The relationship between demographic factors and brain hierarchical changes following antidepressant treatment in...

To investigate the associations between demographic factors and brain hierarchical changes following successful selective serotonin reuptake inhibitor (SSRI) treatment, 57 major depressive disorder (MDD) patients who achieved remission after a 12-week SSRI treatment and 39 healthy controls (HCs) were recruited. MDD patients underwent diffusion tensor imaging (DTI) scans before treatment and after the 12-week SSRI treatment. Depression severity was evaluated with the Hamilton Rating Scale for Depression (HAMD) using the total score and the subscales: retardation, cognitive impairment, anxiety, and sleep disturbance. All HCs also underwent DTI scans after enrollment. Building on gradient mapping techniques, we developed a set of measures to quantify the dispersion within functional communities and also studied demographic-relevant differences in the three-dimensional gradient space of remitted MDD patients. We defined the Z-scores of the gradients in the pre-treatment group relative to the HC group as the disease pattern, post-treatment group relative to the HC group as the recovery pattern. The results showed that the disease pattern of depression is associated with age, as older age groups exhibit more severe impairments in depression. A significant difference was detected in the dispersion of the frontoparietal network (FPN) between pre-treatment and post-treatment patients. With the moderating effect of the age of onset, the dispersion of the FPN was related to the improvement in cognitive impairment, the dorsal attention network (DAN) was related to the improvement in retardation symptoms. Our findings help clinicians be alert to the role of demographic effects on clinical efficacy when treating depressed patients.