Applying the disgust conditioning model of food avoidance: A case study of acceptance-based interoceptive exposure

Early change in gastric-specific anxiety sensitivity as a predictor of eating disorder treatment outcome

Eating disorders (EDs) are often accompanied by gastrointestinal (GI) distress. Anxiety sensitivity is the tendency to interpret sensations of anxiety as threatening or dangerous, and includes both broad physical symptoms (e.g., elevated heartrate) and GI-specific symptoms. Physical and GI-specific anxiety sensitivity may be important risk and maintaining factors in EDs. This study tested the hypothesis that greater reductions in both types of anxiety sensitivity during the first month of treatment would predict lower ED symptoms and trait anxiety at discharge and 6-month follow-up. Patients (n = 424) in ED treatment reported physical and GI-specific anxiety sensitivity, ED symptoms, and trait anxiety at treatment admission, 1-month into treatment, discharge, and 6-month follow-up. Analyses were conducted with hierarchical linear regression with imputation, controlling for relevant covariates. Results indicated that early reduction in GI-specific but not general physical anxiety sensitivity predicted both lower ED symptoms and lower trait anxiety at discharge and 6-month follow-up. These findings demonstrate the importance of GI-specific anxiety sensitivity as a potential maintaining factor in EDs. Developing and refining treatments to target GI-specific anxiety sensitivity may have promise in improving the treatment not only of EDs, but also of commonly co-morbid anxiety disorders.

Further validation of the visceral sensitivity index: Psychometric properties and utility for predicting disordered eating in a diverse university sample

Gastrointestinal (GI) visceral sensitivity (i.e., anxiety/worry over GI sensations) may be a key maintaining factor for disordered eating; however, it is unknown whether GI visceral sensitivity predicts the range of disordered eating behaviors in nonclinical samples. The current preregistered study aimed to replicate previous construct validity findings of the Visceral Sensitivity Index (VSI; i.e., factor structure, convergent and discriminant validity) and examine its criterion-related validity for predicting a range of disordered eating attitudes and behaviors in a diverse undergraduate sample. A total of 591 university students were retained in the final analytic sample (53 % women; 23 % Hispanic [Any Race], 10 % Asian, 9 % Black) and completed the VSI, disordered eating, and additional validity measures. A confirmatory factor analysis tested the factor structure of the VSI, and correlations were used to examine convergent and discriminant validity. Hierarchical regressions and t-tests were used to examine criterion-related validity. Results replicated previous construct validity findings in a diverse undergraduate sample. Exploratory analyses supported invariance of the VSI across gender and the VSI discriminated between individuals at high- versus low-risk for an eating disorder and predicted a range of disordered eating attitudes (e.g., body dissatisfaction) and behaviors (e.g., restricting, binge eating, purging, compulsive exercise). GI-specific anxiety appears to be transdiagnostic across disordered eating behaviors and relevant across the spectrum of disordered eating severity. Future work may include developing transdiagnostic models of GI visceral sensitivity in disordered eating and investigating inclusion of the VSI in university screening efforts.

Phase-Transitions in Disgust During Self-Initiated Eating Among Adolescents With Anorexia Nervosa and Related Low-Weight Eating Disorders and Matched Controls

BACKGROUND

Understanding the emotional context of feeding behavior may help identify causal mechanisms of food avoidance among individuals with anorexia nervosa. Although predominant food avoidance models assume fear of fat drives feeding behavior, disgust may be more theoretically and proximally relevant to moment-to-moment experiences of feeding. This study, therefore, aimed to examine affect and food avoidance using automated affect analysis from facial response by measuring time-specific transitions in disgust during a laboratory eating paradigm. We hypothesized that phase transitions in disgust would distinguish temporally self-initiated eating from food avoidance.

METHODS

Sixty-three adolescents with anorexia nervosa or another low-weight eating disorder (LWED) and 27 age- and sex-matched controls were recruited as part of a larger study; 45 patients and 22 controls provided data on autonomous eating and facial affect during a laboratory meal. Dynamic structural equation models quantified moment-to-moment relationships between disgust and feeding behavior.

