Gray matter volume deficits and correlation with insight and negative symptoms in first-psychotic-episode subjects

To determine brain areas reduced in first episode of psychotic subjects and its association with lack of insight and negative symptoms.

Twenty-one drug naive first-episode subjects and 20 controls underwent a structural MRI scan and were clinically assessed. Optimized voxel-based-morphometry analysis (VBM) was implemented to find between-group differences and correlations between GM volume and: (i) lack of insight and (ii) negative symptoms.

Patients showed GM reduction in prefrontal and left temporal areas. A significant correlation was found between insight and GM volume in the cerebellum (corrected P = 0.01), inferior temporal gyrus (corrected P = 0.022), medial superior frontal gyrus (corrected P < 0.001), and inferior frontal gyrus (corrected P = 0.012), as the insight decreased, the volume decreased. Negative symptoms correlated with decreased GM volume at cerebellum (corrected P = 0.037) and frontal inferior regions (corrected P < 0.001), the more negative symptoms, the less volume.

Our findings support an association between prefrontal, temporal, and cerebellar deficits and lack of insight in schizophrenia and confirm previous findings of GM deficits in patients since the first episode of psychosis.