Abstract:Objective To explore the differences in degree centrality( DC) of brain functional networks in adolescents with comorbidity of major depressive disorder( MDD) and obesity based on resting state functional magnetic resonance imaging( rs-fMRI). Methods A total of 75 adolescents with MDD who received outpatient or inpatient treatment at Suzhou Guangji Hospital between October 2022 and July 2023 were selected as research subjects and divided into a MDD comorbid with obesity group( fMDD group, n=37) and MDD group( n=38). During the same period, 35 healthy individuals were recruited from the community as the healthy control group (HC group). All participants underwent rs-fMRI scans. The statistical analysis module in the DPABI software was used to perform a one-way analysis of variance( ANOVA) on the three sets of image data collected, in order to compare the differences in DC values among the three groups of subjects. The correlations between DC values and the Eysenck Personality Questionnaire for Children( EPQ-C), Adolescent Self-Rating Life Events Check List( ASLEC), Patient Health Questionnaire-9( PHQ-9) and Simplified Coping Style Questionnaire( SCSQ) were analyzed. Results Compared with HC group, fMDD group showed statistically significant reductions in DC values in the left thalamus, right thalamus, and right insula( t=-4.82、-5.14、-4.81,all P<0.001). Compared with HC group, MDD group showed lower DC values in the left thalamus and right thalamus, with the differences being statistically significant( t=-4.53、-4.72,all P<0.001). Compared with MDD group, fMDD group showed higher DC values in the left orbitofrontal cortex, with the difference being statistically significant( t=4.60, P< 0.001). Pearson correlation analysis revealed that DC values in the right insula were negatively correlated with extraversion-introversion scores in the EPQ-C (r=-0.432, P=0.008), and with learning stress factor and loss factor scores in the ASLEC( r=-0.367, -0.417;P=0.025、0.010), and DC values in the right thalamus were negatively correlated with learning stress factor and loss factor scores in the ASLEC( r=-0.331, -0.390; P=0.046、0.017), all these differences were statistically significant. Spearman correlation analysis revealed a statistically significant negative correlation between the DC values in the left thalamus and the positive coping scores in the SCSQ( r=-0.338, P=0.041). Conclusions Adolescents with comorbidity of MDD and obesity exhibit abnormalities in DC of specific brain functional networks, and functional abnormalities in the thalamus and insula are closely associated with personality traits and life stresses. Increased DC in the left orbitofrontal cortex may be a characteristic neuroimaging manifestation that distinguishes MDD comorbid with obesity from MDD alone.