Kahlbaum made an appeal for the adoption of the clinical method in psychiatry in his 1874 book on catatonia. Without Kahlbaum and Hecker there would be no dementia praecox.
  Upon his appointment to a full professorship in psychiatry at the University of Dorpat (now Tartu, Estonia) in 1886, Kraepelin gave an inaugural address to the faculty outlining his research programme for the years ahead. Attacking the "brain mythology" of Meynert and the positions of Griesinger and Gudden, Kraepelin advocated that the ideas of Kahlbaum, who was then a marginal and little known figure in psychiatry, should be followed. Therefore, he argued, a research programme into the nature of psychiatric illness should look at a large number of patients over time to discover the course which mental disease could take. It has also been suggested that Kraepelin's decision to accept the Dorpat post was informed by the fact that there he could hope to gain experience with chronic patients and this, it was presumed, would facilitate the lon
caption: Karl Ludwig Kahlbaum (1828–1899)
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