Cerebral cortical thickness and gyrification changes in first-episode psychoses and multi-episode schizophrenia

Cortical thickness (CT) and local gyrification index (LGI) in psychotic disorders may show modifications that relate to clinical course. This observational study aimed to analyse such variables in patients with schizophrenia, compared to healthy controls (HCs). We compared CT and LGI of 18 patients with first-episode psychosis with that of 21 with multi-episode schizophrenia and 16 HCs. CT corrected for false-positive cases (Family-Wise Error Rate) showed a reduction in the multi-episode group compared to HCs in left temporal and parietal, and right temporal, parietal, occipital, and hippocampal cortices. Family-wise corrected LGI was increased in the left inferior and middle frontal cortices, and in the right fusiform gyrus, cingulate, lingual, and parahippocampal gyri in first onset patients compared to HCs. Increased LGI was absent from later stages of psychosis, suggesting that specific CT and LGI alterations may underlie different stages of illness.