Behavioral inhibition moderates the association between overvaluation of shape and weight and noncompensatory purging in eating disorders.

ABSTRACT

OBJECTIVE: The cognitive-behavioral therapy (CBT) model of eating disorders suggests that compensatory purging behaviors (e.g., self-induced vomiting, inappropriate laxative use) are primarily driven by binge eating. However, many individuals endorse purging in the absence of binge eating (i.e., noncompensatory purging [NCP]). Research is needed to understand why some individuals purge in the absence of objective or subjective binge-eating episodes. METHOD: Given the importance of overvaluation of shape/weight in the CBT model, and the existing evidence linking temperamental characteristics like behavioral inhibition (i.e., the tendency to withdraw in response to threat cues) with purging in general, we tested whether behavioral inhibition moderated the relationship between overvaluation of shape/weight and NCP in a sample of individuals in a residential eating disorder treatment center (N = 143). RESULTS: Overvaluation was more strongly related to NCP in individuals with high (relative to low) levels of behavioral inhibition. Among individuals low in behavioral inhibition, overvaluation predicted engagement in NCP to a much weaker extent. DISCUSSION: For those high (relative to low) in behavioral inhibition, both emotional avoidance and overvaluation may be important targets in the treatment of NCP, particularly in the absence of binge eating.