A Confirmatory Efficacy Study of Interoceptive Exposure for Adolescents with Low Weight Eating Disorders

Project Summary/Abstract Low weight eating disorders, such as anorexia nervosa/atypical anorexia nervosa, are severe psychiatric disorders that often develop in adolescence, have a chronic course, and evidence poor response to treatment at great public health cost. Two core features of LW-EDs are food avoidance and preoccupation with shape and weight. Preliminary data from our initial mechanism study indicate that family based interoceptive exposure (FBT-E) therapy reduces food avoidance, increases autonomous eating and nonjudgement body awareness, and enhances extinction learning to aversive food cues to a greater degree than existing family- based therapy (FBT). Feasibility data indicated high retention, treatment fidelity, and established reliable measures of treatment adherence despite similar short-term (6-week) within-treatment changes in expected body weight. Long-term (6-month) follow-up of these interventions in open trial indicate significantly higher expected body weight among those having received FBT-E. Short-term and long-term changes in weight were highly correlated with changes in expected body weight. Consequently, we will test the confirmatory efficacy of FBT-E vs FBT and 12-month follow-up in a parallel group randomized clinical controlled trial in 120 adolescents aged 12-18. We have three specific aims, including: (1) to determine short term and long term efficacy of FBT-E vs FBT in expected body weight, global eating disorder symptoms, and clinical impairment; (2) to determine efficacy of FBT-E vs. FBT on laboratory measures of autonomous eating, nonjudgmental body awareness, and extinction learning; and (3) estimate whether temporal precedence and mechanistic value (mediation) of early changes in autonomous eating, non-judgmental body awareness, and extinction learning on treatment effects and longitudinal outcomes. Assessments and data analyses will be blinded to treatment. With N=120 participants (n = 60 per group) we can detect moderate sized effects for primary and secondary outcomes. Results will provide data to support novel treatment for LW-EDs and provide theoretical robust model for understanding pathology for children and families that suffer with LW-EDs.