Emil Kraepelin

A German experimental psychiatrist who classified types of mental illness and studied their neurological bases.

Emil Kraepelin was a pioneer in the development of psychiatry as a scientific discipline. He was convinced that all mental illness had an organic cause, and he was one of the first scientists to emphasize brain pathology in mental illness. A renowned clinical and experimental psychiatrist, Kraepelin developed the modern classification system for mental disease. After analyzing thousands of case studies, he introduced and defined the terms dementia praecox (schizophrenia), manic-depressive psychosis, and paranoia. Kraepelin was a founder of psychopharmacology, and his experimental work focused on the effects of intoxicants on the central nervous system, on the nature of sleep, and on the effects of fatigue on the body.

Kraepelin, the son of a civil servant, was born in 1856 in Neustrelitz, in the Mecklenburg district of Germany. He was first introduced to biology by his brother Karl, 10 years his senior and, later, the director of the Zoological Museum of Hamburg. Kraepelin began his medical studies at 18, in Leipzig and Wurzburg, Germany. At Leipzig, he studied psychology with Wilhelm Wundt and wrote a prize-winning essay, “The Influence of Acute Illness in the Causation of Mental Disorders.” He received his M.D. in 1878.

Publishes first edition of his psychiatry compendium

In 1879, Kraepelin went to work with Bernhard von Gudden at the University of Munich, where he completed his thesis, The Place of Psychology in Psychiatry. Returning to the University of Leipzig in 1882, he worked in Wilhelm Heinrich Erb's neurology clinic and in Wundt's psychopharmacology laboratory. His major work Compendium der Psychiatrie was first published in 1883. In it, he argued that psychiatry was a branch of medical science and should be investigated by observation and experimentation like the other natural sciences. He called for research into the physical causes of mental illness and established the foundations of the modern classification system for mental disorders. Kraepelin proposed that by studying case histories and identifying specific disorders, the progression of mental illness could be predicted, after taking into account individual differences in personality and patient age at the onset of disease. In 1884 he became senior physician in Leubus, and the following year he was appointed director of the Treatment and Nursing Institute in Dresden. In 1886, at the age of 30, Kraepelin was named professor of psychiatry at the University of Dorpat. Four years later, he became department head at the University of Heidelberg, where he remained until 1904.

Following the experimental protocols he had learned in Wundt's laboratory, Kraepelin examined the effects of alcohol, morphine, and other drugs on human subjects. Applying Wundt's association experiments to psychiatric problems, Kraepelin found that the associations made by psychotic patients were similar to those made by fatigued or intoxicated subjects. In both cases, the associations tended to be superficial and based on habit rather than on meaningful relationships. Kraepelin also made a study of primitive peoples, and he examined the frequency of insanity and paralysis in tropical regions. His research on mental illness led him to speak out for social reforms. He crusaded against the use of alcohol and against capital punishment, and he spoke out in favor of indeterminate criminal sentences. He developed a museum depicting the barbarous treatment that was prevalent in asylums for the insane.

Studies pathologies of mental disorders

In 1904, Kraepelin was named director of the new psychiatric clinic in Munich and professor of psychiatry at the university there. Under his direction, the Munich Clinic became a renowned center for teaching and research in psychiatry. The training of his postgraduate students combined clinical observations with laboratory investigations. Kraepelin rejected the psychoanalytical theories that placed innate sexuality or early sexual experiences at the root of mental illness. Likewise, he rejected as unscientific the philosophical speculations that were at the center of much of early twentieth-century psychology. Kraepelin's research was based on the painstaking collection of clinical data. He was particularly interested in the neuropathology of mental illness, and many important scientists, including Alois Alzheimer, conducted their histological studies of diseased tissues at his clinic.

Kraepelin retired from teaching at the age of 66 and devoted his remaining years to establishing the German Institute for Psychiatric Research, which became a Kaiser Wilhelm Institute within the University of Munich. Built with financial assistance from the Rockefeller Foundation, the institute was dedicated two years after Kraepelin's death in Munich in 1926. The final edition of Compendium der Psychiatrie appeared in 1927. Its four volumes held ten times more information than the first edition of 1883. Comparisons of the nine editions reveal phenomenal progress in the science of psychiatry over the 44-year period. Part of the Compendium was published in English as Manic-Depressive Insanity and Paranoia. Considerable amount of Kraepelin's classification system remained in use in the early twenty-first century. Kraepelin's influence continues to the present day, with the publication of the DSM-5 in 2013.



Decker, Hannah. The Making of DSM-III: A Diagnostic Manual's Conquest of American Psychiatry. New York: Oxford University Press, 2013.

Kraepelin, Emil. Clinical Psychiatry. New York: Macmillan, 1907.

Kraepelin, Emil. Manic-Depressive Insanity and Paranoia. New York: Arno Press, 1976.

Talbott, John H. A Biographical History of Medicine: Excerpts and Essays on the Men and Their Work. New York: Grune & Stratton, 1970.