Decreased inter- and intra-network connectivity after group cognitive behavioral therapy in patients with unmedicated obsessive-compulsive disorder.

Background: Group cognitive behavioral therapy (GCBT) is increasingly being used to treat obsessive-compulsive disorder (OCD) because of its high efficiency, economy, and interaction among group members. However, the changes in network functional connectivity (FC) in patients with OCD with GCBT remain unclear.

Aim: To investigate inter- and intra-network resting-state FC (rs-FC) abnormalities before and after GCBT in unmedicated patients with OCD and validate the efficacy of GCBT.

Methods: Overall, 33 individuals with OCD and 26 healthy controls underwent resting-state functional magnetic resonance imaging. The patients were rescanned 12 weeks after GCBT. Four cognition-related networks-default mode network (DMN), dorsal attention network (DAN), salience network (SAN), and frontoparietal network (FPN)-were selected to examine FC abnormalities within and between OCD networks before and after GCBT. Neuropsychological assessments including memory, executive function, speech, attention, and visuospatial ability were reassessed following GCBT. Pearson's correlations were used to analyze the relationship between aberrant FC in cognition-related networks and altered neuropsychological assessments in patients.

Results: Rs-FC within the DMN and DAN decreased significantly. Additionally, rs-FC between the DMN-DAN, DMN-FPN, DMN-SAN, and DAN-SAN also decreased. Significant improvements were observed in cognitive functions, such as memory, executive function, attention, and visuospatial ability. Furthermore, reduced rs-FC within the DMN correlated with visuospatial ability and executive function; DAN positively correlated with Shape Trails Test (STT)-A test elapsed time; DMN-DAN negatively correlated with Rey-Osterrieth Complex Figure (Rey-O) mimicry time and the three elapsed times of the tower of Hanoi; DMN-SAN negatively correlated with Rey-O imitation time and positively correlated with STT-A test elapsed time; and DMN-FPN negatively correlated with Auditory Word Learning Test N1 and N4 scores.

Conclusion: Decreased rs-FC within the DMN and DAN, which correlated with executive function post-treatment, has potential as a neuroimaging marker to predict treatment response to GCBT in patients with OCD.