Study of prefrontal cortex activation characteristics of patients with psychiatric disorders in verbal fluency task using functional near-infrared spectroscopy

BackgroundFunctional near-infrared spectroscopy （fNIRS） is a new generation of imaging tool that can be used to assist the diagnosis of psychiatric disorders. However， whether the patterns of prefrontal cortex activation observed by fNIRS are specific for different psychiatric disorders remains to be explored.ObjectiveTo investigate the characteristics of prefrontal cortex activation in patients with depression， anxiety disorder， bipolar disorder and schizophrenia in verbal fluency task （VFT） using fNIRS.MethodsFrom September to December 2021， 39 patients with schizophrenia， 205 patients with depressive disorder， 212 patients with anxiety disorder and 77 patients with bipolar disorder meeting the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders， fifth edition （DSM-5） were recruited in the outpatient and inpatient department of West China Hospital， Sichuan University. fNIRS was used to monitor the prefrontal cortex hemodynamic changes of patients under VFT， and the clinical symptoms of patients were assessed by Symptom Checklist 90 （SCL-90） and Hypomania Checklist-32 items（HCL-32）. Differences in mean oxyhemoglobin （HbO2） concentration and the initial slope from 2 to 7 second during VFT were compared among patients with different diseases， and the correlation between mean HbO2 concentration/initial slope and clinical symptoms was analyzed by partial correlation analysis.ResultsThe concentration of HbO2 in channel 4 （Z=2.828， P=0.028） and channel 6 （Z=2.912， P=0.022） in patients with depression were significantly higher than those in patients with schizophrenia. Patients with anxiety had significantly higher changes in mean HbO2 concentration in channel 4 （Z=3.154， P=0.010）， channel 5 （Z=3.021， P=0.015）， channel 6 （Z=2.980， P=0.017） and of all channels （Z=2.881， P=0.024） than those of schizophrenia patients. There was a statistically significant difference in the initial slope of channel 3 between patients with depressive disorder and those with bipolar disorder （Z=2.691， P=0.039）. Among patients with bipolar disorder， the anger-hostility scores of SCL-90 were negatively correlated with the mean HbO2 concentration changes in channel 4 （r=-0.505， P=0.004）， channel 6 （r=-0.390， P=0.004）， channel 15 （r=-0.546， P=0.002）， channel 16 （r=-0.550， P=0.002） and the mean HbO2 concentration changes of all channels （r=-0.491， P=0.006）.ConclusionPatients with schizophrenia had lower activation in frontopolar and orbitofrontal region than patients with depression and anxiety disorder， and the initial slope of the right frontopolar， inferior frontal and orbitofrontal region in patients with depression is higher than patients with bipolar disorder. In addition， patients with bipolar disorder had less activation in the frontopolar and orbitofrontal lobe， the insular cover of Broca's area and the upper outer frontal cortex， and were more irritable and hostile. ［Funded by 1·3·5 Project for Disciplines of Excellence-Clinical Research Incubation Project， West China Hospital， Sichuan University （number， ZYJC21083）］