RESULTS

Self-initiated eating was associated with greater increases in disgust, but not fear, intensity among those with LWED relative to control participants and greater disgust intensity predicted lower likelihood of self-initiated eating.

DISCUSSION

Phasic transitions in disgust provide moment-to-moment evidence of affective influence on self-initiated eating and lend credibility to the hypothesis that disgust contributes to food avoidance and initiation in individuals with LWED.

Obsessive-Compulsive Symptomatology and Disgust Propensity in Disordered Eating Behaviors of Adolescents with Celiac Disease

BACKGROUND

Considering the importance of underlying psychopathological mechanisms that mediate maladaptive eating behaviors in celiac disease (CD) in the determination of cognitive-behavioral therapeutic approaches, we investigated the impact of obsessive-compulsive symptomatology and disgust propensity on disordered eating attitudes (DEA) and poor gluten-free diet (GFD) compliance in adolescents with CD.

METHOD

Adolescents with biopsy-proven CD (n = 148, aged 12-18 years) were compared with age- and sex-matched controls (n = 104) in terms of eating attitudes/behaviors, obsessive-compulsive symptoms, and disgust propensity, as well as depression and anxiety to rule out depression- and anxiety-related covariates. The clinical implications associated with poor GFD compliance were determined using between-subgroup analysis. Multivariate linear regression and multiple logistic regression were used to identify predictors of DEA and GFD noncompliance, respectively.

RESULTS

In adolescents with CD, DEA was remarkably associated with obsessive-compulsive symptom severity and disgust propensity, especially in contamination and core disgust sub-dimensions. Obsessionality and disgust propensity were independent predictors of DEA, of which the obsessive-compulsive symptom severity was the most decisive predictor of DEA. Higher DEA severity and lower body mass index were independent predictors of poor GFD compliance.

CONCLUSION

Higher obsessionality, accompanied by disgust-related evaluative conditioning processes, may contribute to constructing a cognitive network consisting of hypervigilance and catastrophic interpretations towards benign somatic stimulations, food-related preoccupations, and avoidant behaviors in the disordered eating of adolescents with CD. The reciprocal relationship between lifelong GFD and DEA, mediated by obsessionality and disgust propensity, was supported by current findings that could guide clinicians in the management of maladaptive eating behaviors in adolescents with CD.

Psychological interventions for interoception in mental health disorders: A systematic review of randomized-controlled trials

Disturbed interoception (i.e., the sensing, awareness, and regulation of internal body signals) has been found across several mental disorders, leading to the development of interoception-based interventions (IBIs). Searching PubMed and PsycINFO, we conducted the first systematic review of randomized-controlled trials (RCTs) investigating the efficacy of behavioral IBIs at improving interoception and target symptoms of mental disorders in comparison to a non-interoception-based control condition [CRD42021297993]. Thirty-one RCTs fulfilled inclusion criteria. Across all studies, a pattern emerged with 20 (64.5%) RCTs demonstrating IBIs to be more efficacious at improving interoception compared to control conditions. The most promising results were found for post-traumatic stress disorder, irritable bowel syndrome, fibromyalgia and substance use disorders. Regarding symptom improvement, the evidence was inconclusive. The IBIs were heterogenous in their approach to improving interoception. The quality of RCTs was moderate to good. In conclusion, IBIs are potentially efficacious at improving interoception for some mental disorders. In terms of symptom reduction, the evidence is less promising. Future research on the efficacy of IBIs is needed.

Development and initial pilot validation of a treatment fidelity instrument for family-based interoceptive exposure for adolescents with low-weight eating disorders

BACKGROUND

This pilot study outlines the development and psychometric evaluation of a therapist adherence coding measure for a novel treatment, Family-Based Treatment Interoceptive Exposure (FBT-IE).

