Functional Associations of Temperamental Predisposition and Brain Responses While Processing Stressful Word Stimuli Related to Interpersonal Relationships in Bulimia Nervosa Patients: an fMRI Study

Abstract

Bulimia nervosa (BN) is characterized by frequent episodes of uncontrolled overeating and difficulties in adapting to stressful situations. BN patients tend to be sensitive to frustration and impulsive. Personality traits may be associated with the abilities of BN patients to adapt to stressful situations, especially in interpersonal relationships. The aim of the present study was to investigate the functional abnormalities in various brain systems while processing stressful word stimuli related to interpersonal relationships in BN patients. Functional magnetic resonance imaging was used to examine the brain responses of 15 BN patients and 20 healthy women while processing unpleasant words related to interpersonal relationships. We also investigated the relationships between brain responses and temperament trait scale from the Temperament and Character Inventory. BN patients showed significant activations of medial prefrontal cortex and anterior cingulate cortex (ACC) while processing these words. ACC activation was significantly greater in BN patients than in healthy women. Among BN patients, the score of the harm avoidance was positively correlated with the activation of the ACC, and the score of the novelty seeking was negatively correlated with the activations in the left inferior frontal gyrus (IFC) and the insula. These results suggest that ACC activation may play crucial roles in emotional processing impairments of BN. Reduced activations of IFC and insula while processing stressful words may reflect a general failure of self-regulation. These abnormal functional responses to stressful stimuli may be involved in difficulties in adapting to stressful situations in BN patients.