Reduced White Matter Integrity Associated With Cognitive Deficits In Patients With Drug-naive First-episode Schizophrenia

Objective: Patients with schizophrenia have shown widespread white matter microstructural abnormalities and cognitive deficits,but the definitive relationship between white matter and cognitive performance remains unclear.In this study,we explored white matter abnormalities in drug-na(?)ve patients with first-episode schizophrenia,then investigated the possible relationship between cognitive deficits and white matter integrity in drug-na(?)ve first-episode schizophrenia patients to find a potential biological biomarker.Methods: Fifty-five drug-naive first-episode schizophrenia(dn-FES)and 55 healthy individuals underwent 3.0 T magnetic resonance diffusion-weighted imaging and cognitive assessments using the Chinese version of the Measurement and Treatment Research to Improve Cognition in Schizophrenia(MATRICS)Consensus Cognitive Battery(MCCB).The intelligence quotient(IQ)was estimated using the Chinese version of the Wechsler Adult Intelligence Scale-Revised,and the psychiatric symptoms were assessed using the Positive and Negative Syndrome Scale(PANSS).Tract-based spatial statistics(TBSS)was used to compare fractional anisotropy(FA)map between groups.And Pearson correlation analysis was used to further explore the correlation between the FA value and cognitive performance in dn-FES.Results: Compared with the control group,the dn-FES group showed decreased FA in white matter of the right posterior thalamic radiation,right posterior corona radiata,right superior longitudinal fasciculus,right retrolenticular part of the internal capsule,right tapetum,splenium of the corpus callosum,right sagittal stratum,and right inferior longitudinal fasciculus(p<0.05),and the dn-FES group had significantly lower scores in intelligence quotient and the seven cognitive domains(p<0.05).Correlational analyses revealed that the positive correlation between social cognition and the FA value in right posterior thalamic radiation,right posterior corona radiata,right superior longitudinal fasciculus,right retrolenticular part of the internal capsule,right tapetum and the splenium of the corpus callosum(r=0.309,p=0.037),and the FA value in the right superior longitudinal fasciculus was not only significantly positively correlated with the speed of processing(r=0.352,p=0.016),but also significantly positively correlated with the social cognition(r=0.355,p=0.015)in dn-FES patients.There was no correlation between reduced FA and clinical symptoms in dn-FES patients.Conclusion: There were extensive microstructural abnormalities in white matter integrity and were mainly in the right cerebral hemisphere of dn-FES patients.Disrupted white matter integrity in these regions,such as right superior longitudinal fasciculus,right thalamic radiation,was associated with cognitive deficits which may provide a potential biological biomarker for the schizophrenia.