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It has been proposed that approach and avoidance processes may be critically involved in the development and maintenance of eating disorders (EDs), including anorexia nervosa (AN) and bulimia nervosa (BN). The Behavioural Inhibition System and Behavioural Activation System Scales (BIS/BAS) and Appetitive Motivation Scale (AMS) questionnaires were administered to 286 participants: 91 healthy controls (HCs), 121 participants with a current ED, either AN (restrictive and binge purge subtypes), or BN and 74 participants recovered from an ED. Individuals with EDs had higher levels of sensitivity to punishment and lower levels of reward reactivity than controls. Individuals in recovery from an ED scored the same as those in the acute group, with the exception of BAS fun seeking, for which they scored significantly higher than those with restricting AN. Discriminant analysis revealed that HCs were maximally separated from those in the acute and recovered ED groups along a dimension reflecting high punishment sensitivity and low reward sensitivity. Classification analysis demonstrated that ED and HC group membership was predicted from reward and punishment sensitivity measures; however recovered participants tended to be misclassified as ED. This study suggests high punishment sensitivity and low reward reactivity/sensitivity might form a personality cluster associated with the risk of developing an ED.

Processes concerning approach and avoidance motivation are a prominent feature in the landscape of personality and psychopathology research, and it has been suggested that two brain-behaviour systems regulate approach of appetitive stimuli and avoidance of aversive stimuli (e.g. Cloninger, 1987, Gray, 1991, Fowles, 1993, Zuckerman, 2005, Depue, 2006, Elliot, 2008, Carver et al., 2009 and Smillie et al., 2010). The approach system, the Behavioural Activation System (BAS), is theorised to underlie personality dispositions reflecting reward-sensitivity, including Extraversion or Impulsivity (see Pickering and Smillie, 2008). The avoidance system, the Behavioural Inhibition System (BIS), is thought to relate to personality dispositions reflecting punishment-sensitivity, including anxiety and Neuroticism (see Corr et al., 1997). In this article, we refer to punishment sensitivity more broadly, as the theoretical predictions and psychometric measures employed do not distinguish between these processes (fear/anxiety). In recent years, it has been proposed (Loxton and Dawe, 2001, Dawe and Loxton, 2004, Loxton and Dawe, 2006 and Loxton and Dawe, 2007) that approach and avoidance processes may be critically involved in the development and maintenance of eating disorders (EDs). There are a range of reasons why individuals may engage in disordered eating behaviours such as bingeing and purging. For example, using confirmatory factor analysis, Wedig and Nock (2010) recently reported that people binge and purge to regulate their emotional state, specifically to decrease negative emotions and increase positive emotions, or for social reasons, namely to communicate needs to others, or to escape social interaction. Claes et al. (2010), using discriminant analysis found that individual differences in BIS motivation and top-down control independently predicted bingeing/purging behaviours. However, the proposed relationship between reinforcement sensitivity theory and EDs has been necessarily speculative (Dawe and Loxton, 2004, p. 7). Nevertheless, it has been suggested that the elevated anxiety frequently found in ED populations (e.g., Vitousek and Manke, 1994 and Grau and Ortet, 1999) might have a basis in dispositional punishment sensitivity. For example, Ampollini et al. (1999) report that high levels of harm avoidance (a BIS-related construct) are associated with anxiety and depression, which are core features of EDs (Godart et al., 2003, Blinder et al., 2006 and Pallister and Waller, 2008). Several authors have confirmed associations between punishment sensitivity and disordered eating (Loxton and Dawe, 2001, Kane et al., 2004 and Nederkoorn et al., 2004; Claes et al., 2006). In a recent systematic review, Harrison et al. (2010) found that people with an ED had elevated scores on trait measures of punishment sensitivity (anxiety and harm avoidance measured using the Tridimensional Personality Questionnaire (TPQ) (Cloninger, 1987) and the Temperament and Character Inventory (TCI) (Cloninger, 1993) relative to healthy controls. Genetic data support the notion that such relationships reflect dispositional tendencies rather than transient states or symptoms. For instance, Wilksch and Wade (2009) report higher punishment sensitivity, as measured using the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (Torrubia et al., 2001), in non-affected twin siblings of ED women, even after controlling for the temperament scores of the sister. This finding positively correlated with the importance of shape and weight (r = 0.44). Dawe and Loxton (2004) suggest that increased reward sensitivity is associated specifically with vulnerability towards developing binge-eating behaviour. Their proposal has been supported using self-report and behavioural measures of reward sensitivity (Loxton and Dawe, 