Abstract：
Low social support increases the risk of Major depressive disorder (MDD), yet its effects on brain function are unclear. Thirty-two MDD patients with low social support, 52 with high social support, and 54 healthy controls were recruited. We investigated regional brain activity in MDD patients with low social support using resting-state functional Magnetic Resonance Imaging, employing measures such as degree centrality (DC), regional homogeneity, amplitude of low-frequency fluctuations, and fractional amplitude of low-frequency fluctuations. Abnormal regions identified in these analyses were selected as regions of interest for functional connectivity (FC) analysis. We then explored relationships among social support, brain dysfunction, MDD severity, and insecurity using partial correlation and moderated mediation models. Our findings reveal that MDD patients with low social support show decreased DC in the right superior temporal pole and right medial geniculate nucleus, coupled with increased FC between the right superior temporal pole and right inferior temporal gyrus, and the right supramarginal gyrus compared to those with high social support. Furthermore, the DC of the right medial geniculate nucleus positively correlates with social support, while the FC between the right superior temporal pole and right supramarginal gyrus negatively correlates with both social support and subjective support. Additionally, a moderated mediation model demonstrates that the FC between the right superior temporal pole and right supramarginal gyrus mediates the relationship between social support and depression severity, with security moderating this mediation. These findings underscore the impact of low social support on brain function and depression severity in MDD patients.
摘要：
低社会支持会增加重度抑郁症（MDD）的风险，然而，它对大脑功能的影响尚不清楚。32例社会支持低的MDD患者，52有很高的社会支持，并招募了54名健康对照。我们使用静息状态功能磁共振成像研究了社会支持低的MDD患者的局部脑活动，采用度中心性(DC)等措施，区域同质性，低频波动的振幅，和低频波动的分数振幅。选择在这些分析中鉴定的异常区域作为用于功能连接(FC)分析的感兴趣区域。然后我们探索了社会支持之间的关系，脑功能障碍,MDD严重性,使用偏相关和适度中介模型和不安全感。我们的研究结果表明，社会支持低的MDD患者在右颞上极和右内侧膝状核表现出减少的DC。加上右颞上极和右颞下回之间的FC增加，与那些具有高社会支持的人相比，右缘上回。此外，右内侧膝状核的DC与社会支持呈正相关，而右颞上极和右上脑回之间的FC与社会支持和主观支持均呈负相关。此外,一个有调节的中介模型表明，右颞上极和右腹上回之间的FC中介社会支持和抑郁严重程度之间的关系，安全调节这种调解。这些发现强调了低社会支持对MDD患者脑功能和抑郁严重程度的影响。
