Schizophrenia and N-methyl-D-aspartate receptors: evolutionary adaptations from malfunctioning molecules?

In the history of evolution, biologic organisms have formed traits with both adaptive and sometimes maladaptive significance to their surrounding environments. The sickle cell mutation genes conferring resistance to malarial infection in human heterozygotes is an example of how certain genetic abnormalities can serve adaptive significance to an organism. Schizophrenia and the "Odyssyian personality" have often been cited as a neuropsychiatric correlate for evolutionary adaptive benefit in an organism. This article re-examines the possibility that schizophrenia-related genes can serve a beneficial adaptive role and that altered function of the N-methyl-D-aspartate receptor is the molecular correlate of such adaptive significance.