POSTMORTEM STUDIES OF THE HIPPOCAMPAL-FORMATION IN SCHIZOPHRENIA

Many postmortem studies report differences between the hippocampal for mations of patients with schizophrenia and those of controls, These di fferences include volume changes, cell density changes, periventricula r gliosis, senile degenerative changes, and abnormalities of neuronal size, position, or orientation, However, the findings are almost never common to all schizophrenia patients within a series. Furthermore, so me well-designed studies are negative, and different positive reports are mutually contradictory, Some of the inconsistencies are methodolog ical, The normal variation, over small distances, in the cytoarchitect ure of the temporal allocortex creates particular difficulties when th is region is studied with a limited number of sections, especially if the sample size is small, Other inconsistencies are probably the resul t of case selection. We review the methods and findings of some of the se studies, stressing the dangers of eliminating (rather than evaluati ng) cases with definite neuropathologic changes, We conclude that the existing postmortem studies of temporal lobe morphology provide little conclusive evidence for the neural substrate of schizophrenia.