Investigation of Gastrointestinal Interoception in the Maintenance of Disordered Eating Behaviors - Eating disorders are among the deadliest psychiatric illnesses. High treatment dropout rates and poor prognosis may be due to existing treatments inadequately addressing dysfunction in gastrointestinal (GI) interoception (i.e., altered processing of GI sensations). Indeed, aversive conditioning theories of restrictive eating disorders (i.e., anorexia nervosa [AN], atypical AN, and avoidant restrictive food intake disorder) posit that heightened GI visceral sensitivity (i.e., constant monitoring and worry about GI sensations) maintains restrictive eating disorders), yet this has not been tested. This gap is critical, particularly because high dropout rates during treatment may be because renourishment elicits many of the same GI sensations (e.g., bloating, fullness) that individuals with restrictive eating disorders fear. Further, it is unclear why individuals with restrictive eating disorders exhibit altered experience of GI sensations. It may be that these individuals are responding to different cues than those without an eating disorder due to aberrant GI physiological functioning (e.g., gastric arrhythmias) or that they are experiencing altered perceptual representation (i.e., interoception) of normative GI cues. It is critical to examine the mechanisms underlying altered GI experience in restrictive eating disorders to inform treatment strategies (i.e., medical intervention, GI interoceptive exposures, or both). Consistent with NIMH’s Strategic Plan Goal 3 and special interest in interoception, this study will contribute to enhancing interventions for restrictive eating disorders via the following aims: Aim 1: Determine whether visceral sensitivity leads to the daily maintenance of restricting and compensatory behaviors using ecological momentary assessment (EMA); Aim 2: Identify mechanisms of altered GI experience (i.e., altered GI biology, interoception, or both) in restrictive eating disorders and determine the specificity of GI compared to cardiac interoception for predicting eating disordered behaviors via laboratory tasks and psychophysiology. The proposed study will recruit adults from a university community screening positive for a restrictive eating disorder (n = 75) for an EMA study (14 days). The baseline visit includes behavioral measures of interoception (including GI) and electrogastrography (EGG) and electrocardiography (ECG) recordings. It is anticipated that greater within-person visceral sensitivity will precede disordered eating behavior, and that within-person visceral sensitivity will decrease following disordered eating behavior. Compared to a healthy comparison sample (drawn from the sponsor and co-sponsor’s ongoing collaboration), individuals with restrictive eating disorders will exhibit altered GI activity and altered GI interoception. The proposed study offers exceptional training and professional development opportunities for the applicant, including learning to collect and clean psychophysiology data and conduct analyses in a multilevel modeling framework. This fellowship will strengthen the applicant’s independent research skills in preparation for their long-term career goal of obtaining a research position in a high-research output institution.
