Major depressive disorder (MDD) is highly heterogeneous in its clinical presentation. The present exploratory study used magnetoencephalography (MEG) to investigate electrophysiological intrinsic connectivity differences between healthy volunteers and unmedicated participants with treatment-resistant MDD. The study examined canonical frequency bands from delta through gamma. In addition to group comparisons, correlational studies were conducted to determine whether connectivity was related to five symptom factors: depressed mood, tension, negative cognition, suicidal thoughts, and amotivation. The MDD and healthy volunteer groups did not differ significantly at baseline when corrected across all frequencies and clusters, although evidence of generalized slowing in MDD was observed. Notably, however, electrophysiological connectivity was strongly related to suicidal thoughts, particularly as coupling of low frequency power fluctuations (delta and theta) with alpha and beta power. This analysis revealed hub areas underlying this symptom cluster, including left hippocampus, left anterior insula, and bilateral dorsolateral prefrontal cortex. No other symptom cluster demonstrated a relationship with neurophysiological connectivity, suggesting a specificity to these results as markers of suicidal ideation.

严重抑郁症（MDD）在临床表现上高度异质。本探索性研究使用了脑磁图（MEG）来研究健康志愿者与具有抗药性MDD的未经药物治疗的参与者之间的电生理内在连通性差异。该研究检查了从δ到γ的典型频带。除了进行小组比较外，还进行了相关研究，以确定连通性是否与五个症状因素相关：情绪低落，紧张，负性认知，自杀念头和动机。尽管观察到MDD普遍减慢的证据，但在所有频率和群中校正后，MDD和健康志愿者组在基线时均无显着差异。但是，值得注意的是 电生理连通性与自杀念头密切相关，尤其是低频功率波动（δ和θ）与α和β功率的耦合。该分析揭示了该症状群的枢纽区域，包括左海马，左前岛和双侧背外侧前额叶皮层。没有其他症状群集显示出与神经生理学连通性的关系，表明对这些结果的特异性是自杀意念的标志。