The dorsolateral prefrontal cortex (DLPFC), a key structure in the executive system, has consistently emerged as a crucial element in the pathophysiology of obsessive–compulsive disorder (OCD). However, the neural primacy of the DLPFC remains elusive in this disorder. We investigated the causal interaction (measured by effective connectivity) between the DLPFC and the remaining brain areas using bivariate Granger causality analysis of resting-state fMRI collected from 88 medication-free OCD patients and 88 matched healthy controls. Additionally, we conducted seed-based functional connectivity (FC) analyses to identify network-level neural functional alterations using the bilateral DLPFC as seeds. OCD patients demonstrated reduced FC between the right DLPFC and right orbitofrontal cortex (OFC), and activity in the right OFC had an inhibitory effect on the right DLPFC. Additionally, we observed alterations in both feedforward and reciprocal influences between the inferior temporal gyrus (ITG) and the DLPFC in patients. Furthermore, activity in the cerebellum had an excitatory influence on the right DLPFC in OCD patients. These findings may help to elucidate the psychopathology of OCD by detailing the directional connectivity between the DLPFC and the rest of the brain, ultimately helping to identify regions that could serve as treatment targets in OCD.

背侧前额叶皮层（DLPFC）是执行系统中的关键结构，一直是强迫症（OCD）病理生理学中的关键要素。但是，在这种疾病中，DLPFC的神经优势仍然难以捉摸。我们使用双变量Granger因果关系分析对88位无药物性强迫症的OCD患者和88位健康对照者进行了调查，研究了DLPFC与其余大脑区域之间的因果相互作用（通过有效连通性衡量）。此外，我们进行了基于种子的功能连接（FC）分析，以使用双边DLPFC作为种子来识别网络级神经功能改变。强迫症患者表现出右DLPFC和右眶额皮质（OFC）之间的FC降低，右OFC中的活性对右DLPFC有抑制作用。此外，我们观察到患者下颞回（ITG）与DLPFC之间的前馈和倒数影响都有变化。此外，小脑活动对强迫症患者右DLPFC有兴奋性影响。这些发现可能会通过详细说明DLPFC与大脑其余部分之间的方向连通性来帮助阐明OCD的精神病理学，最终有助于确定可用作OCD治疗目标的区域。