Low weight eating disorders are severe psychiatric disorders that most often develop in adolescence, have a chronic course, and evidence poor response to treatment. This project examined the hypothesis that the insula-amygdala-ventral striatum (IAVS) neurocircuit is responsible for abhorrent food-cue learning in adolescents with LW-EDs and that this learning underlies the core construct of food avoidance. We tested this hypothesis by experimentally manipulating the functionally connectivity of this neurocircuit by utilization of novel clinical treatment, family based interoceptive exposure (FBT-IE) vs. standard family therapy. To delineate this aversive neurocircuit, we utilized novel computational approach integrating facial electromyography into the fMRI of food-cue reversal learning task. This fMRI-EMG was designed to empirically establish aversive responses to food-cues among patients and pleasurable responses to food avoidance. We sought to distinguish pathological responses of the IAVS neurocircuit and its relationship to affective response from healthy controls, establishing the neurocircuit as a key source for divergences in eating, clinical symptoms, and behavior between groups. In addition, we sought to test weather FBT-IE leads to differential changes in clinical, laboratory eating, neurocircuit, and behavioral responses to food cues. At this point, we have completed data collection on 60 patients with LW-EDs and 22 health controls. We have begun analyzing the clinical data. However, 2 of our controls were lost to COVID disruption and 7 of the remaining 20 have incomplete or compromised data. Due to the suspension of activities, we will run out of funding before the end of the NCE because of our efforts to pay staff through the COVID related suspensions. Consequently, this proposed supplement seeks funds to support to staff to complete data collection for the healthy control subjects (8 new subjects, 2 replaced from COVID loss, and 7 replacement of compromised existing data, totaling 17 new healthy control subjects.)
This proposal aims to test a novel neurobiological model of food avoidance in adolescent patients with low weight eating disorders and healthy controls, which hypothesizes hypersensitivity to internal bodily cues and dysregulation in reward learning as maintaining factors of this behavior. Further, the proposal aims to establish modifiability of food avoidance via interoceptive exposure and to identify the primary brain changes associated with this type of intervention.
