National Institute of Mental Health, Clinic, Klecany, 250 67, Czech Republic.
3rd Faculty of Medicine, Charles University, Prague, 100 00, Czech Republic.
BMC Neurosci. 2024 Sep 27;25(1):46. doi: 10.1186/s12868-024-00895-8.
Patients with bipolar disorder (BD) and major depressive disorder (MDD) exhibit depressive episodes with similar symptoms despite having different and poorly understood underlying neurobiology, often leading to misdiagnosis and improper treatment. This exploratory study examined whole-brain functional connectivity (FC) using FC multivariate pattern analysis (fc-MVPA) to identify the FC patterns with the greatest ability to distinguish between currently depressed patients with BD type I (BD I) and those with MDD.
In a cross-sectional design, 41 BD I, 40 MDD patients and 63 control participants completed resting state functional magnetic resonance imaging scans. Data-driven fc-MVPA, as implemented in the CONN toolbox, was used to identify clusters with differential FC patterns between BD patients and MDD patients. The identified cluster was used as a seed in a post hoc seed-based analysis (SBA) to reveal associated connectivity patterns, followed by a secondary ROI-to-ROI analysis to characterize differences in connectivity between these patterns among BD I patients, MDD patients and controls.
FC-MVPA identified one cluster located in the right frontal pole (RFP). The subsequent SBA revealed greater FC between the RFP and posterior cingulate cortex (PCC) and between the RFP and the left inferior/middle temporal gyrus (LI/MTG) and lower FC between the RFP and the left precentral gyrus (LPCG), left lingual gyrus/occipital cortex (LLG/OCC) and right occipital cortex (ROCC) in MDD patients than in BD patients. Compared with the controls, ROI-to-ROI analysis revealed lower FC between the RFP and the PCC and greater FC between the RFP and the LPCG, LLG/OCC and ROCC in BD patients; in MDD patients, the analysis revealed lower FC between the RFP and the LLG/OCC and ROCC and greater FC between the RFP and the LI/MTG.
Differences in the RFP FC patterns between currently depressed patients with BD and those with MDD suggest potential neuroimaging markers that should be further examined. Specifically, BD patients exhibit increased FC between the RFP and the motor and visual networks, which is associated with psychomotor symptoms and heightened compensatory frontoparietal FC to counter distractibility. In contrast, MDD patients exhibit increased FC between the RFP and the default mode network, corresponding to sustained self-focus and rumination.
尽管双相情感障碍 (BD) 和重性抑郁障碍 (MDD) 患者的抑郁发作具有相似的症状，但它们具有不同且了解甚少的潜在神经生物学基础，这常常导致误诊和不当治疗。本探索性研究使用功能连接多变量模式分析 (fc-MVPA) 检查全脑功能连接，以确定具有最大能力区分当前患有 I 型双相情感障碍 (BD I) 的抑郁患者和患有 MDD 的抑郁患者的功能连接模式。
在横断面设计中，41 名 BD I、40 名 MDD 患者和 63 名对照参与者完成了静息态功能磁共振成像扫描。使用 CONN 工具箱中的数据驱动的 fc-MVPA 来识别 BD 患者和 MDD 患者之间具有不同功能连接模式的聚类。所识别的聚类被用作事后种子基础分析 (SBA) 的种子，以揭示相关的连接模式，然后进行二次 ROI-ROI 分析，以描述这些模式之间的连接差异在 BD I 患者、MDD 患者和对照组中。
fc-MVPA 确定了一个位于右侧额极 (RFP) 的聚类。随后的 SBA 显示 MDD 患者的 RFP 与后扣带回皮层 (PCC) 之间以及 RFP 与左侧下/中颞回 (LI/MTG) 之间的连接增加，而 RFP 与左侧中央前回 (LPCG)、左侧舌回/枕叶皮层 (LLG/OCC) 和右侧枕叶皮层 (ROCC) 之间的连接减少。与对照组相比，ROI-ROI 分析显示 BD 患者的 RFP 与 PCC 之间的连接减少，而 RFP 与 LPCG、LLG/OCC 和 ROCC 之间的连接增加；在 MDD 患者中，分析显示 RFP 与 LLG/OCC 和 ROCC 之间的连接减少，而 RFP 与 LI/MTG 之间的连接增加。
当前患有 BD 的抑郁患者和患有 MDD 的抑郁患者之间 RFP 功能连接模式的差异表明存在潜在的神经影像学标志物，这些标志物需要进一步研究。具体来说，BD 患者表现出 RFP 与运动和视觉网络之间的连接增加，这与精神运动症状和增强的额顶叶补偿性连接以对抗注意力分散有关。相比之下，MDD 患者表现出 RFP 与默认模式网络之间的连接增加，这与持续的自我关注和沉思相对应。
