Mount Sinai Researchers Find Specific Therapy That Teaches Patients to Tolerate Stomach and Body Discomfort Improved Functional Brain Deficits Linked to Visceral Disgust That Can Cause Food Avoidance in Adolescent Females with Anorexia Nervosa and other Low-Weight Eating Disorders
Corresponding Author: Kurt P. Schulz, PhD, Associate Professor, Center of Excellence in Eating and Weight Disorders, Icahn School of Medicine at Mount Sinai, New York, and other co-authors
Bottom Line: A trial of interoceptive exposure - a therapy that teaches patients how to tolerate stomach and body discomfort in order to reduce restrictive eating - improved functional deficits in a brain region (the anterior insula) that's involved in the visceral disgust that epitomizes food avoidance in adolescent females with low-weight eating disorders like anorexia nervosa.
Results: This randomized, controlled study tested and compared the effect of interoceptive exposure therapy and traditional family-based treatment. Interoceptive exposure involved providing patients in the intervention group with a novel shake in a gigantic cup (think BIG GULP from 7-11) that is opaque (~1800 Kcal) and having the adolescent drink as much of it as they could tolerate, under the guidance of the study team, to elicit stomach/body discomfort. During this session, the study team taught the participant skills to tolerate the distress and used associative learning (pairing the training with something positive like their favorite music) to change the valence of the challenge from punitive to pleasant. The family-based therapy group underwent traditional refeeding therapy, which teaches parents how to increase the amount of food eaten to gain weight. The researchers found that interoceptive therapy improved the functional deficit in left anterior insula cortex and marginally improved palatability ratings when unlearning edible food-cue associations compared to a family-based control treatment in adolescents with low-weight eating disorders.
Adolescents with low-weight eating disorders presented a distinctive pattern of functional decreases across broad regions of the brain when learning and unlearning edible food-cue associations but not rotten food-cue pairs compared to healthy adolescent females. This pattern included functional deficits in regions of the left and right anterior insula cortex implicated in the sensation of disgust when unlearning cues associated with images of edible food.
Why the Research Is Interesting: The unique focus on the anterior insula brain region involved in the sensation of disgust, together with the use of a new treatment for food avoidance that targets the same brain circuits, present a window into possible triggers and pathways to anorexia nervosa and other low-weight eating disorders.
Who: Adolescent females with low-weight eating disorders were compared to healthy adolescent females
When: Adolescent females with low-weight eating disorders were studied before and after a brief trial of either interoceptive exposure or a family-based control treatment
What: The study measured the use or activation of specific brain regions and circuits during a food-cue learning test in response to interoceptive exposure or traditional refeeding treatment.
How: Adolescents were scanned with functional magnetic resonance imaging. This imaging technique measures the change in magnetic properties that occur when localized regions of the brain use blood oxygen. Brain cell activity triggers a rapid increase in blood flow and volume that increases local blood oxygenation levels. The resultant increase in blood oxygen level-dependent signal serves as an indirect measure of neuronal activity in localized regions of the brain.
Study Conclusions: The results implicate anterior insula cortex in the disease process of food avoidance driven by bodily sensations of disgust. Adolescents with low-weight eating disorders exhibit a distinctive pattern of functional brain deficits in response to images of edible food-cue associations that suggest they divert attention from cues paired with images of edible high-calorie food. The diversion of attention may render the disturbing patterns of food avoidance resistant to change and could explain the functional deficits in anterior insula cortex as a failure to unlearn or change the emotional value of cues previously paired with edible food images. The positive impact of interoceptive exposure on the function of the anterior insula cortex during the unlearning of edible food-cue associations points to this brain region as a potential therapeutic target for treatments for food avoidance driven by bodily sensations of disgust.
Paper Title: Interoceptive Exposure Impacts Food-Cue Extinction in Adolescents with Low-Weight Eating Disorders: An fMRI Study
Said Mount Sinai's Dr. Tom Hildebrandt (senior author) of the research:
"Successfully targeting a disgust-based nuerocircuit with interoceptive exposure offers many possibilities for understanding and improving treatment for anorexia nervosa, but also other anxiety disorders where disgust may play a critical role in impairment, such as obsessive-compulsive disorder, post-traumatic stress disorder, or somatoform disorders."
