Obsessive–compulsive disorder (OCD) is a disabling neuropsychiatric disorder whose neurobiological basis remains unclear. Magnetic resonance imaging (MRI) studies have reported functional and structural alterations of the anterior cingulate cortex (ACC) in OCD. In this study, we explored the functional activity of subregions of the ACC and effective connectivity (EC) between ACC subregions and the whole brain in OCD. We used a Granger causality analysis (GCA) to identify the direction of information flow and whether the impact of that flow was excitatory or inhibitory. We performed resting‐state functional MRI in 31 patients with OCD and 36 healthy controls and analyzed the amplitude of low‐frequency fluctuation (ALFF) and coefficient‐based GCA. The left pregenual ACC (pACC) in patients with OCD showed decreased ALFF relative to controls. There was significantly decreased excitatory output from the left pACC to both right dorsal superior frontal gyrus (dSFG) and left precuneus in patients compared with controls. Patients also had decreased inhibitory input to left pACC from left ventral SFG and left thalamus and caudate relative to controls. Results were similar in drug‐naive patients and those with prior but not current psychopharmacological treatment. In patients, path coefficients of GCA from left pACC to right dSFG showed significant negative correlations with obsession and anxiety ratings. Decreased spontaneous neural activity and altered EC of pACC with widely distributed cortical circuitry, and associations with clinical ratings highlight the importance of pACC functional alteration in OCD.

中文翻译：

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强迫症患者前扣带回皮层的自发活动和有效连通性的改变。

强迫症（OCD）是一种致残的神经精神疾病，其神经生物学基础尚不清楚。磁共振成像 (MRI) 研究报告了强迫症患者前扣带回皮层 (ACC) 的功能和结构改变。在这项研究中，我们探索了 ACC 亚区的功能活动以及 ACC 亚区与强迫症全脑之间的有效连接（EC）。我们使用格兰杰因果分析 (GCA) 来确定信息流的方向以及该流的影响是兴奋性还是抑制性。我们对 31 名强迫症患者和 36 名健康对照者进行了静息态功能性 MRI，并分析了低频波动 (ALFF) 的幅度和基于系数的 GCA。与对照组相比，强迫症患者的左侧前体 ACC (pACC) 显示 ALFF 减少。与对照组相比，患者从左侧 pACC 到右侧额上回 (dSFG) 和左侧楔前叶的兴奋性输出显着降低。与对照组相比，患者的左腹侧 SFG 和左丘脑和尾状核对左 pACC 的抑制输入也减少。结果在未接受药物治疗的患者和接受过但未接受过当前精神药理学治疗的患者中相似。在患者中，从左 pACC 到右 dSFG 的 GCA 路径系数与痴迷和焦虑评分呈显着负相关。具有广泛分布的皮质回路的 pACC 自发神经活动减少和 EC 改变，以及与临床评级的关联突出了 pACC 功能改变在 OCD 中的重要性。