dementia praecox
a progressively deteriorating psychotic disorder marked by severe, incurable cognitive disintegration beginning in early adulthood (Latin, “premature dementia”). The term, now obsolete, was first used in 1891 by psychiatrist and neuroanatomist Arnold Pick (1851–1924) and subsequently formalized by German psychiatrist Emil Kraepelin as a taxonomic concept, defining it as one of two major classes of mental illness (the other being manic-depressive illness; see bipolar disorder) and distinguishing it from the “senile dementia” of advanced age. It is said to have originated as a translation of démence précoce, coined in 1852 by Austrian-born French psychiatrist Bénédict A. Morel (1809–1873), but some dispute that connection, arguing that Morel’s term was only a passing description of a group of young patients who suffered from “stupor,” a condition
unrelated to the psychotic disorder that Kraepelin described more than 40 years later. Whatever its exact origins, the more prevalent Latin term was eventually replaced after Swiss psychiatrist Eugen Bleuler reframed the Kraepelinian concept, deemphasizing its characterization as an early dementia with an irreversible disease course, and renamed it schizophrenia in 1908.