Research On The Prefrontal Cortex Of Patients With Major Depressive Disorder By Near Infrared Spectscopy

Major depressive disorder (MDD) is a severe and common mental disorder with alifetime prevalence of6.7per100, and its diagnosis mainly relies on psychiatricinterview without objective biological marker. Multi-channel near-infrared spectroscopy(NIRS) is a noninvasive and low-cost functional neuroimaging technique in psychiatricresearch, and it has been widely used for detecting the spatiotemporal charactersitics ofbrain activity.In order to evaluate the clinical value of NIRS data in the assistant diagnosis ofmajor depressive disorder (MDD), prefrontal cortex (PFC) hemoglobin concentrationchanges of30MDD patients were detected by NIRS under voice fluency task (VFT)and the datum were analyzed.30MDD patients with depressive, anxious andobsessive-compulsive symptoms were assessed by Hamilton Rating Scale forDepression (HAMD), Hamilton Anxiety Rating Scale (HAMA) and Yale-BrownObsessive Compulsive Scale (Y-BOCS). Then hemoglobin concentration changes inPFC were detected by NIRS. Repeated measures analysis of variance, t-test andSpearman correlation analysis were used for analyzing. The results showed thatoxygenation hemoglobin concentration increase in lateral and lower channels in PFC ofMDD patients were significantly lower than the control group, indicating the existenceof hypofusion or hypoactivation. Correlation analysis showed that oxygenatedhemoglobin concentration changes in right dorsolateral prefrontal cortex (DLPFC) wereasssociated with the severity of anxious symptom, while bilateral PFC andantero-medical PFC were associated with the severity of depression, especiallyoxygenated hemoglobin concentration changes in channel21, which was located indorsolateral prefrontal cortex (DLPFC), showed the strongest corralation. However, nostatistical correlation was observed between the oxygenated hemoglobin concentration([oxy-Hb]) changes and the severity of obsessive-compulsive symptom. It suggests that[oxy-Hb] in DLPFC may reflect the severity of anxious and depressive symptoms inNIRS. Then,30MDD subjects and30healthy cases were chosen randomly and theirgraphs of hemoglobin concentration changes during VFT task were drawn. Accordingto the graphic peak and amplitude, graphs were divided into three categories, and the frequency of three categories in each channel was calculated. The results showed thatcompared with control group, the frequency of category Ⅰ decreased, indicatingfrequency of categoryⅠgraph holds the potential in clinical application.In summary, the study explored the clinical application of NIRS from the path ofdata analysis and graphical analysis respectively. The strong correlation betweenDLPFC and depressive and anxious symptoms was found, and the different functionalperformance from anxiety and depression indicating obsession-compulsion’sspecialization, providing more clues for the clinical application of NIRS.