A preliminary naturalistic clinical case series study of the feasibility and impact of interoceptive exposure for eating disorders

Trajectories of negative affect prior to and following disordered eating behaviors among women with eating disorder pathology: An examination of the role of state-interoception

OBJECTIVE

Affect regulation theories of eating disorders (ED) posit that negative affect increases in the hours before and decreases following disordered eating behaviors (DEBs) in daily life, yet findings from studies assessing affective changes post-DEBs are mixed. This inconsistency may be due to the previously unassessed role of other transdiagnostic processes in these associations, such as interoception (the ability to sense and integrate information from bodily sensations). To address this research gap, the present study examined whether different interoception dimensions moderated negative affect trajectories surrounding DEBs in the natural environment.

METHOD

150 women with ED pathology (Mage = 21.0, SD = 4.1) completed 4 surveys targeting affect and DEBs each day for a 10-day ecological momentary assessment period. Polynomial multilevel models examined negative affect trajectories pre- and post-DEBs (dietary restriction, overeating, loss of control eating), and whether these trajectories varied based on daily interoception dimensions (not distracting, self-regulation, body listening and trust).

RESULTS

Negative affect increased prior to loss of control eating-but not dietary restriction or overeating-and decreased following all DEBs. Further, the magnitude of the decrease in negative affect that emerged post-dietary restriction decreased in strength as daily "not distracting" interoception increased. The other interoception dimensions did not moderate negative affect trajectories surrounding DEBs.

CONCLUSIONS

Allowing oneself to experience (vs. distract from) uncomfortable bodily sensations may weaken affect dysregulation processes that follow dietary restriction in daily life and are theorized to maintain DEBs. These results provide insight that may strengthen EDs theories, research, and inform interoception-focused interventions.

Experiential Avoidance During Mealtimes Among Individuals With Eating Disorders

The relationship between negative emotions and avoidance is widely theorized as a bidirectional cycle implicated in a range of psychopathology. Historically, research on this cycle has examined one type of negative emotion: anxiety. Yet, a broader range of internal experiences may be implicated in the maintenance of unhealthy avoidance cycles in psychopathology. This study examines prospective relationships among anxiety, guilt, physical discomfort, and experiential avoidance during mealtimes for individuals with eating disorders (EDs). Participants (N = 108) completed ecological momentary assessments four times a day for 25 days. We computed multilevel models to examine between- and within-person effects of negative emotions and physical discomfort on experiential avoidance. When including guilt and anxiety in one model, guilt, but not anxiety, explained the significant variance in experiential avoidance at the next meal. Mealtime physical discomfort and experiential avoidance evidenced reciprocal prospective relationships. Future research should test whether interventions targeting experiential avoidance and physical discomfort at mealtimes disrupt guilt.

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.

ARFID Parent Training Protocol ("ARFID-PTP"): Results of a Randomized Pilot Trial Evaluating a Brief, Parent-Training Program for Avoidant/Restrictive Food Intake Disorder

OBJECTIVE

Accessible treatment options for avoidant/restrictive food intake disorder (ARFID) in children are limited. The current study sought to assess acceptability, feasibility, and preliminary efficacy of a brief, virtual intervention for ARFID in children ("ARFID-PTP").

METHOD

Families of children ages 5-12 with ARFID (n = 30) were randomized to immediate or waitlist treatment groups, with both groups ultimately receiving ARFID-PTP. ARFID-PTP consists of two, 2-h individual treatment sessions with an optional booster session at 4-week follow-up. Families completed acceptability and feasibility measures at end-of-treatment, as well as preliminary efficacy measures at 4-week, 3-month, and 6-month follow-up.

RESULTS

Of 30 families who completed an intake session, 27 (90%) completed treatment. Families rated acceptability as high (MCEQ-C = 7.75). Treatment was feasible by participant retention. Exposure adherence was lower than expected, and booster session requests were higher than expected, indicating that achieving feasibility across measures may require treatment modifications. Regarding preliminary efficacy, children in the immediate treatment group had a decrease in ARFID symptoms compared to those on the waitlist. Overall, at 6-month follow-up linear mixed models showed participants had significantly reduced ARFID symptoms by presentation (p < 0.05) and in follow-up completers, children incorporated eight new foods on average.

