[Karl Ludwig Kahlbaum (1828-1899)--a protagonist in modern psychiatry].

Kahlbaum was one of the most influencial psychiatrists of the 19th century. He paved the way for Kraepelin and inspired the development of 20th century clinical psychiatry. With his work he contributed to new ideas in general psychopathology and in psychiatric nosology. He described "clinical state-course-entities" and developed the concept of "exogenous reaction types", which would later be known as the "Bonhoeffer-paradigm". Kahlbaum was also the first to differentiate between centripetal, intracentral and centrifugal psychic functions, which was later transformed into the "psychic reflex circuit" by Wernicke. The concept of organic versus non-organic psychoses proved to be a heuristically fruitful classification system even for modern psychiatry. Kahlbaum was the first German psychiatrist to describe several disorders and syndromes and to coin new psychiatric terminology for them, including paraphrenia, hebephrenia, catatonia and cyclothymia. These terms and their originally associated meaning are still in use today. Kahlbaum's ambitious scientific aim was to develop specific therapeutic strategies which were based on a methodologically and etiologically sound classification system.