Cortical brain development in schizophrenia: insights from neuroimaging studies in childhood-onset schizophrenia

Childhood-onset schizophrenia (COS; defined as onset by age 12 years) is rare, difficult to diagnose, and represents a severe and chronic phenotype of the adult-onset illness. A study of childhood-onset psychoses has been ongoing at the National Institute of Mental Health (NIMH) since 1990, where children with COS and severe atypical psychoses (provisionally labeled "multidimensionally impaired" or MDI by the NIMH team) are studied prospectively along with all first-degree relatives. COS subjects have robust cortical gray matter (GM) loss during adolescence, which appears to be an exaggeration of the normal cortical GM developmental pattern and eventually mimics the pattern seen in adult-onset cases as the children become young adults. These cortical GM changes in COS are diagnostically specific and seemingly unrelated to the effects of medications. Furthermore, the cortical GM loss is also shared by healthy full siblings of COS probands suggesting a genetic influence on the abnormal brain development.