DISCUSSION

ARFID-PTP is acceptable and preliminarily efficacious. The protocol may benefit from modifications to increase feasibility; however, booster session content and treatment outcomes suggest a priori feasibility markers may not accurately capture the utility of ARFID-PTP. Further work should continue to examine the efficacy ARFID-PTP, particularly in diverse samples where treatment accessibility is urgently needed.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04913194.

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.

Perceptual Dysfunction in Eating Disorders

Eating disorders (EDs) are characterized by abnormal responses to food and weight-related stimuli and are associated with significant distress, impairment, and poor outcomes. Because many of the cardinal symptoms of EDs involve disturbances in perception of one's body or abnormal affective or cognitive reactions to food intake and how that affects one's size, there has been longstanding interest in characterizing alterations in sensory perception among differing ED diagnostic groups. Within the current review, we aimed to critically assess the existing research on exteroceptive and interoceptive perception and how sensory perception may influence ED behavior. Overall, existing research is most consistent regarding alterations in taste, visual, tactile, and gastric-specific interoceptive processing in EDs, with emerging work indicating elevated respiratory and cardiovascular sensitivity. However, this work is far from conclusive, with most studies unable to speak to the precise etiology of observed perceptual differences in these domains and disentangle these effects from affective and cognitive processes observed within EDs. Further, existing knowledge regarding perceptual disturbances in EDs is limited by heterogeneity in methodology, lack of multimodal assessment protocols, and inconsistent attention to different ED diagnoses. We propose several new avenues for improving neurobiology-informed research on sensory processing to generate actionable knowledge that can inform the development of innovative interventions for these serious disorders.

Development and Validation of a Broad and Fear-Adaptable Measure of Fear Approach and Application to Common Eating Disorder Fears

Fear approach is a theorized mechanism of exposure treatment for anxiety-based disorders. However, there are no empirically established self-report instruments measuring the tendency to approach feared stimuli. Because clinical fears are heterogeneous, it is important to create a measure that is adaptable to person- or disorder-specific fears. The current study (N = 455) tests the development, factor structure, and psychometric properties of a self-report instrument of fear approach broadly and the adaptability of this measure to specific eating disorder fears (i.e., food, weight gain). Factor analyses identified a unidimensional, nine-item factor structure as the best fitting model. This measure had good convergent, divergent, and incremental validity and good internal consistency. The eating disorder adaptations retained good fit and strong psychometric properties. These results suggest that this measure is a valid, reliable, and adaptable measure of fear approach, which can be used in research and exposure therapy treatment for anxiety-based disorders.

Elevated interoceptive deficits in individuals with eating disorders and self-injurious thoughts and behaviors: A replication and extension

INTRODUCTION

People with eating disorders (EDs) frequently report self-injurious thoughts and behaviors (SITBs). We aimed to replicate and extend findings demonstrating greater interoceptive deficits according to SITB severity. We predicted that interoceptive deficits would be greater among people with versus without lifetime SITBs and among those with multiple suicide attempts compared with single attempts or nonsuicidal self-injury. We also predicted that interoception would be increasingly impaired with greater current suicidality severity.

METHOD

Adults (N = 118) seeking ED treatment reported current and lifetime SITBs upon admission to treatment. We used planned contrasts to compare interoceptive deficits (self-reported using the Eating Disorders Inventory) by SITB and current suicidality groups (assessed by self-report and clinical interview).

RESULTS

Interoceptive deficits were greater among people with any SITB history compared to those without. People with multiple suicide attempts did not differ in interoceptive deficits from those with single attempts or only nonsuicidal self-injury. Interoceptive deficits were elevated among those with any current suicidality compared to those with no suicidal symptoms; interoceptive deficits did not differ according to severity of suicidality.

CONCLUSION

Among those with EDs, interoceptive deficits are elevated among those with concurrent SITBs. Interventions aimed at improving interoception may reduce the risk for SITBs.

