The timing and functional consequences of structural brain abnormalities in schizophrenia

Evidence from structural imaging studies provides some support that schizophrenia arises from an abnormality occurring early in brain development. For example, a para-cingulate sulcus occurs less frequently in first episode psychosis and in chronic schizophrenia patients than in healthy control subjects. Since sulcal/gyral folding is nearly complete by the third trimester of gestation, it is likely that the anomalous fissurization observed in the cingulate cortex arises early in development. However, cross-sectional studies at various phases of the illness and longitudinal studies suggest possible progression of structural abnormalities during the course of the illness. In particular, data from a small longitudinal study of individuals at high risk for developing psychosis, provides evidence of change in temporal lobe structures during the transition from prodromal phase to overt psychosis. Overall, the evidence supports the hypothesis that an early neurodevelopmental insult interacts with either normal or abnormal post-pubertal brain maturation to produce further (late neurodevelopmental) brain structural and functional changes.