METHODS

The IE Adherence Coding Framework (IE-ACF) was developed from the FBT-IE Manual using an iterative process. Items on the IE-ACF were coded by two independent coders as either present or absent with therapists considered adherent if both independent coders coded the item as "present." Videotaped sessions of FBT-IE of 30 adolescents with low-weight eating disorders (DSM-5 typical/atypical anorexia nervosa) and their families were coded. Participants received the FBT-IE intervention as part of a randomized controlled trial.

RESULTS

Seventy FBT-IE videos were coded. The IE-ACF identified a mean (SD) rating of 80% (±5%) therapist adherence to the protocol across the six-session treatment, with a per item adherence ranging from 36-100%. Two independent coders demonstrated moderate to almost perfect inter-rater reliability (κ range 0.78-0.96) across the sessions.

CONCLUSION

IE-ACF measured therapist adherence to our novel FBT-IE treatment for adolescents with low-weight eating disorders. Through this study, we demonstrated that 1) our therapists were adherent to the FBT-IE manual in the context of an ongoing clinical trial and 2) that independent coders reliably coded sessions using our novel IE-ACF.

Disgust and fear reactions uniquely affect intrusions and posttraumatic stress symptoms

Disgust reactions commonly occur during/following trauma and predict posttraumatic stress (PTS) symptoms. Yet, disgust is not mentioned in DSM-5 PTSD criteria. To investigate disgust's clinical significance in PTSD, we measured the relationship between disgust (and fear) reactions to a personal trauma, and problematic intrusion characteristics (e.g., distress) and intrusion symptom severity. We focused on intrusions because they are a transdiagnostic PTSD symptom, though we also measured overall PTS symptoms to replicate prior work. Participants (N = 471) recalled their most traumatic/stressful event from the past six months. They then rated disgust and fear reactions to this event and completed the Posttraumatic Stress Disorder Checklist-5. Participants who had experienced intrusions about their event in the past month (n = 261) rated these intrusions on several characteristics (e.g., distress, vividness). We found stronger traumatic event-related disgust reactions were associated with more problematic intrusion characteristics, higher intrusion symptom severity, and higher overall PTS symptom severity. Notably, disgust reactions uniquely predicted these variables after statistically controlling for fear reactions. We conclude disgust reactions to trauma may be similarly pathological to fear reactions for intrusion and broader PTS symptoms. Therefore, PTSD diagnostic manuals and treatments should recognize disgust as a trauma-relevant emotion.

Exploring the role of disgust sensitivity and propensity in selective eating

While disgust is a clinically and theoretically relevant construct for selective eating, limited research has examined how different aspects of disgust relate to selective eating severity in adults. Thus, the present study sought to 1) compare disgust propensity (how easily people are disgusted) and disgust sensitivity (how unpleasant disgust is) across a spectrum of selective eaters, 2) explore the specificity of the associations between disgust sensitivity/propensity and selective eating across selective eating and related phenotypes, and 3) explore whether the relationship between selective eating and disgust is food-specific. Participants were 554 adults recruited on Amazon's Mechanical Turk who completed cross-sectional surveys on study constructs. The sample was recruited to over-represent individuals with high levels of selective eating. Results support that disgust propensity, but not sensitivity, was elevated in the impaired selective eating group compared to non-impaired selective eaters and non-selective eaters. Only the selective eating phenotype was independently associated with both disgust sensitivity and propensity. Correlation results supported that the associations between selective eating and disgust were specific to the disgust elicited by food (i.e., animal protein, fruits, vegetables). Overall, results support that disgust propensity and disgust sensitivity play a role in selective eating. Results imply that disgust sensitivity associated with selective eating appears limited to the food domain and may be more specific to disgust eliciting food itself, rather than signs of food contamination or spoilage.