Clarifying the pathway from anxiety sensitivity to binge eating: The mediating role of depressive symptoms in a 3-week, 3-wave longitudinal study of undergraduates

Anxiety sensitivity (AS) - characterized by a persistent fear that arousal-related bodily sensations will lead to serious cognitive, physical, and/or social consequences - is associated with various psychopathologies, including depressive symptoms and binge eating. This 3-week, 3-wave longitudinal study examined the relation between AS (including its global AS factor and lower-order AS cognitive, physical, and social concern dimensions), depressive symptoms, and binge eating among 410 undergraduates from two universities. Using generalized estimating equation models, we found that global AS, AS social concerns, and depressive symptoms predicted binge eating during any given week. Mediation analyses showed that global AS (as a latent variable with its lower-order AS dimensions as indicators), AS cognitive concerns, and AS physical concerns at Wave 1 predicted subsequent increases in depressive symptoms at Wave 2, which, in turn, led to increases in binge eating at Wave 3. Findings contribute to a better understanding of the interplay between AS, depressive symptoms, and binge eating, highlighting the role of binge eating as a potential coping mechanism for individuals with high AS, particularly in managing depressive symptoms. This study underscores the importance of AS-targeted intervention and prevention efforts in addressing depressive symptoms and binge eating.

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.

Interoceptive deficits moderate the relationship between bulimia symptoms and suicide risk

Objective: Interoceptive deficits have been linked to suicidality and eating disorders. The relationship between disordered eating symptoms and suicidality may depend on the level of interoceptive deficits. It was expected that interoceptive deficits would moderate the relationship between disordered eating symptoms (oral control, dieting, and bulimia) and suicidality (suicide attempts, ideation, and communication) when interoceptive deficits were high. Methods: University students (N = 417, Mage = 19.75, 78.2% white, 72.4% female) completed self-report measures that assessed disordered eating, interoceptive deficits, and suicide history. Results: Interoceptive deficits emerged as a significant moderator only in the association between bulimia symptoms and suicidality, when interoceptive deficits were high. Conclusions: The results of this study indicate that bulimia symptoms may have a unique interaction with interoceptive deficits and suicidality. Future research should focus on targeting interoceptive deficits in treatment to help reduce disordered eating symptoms and suicide risk, particularly for students with bulimia symptoms.

Eating Disorder Symptom and Fear Change Trajectories During Imaginal Exposure Therapy: A Slope Network Analysis

Eating disorders (EDs) are characterized by fears related to food, body image, and social evaluation. Exposure-based interventions hold promise for targeting a range of ED fears and reducing ED psychopathology. We investigated change mechanisms and optimal fear targets in imaginal exposure therapy for EDs using a novel approach to network analysis. Individuals with an ED (N = 143) completed up to four online imaginal exposure sessions. Participants reported ED symptoms and fears at pretreatment, posttreatment, and 6-month follow-up. We constructed networks of symptoms (Model 1), fears (Model 2), and combined symptoms and fears (Model 3). Change trajectory networks from the slopes of symptoms/fears across timepoints were estimated to identify how change in specific ED symptoms/fears related to change in other ED symptoms/fears. The most central changing symptoms and fears were feeling fat, fear of weight gain, guilt about one's weight/shape, and feared concerns about consequences of eating. In Model 3, change in ED fears bridged to change in desire to lose weight, desiring a flat stomach, following food rules, concern about eating with others, and guilt. As slope networks present averages of symptom/fear change slopes over the course of imaginal exposure therapy, further studies are needed to examine causal relationships between symptom changes and heterogeneity of change trajectories. Fears of weight gain and consequences of eating may be optimal targets for ED exposure therapy, as changes in these fears were associated with maximal change in ED pathology. Slope networks may elucidate change mechanisms for EDs and other psychiatric illnesses.

