Similarities and differences in revised reinforcement sensitivities across eating disorder subtypes

Reinforcement Sensitivity Theory has been used to investigate personality in the development and maintenance of disordered eating. However, the vast majority of research from this perspective has been limited by the use of measures developed to assess the original theory, rather than the significantly revised theory, potentially overlooking key personality differences in eating disorder subtypes. The current study aimed to overcome limitations when using measures based on the original theory by investigating differences and similarities in reinforcement sensitivity across eating disorder subtypes and healthy controls. The measure based on the revised theory assesses i) reward sensitivity [goal-drive persistence; reward interest, reward reactivity], ii) impulsivity, iii) behavioural inhibition, and iv) threat sensitivity. A total of 374 women from the community participated, including those with a past or present AN-R diagnosis (AN-R = 109); those with a past or present binge-type ED (Binge-type = 132); and healthy controls (HC = 133). Participants completed a questionnaire assessing personality, eating disorder symptoms, and past or present eating disorder diagnoses. Results showed that both the AN-R and Binge-type groups were higher in behavioural inhibition and threat sensitivity compared to the HC group. The Binge-type group showed higher impulsivity relative to the AN-R and HC group, and lower Goal-Drive Persistence relative to the HC group. The AN-R group showed lower Reward Interest and Reward Responsiveness relative to the HC group. This study supports and extends previous research with the findings of heightened threat and anxiety sensitivity in those with diagnosed eating disorders. Additionally, among those with a past or present eating disorder, the findings implicate impulsivity in differentiating bingeing versus restricting subtypes.