Evaluating the predictions of an interoceptive inference model of bulimia nervosa.

OBJECTIVE: Bulimia nervosa (BN) is associated with loss-of-control (LOC) eating episodes that frequently occur in response to negative emotions. According to recent neurocomputational models, this link could be explained by a failure to accurately update beliefs about the body in states of high arousal. Specifically, these interoceptive inference models suggest that under-relying on signals from one's body about sensory experience ("low sensory precision") and/or over-relying on previously held beliefs ("excessively precise priors") lead to inaccurate perception and maladaptive behaviors. We conducted an initial test of these core predictions of the interoceptive inference model in BN using self-report measures. METHODS: We compared women with BN (n = 30) and age-, BMI-, and full-scale IQ-matched controls (n = 31) on trust in sensory information from the body and two types of beliefs about what can be done to regulate high negative affect. Within the BN group, we tested interrelations among these measures and explored their associations with LOC eating frequency. RESULTS: Compared with healthy controls, the BN group reported lower levels of trust in sensory information and stronger beliefs that once upset, there is little one can do, apart from eating, to self-regulate. These beliefs were associated with each other and with lower body trust. Beliefs about the uncontrollability of emotion were associated with more frequent subjective binge-eating episodes. CONCLUSIONS: Findings provide initial support for the core predictions of an interoceptive inference account of BN: low trust in sensory information ("sensory precision") may promote an overreliance on maladaptive "prior beliefs" about the effects of eating on negative emotions, ultimately interfering with accurate updating of beliefs about other strategies that could regulate emotions and maintain LOC eating. Low body trust, strong expectations about emotions, and their neurocomputational underpinnings could be promising combined treatment targets for BN.

Interoception, the brain's processing of bodily signals, is critical for emotional and behavioral control. Disturbances in interoception may contribute to emotion dysregulation and problematic behaviors across a range of psychiatric disorders, including eating disorders, but the exact mechanisms remain unclear. Recent "interoceptive inference" models of psychopathology propose that dysregulated emotions and maladaptive behaviors persist because, during intense emotional states, individuals under-rely on information from bodily signals and over-rely on pre-existing expectations ("prior beliefs"). In this study, we tested these core predictions among individuals with bulimia nervosa (BN). We compared women with BN and healthy controls on self-reported measures of bodily trust and two types of pre-existing beliefs about responses to negative emotions. We found the first evidence of lower trust in bodily signals in individuals with BN compared to controls. This reduced trust was linked to stronger beliefs that there is little one can do, apart from eating, to regulate emotions. These beliefs, in turn, were associated with more frequent eating episodes characterized by loss of control. Though more research is needed to replicate these results, they provide preliminary support for a model that could explain why individuals with BN are more likely to have uncontrolled eating in the context of strong negative emotions.

Effects of borderline personality disorder symptoms on dialectical behavior therapy outcomes for eating disorders.

Existing literature on the effects of borderline personality disorder (BPD) and eating disorder (ED) comorbidity in terms of clinical presentation and treatment outcome has been limited and inconclusive. The present study examined whether clients with EDs and varying levels of BPD symptoms presented with more severe ED symptoms at admission, and whether they responded to dialectical behavior therapy (DBT)-based treatment. Participants (N = 176) were adults in a DBT-based partial hospitalization program for EDs at an academic medical center. Participants completed self-report measures at admission, 1-month postadmission, discharge, and 6-month follow-up. Results suggested that patients with elevated BPD symptoms at admission had greater ED symptoms during treatment, evidenced by small to moderate effect sizes. However, patients with high BPD symptoms demonstrated steeper declines in binge eating, fasting, and parasuicidal behavior early during treatment compared to patients with low BPD symptoms. Individuals with high BPD symptoms at admission (i.e., probable BPD diagnosis) were as likely to meet remission criteria and relapse as individuals with low BPD symptoms, though this null finding may be influenced by small cell sizes. Our findings also suggest that DBT skills use does not predict changes in symptoms. In sum, our findings suggest that while clients with higher BPD symptoms may improve during DBT-based partial hospitalization, their ED symptoms may remain more severe. Future studies are needed to determine whether adjunctive treatments improve outcomes for clients with EDs and comorbid BPD symptoms in DBT programs and whether skills use quality is a better predictor of ED symptom changes. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Impaired belief updating and devaluation in adult women with bulimia nervosa.

Recent models of bulimia nervosa (BN) propose that binge-purge episodes ultimately become automatic in response to cues and insensitive to negative outcomes. Here, we examined whether women with BN show alterations in instrumental learning and devaluation sensitivity using traditional and computational modeling analyses of behavioral data. Adult women with BN (n = 30) and group-matched healthy controls (n = 31) completed a task in which they first learned stimulus-response-outcome associations. Then, participants were required to repeatedly adjust their responses in a "baseline test", when different sets of stimuli were explicitly devalued, and in a "slips-of-action test", when outcomes instead of stimuli were devalued. The BN group showed intact behavioral sensitivity to outcome devaluation during the slips-of-action test, but showed difficulty overriding previously learned stimulus-response associations on the baseline test. Results from a Bayesian learner model indicated that this impaired performance could be accounted for by a slower pace of belief updating when a new set of previously learned responses had to be inhibited (p = 0.036). Worse performance and a slower belief update in the baseline test were each associated with more frequent binge eating (p = 0.012) and purging (p = 0.002). Our findings suggest that BN diagnosis and severity are associated with deficits in flexibly updating beliefs to withhold previously learned responses to cues. Additional research is needed to determine whether this impaired ability to adjust behavior is responsible for maintaining automatic and persistent binge eating and purging in response to internal and environmental cues.