Do specific modules of cognitive behavioral therapy for depression have measurable effects on youth internalizing symptoms? An idiographic analysis

OBJECTIVE

Understanding the efficacy of each module of cognitive behavioral therapy (CBT) may inform efforts to improve outcomes for youth depression, but effects of specific modules have been difficult to examine. Idiographic interrupted time series models offer a robust way to estimate module effects on an individual's symptoms. This study examined the association of specific CBT modules for depression on internalizing symptoms among depressed youths who received modular CBT in a randomized trial.

METHODS

Individual models were created for three youths who met study criteria. Youths completed weekly symptom reports, and clinicians completed records of modules delivered. First order auto-regressive models quantified the change in average internalizing symptom severity between pre- and post-module delivery.

RESULTS

All youths had 1-3 modules that were significantly associated with symptom reduction and 1-3 modules associated with deterioration. The 5 modules associated with improvement in at least one youth also lacked association (engagement, relaxation, cognitive reframing), or were associated with worsening (activity selection, parent psychoeducation) in others. Seven modules showed no measurable benefit, or detriment to any youth.

CONCLUSION

This study demonstrated that specific modules have measurable effects, but more work is needed to build an evidence base of specific module effects to inform treatment personalization for youth depression.

The association between anxiety sensitivity and food cravings among individuals seeking treatment for weight-related behaviors

BACKGROUND

A better understanding of risk-factors associated with state-like food cravings may be one clinically relevant component in an effort to better understand obesity. Existing work has shown anxiety sensitivity (AS) to be a significant risk factor for increased cravings across a variety of health behaviors (e.g., smoking, alcohol use). Yet, no work has examined the relationship between AS and state-like food cravings. Therefore, the current study sought to examine the association between AS and a variety of state-like food cravings, including: (1) an intense desire to eat, (2) anticipation of relief from negative states and feelings/improvement in mood that may result from eating, (3) obsessive preoccupation with food or lack of control over eating, and (4) craving as a physiological state.

METHODS

Participants included 161 (Mage = 31.58, SD = 10.71; 60.9 % female) individuals seeking treatment for weight-related behaviors.

RESULTS

Results indicated that elevated AS was associated with reinforcement-based and physiological food cravings.

CONCLUSION

Our findings indicate that there may be clinical utility in screening for AS among individuals seeking treatment for weight-related behaviors in efforts to better understand specific types of food craving.

The structure of eating disorder and somatic symptoms

Individuals with eating disorders (EDs) often present with somatic concerns in treatment, such as bloating, fullness, and feeling tight clothes on skin. However, most research generally focuses on general interoception (e.g., heartbeat) rather than sensations relevant to EDs (e.g., sensations related to the gastrointestinal system or body movement). In the current study (N = 181), we used network analysis to model the structure of ED symptoms and somatic concerns among individuals with anorexia nervosa, bulimia nervosa, and other specified feeding and eating disorder. Results showed that heightened sensitivity to somatic concerns had the highest strength centrality within a symptom network comprising ED and somatic symptoms. Exploratory graph analysis identified four symptom dimensions: cognitive-affective ED symptoms, behavioral ED symptoms, general interoception, and ED-specific proprioception. Findings suggest that heightened sensitivity to somatic concerns may maintain ED symptoms and mutually reinforce other somatic concerns. Implications concerning assessment and treatment of EDs are discussed.

Elevated fullness and bloating as correlates of eating pathology: Implications for screening

A minority of individuals with eating disorders report being asked about their eating by health care professionals; delayed detection of eating disorders may contribute to poorer outcomes. The current study investigated common meal-related gastrointestinal symptoms (i.e., elevated fullness and bloating) as correlates of eating pathology that may be more readily disclosed to health professionals and indicate the need to assess for eating pathology. The current study also tested the hypothesis that elevated fullness and bloating are more strongly linked to eating pathology among those with higher body dissatisfaction. 281 university students (70.1% female, 84.3% white) completed gastrointestinal symptom and eating pathology assessments. Elevated fullness and bloating were each associated with increased purging, restrictive eating behaviors, and likelihood of having an eating disorder. Elevated fullness and bloating were more strongly linked to purging and probable eating disorder diagnosis with higher, relative to lower, body dissatisfaction. However, body dissatisfaction did not moderate the relationship between gastrointestinal symptoms and restrictive eating behaviors. Results indicate that elevated fullness and bloating are correlates of eating pathology. Healthcare professionals should consider and/or assess for eating pathology when elevated fullness and bloating are reported; further assessment of body dissatisfaction may be helpful in identifying purging behaviors.

