Abnormal functional connectivity (FC) within discrete brain networks is involved in the pathophysiology of obsessive-compulsive disorder (OCD) with inconsistent results. In the present study, we investigated the FC patterns of 40 drug-naive patients with OCD and 38 healthy controls (HCs) through an unbiased voxel-wise global brain FC (GFC) analysis at rest. Compared with HCs, patients with OCD showed decreased GFC within the default mode network (DMN) (i.e., left posterior cingulate cortex/lingual gyrus) and sensorimotor network (i.e., left precentral gyrus/postcentral gyrus) and increased GFC within the executive control network (ECN) (i.e., left dorsal lateral prefrontal cortex and left inferior parietal lobule). Receiver operating characteristic curve analyses further indicated that the altered GFC values within the DMN, ECN, and sensorimotor network may be used as neuroimaging markers to differentiate patients with OCD from HCs. These findings indicated the aberrant FC patterns of the DMN, ECN, and sensorimotor network associated with the pathophysiology of OCD and provided new insights into the changes in brain organization function in OCD.

Objectives: Although cognitive behavioral therapy (CBT) is an effective treatment for obsessive–compulsive disorder (OCD), the treatment mechanisms remain poorly understood. This study aimed to investigate the effects of CBT on changes in the intrinsic whole‐brain functional network of OCD patients.Materials and Methods: Twenty drug‐naive and noncomorbid OCD patients were recruited, and resting‐state functional magnetic resonance imaging was performed before and after 12 weeks of CBT. Moreover, 20 healthy controls were scanned twice with a 12‐week interval. A graph‐theory degree centrality (DC) approach and functional connectivity method were used to analyze the whole‐brain functional network hub and connectivity changes in OCD patients before and after CBT treatment.Results: A significant group × time interaction on DC was found in the left dorsolateral prefrontal cortex (DLPFC); the DC in the left DLPFC was significantly reduced after CBT treatment. Resting‐state functional connectivity (RSFC) between the left DLPFC and right orbitofrontal cortex was increased in the OCD patients at baseline, and normalized after CBT treatment. RSFC changes between the left DLPFC and default mode network (DMN) positively correlated with changes in clinical symptoms in OCD patients.Conclusions: These findings suggest that CBT can modulate changes in intrinsic functional network hubs in the cortico–striato–thalamo‐cortical circuit in OCD patients. Cognitive control network and DMN connectivity may be a potential imaging biomarker for evaluating CBT treatment for OCD.

Background: Cognitive behavioral therapy (CBT) is an effective treatment for Obsessive–compulsive disorder (OCD). Structural and functional white matter defects may suggest a vital neurobiological basis of OCD. However, the effects of CBT on white matter in OCD remain unknown.Objective: The aim was to investigate white matter changes and the effect of CBT on white matter in OCD patients.Methods: Fractional anisotropy (FA) maps were acquired using DTI. Participants included 85 patients with OCD and 90 healthy controls. VBM was then performed to detect regions with significant group differences.Results: Obsessive–compulsive disorder patients exhibited significantly reduced FA values in bilateral OFC, right cerebellum, and left SPG, while higher FA values were observed in right PUT compared with healthy controls. Following CBT, OCD patients showed higher FA values in right MFG, left OFC, right cerebellum, and left MTG, and decreased FA values in right PUT in comparison with pretreatment. Furthermore, FA values in the left OFC of patients were significantly positively correlated with the Y‐BOCS and its associated Compulsions subscale, and FA values in the right PUT were positively correlated with Compulsions subscale. In addition, the percentage change in FA values in left MTG was positively correlated with the percentage reduction in Compulsions subscale, while the percentage change in FA values in left OFC and right PUT was negatively correlated with the percentage reductions in Obsessive and Compulsions subscale, respectively.Conclusions: Our findings demonstrate the abnormalities of white matter microstructure in unmedicated patients with OCD. These abnormalities may be partly reversed by CBT.