NEUROPEPTIDE DEFICITS IN SCHIZOPHRENIA VS ALZHEIMERS-DISEASE CEREBRAL-CORTEX

Neuropeptide concentrations there determined in the postmortem cerebra l cortex from 19 cognitive-impaired schizophrenics, 4 normal elderly s ubjects, 4 multi-infarct dementia (MID) cases, and 13 Alzheimer's dise ase (AD) patients, Only AD patients met criteria for AD, The normal el derly and MID cases were combined into one control group. Somatostatin concentrations were reduced in both schizophrenia and AD. Neuropeptid e Y concentrations were reduced only in schizophrenia, and corticotrop in-releasing hormone concentrations were primarily reduced in AD, Conc entrations of vasoactive intestinal polypeptide and cholecystokinin al so were reduced in schizophrenia, although not as profoundly as somato statin or neuropeptide Y. In AD, cholecystokinin and vasoactive intest inal peptide were unchanged Neuropeptide deficits in schizophrenics we re more pronounced in the temporal and frontal lobes than in the occip ital lobe. The mechanisms underlying these deficits in schizophrenia a nd AD are likely distinct In schizophrenia, a common neural element, p erhaps the cerebral cortical gaba-aminobutyric acid (GABA)-containing neuron, may underlie these deficits.