抑郁症患者动态功能连接状态以及图论属性异常研究

Objective To explore the abnormality in dynamic functional brain network and graph properties of patients with major depressive disorder (MDD).Methods In this study, 51 MDD patients with depression who were admitted to the Third People's Hospital of Tianshui City, Gansu Province from June 2017 to June 2018, and 61 healthy controls (HC) with age and gender matched were recruited. The resting state functional magnetic resonance imaging (fMRI) data were collected, and the 17-Item Hamilton Depression Scale (HAMD17) and Hamilton Anxiety Scale (HAMA) were used to evaluate their depression. By using group independent component analysis to resting-state fMRI data, the sliding windows approach and K-means clustering, the dynamic functional network connectivity (FC) and network topology variability were explored. Results Four recurring transient dynamic functional states were identified, among which the State2 and State4 exhibited significant group differences in FC and temporal properties. (1) Compared with HCs, MDD patients exhibited longer fraction time (Z=-2.653, P=0.008) and mean dwell time (Z=-2.419, P= 0.016) in State2. (2) On the contrary, the MDD patients presented with a shorter fraction time (Z= 2.470, P=0.014) and mean dwell time (Z=2.240, P=0.025) in State4. (3) In State2, MDD patients showed that the connection between the default mode network and the cognitive control network was significantly weakened, while the connection between the cerebellar network and the visual network was significantly enhanced. (4) In state 4, the abnormal changes in FC of the depression group were mainly manifested in the weakening of the connection between the cognitive-related network and the perception-related network, and in the strengthening of the connection between the subcortical network and the cerebral cortex. (5) Further the exploration on graph-theory analysis suggested that MDD patients had lower global efficiency variability (Z=2.036, P=0.042). Conclusion The dynamic FC and temporal properties of MDD patients have changed in two different states, and the variability of global efficiency is reduced.