Depressive patients frequently present with somatic complaints such as pain and fatigue. The anterior insula (AI) is a crucial region for somatic processing, but reported contributions of AI dysfunction to somatic symptoms have varied across studies. We speculated that functional heterogeneity among AI subdivisions may contribute to this inconsistency. To reveal the correlation between each subdivision and somatic symptoms, we investigated resting-state functional connectivity (RSFC) based on seeds within distinct AI subdivisions in 45 depressive patients and 35 matched healthy controls (HCs). Depressive and somatic symptoms were assessed using the Hamilton Depression Rating Scale (HDRS) and the 15-item somatic symptom severity scale of the Patient Health Questionnaire (PHQ-15), respectively. The contributions of AI subregion-specific pathways to depression were further validated by examining changes in symptom severity and RSFC following electroconvulsive therapy (ECT). At baseline, depressive patients exhibited weaker RSFC between ventral AI (vAI) and right orbitofrontal cortex (rOFC) than HCs. Moreover, vAI–rOFC RSFC strength was negatively correlated with PHQ-15 and HDRS scores, indicating that weaker RSFC predicted greater symptom severity. ECT reduced depressive and somatic symptoms, and symptom mitigation was correlated with enhanced vAI–rOFC RSFC. The findings suggest that reduced vAI–rOFC RSFC underlies the somatic symptoms of depression and that enhancing vAI–rOFC RSFC can contribute to amelioration of somatic symptoms.

抑郁症患者经常出现躯体不适，如疼痛和疲劳。前脑岛 (AI) 是躯体处理的关键区域，但报告的 AI 功能障碍对躯体症状的贡献因研究而异。我们推测 AI 细分之间的功能异质性可能导致这种不一致。为了揭示每个细分与躯体症状之间的相关性，我们基于 45 名抑郁症患者和 35 名匹配的健康对照 (HC) 不同 AI 细分中的种子研究了静息状态功能连接 (RSFC)。抑郁和躯体症状分别使用汉密尔顿抑郁评定量表 (HDRS) 和患者健康问卷 (PHQ-15) 的 15 项躯体症状严重程度量表进行评估。通过检查电休克疗法 (ECT) 后症状严重程度和 RSFC 的变化，进一步验证了 AI 子区域特异性通路对抑郁症的贡献。在基线时，与 HC 相比，抑郁患者在腹侧 AI (vAI) 和右侧眶额皮质 (rOFC) 之间表现出较弱的 RSFC。此外，vAI-rOFC RSFC 强度与 PHQ-15 和 HDRS 评分呈负相关，表明较弱的 RSFC 预测更严重的症状。ECT 减轻了抑郁和躯体症状，症状缓解与增强的 vAI-rOFC RSFC 相关。研究结果表明，减少的 vAI-rOFC RSFC 是抑郁症躯体症状的基础，而增强 vAI-rOFC RSFC 有助于改善躯体症状。