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Background: Prefrontal cortex gyrification has been suggested to be altered in patients with schizophrenia and first episode psychosis. Therefore, it may represent a possible trait marker for these illnesses and an indirect evidence of a disrupted underlying connectivity. The aim of this study was to add further evidence to the existing literature on the role of prefrontal gyrification in psychosis by carrying out a study on a sizeable sample of chronic patients with schizophrenia and non-affective first-episode psychosis (FEP-NA) patients., Methods: Seventy-two patients with schizophrenia, 51 FEP-NA patients (12 who later develop schizophrenia) and 95 healthy controls (HC) underwent magnetic resonance imaging (MRI). Cortical folding was quantified using the automated gyrification index (GI). GI values were compared among groups and related to clinical variables., Results: Both FEP-NA and patients with schizophrenia showed a higher mean prefrontal GI compared to HC (all p<0.05). Interestingly, no differences have been observed between the two patients groups as well as between FEP-NA patients who did and did not develop schizophrenia., Conclusions: Our results suggest the presence of a shared aberrant prefrontal GI in subjects with both schizophrenia and first-episode psychosis. These findings support the hypothesis that altered GI represents a neurodevelopmental trait marker for psychosis, which may be involved in the associated neurocognitive deficits., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Hemodynamic changes in the brain have been reported in major psychosis in respect to healthy controls, and could unveil the basis of structural brain modifications happening in patients. The study of first episode psychosis is of particular interest because the confounding role of chronicity and medication can be excluded. The aim of this work is to automatically discriminate first episode psychosis patients and normal controls on the basis of brain perfusion employing a support vector machine (SVM) classifier. 35 normal controls and 35 first episode psychosis underwent dynamic susceptibility contrast magnetic resonance imaging, and cerebral blood flow and volume, along with mean transit time were obtained. We investigated their behavior in the whole brain and in selected regions of interest, in particular the left and right frontal, parietal, temporal and occipital lobes, insula, caudate and cerebellum. The distribution of values of perfusion indexes were used as features in a support vector machine classifier. Mean values of blood flow and volume were slightly lower in patients, and the difference reached statistical significance in the right caudate, left and right frontal lobes, and in left cerebellum. Linear SVM reached an accuracy of 83% in the classification of patients and normal controls, with the highest accuracy associated with the right frontal lobe and left parietal lobe. In conclusion, we found evidence that brain perfusion could be used as a potential marker to classify patients with psychosis, who show reduced blood flow and volume in respect to normal controls., (Copyright © 2015 Elsevier B.V. All rights reserved.)