Structural neuroimaging abnormality and neurocognitive deficit in the first-degree relatives of schizophrenia patients (FDR) compared to the first-episode patients with schizophrenia (FEP) and healthy controls

The existing evidence regarding structural neuroimaging alternations during the premorbid and prodromal stages of psychosis remains limited and inconsistent. Gaining a deeper insight into the morphological brain variations could potentially advance the early diagnosis of high-risk individuals for psychosis, thereby offering a clearer understanding of the underlying mechanisms that lead to the progression towards mental disorders, particularly schizophrenia. In our study, we conducted comprehensive face-to-face clinical interviews, psychiatric symptom assessments, and neurocognitive evaluation for 25 first-episode patients with schizophrenia (FEP), 35 first-degree relatives of schizophrenia patients (FDR), and 22 healthy controls (HC). We also collected structural magnetic resonance imaging (sMRI) data for all participants. The results demonstrated that the FEP group experienced the most severe clinical symptoms, the lowest global function, and the poorest neurocognitive function, followed by the FDR and HC groups. FEP group exhibited significant reductions in the surface area, cortical thickness, or volume of the right cuneus cortex, bilateral entorhinal cortex, left para-hippocampal gyrus, bilateral temporal pole, and right insula cortex compared to the FDR and HC groups. However, no significant difference in surface area, cortical thickness, and volume of all the regions of interest (ROIs) were found between the FDR group and HC group. To conclude, neurocognitive decline and gray matter reduction could serve as neuroimaging biomarkers for the onset and progression of psychosis. It is imperative to conduct further comprehensive researches to identify additional promising biomarkers, which will facilitate the early detection and intervention for individuals at risk of developing psychosis.