Hippocampal damage and schizophrenia: A critique of Mednick's theory.

Discusses S. A. Mednick's hypothesis that anoxia produced by pregnancy and birth complications causes hippocampal damage which in turn leads to schizophrenia in a predisposed individual. He further suggests that since the hippocampus exerts an inhibitory influence on reticular formation control of ACTH, a lesion in the hippocampus could cause oversecretion of ACTH. Contrary to Mednick's position, a survey of recent research findings showed: (a) Hippocampal control of ACTH is not inhibitory. Experimentally induced lesions of the hippocampus inhibit or facilitate ACTH release depending on the type of stress induced. (b) There are species differences in the type of behavioral deficits observed after a hippocampectomy. (c) The site of anatomical destruction due to anoxia will differ depending upon the species studied and the gestation level of the fetus exposed to anoxic conditions. Hippocampal damage is seldom found in the premature or full-term neonate primate. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)