Prediction Of Antidepressant Efficacy And Symptom Assessment In MDD Patients

Objective: Major depressive disorder(MDD)is a severe and complex mental disorder caused by a variety of reasons.Patients are mainly manifested as long-term sustained mood depression,accompanied by sleep disorders,decline in volitional activity,slow thinking and other symptoms,serious cases will even produce suicidal thoughts.Not only patients feel pain themselves,but depression also imposes a serious financial burden on families and society.At present,many scholars have conducted extensive studies on the etiology of major depression,including genetics psychosocial aspects.Although past studies have shown that patients with MDD have numerous abnormalities in brain structure and function,the definitive pathogenesis of MDD remains unclear to some extent.Numerous data demonstrate that the anterior part of the left hippocampus,the left rostral hippocampus,is highly relevant to the pathological mechanism of MDD,and that its pathological changes may have important predictive value to antidepressant efficacy in patients with major depression.The purpose of this study was to investigate the predictive value of the function and structure of a specific subregion of the hippocampus,the left rostral hippocampus,,and to reveal the importance of dynamic Functional Connectivity(d FC)as a biomarker of neuroimaging.It also provides new evidence for the application of neuroimaging techniques in the prediction of therapeutic efficacy.It is also important to use big data to explore neuroimaging indicators,including using the left rostral hippocamal volume and the global-brain abnormal Amplitude of Low Frequency Fluctuations(ALFF)to mediate and moderate the relationship between depression and anxiety symptoms in patients with major depression.It helps to clarify the relationship between depression and anxiety in clinical practice,so as to provide evidence for clinicians to conduct individualized treatment for patients with major depression.Materials and methods: Research 1 data were collected from 36 patients with MDD and 43 healthy controls(HCs).The dynamic functional connectivity(d FC)of hippocampal subregion was obtained using a sliding window approach based on rsf MRI(resting state functional magnetic resonance imaging).After 3 months-therapy,36 patients underwent a second rs-f MRI scan and were then divided into two groups based on clinical response,the group that responded to treatment and the group that did not respond to treatment.Statistical methods were used to examine whether there was a significant difference in abnormal d FC between the response and the non-response group.Voxel-based morphometry analysis(VBM)was used to calculate the relative volume of the left rostral hippocampus,previous studies have pointed out that there is a complex relationship between hippocampal volume and its functional connectivity.So we used the mediation model to investigate the between the volume,abnormal d FC and Hamilton Depression Scale scores(HAMD).In Research 2,we partly used R-f MRI data came from the REST-meta-MDD consortium initiated in China,which included25 datasets of 2380 individuals(1276MDD patients and 1104 HC)from 17 hospitals.After employing common exclusion criteria but different inclusion criteria,we used VBM analysis to calculate the relative volume of the left rostral hippocampus,the Hamilton Depression Scale and Hamilton Anxiety Scale(HAMA)were then included in the mediation model analysis.In Research 3,the same data were used to calculate the abnormal ALLF between groups,and the HAMD scores and HAMA scores were included in the moderation analysis.Results: Research 1 showed that compared to healthy controls,patients with MDD showed abnormal d FC in the right precentral gyrus(Pre CG.R),the left postcentral gyrus(Po CG.L),and the left superior temporal gyrus(STG.L),which correlated with the depressive symptoms,and could distinguish between the respond group and nonrespond group.Also,abnormal d FC can mediate the relationship between relative left rostral hippocampal volume and depression remission rate.Research 2 showed that the relative volume of the left rostral hippocampus can mediate the relationship between depressive symptoms and anxiety symptoms.Study 3 shows that the MDD group showed significant ALFF differences in several brain regions compared to the HC group,meanwhile the abnormal ALFF of the right superior frontal gyrus medial orbital(ORBsupmed.R)and the left inferior temporal gyrus(ITG.L)can moderate the relationship between depressive symptoms and anxiety symptoms.Conclusion: This study highlights the key role of the structure and function of the left rostral hippocampus especially the dynamic functional connectivity in predicting the 3-month antidepressant effect in patients with MDD.Meanwhile,big datasets are a stable and reliable way to prove the important role of the left rostral hippocampal structure and abnormal ALFF in depression and anxiety,which is conducive to the development of more stable and reliable neuroimage markers and provide effective and personalized treatment for patients with MDD.