Regional brain volumes in body dysmorphic disorder compared to controls.

Objectives: Body dysmorphic disorder (BDD) is characterized by a preoccupation with a misperceived flaw in appearance, causing significant distress and disability. Neuropsychological research has revealed deficits in executive function and inhibitory control of emotional responses. The few previous structural neuroimaging studies have had inconclusive findings and we aimed to take this field of research forward by contributing high quality structural data.

Methods: To investigate regional brain volumes we compared 20 BDD participants and 20 matched controls using high-resolution structural T1-weighted magnetic resonance imaging (MRI). The MRI data was subjected to cortical reconstruction and volumetric segmentation using Freesurfer software.

Results: Results showed the right orbitofrontal cortex, bilateral thalamus, left anterior cingulate cortex, hippocampus and amygdala were significantly smaller in the BDD sample compared to controls. The most pronounced differences were in the right orbitofrontal cortex and left anterior cingulate cortex, as these areas were smaller in BDD participants independent of reduced global brain volumes. Duration of illness significantly negatively correlated with right orbitofrontal cortex volumes.

Conclusions: This is the largest volumetric neuroimaging study in BDD to date and provides important data on volumetric differences that implicate fronto-limbic circuits.