Experimental Manipulation of Intolerance of Uncertainty in Adults with Anorexia Nervosa and its Contribution to Eating Pathology

Abstract

Growing research highlights the relevance of Intolerance of Uncertainty (IU) in Anorexia Nervosa (AN). Recent findings show clinical levels of IU in AN, and increased IU is associated with greater degrees of negative mood and impairments in daily functioning. Despite its potential implications for treatment improvements, there are no experimental studies exploring changeability of IU in AN. Adopting an experimental paradigm used in anxiety samples, the aim of this study is to examine whether IU can be experimentally manipulated in AN and to investigate the contribution of IU to eating pathology (EP) in women with AN. Adult females with a DSM 5 AN diagnosis were recruited from a specialized eating disorder clinic. All participants completed the Eating Disorder Examination Questionnaire, Intolerance of Uncertainty Scale and visual analogue scales for state IU and EP before receiving either a high or low IU manipulation; after the manipulation levels of IU were assessed again. It was hypothesized that participants in the high IU condition would report significantly higher levels of eating pathology than participants in the low IU condition, post the manipulation. Results revealed clinical levels of IU in both groups. Against the expectations of the study, there were no differences between the high IU group and the low IU group after the manipulation, hence no analyses associations of IU on EP were implemented. Surprisingly, although in the high IU condition, levels of IU did not increase, in the low IU condition levels of IU reduced significantly, suggesting that malleability of levels of state IU in AN is feasible. Further experimental investigations into the changeability of IU are needed to improve our understanding of its contribution to AN development and maintenance.