A Prefrontal Near-infrared Spectroscopy Study Of Bipolar And Unipolar Depression Patients Under The Verbal Fluency Task

Objective:Through the analysis of functional near-infrared spectroscopy in patients with bipolar depression(BDd)and unipolar depression(UD),this study explored the differences of activation levels of prefrontal cortex in patients with BDd and UD under verbal fluency task,and the correlation between the severity of different symptoms and hemodynamic response,which provide a theoretical basis for the pathological mechanism and diagnosis of BDd and UD.Methods:1.According to the study criteria,68 patients with BDd,76 patients with UD and73 healthy controls(HC)were recruited.The 24-item Hamilton Depression Rating Scale(HAMD),Hamilton Anxiety Scale(HAMA),Young Mania Rating Scale,Acceptance and Action Questionnaire,and the Cognitive Fusion Questionnaire were used to clinically assess the three groups of subjects.2.Three groups of subjects were tested on the verbal fluency task using functional near-infrared spectroscopy,a paradigm that can evaluate subjects’ verbal ability,semantic memory,and executive functions.3.Compare the differences in age,gender,education,clinical symptoms,and activation levels of prefrontal cortex among the UD,BDd,and HC groups,and analyze the correlation between patients’ anxiety,depression,psychological flexibility,and hemodynamic responses.Results:1.The differences between the three groups were not statistically significant in gender,age and education(P>0.05).The differences between the three groups in HAMA,HAMD,Acceptance and Action Questionnaire and Cognitive Fusion Questionnaire scores were statistically significant(P<0.01),but there was no statistically significant difference between the two groups of patients(P>0.05).2.Oxy-hemoglobin concentration changes in the dorsolateral prefrontal cortex(DLPFC),Broca’s area and frontal pole(FP)were less in the UD and BDd groups than in the HC group,and the difference was statistically significant(P<0.05).Oxyhemoglobin concentration changes in the right DLPFC(CH11)and FP(CH29)in UD group were lower than BDd group,and the difference was statistically significant(P<0.05).3.In UD patients,the right FP was negatively correlated with HAMD(P<0.05),the DLPFC,and the left Broca’s area were positively correlated with HAMD(P<0.05);the premotor cortex(PC)and supplementary motor cortex(SMA),DLPFC were negatively correlated with HAMA.In BDd patients,the FP,left DLPFC were negatively correlated with HAMD(P<0.05);Broca’s area,left FEF,left FP,left DLPFC and left PC and SMA were negatively correlated with HAMA(P<0.05).4.In UD patients,experiential avoidance was positively correlated with HAMA and HAMD(P<0.01);cognitive fusion was positively correlated with HAMA(P<0.01);experiential avoidance was positively correlated with cognitive fusion(P<0.01).In BDd patients,experiential avoidance was positively correlated with HAMA and HAMD(P<0.01);cognitive fusion was positively correlated with HAMA and HAMD(P<0.01);experiential avoidance was positively correlated with cognitive fusion(P<0.01).5.In UD patients,Broca’s area,right PC and SMA and left DLPFC were negatively correlated with experiential avoidance(P<0.05).In BDd patients,right Broca’s area,left FP,left DLPFC and left PC and SMA were negatively correlated with experiential avoidance(P<0.05);right DLPFC,left FP were negatively correlated with cognitive fusion(P<0.05).Conclusion:1.BDd and UD patients had significantly lower activation levels in the DLPFC,Broca’s area and FP than HC,which indicates a common pathophysiological basis for two diseases.The activation levels of channel 11 and 29 may be potential biomarkers to assist in the differential diagnosis between BDd and UD.2.Abnormal activity of the left DLPFC,right FP may be related to the severity of depression,and abnormal activity of the left DLPFC,left PC and SMA may be related to the severity of anxiety.3.The higher the patient’s level of cognitive fusion,the higher the level of experiential avoidance,the poorer the psychological flexibility,and the more severe the anxiety and depression.The left DLPFC and right Broca’s area may be associated with the degree of experiential avoidance,and these brain areas may be the neural mechanism of mental flexibility.