Evaluating the predictive validity of purging disorder by comparison to bulimia nervosa at long-term follow-up

OBJECTIVE

The current study sought to examine the predictive validity of the purging disorder diagnosis at long-term follow-up by comparing naturalistic outcomes with bulimia nervosa.

METHOD

Women with purging disorder (N = 84) or bulimia nervosa (N = 133) who had completed comprehensive baseline assessments as part of one of three studies between 2000 and 2012 were sought for follow-up assessment. Nearly all (94.5%) responded to recruitment materials and 150 (69% of sought sample; 83.3% non-Hispanic white; 33.40 [7.63] years old) participated at an average of 10.59 (3.71) years follow-up. Participants completed the Eating Disorder Examination, the Structured Clinical Interview for DSM-IV, and a questionnaire battery. Diagnostic groups were compared on eating disorder (illness status, recovery status, and eating pathology) and related outcomes. Group differences in predictors of outcome were explored.

RESULTS

There were no significant differences in eating disorder presence (p = .70), recovery status (p = .87), and level of eating pathology (p = .17) between diagnostic groups at follow-up. Post hoc equivalence tests indicated group differences were smaller than a medium effect size (p's ≤ .005). Groups differed in diagnosis at follow-up (p = .002); diagnostic stability was more likely than cross-over to bulimia nervosa for women with baseline purging disorder (p = .004).

DISCUSSION

Although purging disorder and bulimia nervosa do not differ in long-term outcomes, the relative stability in clinical presentation suggests baseline group differences in clinical presentation may be useful in augmenting treatments for purging disorder.

PUBLIC SIGNIFICANCE STATEMENT

While purging disorder is classified as an "other specified" eating disorder, individuals who experience this disorder have comparable negative long-term outcomes as those with bulimia nervosa. This highlights the importance of screening for and treating purging disorder as a full-threshold eating disorder.

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.

Altered Interoceptive Sensibility in Adults With Chronic Tic Disorder

BACKGROUND

Interoception refers to the sensing, interpretation, integration, and regulation of signals about the body's internal physiological state. Interoceptive sensibility is the subjective evaluation of interoceptive experience, as assessed by self-report measures, and is abnormal in numerous neuropsychiatric disorders. Research examining interoceptive sensibility in individuals with chronic tic disorders (CTDs), however, has yielded conflicting results, likely due to methodologic differences between studies and small sample sizes.

OBJECTIVE

We sought to compare interoceptive sensibility between adults with CTD and healthy controls, adjusting for co-occurring psychiatric symptoms, and to examine the relationship of interoceptive sensibility with other CTD clinical features, in particular, premonitory urge.

METHODS

We recruited adults with CTDs and sex- and age-matched healthy controls to complete the Multidimensional Assessment of Interoceptive Awareness, Version 2 (MAIA-2), as well as a battery of measures assessing psychiatric symptoms prevalent in CTD populations. CTD participants additionally completed scales quantifying tic severity, premonitory urge severity, and health-related quality of life. We conducted between-group contrasts (Wilcoxon rank-sum test) for each MAIA-2 subscale, analyzed the effect of psychiatric symptoms on identified between-group differences (multivariable linear regression), and examined within-group relationships between MAIA-2 subscales and other clinical measures (Spearman rank correlations, multivariable linear regression).

RESULTS

Between adults with CTD (n = 48) and healthy controls (n = 48), MAIA-2 Noticing and Not-Worrying subscale scores significantly differed. After adjusting for covariates, lower MAIA-2 Not-Worrying subscale scores were significantly associated with female sex (β = 0.42, p < 0.05) and greater severity of obsessive-compulsive symptoms (β = -0.028, p < 0.01), but not with CTD diagnosis. After adjusting for severity of tics and obsessive-compulsive symptoms, a composite of MAIA-2 Noticing, Attention Regulation, Emotional Awareness, Self-Regulation, Body Listening, and Trusting subscales (β = 2.52, p < 0.01) was significantly associated with premonitory urge.