2001 and Kane et al., 2004), although a later study failed to confirm these findings (Loxton and Dawe, 2007). These studies assessed reward sensitivity using a reaction-time paradigm called the Card Arranging Reward Reactivity Objective Test (CARROT; Powell et al., 1996). In order to provide an alternative assessment (i.e., not based on reaction time), Farmer et al. (2001) used the Taffle Task (Taffel, 1955), in which participants are rewarded financially each time they use certain pronouns during a sentence construction task. A higher frequency of binge eating episodes was associated with increased use of rewarded pronouns. In a student sample, Franken and Muris (2005) found that sensitivity to reward, measured using the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (Torrubia et al., 2001) was significantly related to food craving and BMI, highlighting reward sensitivity as a potential vulnerability factor for developing an ED. Furthermore, Davis and Fox (2008) found that BMI was a statistically significant predictor of reward sensitivity, measured using the Sensitivity to Punishment and Sensitivity to Reward Questionnaire (SPSRQ) (Torrubia et al., 2001) for normal and overweight men. In a systematic review, Harrison et al. (2010) found that individuals with bulimia nervosa (BN) or anorexia nervosa (AN) binge/purge subtypes showed elevated scores on reward-sensitivity questionnaires (Tridimensional Personality Questionnaire (TPQ), Cloninger, 1987, and the Temperament and Character Inventory (TCI), Cloninger, 1993; Behavioural Inhibition System and Behavioural Activation System Scales (BIS/BAS scales, Carver and White, 1994) in comparison to controls. Conversely, individuals with AN restricting type were less sensitive to reward than matched controls. Since this review was published, Claes et al. (2010) have reported BIS BAS data for an additional 40 patients with EDs (AN (23 with restricting AN, 6 with binge purge AN and 11 with BN) and found no difference between those with a restricting ED in comparison to those with a binge purge ED. Wagner et al. (2007), using a monetary reward task, found that activity in the subgenual anterior cingulated cortex and its ventral striatal target were similar during positive and negative feedback, indicating that individuals with a history of AN may have difficulty discriminating between positive and negative feedback. Wagner et al. (2008) have also found that people with AN, in comparison to controls, have a reduced response to food stimuli in insular–striatal circuits, suggesting a difference in the way individuals with AN process taste stimuli. Kaye et al. (2009) have argued that in the absence of appropriate reward processing through ventral-striatal/DA paths, individuals who have recovered from AN might focus on a detailed strategy, rather than the global situation, which has important implications for informing clinicians regarding treatment. It is useful to look to recovered populations to understand more about the potential role of punishment and reward sensitivity in the aetiology of EDs, particularly considering the chronic nature of the illness. The systematic review by Harrison et al. (2010) found that novelty seeking did not alter in the recovered form of BN, although there was some evidence that the high levels of harm avoidance were less pronounced in the recovered from of AN, albeit with a high level of variability between studies. Using functional magnetic resonance imaging paradigms, Wagner et al. (2007) found altered reward processing in women who had recovered from AN with a monetary reward task, and Frank et al. (2006) found women recovered from BN had a reduced reward response to glucose in comparison to artificial saliva. Using positron emission tomography, Frank et al. (2005) also found participants recovered from AN had reduced D2/D3 receptor binding in the ventral striatum, a region involved in the modulation of responses to reward stimuli. Wagner et al. (2006, p276), using latent profile analysis, identified “inhibited” and “disinhibited” personality clusters in individuals recovered from both AN and BN, and Klump et al. (2004, p. 1407) commented that higher levels of harm avoidance and lower self-directedness and cooperativeness found in individuals with EDs compared to controls “may be trait-related disturbances and contribute to the disorders' pathogenesis.” This finding is supported by the review of Kaye et al. (2009). Taken together, the findings suggest that reward and punishment sensitivity may play an important role in the development and maintenance of EDs and it would be beneficial to expand on these interesting data.

This study provides further evidence for the association between high levels of punishment sensitivity and eating psychopathology. The study also suggests that people with EDs are characterised by lower levels of reward sensitivity. Those who had recovered from an ED did not differ from those who were acutely ill, suggesting high punishment sensitivity and low reward reactivity/sensitivity might form a personality cluster associated with the risk of developing an ED. These data add to the knowledge of how constructs from Gray's reinforcement sensitivity theory relate to the development and maintenance of disordered eating.