Kang June, Kim Aram, Kang Youbin, Han Kyu-Man, Ham Byung-Joo
Department of Brain and Cognitive Engineering, Korea University, Seoul 02841, Korea.
Department of Biomedical Sciences, Korea University College of Medicine, Seoul 02841, Korea.
Exp Neurobiol. 2022 Apr 30;31(2):97-104. doi: 10.5607/en22008.
Trait impulsivity is a known risk factor for suicidality, and the prefrontal cortex plays a key role in impulsivity and its regulation. However, the relationship between trait impulsivity, neural basis, and suicidality has been inconsistent. Therefore, this study aimed to explore the relationship between impulsivity and its structural correlates (prefrontal gray matter volume), suicidal ideation, and actual suicide attempts. A total of 87 individuals with major depressive disorder participated in study, and the gray matter volume of the prefrontal regions was extracted from T1 images based on region of interest masks. The variables for the mediation models were selected based on correlation analysis and tested for their ability to predict suicide attempts, with impulsivity and suicidal ideation as the mediation variables and gray matter volume as the independent variable. A significant correlation was observed between suicidal ideation and the left dorsolateral prefrontal cortex and right dorsomedial prefrontal cortex. The dual-mediation model revealed a significant indirect relationship between gray matter volume in both regions and suicide attempts mediated by motor impulsivity and suicidal ideation. The counterintuitive positive relationship between gray matter volume and suicidality was also discussed.
特质冲动性是自杀行为的一个已知风险因素，前额叶皮质在冲动性及其调节中起关键作用。然而，特质冲动性、神经基础和自杀行为之间的关系并不一致。因此，本研究旨在探讨冲动性与其结构相关性（前额叶灰质体积）、自杀意念和实际自杀未遂之间的关系。共有87名重度抑郁症患者参与了研究，并基于感兴趣区域掩码从T1图像中提取前额叶区域的灰质体积。中介模型的变量基于相关分析进行选择，并测试它们预测自杀未遂的能力，以冲动性和自杀意念作为中介变量，灰质体积作为自变量。观察到自杀意念与左侧背外侧前额叶皮质和右侧背内侧前额叶皮质之间存在显著相关性。双中介模型显示，这两个区域的灰质体积与由运动冲动性和自杀意念介导的自杀未遂之间存在显著的间接关系。还讨论了灰质体积与自杀行为之间违反直觉的正相关关系。