CONCLUSION

Study results revealed three novel findings: adults with CTD experience increased anxiety-associated somatization and increased general body awareness relative to healthy controls; anxiety-associated somatization is more closely associated with sex and obsessive-compulsive symptoms than with CTD diagnosis; and increased general body awareness is associated with greater severity of premonitory urges.

Skill Acquisition During Transdiagnostic Treatment With the Unified Protocol

The Unified Protocol (UP) for Transdiagnostic Treatment of Emotional Disorders is an emotion-focused, cognitive-behavioral intervention developed to address the full range of anxiety, depressive, and related disorders. The UP consists of core therapeutic skills that, though unique in focus, are each designed to promote an approach-oriented stance toward emotional experiences. The goal of the present investigation was to characterize changes in these skills for patients that received a course of treatment with the UP, as well as to examine associations between skills and symptoms changes. Patients with principal anxiety disorders, assigned to receive treatment with the UP (N = 88) as part of a randomized controlled trial, were included in this study. They completed validated self-report measures of UP skills (Understanding Emotions, Mindful Emotion Awareness, Cognitive Flexibility, Countering Emotional Behaviors, and Interoceptive Awareness and Tolerance), as well as clinician-rated measures of psychological symptoms. Skill measures improved significantly over the course of 12 to 16 UP treatment sessions and changes in these skills measures were associated with improvements in anxiety symptoms. Determining whether improvement on all the skills learned during a course of treatment with UP is associated with symptom remission is critical to establishing the most streamlined and efficient interventions that may ultimately be best suited to widespread dissemination.

Feeling imperfect and imperfectly feeling: A network analysis on perfectionism, interoceptive sensibility, and eating symptomatology in anorexia nervosa

OBJECTIVE

In recent years, the network analysis (NA) methodology has been applied to identify the central features of the psychopathology of anorexia nervosa (AN) and specific connections to previously recognized vulnerabilities. However, an NA investigating both multidimensional perfectionism and interoceptive sensibility in connection to eating symptomatology is currently missing.

METHOD

A total of 260 individuals (139 patients with AN, 121 healthy control individuals) completed the Frost Multidimensional Perfectionism Scale, the Multidimensional Assessment of Interoceptive Awareness and the Eating Disorders Inventory-2. Using state-of-the-art techniques, we estimated a main network with data from all participants and then compared the two separated networks. We checked the variables for empirical overlap through goldbricker, combined as suggested and implemented the empirical measure of the bridge nodes.

RESULTS

Ineffectiveness and need for control over self and body (resulting from combining Asceticism and Drive for Thinness) were the most central nodes, whereas perfectionistic evaluative concerns (resulting from combining Doubts about Actions and Concern over Mistakes) and mistrust in body sensations were the bridge nodes. No significant differences between the patient and control networks emerged.

CONCLUSIONS

Perfectionistic evaluative concerns and mistrust in body sensations could be key components in the relationships among perfectionism, interoceptive sensibility and eating symptomatology.

Validating the visceral sensitivity index in an eating disorder sample

OBJECTIVE

Individuals with eating disorders (EDs) often have difficulty tolerating uncomfortable body sensations. As such, anxiety sensitivity specific to gastrointestinal (GI) sensations, has relevance for EDs. However, to date, no validated measures of this construct exist in EDs. Thus, the present study sought to validate the visceral sensitivity index (VSI), a 15-item measure originally validated in an irritable bowel syndrome sample, in an ED sample and explore associations with ED symptoms.

METHOD

Two hundred and sixty-six adolescents (n = 116) and adults (n = 150) in an ED partial hospital program completed the VSI and related measures at admission. Confirmatory factor analysis examined the factor structure of the VSI and hierarchical regression analyses explored associations between the VSI and ED symptoms.