General versus hunger/satiety-specific interoceptive sensibility in predicting disordered eating

Dysfunctional interoceptive processing of hunger and satiety cues is particularly relevant to disordered eating behaviors. However, researchers often rely on general measures of interoceptive sensibility (IS¹; self-reported experience of internal bodily cues) which conflate interoceptive processes across biological systems (e.g., gastric, cardiac) when assessing the role of interoception in disordered eating. Participants (N = 213; 50% female, age M = 20.77 years) were recruited from a large southeastern university for this online study and completed the Intuitive Eating Scale-2 (hunger/satiety-specific), the Multidimensional Assessment of Interoceptive Awareness-2 (general), and the Eating Disorder Inventory Interoceptive Awareness Subscale (general) as measures of IS. The Eating Pathology Symptoms Inventory was used to assess disordered eating attitudes and behaviors. Controlling for sex and body mass index, hunger/satiety-specific IS was associated with binge eating, purging, and cognitive restraint over and above general IS measures and emerged as the dominant predictor of each. Hunger/satiety-specific IS did not predict restricting behavior. Dysfunctional processing of hunger and satiety cues may be a particularly important risk factor to target in screenings and interventions for disordered eating. Findings highlight the importance of careful selection of IS measures in research and targeting hunger/satiety-specific IS in clinical interventions for disordered eating.

Gastrointestinal Interoception in Eating Disorders: Charting a New Path

PURPOSE OF REVIEW

Abnormal interoception has been consistently observed across eating disorders despite limited inclusion in diagnostic conceptualization. Using the alimentary tract as well as recent developments in interoceptive neuroscience and predictive processing as a guide, the current review summarizes evidence of gastrointestinal interoceptive dysfunction in eating disorders.

RECENT FINDINGS

Eating is a complex process that begins well before and ends well after food consumption. Abnormal prediction and prediction-error signals may occur at any stage, resulting in aberrant gastrointestinal interoception and dysregulated gut sensations in eating disorders. Several interoceptive technologies have recently become available that can be paired with computational modeling and clinical interventions to yield new insights into eating disorder pathophysiology. Illuminating the neurobiology of gastrointestinal interoception in eating disorders requires a new generation of studies combining experimental probes of gut physiology with computational modeling. The application of such techniques within clinical trials frameworks may yield new tools and treatments with transdiagnostic relevance.

Lessons learned developing and testing family-based interoceptive exposure for adolescents with low-weight eating disorders

BACKGROUND

Anorexia nervosa (AN) usually develops in early adolescence and is characterized by high rates of morbidity and mortality. Family-based therapy (FBT) is the leading evidence-based treatment for adolescents with AN, but not all patients experience sufficient improvement. The purpose of this manuscript is to describe the development and subsequent experience with a Family-Based Interoceptive Exposure (FBT-IE) for adolescents with a broader form of low-weight eating disorders.

METHODS

The novel IE-based behavioral intervention is a six-session family-based treatment module designed to directly target and modify disgust by altering the prefrontal regulation of the insula response to aversive stimuli by decreasing visceral sensitivity (e.g., bloating). Each session teaches a new skill regarding tolerating distress to visceral sensations associated with disgust and an in-vivo "IE exercise," in which the family is provided with a meal replacement shake of unknown content and caloric density.

RESULTS

In this novel treatment, the patient learns to tolerate disgust in the context of a challenging food stimulus as a way to increase consumption of restricted foods outside of session.

CONCLUSION

We discuss successes and challenges executing this treatment with patients with low-weight eating disorders and propose future directions for the intervention.

Do children with recurrent abdominal pain grow up to become adolescents who control their weight by fasting? Results from a UK population-based cohort

OBJECTIVE

Gastrointestinal (GI) problems are common in eating disorders, but it is unclear whether these problems predate the onset of disordered eating. Recurrent abdominal pain (RAP) is the most prevalent GI problem of childhood, and this study aimed to explore longitudinal associations between persistent RAP (at ages 7 and 9) and fasting for weight control at 16.

METHOD

The Avon Longitudinal Study of Parents and Children (ALSPAC) is a UK population cohort of children. Childhood RAP was reported by mothers and defined as RAP 5+ (5 pain episodes in the past year) in our primary analysis, and RAP 3+ (3 pain episodes) in our sensitivity analysis. Fasting for weight control was reported by adolescents at 16. We used logistic regression models to examine associations, with adjustments for potential confounders.

