Insular cortex abnormalities in schizophrenia: a structural magnetic resonance imaging study of first-episode patients

The insular cortex is a limbic integration region that is engaged in emotio nal and cognitive functions. To investigate possible insular cortex abnorma lities in schizophrenia, we measured insular gray matter volume and cortica l surface size in drug-naive first-episode patients. Magnetic resonance ima ges were used to explore the morphology of the insular cortex of 25 healthy male volunteers, and 25 male schizophrenic patients. Groups were matched f or age, sex, height, and parental socio-economic status. Clinical dimension scores were correlated with insular gray matter volume and cortical surfac e area. Patients had a significant reduction in cortical surface area [patients=202 0 (206); controls=2142 (204); F=5.83, df=1,47; P=0.01] and gray matter volu me [patients=8.12 (0.77); controls=8.57 (0.94); F=3.93, df =1.47;P=0.05] in the left insular, cortex. Insular gray matter volume and cortical surface size correlated negatively and significantly with the psychotic symptom dim ension. Schizophrenic patients show morphological abnormalities in the insu lar cortex at early stages of the illness. These abnormalities are related to the severity of psychotic symptoms. Further investigations are needed to evaluate the role of the insula in the pathophysiology of schizophrenia. ( C) 2000 Elsevier Science B.V. All rights reserved.