Schizophrenia: a neurodevelopmental or neurodegenerative disorder?

New reports implicate deviant neurodevelopment, under the influence of both genetic and early environmental factors, in the aetiology of schizophrenia. However, it is still not clear how developmental impairment in childhood is transformed into frank psychosis. Several longitudinal magnetic resonance imaging studies claim to show progression of structural brain abnormalities, and some investigators speculate that a neurodegenerative process superimposed on pre-existing abnormalities, may account for this. However, neuropathological studies do not indicate neurodegeneration over and above that of ageing, and there is little evidence that cognitive and neurological function decline dramatically over the course of schizophrenia, It is not yet necessary to disinter the corpse of Kraepelin's progressive disease model. (C) 2002 Lippincott Williams Wilkins.