抑郁症首次发病未治疗患者脑网络模块化研究

Brain network modularity study in treatment-naive, first episode major depressive disorder

目的观察首次发病未治疗抑郁症患者脑功能网络中模块化及其相关特征的改变，为了解抑郁症的脑网络机制提供证据。方法纳入首次发病、未经治疗的抑郁症患者（病例组，50例）及年龄、性别、受教育程度相匹配的健康志愿者（对照组，37名），基于静息态fMRI的数据，构建全脑功能连接网络，比较2组受试者的模块化相关指标，包括全脑模块化程度、模块内连接和模块间连接的差别，及其与疾病严重度的相关性。结果病例组分为4个模块，对照组分为3个模块。模块化相关指标的分析显示，与对照组比较，病例组左侧眶部额中回、左侧枕上回、左侧眶部额下回、右侧罗兰多壳盖区域的模块度值显著下降，与临床症状无显著相关（r=0．21，P〉0．05）。全脑模块化程度、模块间连接和模块内连接指标差异无统计学意义（r=0．11,P〉0．05）。结论抑郁症患者眶额皮质、枕上回、罗兰多壳盖区域存在连接性的改变，这些区域可能是抑郁症神经网络异常的相关节点。

Objective To examine the changes of functional network modularity in treatment-nafve, first episode major depressive disorder （MDD） patients and the relationship between modularity related indicators and clinical severity. Methods 50 treatment-naive, first episode patients with MDD and 37 age, gender, and education level matched healthy control （HC） were included. They all received fMRI scanning during quiet, eye closed and awake state. We used the 90 automated anatomical labeling （ALL） template to construct functional connectivity matrix. Several modularity related indicators, including global modularization, intra-module connectivity, inter-module connectivity, were computed. The differences in these indicators were compared between MDD group and HC group. The Pearson correlation analysis were performed to show correlation between the regions showing modularity changes and severity of disease. Result There were 4 modules in MDD patients and 3 modules in HC group. MDD patients showed significant decline in modularity degree in the left middle orbitofrontal gyrus, the inferior orbitofrontal gyrus, the superior occipital gyrus, and the rolandic operculum. No significant correlation were found between modularity degree values of these four regions and the severity of disease （r=0.21,P〉0.05）. No significant differences were found in global modularization, intra connectivity and inter connectivity between two groups （r=0.11,P〉0.05）. Conclusion MDD patients may have changed connectivity in orbitofrontal cortex, superior occipital gyrus and rolandic operculum, which are relevant nodes of neural network basis of MDD.