Department of Psychiatry, The First Hospital of China Medical University, Shenyang, China; Brain Function Research Section, The First Hospital of China Medical University, Shenyang, China.
Brain Function Research Section, The First Hospital of China Medical University, Shenyang, China; Department of Radiology, The First Hospital of China Medical University, Shenyang, China.
Neuroimage Clin. 2023;38:103403. doi: 10.1016/j.nicl.2023.103403. Epub 2023 Apr 11.
Suicidal ideation (SI) is one of the most serious consequences of major depressive disorder (MDD). Understanding the unique mechanism of MDD with SI (MDD + S) is crucial for treatment development. While abundant research has studied MDD, past studies have not reached a consensus on the mechanism of MDD + S. The study aimed to investigate the abnormalities of the gray matter volumes (GMVs) and plasma IL-6 level in MDD + S to further reveal the mechanism of MDD + S.
We tested the plasma IL-6 level using Luminex multifactor assays and collected the Structural Magnetic Resonance Imaging (SMRI) data from 34 healthy controls (HCs), 36 MDD patients without SI (MDD - S) and 34 MDD + S patients. We performed a partial correlation between the GMVs of the brain regions with significant differences and plasma IL-6 level with age, sex, medication, scores of HAMD-17 and HAMA as the covariates.
Compared with HCs and MDD - S, MDD + S had significantly decreased GMVs in the left cerebellum Crus I/II and significantly increased plasma IL-6 level; compared with HCs, both the MDD + S and MDD - S had significantly decreased GMVs in right precentral and postcentral gyri. No significant correlation was found between the GMVs and the plasma IL-6 level in the MDD + S and MDD - S, respectively. While the GMVs of the right precentral and postcentral gyri negatively correlated with the level of IL-6 in the whole MDD (r = -0.28, P = 0.03). The GMVs of the left cerebellum Crus I/II (r = -0.47, P = 0.02), and the right precentral and postcentral gyri (r = -0.42, P = 0.04) negatively correlated with the level of IL-6 in HCs.
The altered GMVs and the plasma IL-6 level may provide a scientific basis to understand the pathophysiological mechanisms of MDD + S.
自杀意念（SI）是重性抑郁障碍（MDD）最严重的后果之一。了解伴 SI 的 MDD（MDD+S）的独特机制对于治疗的发展至关重要。虽然有大量研究探讨 MDD，但过去的研究并未就 MDD+S 的机制达成共识。本研究旨在探讨 MDD+S 患者大脑灰质体积（GMV）和血浆白细胞介素 6（IL-6）水平的异常，以进一步揭示 MDD+S 的发病机制。
我们使用 Luminex 多因子检测试剂盒检测了血浆 IL-6 水平，并从 34 名健康对照者（HCs）、36 名无 SI 的 MDD 患者（MDD-S）和 34 名 MDD+S 患者中收集了结构磁共振成像（SMRI）数据。我们以年龄、性别、用药、HAMD-17 和 HAMA 评分作为协变量，对脑区 GMV 与血浆 IL-6 水平之间的偏相关进行了分析。
与 HCs 和 MDD-S 相比，MDD+S 患者左侧小脑 Crus I/II 的 GMV 明显减少，血浆 IL-6 水平明显升高；与 HCs 相比，MDD+S 和 MDD-S 患者右侧中央前回和中央后回的 GMV 明显减少。MDD+S 和 MDD-S 患者 GMV 与血浆 IL-6 水平之间均无显著相关性。然而，右侧中央前回和中央后回的 GMV 与整个 MDD 患者的 IL-6 水平呈负相关（r=-0.28，P=0.03）。左侧小脑 Crus I/II 的 GMV（r=-0.47，P=0.02）和右侧中央前回和中央后回的 GMV（r=-0.42，P=0.04）与 HCs 患者的 IL-6 水平呈负相关。
GMV 和血浆 IL-6 水平的改变可能为理解 MDD+S 的病理生理机制提供科学依据。
