Momentary Interoceptive Reactivity as a Risk Factor for Self‐Injury, Suicidality, and Disordered Eating in a High‐Risk Restrictive Eating Disorder Sample

ABSTRACT Objective Interoceptive processes have been implicated in the onset and progression of disordered eating and self‐injurious thoughts and behaviors (SITBs), but relatively little is known about how these relationships unfold in the short‐term. To clarify the influence of momentary interoception on self‐damaging behaviors, this study tested whether reactivity and volatility in interoceptive attention predicted disordered eating and SITBs in a high‐risk restrictive eating disorder sample. Method One hundred and thirty adults with anorexia nervosa and atypical anorexia and current or lifetime suicidality completed 21 days of ecological momentary assessment evaluating disordered eating behaviors, SITBs, and interoceptive attention. We used dynamic structural equation modeling to test whether short‐term reactivity and trait‐level volatility in interoceptive attention conferred proximal risk for non‐suicidal self‐injury (NSSI), restriction, binge eating, purging, suicidal ideation, and suicidal behaviors. Results At the within‐person level, greater reactivity in interoceptive attention was associated with increased risk for NSSI, binge eating, purging, and active suicidal ideation, whereas decreased reactivity in interoceptive attention was associated with increased risk for passive suicidal ideation. At the between‐person level, greater volatility in interoceptive attention, reflecting a larger amount of intraindividual residual variance in interoceptive processes, was also associated with increased risk for NSSI, binge eating, and purging. No significant effects were detected for restriction or suicidal behavior. Discussion Impairments in interoception have transdiagnostic relevance for understanding eating disorders and SITB risk. Interventions that reduce the intensity of interoceptive fluctuations may help reduce certain eating disorder symptoms and SITBs in the context of anorexia nervosa and atypical anorexia.