Neurocircuitry of disgust and anxiety in obsessive-compulsive disorder: A positron emission tomography study

Background: Disgust and fear are basic emotions that have different elicitors and expressions, and that appear to be mediated by different neurocircuits. Although obsessive-compulsive disorder (OCD) is classified as an anxiety disorder, disgust may be involved in its pathogenesis. Functional magnetic resonance imaging (fMRI) studies of disgust-inducing visual stimuli in OCD have suggested disorder specific alterations in brain activation during these tasks. Methods: Subjects with OCD and healthy controls (HC) underwent positron emission tomography (PET) brain scanning after injection of H(2) (15)O. During PET, subjects either watched slides designed to evoke feelings of disgust (OCD = 5, HC = 11), expected the delivery of an electrical shock (OCD = 11, HC = 13), or rested (OCD = 11, HC = 14). After the anticipatory anxiety and resting tasks, anxiety ratings, heart rate, and electrodermal measures were obtained. Statistical parametric mapping (SPM) was used to analyze regional cerebr...