Author: Jane Cooper
Cooper, Jane, 2016 An investigation of the role of cognitive bias in eating disorders and its relation to difficulties in emotion regulation, Flinders University, School of Psychology
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Difficulties in emotion regulation contributes to the maintenance of eating disorders and also to the difficulties faced in treatment when tackling behavioural change. The present research investigated factors that influence difficulties in emotion regulation with the aim to understand the relationship between disordered eating and disordered eating behaviours, and these difficulties. The first study assessed the factor structure of one of the most commonly used measures of emotion regulation in eating disorder research, the Difficulties in Emotion Regulation Scale (DERS; Gratz & Roemer, 2004). The scale’s reliability and validity was examined in terms of its ability to predict eating disorder severity and disordered eating behaviours. Results indicated a shorter version of the scale was the best fit to the data in a sample of young women, as well as showing a better ability to predict eating disorder severity. The second study investigated the possible mediators of the relationship between emotion regulation difficulties and disordered eating and disordered eating behaviours. Given that cognitive biases (such as memory and interpretation biases) are implicated in the onset and maintenance of depression and anxiety, and that these disorders are highly comorbid with eating disorders, it was predicted that these cognitive biases would also play a role in eating disorders. This study found negative memory biases were related to disordered eating behaviours, however, it was not related to higher levels of eating disorder psychopathology or difficulties in emotion regulation. Negative interpretation bias related to ambiguous scenarios, on the other hand, was associated with higher levels of disordered eating, disordered eating behaviours, and difficulties in emotion regulation. Bias mediated the relationship between eating disorder severity and difficulties in emotion regulation as well as the relationship between objective binge eating and difficulties in emotion regulation. These relationships were independent of levels of depression and anxiety. The third study attempted to replicate these findings using a sample with clinical levels of disordered eating symptoms. Our findings indicated that negative interpretation bias does not operate similarly in a sub-clinical sample. Negative bias was related to eating disorder severity, disordered eating behaviours (except exercising and fasting), and difficulties in emotion regulation. There was no evidence of mediation over and above the influence of depression and anxiety. However, once depression and anxiety were removed as covariates, interpretation bias mediated the relationship between disordered eating behaviours and difficulties in emotion regulation. Given the cross-sectional nature of the preceding two studies, the final study aimed to investigate whether causality could be shown in an experimental design, using cognitive bias modification (CBM) training to reduce negative interpretation bias and, therefore, symptoms of disordered eating, and difficulties in emotion regulation. The study was conducted in a sample of women who reported clinical symptoms of an eating disorder. The design was a randomized controlled trial, comparing a positive training paradigm, used previously to decrease cognitive biases related to negative self-beliefs, compared to neutral training. Findings indicated no difference between groups on any outcome measure. However, there was a reduction in eating psychopathology and negative affect, and significant improvements in confidence to recover from an eating disorder and weight satisfaction across both conditions. In summary, this research has contributed to a better understanding of the relationship between difficulties in emotion regulation and disordered eating, and in particular the possible mediating role of interpretation bias. However, future research needs to establish causality, before implications for interventions can be explored. Discussion for future directions in research that can progress this agenda is outlined.
Keywords: Eating disorders, emotion regulation, cogntive bias
Subject: Psychology thesis
Thesis type: Doctor of Philosophy
School: School of Psychology
Supervisor: Tracey Wade