The Changes Of Amplitude Of Low Frequency Fluctuation In Patients With Major Depressive Disorder After Antidepressant Treatment:A Resting-state FMRI Study

Objective: In this study,resting-state functional Magnetic Resonance Imaging(r-f MRI)technique was used to analyze the changes of brain function images in major depressive disorder(MDD)patients before and after treatment.This study aimed to find out relative brain regions with abnormal values of Amplitude of Low Frequency Fluctuation(ALFF)in MDD patients,and to explore the effect and pathophysiological mechanism of antidepressant therapy on the brain function of MDD patients.Methods: The subjects were recruited by advertisement or recommended by the Department of Psychological,the First Affiliated Hospital of China Medical University.The written informed consent was obtained before the study began.Then the demographic data were collected,and the scale was used for evaluating and diagnosis.Subjects who met MDD diagnostic criteria accepted a scale assessment and r-f MRI scanning before and after antidepressant treatment.Subjects meeting the following inclusion criteria were included in the case group: 13-45 years old;right-handed;meeting the diagnostic criteria for MDD as specified in DSM-IV Axis I;No other DSM-IV Axis I or Axis II disease;Had never received any antidepressant treatment;After antidepressant treatment,patients’ reduction rate of HAMD-17 was >50%.There were 19 patients defined as case group,including pre-treatment group when the r-f MRI scanning was performed at baseline,and post-treatment group when the r-f MRI scanning was reperformed after treatment.39 healthy subjects were defined as healthy controls group(HC)who were matched with the case group on age,gender,and educatioanal level.HC accepted r-f MRI scanning and HAMD-17 assessment.Demographic data of all participants were analyzed by SPSS 22.0.For the Voxel Based Analysis(VBA)method,Dpabi software,based on Matlab,was used to analyze the differences of ALFF values between the pre-treatment group and the post-treatment group.Two sample t-tests were used to compare the differences between the case group(pre-treatment group and post-treatment group)and the HC.As for aberrant brain regions,region of interest(ROI)method was used,and the ALFF values were analyzed by ANOVA on SPSS 22.0software.The changes of ALFF values between pre-treatment group and post-treatment group were analyzed for Pearson correlation with the decrease of HAMD-17 score after treatment.Results:(1)Compared to the pre-treatment group,the total score of HAMD-17 in the post-treatment group decreased significantly(P<0.05).(2)VBA showed that compared to HC,significantly increased ALFF was found in the right parahippocampal gyrus,left parahippocampal gyrus,and right medial cingulum gyrus while decreased ALFF was found in the left calcarine gyrus in MDD at baseline.Compared with the pre-treatment group,the ALFF values of the post-treatment group increased in the right middle occipital gyrus,while decreased in the left parahippocampal gyrus and the right supplementary motor area.No significant difference in ALFF value was found between the post-treatment group and HC.(3)ROI showed that before treatment,ALFF values of bilateral parahippocampal gyrus,right medial cingulum gyrus in MDD patients were higher than HC’s values,but decreased after treatment.The ALFF value of the left calcarine gyrus in MDD patients was lower than that of HC before treatment,but increased after treatment.For the left parahippocampal gyrus,there was no significant difference of ALFF value between post-treatment group and HC.The ALFF values of the other three brain regions were still had a significant difference between post-treatment group and HC.(4)There was no correlation between the changes of ALFF and HAMD-17 scores in pre-treatment group and post-treatment group.Conclusions: Compared with HC,the function of bilateral parahippocampal gyrus,right medial cingulum gyrus,and left calcarine gyrus in the pre-treatment group of MDD had impaired.After treatment,the brain function changes were found in occipital lobe,parahippocampal gyrus and complementary motor area;Antidepressant treatment had a specific effect on the brain function of left parahippocampal gyrus,suggesting that the changes of ALFF in the left parahippocampal gyrus may be a biological marker for remitted MDD patients.