A Comparative Study Of Functional Near Infrared Spectroscopy Imagine In Patients With Depression

Background:In addition to the core symptoms such as low mood,decreased interest,lack of motivation,pessimism and negativity,depression patients often show cognitive dysfunction.Functional Near-infrared spectroscopy(fNIRS)is a relatively new neuroimaging technique that can reflect cognitive function by detecting changes in brain hemodynamics induced by cognitive tasks.FNIRS can aid in the diagnosis of depression,but it is difficult to distinguish depression patients from other psychiatric patients by detecting brain activation during the verbal fluency task alone.There are few studies on the changes of cognitive function in patients with depression before and after treatment using fNIRS.It is not clear whether fNIRS signal is a characteristic marker of depression or whether it changes with disease status.Ketamine is a novel antidepressant that can rapidly improve depressive symptoms and has anti-suicide effects.The effects of ketamine on cognitive function are unknown.Purpose:1.Combining the VFT and Tower of London task,fNIRS was used to explore differences in brain activation characteristics between patients with depression and schizophrenia.2.To investigate the differences in brain activation induced by the VFT in patients with depression before and after drug treatment.Analyze the correlation between fNIRS signal and clinical symptoms.3.The brain activation of patients with depression during ketamine treatment was repeatedly measured by fNIRS to investigate the effects of ketamine on cognitive function.Methods:1.30 patients with depression,30 with schizophrenia,and 30 healthy controls were recruited.FNIRS was used to measure brain activation during the VFT and TOL.2.60 patients with depression and 60 healthy controls were recruited.The VFT was used as the activation task to compare the differences of brain activation in patients with depression before and after treatment for one month.Analyze the correlation between fNIRS signal and clinical symptoms.3.Multiple measurements of fNIRS were performed in 10 patients with treatmentresistant depression using the VFT as activation task.Results1.The VFT performance of schizophrenia patients was worse than that of depression patients and normal controls.Both patient groups performed worse on the TOL task than the healthy control group.Activation of the broad prefrontal cortex region was significantly reduced in both patient groups compared to the control group.In a specific brain region(the dorsolateral prefrontal cortex),hemodynamic changes were significantly lower in patients with schizophrenia than in those with depression.2.Most patients with depression experienced clinical remission after treatment,but their task performance before and after treatment was worse than that of the health control group.No significant activation was found in the depression group before treatment,while the VFT induced significant activation in the frontal pole region after treatment in the patients who responded to the drug.Intergroup comparison showed significant differences in activation of frontal regions before and after treatment in the group with improved symptoms.There was also a significant difference in activation of the frontal pole region between the group with and without symptom improvement.Correlation analysis found that the fNIRS signal of the frontal pole region of interest channel before treatment was significantly negatively correlated with the improvement of HAMD score(r =-0.665,P = 0.001).3.The clinical symptoms improved significantly in the group treated with esketamine,and the MADRS score was significantly decreased after treatment.MADRS score in the esketamine group was also significantly lower than those in the placebo group at review one month later.The activation of the prefrontal cortex induced by the VFT was observed before treatment,but the prefrontal cortex activation was reduced after administration of esketamine.Prefrontal cortex activation during the VTF recovered at review one month later.The hemodynamic response induced by the VFT task decreased after each treatment,but increased before the next treatment.Conclusion1.Both depression and schizophrenia had cognitive impairment compared to healthy control group.Combining the VFT and the TOL task allowed patients with depression and schizophrenia to be distinguished in specific regions of the dorsolateral prefrontal cortex.2.Patients with depression experienced clinical remission after drug treatment,increased brain activation induced by cognitive tasks in the frontal region.The fNIRS signal in the frontal region was associated with improved clinical symptoms.3.Ketamine may have the effect of inhibiting nerve activity.The cognitive decline caused by ketamine is short-term and reversible.4.This study provides further evidence for the application of fNIRS technology in assisting in the diagnosis of depression,assessing clinical symptoms in patients with depression,and predicting the response to antidepressant therapy.