Abstract
OBJECTIVE: This randomized controlled study tested the effect of interoceptive exposure on anterior insula function and connectivity for the extinction of palatable and rotten food-cue associations in adolescent girls with low weight eating disorders (LWED). METHOD: A food-related conditioning paradigm was performed by 39 adolescent girls with LWED and 19 matched controls during functional magnetic resonance imaging (fMRI). Adolescents with LWED were then randomized to 6 sessions of either interoceptive exposure (n = 18) or family-based (n = 21) treatment, followed by a second functional magnetic resonance imaging scan. Whole-brain activation and insula-driven connectivity for the extinction of palatable and rotten food-cue associations were compared between groups, and changes over treatment were compared between the 2 therapies. RESULTS: Adolescents with LWED exhibited diminished bilateral anterior insula activation for the extinction of palatable food-cue associations compared with controls (t(1,55) = 3.9-4.1, p < .001; Hedges g = 0.47-0.55). Brief interoceptive exposure treatment increased left anterior insula activation for the extinction of palatable food-cue associations (t(1,37) = 5.10, p < .001; Hedges g = 1.59) and nonsignificantly improved palatability ratings for these associations during extinction compared with family-based treatment (β = -1.492, p = .087). There were no effects of group or therapy on connectivity or activation for rotten food-cue associations. CONCLUSION: These results suggest that targeting food avoidance in adolescent girls with LWED using interoceptive exposure engages anterior insula regions that mediate the visceral sensation of disgust and may underlie the resistance to extinction. The findings present a window into possible pathophysiological mechanisms of anorexia nervosa and other LWED PLAIN LANGUAGE SUMMARY: This randomized controlled study tested the effect of interoceptive exposure, which aims to reduce conditioned disgust responses to food. This treatment was compared to family-based treatment and the focus was on changes in anterior insula function. 39 adolescent girls with low-weight eating disorders (LWED) and 19 matched controls underwent food-related conditioning during functional magnetic resonance imaging, followed by interoceptive exposure or family-based treatment and a post-intervention imaging session. Key results showed that brief interoceptive exposure treatment increased left anterior insula activation for the extinction of palatable food-cue associations. These results offer new insights into the role of disgust and possible triggers and pathways to anorexia nervosa and other LWED. CLINICAL TRIAL REGISTRATION INFORMATION: Reward Systems and Food Avoidance in Eating Disorders; https://clinicaltrials.gov/study/NCT02795455.