• The Influence of Oxytocin on Risk-Taking in the Balloon Analogue Risk Task Among Women with Bulimia Nervosa and Binge Eating Disorder

      Leslie, Monica; Leppanen, Jenni; Paloyelis, Yannis; Nazar, Bruno; Treasure, Janet; King's College London; Federal University of Rio de Janeiro
      Previous theoretical models of bulimia nervosa (BN) and binge eating disorder (BED) have implicated cross-domain risk-taking behaviour as a significant maintenance factor in both disorders. The current study sought to test this hypothesis by administering the Balloon Analogue Risk Task (BART) to 25 women with BN or BED and 27 healthy comparison women without history of an eating disorder. Furthermore, we tested the effect of a divided dose of 64IU oxytocin on risk-taking behaviour in the BART. Contrary to our hypothesis, women with BN or BED did not exhibit baseline differences in performance on the BART in the placebo condition (t = 1.42, df = 50, p = .161, d = 0.39). Oxytocin did not have a main effect on performance in the BART (F = 0.01, df = 1, p = .907, η2partial < .001); however, there was an interaction such that participants in the BN/BED participant group, compared to the healthy comparison group, demonstrated safer behaviour on the BART specifically in the oxytocin condition, but not in the placebo condition (F = 4.29, df = 1, p = .044, η2partial = .082). These findings cast doubt on the common assumption that individuals with BN and BED exhibit greater risk-taking behaviour in all domains and add to evidence that oxytocin plays a functional role in modulating behaviours which entail trade-offs between reward approach and risk in humans. We recommend that future dose-response studies further investigate the effect of oxytocin on reward approach behaviour in women with recurrent binge eating behaviour and the clinical significance of this effect.
    • Testing the addictive appetite model of binge eating: The importance of craving, coping, and reward enhancement

      Leslie, Monica; Turton, Robert; Burgess, Emilee; Nazar, Bruno; Treasure, Janet; King's College London; University of Alabama at Birmingham; Federal University of Rio de Janeiro
      In the current study, we examine components of the “addictive appetite” model of recurrent binge eating. Specifically, we tested the influence of addictive processes and the influence of emotional regulation processes on recurrent binge eating behaviour. We recruited 79 women in total for the current study; 22 with bulimia nervosa, 26 weight-matched lean comparison women, 15 women with binge eating disorder, and 16 weight-matched overweight/obese comparison women. Participants completed questionnaire assessments of food craving and motivations for eating. Compared to weight-matched comparison women, women with binge-type eating disorders endorse significantly greater levels of food craving, eating for purposes of coping, and eating for purposes of reward enhancement. A cluster analysis revealed that these three traits distinguish women with binge-type eating disorders from weight-matched comparison women. These findings provide support for the addictive appetite model of binge eating behaviour, and highlight addictive and emotional regulation processes as potential targets for treatment.