RESULTS

After adjustments, we found no association between childhood RAP 5+ and adolescent fasting for weight control at 16 (OR 1.30 (95% Confidence Intervals [CI] 0.87, 1.94) p = .197). However, we did find an association between RAP 3+ and later fasting, in the fully adjusted model (OR 1.50 [95% CI 1.16, 1.94] p = .002), and after excluding those with pre-existing anxiety (OR 1.52 [95% CI 1.17, 1.97] p = .002).

DISCUSSION

Our findings suggest a possible independent contribution of RAP to later risk of fasting for weight control, and RAP should be enquired about in the assessment of eating disorders. However, frequency of childhood abdominal pain (as captured by ALSPAC) may be less important to long-term outcomes than functional impairment.

The Role of Disgust in Eating Disorders

PURPOSE OF REVIEW

In current review, we evaluate the current literature examining the role of disgust in eating disorders (EDs), and provide a theoretical model designed to inform the study and treatment of disgust-based symptoms in EDs.

RECENT FINDINGS

Findings from this review suggest that aberrant disgust-conditioning processes represent promising but understudied mechanisms that may contribute to the risk and maintenance of core eating disorder (ED) psychopathology. In addition, preliminary evidence supports the use of interventions designed to target aversive disgust cues and disrupt maladaptive disgust-based conditioning that may maintain eating pathology. However, experimental studies designed to elucidate the role of disgust and aversive learning processes remain limited. Disgust is a promising risk and maintenance factor in EDs. Future systematic investigation is needed to examine disgust-based processes at a mechanistic level in order to better understand the links between disgust, avoidance behaviors, and EDs. Further investigation of the mechanistic role of disgust in EDs is warranted.

Conceptualizing eating disorder psychopathology using an anxiety disorders framework: Evidence and implications for exposure-based clinical research

Eating disorders (EDs) and anxiety disorders (ADs) evidence shared risk and significant comorbidity. Recent advances in understanding of anxiety-based disorders may have direct application to research and treatment efforts for EDs. The current review presents an up-to-date, behavioral conceptualization of the overlap between anxiety-based disorders and EDs. We identify ways in which anxiety presents in EDs, consider differences between EDs and ADs relevant to treatment adaptions, discuss how exposure-based strategies may be adapted for use in ED treatment, and outline directions for future mechanistic, translational, and clinical ED research from this perspective. Important research directions include: simultaneous examination of the extent to which EDs are characterized by aberrant avoidance-, reward-, and/or habit-based neurobiological and behavioral processes; improvement in understanding of how nutritional status interacts with neurobiological characteristics of EDs; incorporation of a growing knowledge of biobehavioral signatures in ED treatment planning; development of more comprehensive exposure-based treatment approaches for EDs; testing whether certain exposure interventions for AD are appropriate for EDs; and improvement in clinician self-efficacy and ability to use exposure therapy for EDs.

On bells, saliva, and abdominal pain or discomfort: Early aversive visceral conditioning and vulnerability for anorexia nervosa

Gastrointestinal (GI) symptoms are common in anorexia nervosa (AN), can predate illness onset, complicate renourishment, and persist after recovery. We explore how, through processes of aversive visceral conditioning, early GI pain and discomfort may increase vulnerability to AN in some individuals. Processes include enhanced preoccupation with the gut resulting from aversive visceral memories and disruptions in the typical acquisition of self-attunement when children learn to map and interpret interoceptive sensations and develop adaptive actions. We question whether a fear of weight gain, in some cases, may be an epiphenomenon of the recapitulation of actual or perceived GI symptoms that is especially relevant during puberty, especially in girls. This conceptualization has immediate clinical implications and offers ideas for future research. We propose that GI discomfort associated with renourishment may reignite prior aversive visceral experiences. We encourage development of a formulation that organizes the individual's current experience of the body with respect to these prior aversive experiences. Our conceptualization underscores the importance of assessment of GI experiences in individuals with AN; the examination of dietary strategies that minimize GI symptoms and enhance renourishment efficacy; and strategies that attempt to alter this aversive visceral conditioning by mapping sensations to meanings and adaptive actions.