A mechanistic staging model of reward processing alterations in individuals with binge‐type eating disorders

Abstract

Altered reward processing is thought to characterize binge‐type eating disorders, but the exact nature of these alterations is unclear. A more fine‐grained understanding of whether specific aspects of reward processing contribute to the development or maintenance of binge eating may point to new therapeutic targets and personalized treatments. The incentive sensitization theory of addiction proposes that repeated use of a substance increases the desire to approach a reward (‘wanting’) but not pleasure when consuming the reward (‘liking’), suggesting that reward processes driving addiction change over time. We hypothesize that the same may be true for binge eating. Further, consistent with the maladaptive scaling hypothesis, reward processing may be heightened for multiple reinforcers in at‐risk individuals but become tuned toward food once binge eating is initiated. In this article, we propose a mechanistic staging model of reward processing in binge‐type eating disorders that synthesizes existing data and posits that alterations of reward processing depend on illness stage and reward type. We outline translational methods for testing key hypotheses and discuss clinical implications. Considering reward processing alterations in relation to illness stage has the potential to improve treatment outcomes by ensuring that the mechanisms targeted are personalized to the individual patient. Public Significance Individuals with binge‐type eating disorders experience alterations in their desire for, and pleasure from, food. We believe that the exact nature of these alterations in reward processing change over the course of illness—from the at‐risk state to an established illness. If true, treatments for binge‐type eating disorders that target reward processing should be personalized to the illness stage of the patient.

Neuronal activity and reward processing in relation to binge eating

“…These reviews mainly focus on the association between disturbed eating behavior and/or binge eating with specific brain reward pathways but do not take valid subconstructs of reward processing into account [1 ▪▪ ]. However, a better understanding of the specific reward profile involved in a patient's precise behavior will enable caregivers to focus their treatment more on the underlying problem at hand [14 ▪▪ ]. In this article, we give an up-to-date review of evidence on specific subconstructs of reward processing involved in binge eating and their association with brain regions within the neurobiological brain reward circuit.…”

“…Moreover, it stipulates that reward processing does not only involve one brain region but comprises a network interaction between brain areas [41]. Indeed, the reward system also interacts with other brain circuits, including cognitive control, emotion regulation, and interoceptive processing, which also influence the development and maintenance of binge eating behaviors [14 ▪▪ ].…”

“…How binge eating behavior begins, is not clearly explained by the incentive sensitization theory or habit model. However, valuation of food reward, as a trait, is hypothesized to play an important role here [14 ▪▪ ]. Trait impulsivity in adolescents is linked to loss of control eating [42].…”

“…Bodell and Racine [14 ▪▪ ] recently suggested a more integrated model of staging, or maladaptive scaling that states that reward processing evolves over the course of illness in binge eating, starting with the at-risk state, and ending as a fully developed, rigid illness. Taking this approach enables the integration of different theoretical models proposed in the literature and may be highly relevant when choosing the right treatment for binge eating.…”

Integrating aspects of affect, reward, and cognition to develop more comprehensive models of binge‐eating pathology

“…Within the field of eating disorders, reward‐related processes have received considerable attention in recent years (Dawe & Loxton, 2004; Forester et al, 2022; Harrison et al, 2010; Haynos et al, 2020; Kober & Boswell, 2018; Schaefer & Steinglass, 2021; Steinglass & Walsh, 2006; Stojek & MacKillop, 2017; Walsh, 2013; Wierenga et al, 2014; Wonderlich et al, 2021; Wu et al, 2016) with accumulating evidence supporting an association between aberrant reward responding and eating pathology (Avena & Bocarsly, 2012; Harrison et al, 2010; Hildebrandt et al, 2018; Schaefer & Steinglass, 2021; Stojek & MacKillop, 2017; Uniacke et al, 2018; Wonderlich et al, 2021; Wu et al, 2016). Importantly, basic science research has identified numerous distinct reward‐related processes that may have differential relationships with eating disorders (Berridge & Robinson, 2016; Bodell & Racine, 2022). For example, the National Institute of Mental Health (NIMH) Research Domain Criteria (RDoC) propose nine separate reward subconstructs, each with unique behavioral indicators and neural substrates (National Institute of Mental Health, 2023).…”