S20. Error-Processing in OCD: A Meta-Analysis of fMRI Studies and Investigation of Changes Following CBT

Abstract

Background: Functional magnetic resonance imaging (fMRI) studies report brain activation abnormalities in obsessivecompulsive disorder (OCD) patients during error-processing and inhibitory control. However, conclusions are limited by small sample sizes. Moreover, few studies have examined whether brain response to errors and/or inhibitory control demands change with changes in OCD severity (e.g., pre- to post-treatment). Methods: A Seed-based d Mapping (SDM) (www.sdmproject. com) fMRI meta-analysis using unthresholded t-maps compared patients with OCD and controls during error-processing and inhibitory control. Ten datasets including 239 patients with OCD (mean age range=14-39; mean CY-BOCS range=11-27) and 231 healthy controls (mean age range=14-40) were included. Preliminary data from an independent sample of 21 patients with OCD (8 adolescents and 13 adults, age=25.5, Y-BOCS=24.5) who completed a flanker task during fMRI before and after cognitive-behavioral therapy (CBT) was also examined. Results: In the meta-analysis, patients with OCD, relative to controls, showed hyperactivation in right insula, bilateral inferior frontal gyrus (IFG), posterior medial frontal cortex (pMFC) and frontopolar cortex during error-processing, but hypoactivation in anterior cingulate cortex, right insula/IFG/putamen, orbitofrontal cortex and bilateral caudate during inhibitory control (SDM-Z>2, p