ABSTRACT
Schizophrenia is a serious mental illness that usually becomes manifest in adolescence or in early adulthood. Schizophrenia differs from the mental illnesses of definite organic origin in that it does not involve dementia or disorders of memory, orientation, or intelligence comparable to the latter. Eugen Bleuler (1911), father of the term 'schizophrenia', considered it particularly typical of this illness that the patient suffers disorders, gaps, and shifts of associations, which impair his train of thought, interfering with the maintenance of intention or attention. The verbal expressions of deeply regressed schizophrenic patients are frequently very scant and blocked, or so full of extremely subjective phrases and neologisms, or at least semantically idiosyncratic words, that they are difficult or almost impossible to understand. The nuclear group of schizophrenia is considered to consist of three essential subcategories: hebephrenic, catatonic, and paranoid. A generally applicable diagnostic system is important for comparative epidemiological research, as well as otherwise facilitating communication about schizophrenia.
