Effectiveness of cognitive-coping therapy and alteration of resting-state brain function in obsessive-compulsive disorder

Background: Cognitive-coping therapy (CCT), integrating cognitive theory with stress-coping theory, is an efficacious therapy for obsessive-compulsive disorder (OCD). However, the potential brain mediation for the effectiveness remains unclear. We sought to investigate differences of resting-state brain function between OCD and healthy controls and if such differences would be changed by a four-week CCT. Patients and methods: Thirty-one OCD patients were recruited and randomized into CCT (n=15) and pharmacotherapy plus CCT (pCCT, n=16) groups, together with 25 age-, gender- and education-matched healthy controls. The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) was scored to evaluate the severity in symptoms. Resting-state functional magnetic resonance imaging was scanned pre- and post-treatment. Results: For patients, Y-BOCS scores were reduced during four-week treatment for CCT and pCCT (P < 0.001), but no group difference was observed. No differences in amplitude of low-frequency fluctuation (ALFF) values were found between CCT and pCCT either pre- or post-treatment. Compared to controls, ALFF in OCD patients was higher in the left hippocampus, parahippocampus, and temporal lobes, but lower in the right orbitofrontal cortex, rectus, bilateral calcarine, cuneus, lingual, occipital, left parietal, postcentral, precentral, and parietal (corrected P < 0.05). The ALFF in those regions was not significantly correlated to the severity of OCD symptoms. After a 4-week treatment, the ALFF differences between OCD patients and controls disappeared. Limitations: The pharmacotherapy group was not included since OCD patients generally do not respond to pharmacotherapy in four weeks. Conclusions: Our data indicated that resting-state brain function was different between OCD and controls; such differences disappeared after OCD symptoms were relieved.