背景:社交焦虑障碍(SAD)和重度抑郁症(MDD)的特征是动机系统中的行为异常,即,行为抑制系统(BIS)和行为激活系统(BAS)。有限的研究表明,支持情绪的区域的大脑体积,学习/记忆,奖励,认知功能与BIS/BAS有关。为了增加对BIS/BAS的了解,当前的研究使用了网络方法。
方法:SAD患者(n=59),MDD(n=64)和健康对照(n=36)完成了BIS/BAS问卷和结构MRI扫描;基于先前的BIS/BAS研究,感兴趣的体积区域包括皮质和边缘结构。每个诊断组采用贝叶斯高斯图形模型,组间比较。在网络度量中,桥梁中心性是主要利益。方差分析(ANOVA)评估了组间的BIS/BAS行为。
结果:桥中心性显示海马与BAS呈正相关,但不是BIS,MDD;SAD或对照组没有发现。然而,网络密度(即,变量之间关系的总体强度)和度中心性(即,一个变量与所有其他变量之间的整体关系)显示皮质(例如,precuneus,内侧眶额)和皮质下区域(例如,杏仁核,海马)诊断组之间存在差异。方差分析结果显示,与对照组相比,MDD/SAD组的BAS较低,而SAD组的BIS高于MDD组,而这又高于对照组。
结论:初步发现表明网络水平畸变可能是MDD和SAD动机异常的基础。BIS/BAS差异的证据建立在先前的工作基础上,这些工作指出了内在化精神病理学方面的共同和独特的动机差异。
BACKGROUND: Social anxiety disorder (SAD) and major depressive disorder (MDD) are characterized by behavioral abnormalities in motivational systems, namely the behavioral inhibition system (BIS) and behavioral activation system (
BAS). Limited studies indicate brain volume in regions that support emotion, learning/memory, reward, and cognitive functions relate to BIS/
BAS. To increase understanding of BIS/
BAS, the current study used a network approach.
METHODS: Patients with SAD (n = 59), patients with MDD (n = 64), and healthy control participants (n = 36) completed a BIS/
BAS questionnaire and structural magnetic resonance imaging scans; volumetric regions of interest comprised cortical and limbic structures based on previous BIS/BAS studies. A Bayesian Gaussian graphical model was used for each diagnostic group, and groups were compared. Among network metrics, bridge centrality was of primary interest. Analysis of variance evaluated BIS/
BAS behaviors between groups.
RESULTS: Bridge centrality showed hippocampus positively related to BAS, but not to BIS, in the MDD group; no findings were observed in the SAD or control groups. Yet, network density (i.e., overall strength of relationships between variables) and degree centrality (i.e., overall relationship between one variable to all other variables) showed that cortical (e.g., precuneus, medial orbitofrontal) and subcortical (e.g., amygdala, hippocampus) regions differed between diagnostic groups. Analysis of variance results showed BAS was lower in the MDD/SAD groups compared with the control group, while BIS was higher in the SAD group relative to the MDD group, which in turn was higher than the control group.
CONCLUSIONS: Preliminary findings indicate that network-level aberrations may underlie motivational abnormalities in MDD and SAD. Evidence of BIS/BAS differences builds on previous work that points to shared and distinct motivational differences in internalizing psychopathologies.