Motivation to Recover from Bulimia Nervosa: An Application of the Theory of Planned Behaviour

Background
Bulimia nervosa (BN) is an eating disorder (ED) characterised by recurrent episodes of bingeing and purging, and is associated with low motivation for change, a key barrier to recovery. The Transtheoretical Model (TTM) is the predominant framework for understanding motivation to recover from EDs; however, evidence for its applicability is mixed. The Theory of Planned Behaviour (TPB) remains relatively novel in research applications to recovery from EDs, despite existing literature suggesting it might offer a better framework for motivation to recover than the TTM.

Aims
This exploratory study aimed to use the TPB to identify whether there are different predictors of motivation to stop bingeing and purging, and motivation to recover from BN, and overall, whether the TPB has predictive utility for understanding and predicting motivation to recover from BN.

Methods
This was a quantitative study using the BN stage of change questionnaire (TTM), a purpose-designed TPB questionnaire, the Depression, Anxiety, and Stress scale, and the Eating Disorder Examination Questionnaire. Twenty-three adults participated from three community eating disorder services in the UK, and online via social media. Correlational and regression analyses were conducted.

Results
Stage of Change (TTM), attitudes, and perceived behavioural control (TPB) were identified as predictors of both intention to eat normally and not binge or purge, and intention to recover from BN; however, depression was also a predictor for the former. The TPB variables accounted for 18.9% additional variance in intention to eat normally and not binge or purge, and 54.3% in intention to recover.

Conclusions
This is the first study to apply the TPB to understanding and predicting motivation to change in BN. The TPB showed predictive utility above and beyond the TTM for recovery from BN, and attitudes were the most important predictor of change. This provides useful research and clinical implications.