A large body of research demonstrates that deficits in inhibitory control, i.e., the ability to withhold, delay, or interrupt an automatic response, are a crucial maintaining factor for a large swath of rewarding maladaptive behaviors, such as binge eating, purging, self-injury, and substance abuse. While many patients with these behaviors benefit from cognitive behavioral therapies (CBTs), a large subset of patients experience suboptimal outcomes, likely because CBTs do not target directly inhibitory control. As such, there is growing interest whether inhibitory control trainings (ICTs; i.e., computer tasks in which participants are prompted to repeatedly withhold keypress responses to relevant stimuli) can produce improvements in inhibitory control and be a useful augmentation to CBT. Available data suggest that ICTs can produce changes in inhibitory control on the behavioral and neural circuitry levels (target engagement), and that improvements in inhibitory control can produce decreases in lab-based or short-term behavior (target validation). Yet, findings regarding ICT?s ability to produce sustained changes in behavior outside the laboratory remain mixed and limited. However, investigations of ICT that (1) utilize repeated, intensive trainings over a sustained time period; (2) are adaptive to an individual?s performance; and (3) are personalized to an individual?s behavior, have not been conducted. Additionally, we have insufficient understanding of the conditions (e.g., in clinical samples, moderators of response) under which ICTs are effective. As such, there is strong scientific premise for a test of target engagement, validation, and initial efficacy of a repeated, personalized ICT. While ICTs may improve outcomes for a number of disorders, patients with binge eating (i.e., episodes of eating large amounts of food in a discrete time period with a sense of loss of control), specifically those with a diagnosis of bulimia nervosa (BN) and binge eating disorder (BED), are well-suited for a test of ICT as an adjunct to CBT. We will evaluate whether a personalized, repeated computerized ICT can improve inhibitory control and outcomes from CBT for BN and BED. We will randomize individuals with BN (n=40) and BED (n=40; total n=80) to receive a daily, at- home adjunctive ICT or a sham training condition during the first four weeks of CBT. Our primary aims include: (1) Confirm target engagement, i.e., that ICT produces improvements in inhibitory control; (2) Test the hypothesis that CBT+ICT will produce greater improvements in binge eating frequency compared to CBT + sham and (3) Test the hypothesis that improvements in inhibitory control will be associated with changes in binge eating (i.e., target validation). Our secondary aims include: (1) Test the hypothesis that the effect of ICT on binge eating frequency will be strongest for individuals with poorer baseline levels of inhibitory control, greater approach tendencies to highly palatable food, and higher dietary restraint; (2) Test the feasibility and acceptability of a repeated ICT protocol in individuals with binge eating to inform a full-scale effectiveness RCT. As an exploratory aim, we will examine whether diagnosis (BN or BED) moderates the effect of ICT.
Deficits in inhibitory control (i.e., the ability to withhold an automatic response) are a known maintenance factor for a wide range of maladaptive behaviors. Inhibitory control training paradigms show promise for facilitating outcomes from treatment. The current study aims to evaluate target engagement, target validation, and initial efficacy of an adjunctive inhibitory control training for binge eating, an exemplar rewarding maladaptive behavior.
