Impaired cortico-striatal functional connectivity is related to trait impulsivity in unmedicated patients with obsessive-compulsive disorder

Objectives: Convergent evidence has demonstrated that trait impulsivity, a key feature in obsessive-compulsive disorder (OCD), involves dysregulated frontal-striatal circuits. The present study aims to explore relationships between frontal-striatal circuits, trait impulsivity, and obsessive-compulsive symptoms. Methods: Thirty-six unmedicated patients with OCD and 50 healthy controls (HCs) matched for age, sex, and years of education underwent a magnetic resonance imaging (MRI) procedure. Voxel-wise statistical parametric analysis was used to investigate the differences in resting-state functional connectivity between brain regions functionally connected to six pairs of a-priori defined striatal seed regions, between patients with OCD and HCs. Associations between frontal-striatal connectivity and both trait impulsivity and symptom severity of OCD were analyzed. Results: The results showed altered striatal functional connectivity in OCD group compared to HCs, including increased connectivity of dorsal caudate (DC)-orbitofrontal cortex (OFC), ventral striatum (VS)-OFC, VS-medial prefrontal cortex, and putamen-sensorimotor area, and decreased functional connectivity of DC-anterior cingulate cortex (ACC), putamen-ACC, and putamen-dorsolateral prefrontal cortex (DLPFC). Furthermore, the putamen-DLPFC connectivity was negatively correlated with attentional impulsivity in the OCD group, but showed a positive correlation in HCs. Conclusions: The present findings suggested that dorsal cognitive circuits could reflect the level of inhibitory control, which is balanced with the impulsive drive in healthy controls, but breakdown in OCD. Our findings supported that DLPFC-putamen connectivity underlying trait impulsivity, which were involved in the pathophysiology of OCD. The findings have provided new insights into the neurobiological mechanisms of OCD.