APA Dictionary of Psychology

a type of schizophrenia in which the defining features, including social inadequacy and withdrawal, blunted affect, and feelings of depersonalization and derealization, are highly similar to those described by Emil Kraepelin for dementia praecox. It is of early, insidious onset and is associated with a degenerative, irreversible course and poor prognosis. This term is often used interchangeably with process schizophrenia. Also called true schizophrenia; typical schizophrenia. Compare schizophreniform psychosis. [proposed in the late 1930s by Norwegian psychiatrist Gabriel Langfeldt (1895–1983)]