Identifying Critical Periods of Neurodevelopmental Risk: The Turning Point in Schizophrenia Research

Consistent with earlier hypotheses,1 multiple lines of evidence suggest that abnormalities of fetal and neonatal brain formation, of genetic2 or nongenetic origin, may be involved in the development of schizophrenia.3 A number of postmortem investigations of patients with this disorder4,5 have shown abnormalities of the limbic cerebral cortex that are unaccompanied by gliosis, indicative of neurodevelopmental pathology. In investigations of twin pairs discordant for schizophrenia,6 the affected twin has had greater ventricular volume than the unaffected one, suggesting that the disorder may be associated with abnormalities of brain development. In addition, follow-up investigations of infants at risk for schizophrenia7 have shown increased incidence of neurointegrative deficits in children who expressed psychotic disorders as adults.