Amygdala activation and symptom dimensions in obsessive compulsive disorder

BACKGROUND: Despite knowledge of amygdala involvement in fear and anxiety, its contribution to the pathophysiology of obsessive-compulsive disorder (OCD) remains controversial. In the context of neuroimaging studies, it seems likely that the heterogeneity of the disorder might have contributed to a lack of consistent findings. AIMS: To assess the influence of OCD symptom dimensions on amygdala responses to a well-validated emotional face-matching paradigm. METHOD: Cross-sectional functional magnetic resonance imaging (fMRI) study of 67 patients with OCD and 67 age-, gender- and education-level matched healthy controls. RESULTS: The severity of aggression/checking and sexual/religious symptom dimensions were significantly associated with heightened amygdala activation in those with OCD when responding to fearful faces, whereas no such correlations were seen for other symptom dimensions. CONCLUSIONS: Amygdala functional alterations in OCD appear to be specifically modulated by symptom dimensions whose origins may be more closely linked to putative amygdala-centric processes, such as abnormal fear processing.