RESULTS

The original version of the VSI had adequate model fit. An alternative 13-item model removing specific items with poor fit and less theoretical relevance to EDs also demonstrated good fit. The 15-item and 13-item VSI had strong internal consistency (α = .93-.94), and correlation results supported the convergent and divergent validity of both versions. Higher visceral sensitivity was associated with elevated body dissatisfaction, cognitive restraint, purging, restricting, and excessive exercise (p-values <.05), beyond length of illness, body mass index, and trait anxiety.

DISCUSSION

Results support the relevance of GI-specific anxiety in EDs and suggest that the original 15-item VSI and modified 13-item VSI have strong psychometric properties in an ED sample. Given comparable model fit and psychometric properties, both versions of the VSI may be used for future ED research.

The Renfrew Unified Treatment for Eating Disorders and Comorbidity: Long-Term Effects of an Evidence-Based Practice Implementation in Residential Treatment

Background: The Renfrew Unified Treatment for Eating Disorders and Comorbidity (UT) is a transdiagnostic, emotion-focused treatment adapted for use in residential group treatment. This study examined the effect of UT implementation across five years of treatment delivery. Methods: Data were collected by questionnaire at admission, discharge (DC), and 6-month follow-up (6MFU). Patient outcomes were measured by the Eating Disorder Examination-Questionnaire, Center for Epidemiologic Studies-Depression Scale, Brief Experiential Avoidance Questionnaire (BEAQ), Anxiety Sensitivity Index, and Southampton Mindfulness Scale. Data were analyzed for N = 345 patients treated with treatment-as-usual (TAU), and N = 2,763 treated with the UT in subsequent years. Results: Results from multilevel models demonstrated a significant interaction between implementation status (TAU vs. UT) and time, both linear and quadratic, for the depression, experiential avoidance, anxiety sensitivity, and mindfulness variables. Patients treated with the UT showed more improvement in these variables on average, as well as more rebound between DC and 6MFU. Results from multilevel models examining eating disorder outcome showed no significant difference between the TAU and UT for the full sample, but a significant three-way interaction indicated that the UT produced more improvement in the EDE-Q relative to the TAU particularly for patients who entered treatment with high levels of experiential avoidance (BEAQ score). Conclusion: This long-term study of a transdiagnostic, evidence-based treatment in residential care for eating disorders and comorbidity suggests implementation was associated with beneficial effects on depression and emotion function outcomes, as well as eating disorder severity for patients with high levels of baseline emotion regulation problems. These effects did not appear to diminish in the 5 years following initial implementation.

Perceptual insensitivity to the modulation of interoceptive signals in depression, anxiety, and substance use disorders

This study employed a series of heartbeat perception tasks to assess the hypothesis that cardiac interoceptive processing in individuals with depression/anxiety (N = 221), and substance use disorders (N = 136) is less flexible than that of healthy individuals (N = 53) in the context of physiological perturbation. Cardiac interoception was assessed via heartbeat tapping when: (1) guessing was allowed; (2) guessing was not allowed; and (3) experiencing an interoceptive perturbation (inspiratory breath hold) expected to amplify cardiac sensation. Healthy participants showed performance improvements across the three conditions, whereas those with depression/anxiety and/or substance use disorder showed minimal improvement. Machine learning analyses suggested that individual differences in these improvements were negatively related to anxiety sensitivity, but explained relatively little variance in performance. These results reveal a perceptual insensitivity to the modulation of interoceptive signals that was evident across several common psychiatric disorders, suggesting that interoceptive deficits in the realm of psychopathology manifest most prominently during states of homeostatic perturbation.

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.

