Neural correlates of body dissatisfaction in anorexia nervosa

Body dissatisfaction is an important precipitating and maintenance factor in anorexia nervosa (AN) and behavioral studies suggest that a cognitive-affective component and a perceptual component (perceptual disturbance of one's own body) are both important in this pathophysiology. However, the functional neuroanatomy of body dissatisfaction in AN is largely unknown. This study has investigated self-other body-shape comparison to establish neural correlates of body dissatisfaction in patients with AN. 17 women with AN and 18 age and sex-matched healthy control (HC) subjects were scanned using functional magnetic resonance imaging while comparing themselves with images of slim idealized female bodies (active condition) or viewing images of interior home designs (control condition). Participants were asked to compare their body shape or room design with those presented. Patients with AN (in comparison to the HC group) showed greater anxiety to the self-other body-shape comparison, and they were less satisfied with their current body shape. In the patient group (in comparison to the HC group) the self-other body-shape comparison induced more activation of the right sensorimotor brain regions (insula, premotor cortex) and less activation of the rostral anterior cingulate cortex (ACC). Insula hyperactivation along with ACC hypoactivation may be critical for altered interoceptive awareness to body self-comparison and/or for altered implicit motivation to thin-idealized body images in AN patients.