DTI Joint VBM For Young Adult With First-onset Major Depressive Disorder The Preliminary Research On The Brain Structure Changes Before And After Treatment

[Objective) To analyze the structural changes of whole brain gray matter and white matter in young adult with first-onset major depressive disorder(MDD) before and after treatment by using diffusion tensor imaging(DTI) of tract-based spatial statistics(TBSS) and voxel-based morphometry(VBM), to analyze the structural changes of whole brain white matter in structure connection and the relationship between the clinical symptoms, and discuss the pathophysiological mechanism of brain structural and functional pathological changes in MDD.[Materials and Methods] 1.Object of study:Totally include 28cases in line with the Diagnostic and Statistical Manual of mental disorders, the first IV version diagnostic criteria for major depression disorder and 28 age-and gender-matched healthy people, to handle of the 17-items of Hamilton Depression Scale (HAMD-17) assessment. Depressive patients,HAMD-17>18, meanwhile the control group of HAMD-17<8.2.Equipment: Then, MRI scan were obtained ordering to T2-weigthed images、T1-weigthed images、DTI and 3D. The patients were followed up for 12 weeks, treated by antidepressant which the types of medication were not interfered.3.Analytical method:By TBSS ethod based on fiber bundles tracer, to compare the white matter and fiber connections fractional anisotropy (FA) between patients and control; Voxel-based morphometry methods were tested against the two sets of the image of gray matter volume of the brain structure by MRI, difference was statistically significant(P<0.05).[Results](1) The sex age and average years of education of two groups were no significant difference. But the average score of HAMD for depressed patients before was 27.31±5.67, and that for the control group was2.79±2.34. difference was statistically significant(P< 0.05); depressed patients before and after treatment, the patients score of HAMD-17 decreased obviously, and statistically significant (p<0.05).(2) DTI analysis:①Compared with controls. MDD patients exhibited significant decreased fractional anisotropy (FA) values in the two sides of frontal lobe, corpus callosum, the two sides of middle temporal gyrus, inferior temporal gyrus hippocampus and left cingulate gyrus, left precentral gyrus. (p<0.05).②Depressed patients before and after treatment: patients with genu and body of corpus callosum, fornix, bilateral internal capsule, corona radiata, left middle frontal gyrus, inferior frontal gyrus, precentral gyrus, pedunculus cerebri, thalamus, external capsule and right superior frontal gyrus fractional anisotropy (FA) values increased.(3) VBM analysis: ①compared to healthy control group,grey matter volume of left superior/middle frontal gyrus,right superior temporal gyrus,left amygdaloid body, left cingulate gyrus,left lentiform nucleus,right head of caudate nucleus and left insular lobe were decreased in the first-episode MDD group,difference was statistically significant(P< 0.05).②Depressed patients before and after treatment:Gray matter volume of bilateral middle frontal gyrus, superior, middle,and inferior temporal gyrus, anterior cingulate cortex, thalamus, precuneus, left superior frontal gyrus, caudate nucleus, orbit frontal cortex, transverse temporal gyri, paracentral lobule, precentral gyrus, postcentral gyrus, posterior cingulate cortex increased.[Conclusion] Major depression in patients with cerebral gray matter volume changes and FA valuesmainly related to exist the limbic system-pallidum-the thalamus cortex-the striatum loop of brain structure abnormalities in multiple regions, Many abnormal brain structure and the links between brain areas, may be the pathogenesis key of depression.