Mapping Cortical and Subcortical Asymmetry in Obsessive-Compulsive Disorder: Findings from the ENIGMA Consortium

Objective: Magnetic resonance imaging (MRI) studies have shown brain structural differences between people with Obsessive-Compulsive Disorder (OCD) and healthy controls. Lateralized dysfunction has been suggested in this disorder on the basis of functional imaging and neuropsychological data, but few studies have specifically examined structural brain asymmetry in OCD.

Method: We studied a collection of 16 pediatric datasets (501 OCD patients and 439 healthy controls), as well as 30 adult datasets (1777 patients and 1654 controls) from the OCD Working Group within the ENIGMA (Enhancing Neuro-Imaging Genetics through Meta-Analysis) consortium. Asymmetries of the volumes of subcortical structures, and of regional cortical thickness and surface area measures, were assessed based on T1-weighted MRI scans, using harmonized image analysis and quality control protocols. We surveyed possible alterations of brain asymmetry in OCD patients. We also explored potential associations of asymmetry with specific aspects of the disorder and medication status.

Results: In the pediatric data, the largest case-control differences were observed for volume asymmetry of the thalamus (Cohen’s d = 0.19) and the pallidum (d = -0.21). Exploratory analyses suggested links between these putative asymmetry changes and medication status, OCD severity, and/or anxiety and depression comorbidities. No significant case-control difference was found in the adult data.

Conclusions: This was by far the largest study of brain asymmetry in OCD. Our study adds to literature implicating the thalamus in the pathophysiology of pediatric OCD, and additionally implicates the pallidum in pediatric cases, but also shows that any case-control differences of structural brain asymmetry are subtle.

We present the full set of results. This site will help researchers to query the results by specifying Age Groups, Volume/Cortical Measures, and Regions of Interest.

The image by default on the right shows an overview of age distribution of each dataset.