Heightened affective response to perturbation of respiratory but not pain signals in eating, mood, and anxiety disorders

Several studies have recently suggested that an abnormal processing of respiratory interoceptive and nociceptive (painful) stimuli may contribute to eating disorder (ED) pathophysiology. Mood and anxiety disorders (MA) are also characterized by abnormal respiratory symptoms, and show substantial comorbidity with ED. However, no studies have examined both respiratory and pain processing simultaneously within ED and MA. The present study systematically evaluated responses to perturbations of respiratory and nociceptive signals across the levels of physiology, behavior, and symptom report in a transdiagnostic ED sample (n = 51) that was individually matched to MA individuals (n = 51) and healthy comparisons (HC; n = 51). Participants underwent an inspiratory breath-holding challenge as a probe of respiratory interoception and a cold pressor challenge as a probe of pain processing. We expected both clinical groups to report greater stress and fear in response to respiratory and nociceptive perturbation than HCs, in the absence of differential physiological and behavioral responses. During breath-holding, both the ED and MA groups reported significantly more stress, feelings of suffocation, and suffocation fear than HC, with the ED group reporting the most severe symptoms. Moreover, anxiety sensitivity was related to suffocation fear only in the ED group. The heightened affective responses in the current study occurred in the absence of group differences in behavioral (breath hold duration, cold pressor duration) and physiological (end-tidal carbon dioxide, end-tidal oxygen, heart rate, skin conductance) responses. Against our expectations, there were no group differences in the response to cold pain stimulation. A matched-subgroup analysis focusing on individuals with anorexia nervosa (n = 30) produced similar results. These findings underscore the presence of abnormal respiratory interoception in MA and suggest that hyperreactivity to respiratory signals may be a potentially overlooked clinical feature of ED.

Body mistrust bridges interoceptive awareness and eating disorder symptoms

Interoceptive awareness (IA), or the awareness of internal body states, is known to be impaired in individuals with eating disorders (EDs); however, little is understood about how IA and ED symptoms are connected. Network analysis is a statistical approach useful for examining how symptoms interrelate and how comorbidities may be maintained. The present study used network analysis to (1) test central symptoms within an IA-ED network, (2) identify symptoms that may bridge the association between IA and ED symptoms, and (3) explore whether central and bridge symptoms predict ED remission at discharge from intensive treatment. A regularized partial correlation network was estimated in a sample of 428 adolescent (n = 187) and adult (n = 241) ED patients in a partial hospital program. IA was assessed using items from the Multidimensional Assessment of Interoceptive Awareness, and ED symptoms were assessed using items from the Eating Disorder Examination-Questionnaire. Central symptoms within the network were strong desire to lose weight, feeling guilty, and listening for information from the body about emotional state. The most central symptom bridging IA and ED symptoms was (not) feeling safe in one's body. Of the central symptoms, greater desire to lose weight predicted lower likelihood of remission at treatment discharge. Bridge symptoms did not significantly predict remission. Body mistrust may be a mechanism by which associations between IA and EDs are maintained. Findings suggest targeting central and bridge symptoms may be helpful to improve IA and ED symptoms. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Mediating role of experiential avoidance in the relationship between anxiety sensitivity and eating disorder psychopathology: A clinical replication

OBJECTIVE

This study sought to examine whether anxiety sensitivity was associated with eating disorder (ED) symptom severity among patients with severe EDs, and to determine whether this relationship was mediated by experiential avoidance.

METHOD

Adolescent and adult females (N = 625) seeking residential ED treatment completed self-report measures of anxiety sensitivity, experiential avoidance, and ED psychopathology. Linear regression evaluated the cross-sectional association between ED symptom severity and three dimensions of anxiety sensitivity (social, physical, and cognitive). Regression-based mediation analysis with bootstrapping tested the associations among the three dimensions of anxiety sensitivity and ED symptom severity through experiential avoidance.

RESULTS

The social dimension of anxiety sensitivity was positively associated with severity of ED psychopathology. Experiential avoidance mediated this association.

DISCUSSION

ED symptoms in this sample were more severe among patients who endorsed greater concern about appearing nervous or anxious to others. The current results indicate that this relationship was driven by a tendency to avoid experiences that evoke emotional discomfort. If replicated, these findings suggest that targeting both social anxiety sensitivity and experiential avoidance may improve ED treatment outcomes. Further study of the mechanistic relationships among social anxiety sensitivity, experiential avoidance, and ED psychopathology, is warranted.