Kraepelin also demonstrated specific patterns in the genetics of these disorders and specific and characteristic patterns in their course and outcome. Generally speaking, there tend to be more schizophrenics among the relatives of schizophrenic patients than in the general population, while manic-depression is more frequent in the relatives of manic-depressives.
He also reported a pattern to the course and outcome of these conditions. Kraepelin believed that schizophrenia had a deteriorating course in which mental function continuously (although perhaps erratically) declines, while manic-depressive patients experienced a course of illness which was intermittent, where patients were relatively symptom-free during the intervals which separate acute episodes. This led Kraepelin to name what we now know as schizophrenia, dementia praecox (the dementia part signifing the irreversible mental decline). It later became clear that dementia praecox did not necessarily lead to mental decline and so was renamed by Eugene Bleuler to correct the misnomer.
Kraepelin is credited with the classification of what was previously considered to be a unitary concept of psychosis, into two distinct forms:
- Manic Depression (now seen as comprising a range of mood disorders such as Major Depression and Bipolar Disorder), and
- Dementia praecox, which was later renamed schizophrenia by
Eugene Bleuler.
Kraepelin was also a colleague of Alois Alzheimer, and co-discoverer with Alzheimer of Alzheimers Disease.
In addition to his distinction between dementia praecox and manic-depression, Kraepelin should be credited with being the founder of modern scientific psychiatry, psychopharmacology and psychiatric genetics, according to the eminent psychologist H. J. Eysenck in his Encyclopedia of Psychology. Kraepelin postulated that psychiatric diseases are principally caused by biological and genetic disorders. His psychiatric theories dominated the field of psychiatry at the beginning of the twentieth century. He vigorously opposed the approach of Freud who regarded and treated psychiatric disorders as caused by psychological factors. Though Kraepelin's contribution was largely ignored through most of the twentieth century due to the success of Freudian etiological theories, Kraepelin's basic concepts now dominate psychiatric research and academic psychiatry, and today the published literature in the field of psychiatry is overwhelmingly biological and genetic in its orientation. Largely for political reasons, Kraepelin's great contribution in discovering schizophrenia and manic-depression remains relatively unknown to the general public and his work is little read, despite the recent widespread adoption of his fundamental theories on the etiology and diagnosis of psychiatric disorders which form the basis of all major diagnostic systems in use today, especially the American Psychiatric Association's DSM-IV and the World Health Organization's ICD system.
For a more complete description of the epic social and political battle that gave rise to Freudianism (from an anti-Freudian perspective), see psychiatrist E. Fuller Torrey's "The Freudian Fraud".
