Changes of microstructure of white matter and clinical high risk for psychosis / 中华行为医学与脑科学杂志

The research on clinical high-risk for psychosis is a hotspot in recent years, which is helpful to the early identification and early intervention of psychosis. White matter fibers are the important structural basis of complex information transmission function among brain regions. The existing literatures show that there are abnormal white matter microstructures in individuals at clinical high-risk for psychosis, which is related to their clinical symptoms and social function. Diffusion tensor imaging is the only non-invasive technique to study the microstructure of brain white matter. This paper reviews the existing evidences of microstructural abnormalities of white matter at clinical high-risk for psychosis by diffusion tensor imaging, in order to comprehensively analyze the potential neurobiomarkers in the early stage of the disease and the pathological evolution characteristics in the development of the disease.

Prediction of functional connectivity of fronto-limbic network in the outcome of subjects with clinical high-risk for psychosis / 上海交通大学学报（医学版）

Objective: To explore the role of functional connectivity (FC) within the fronto-limbic network in predicting the onset of psychosis in the subjects with clinical high-risk for psychosis (CHR). Methods: A total of 164 CHR subjects and 89 healthy controls (HC) who underwent resting-state functional MRI were recruited. FCs between frontal [medial prefrontal cortex and bilateral or-bitofrontal cortex (OFC)] and limbic (bilateral hippocampus and bilateral amygdala) brain regions at baseline were calculated. CHR subjects were further divided into 3 subgroups, i.e., CHR converters (CHR-C) group, symptomatic CHR (CHR-S) group and remitted CHR (CHR-R) group according to clinical outcome after one-year follow-up. The FCs of fronto-limbic network were compared between the groups and among the subgroups, and their interaction with brain regions, as well as their correlations with positive and negative symptoms were analyzed. Results: There was no significant main effect of group (P=0.110), but a significant interaction of subgroups and brain regions (P=0.049). CHR-C group had lower FC between bilateral OFC and bilateral amygdala than HC group and CHR-R group (all P<0.05). The FCs between left OFC and left hippocampus in the three CHR subgroups were all lower than that in HC group (all P<0.05). In addition, the FC between left OFC and right amygdala was positively correlated with the severity of negative symptoms in CHR-C group, while the FCs between left OFC and bilateral hippocampus and between right OFC and left hippocampus were negatively correlated with the severity of positive symptoms in CHR-C group. Conclusion: The decrease of OFC-hippocampus connectivity may be common in the subjects with CHR, while the decrease of OFC-amygdala connectivity may predict CHR subjects will convert to schizophrenia in the later stage.

Characteristics of smooth pursuit eye-movement in subjects at clinical high risk for psychosis / 中国神经精神疾病杂志

Objective To investigate the eye-movement features of smooth pursuit in subjects at clinical high risk for psychosis.Methods sixty subjects at clinical high risk for psychosis and sixty healthy controls were recruited.The smooth pursuit tasks were assessed in both horizontal (0.4 Hz) and Lissajous (0.2 or 0.4 Hz) condition.The Wechsler Memory Scale-third edition and spatial span subtest were used to assess working memory.The difference of the smooth pursuit performance between the two groups and the relationship between smooth pursuit and working memory were analyzed.Results Subjects at clinical high risk for psychosis showed significantly lower Horizontal components for pursuit gain [Lissajous 0.2 Hz task (0.82±0.12) vs.(0.89±0.09),Lissajous 0.4 Hz task (0.78±0.13) vs.(0.84±0.14)],lower vertical components for pursuit gain [Lissajous 0.2 Hz task (0.80±0.14) vs.(0.86±0.12),Lissajous 0.4 Hz task (0.71±0.15)vs.(0.77±0.16)] and higher mean positional error [Lissajous 0.2 Hz task (37.00±19.10) vs.(30.45± 16.18),Lissajous 0.4 Hz task (44.18±19.70) vs.(37.61±16.26)] compared to healthy controls (P＜0.05).There was a significant correlation between pursuit gain and performance on Spatial Span (Horizontal components:r=0.361,P=0.005;vertical components:r=0.327,P=0.01 1) in the Subjects at clinical high risk for psychosis.Conclusions Subjects at clinical high risk for psychosis showed deficits in smooth pursuit,and the deficits were related to the working memory.