Autopsy study of Alzheimer's disease brain pathology in schizophrenia

The brains of 125 schizophrenic patients (DSM-IV criteria) without other major diseases likely to affect brain morphology were examined at autopsy in our hospital for an evaluation of the number of neurofibrillary tangles (NFT) and senile plaques (SP) as indicators of the incidence of Alzheimer's disease (AD) brain pathology. The clinical degree of dementia and the presence or absence of delirium and Parkinsonism were determined in a review of the patients' charts. No significant difference in the degree of AD brain pathology between the 12 schizophrenics more than 75 years old and 12 age-matched normal controls was present. We conclude that AD pathology seems to be no more frequent among schizophrenic patients than in the normal population, and that the severe cognitive impairment observed in schizophrenics is based on neither neuronal degeneration nor neuronal loss like that occurring in AD. We believe that future morphological studies of cognitive impairments in schizophrenics will require a more detailed investigation at the receptor level.