Psychophysiological responses to idiosyncratic stress in bulimia nervosa and binge eating disorder

Noradrenergic control of neurobehavior in human binge-eating disorder and obesity (NOBEAD): A smartphone-supported behavioral emotion regulation intervention study protocol integrating molecular brain imaging

OBJECTIVE

The neurobehavioral underpinnings of binge-eating disorder (BED), co-occurring with obesity (OB), are largely unknown. This research project conceptualizes BED as a disorder with dysfunctional emotion regulation (ER) linked with changes in central noradrenaline (NA) transmission and NA-modulated neuronal networks.

METHODS

We expect abnormalities in NA activity in both BED and OB, but most pronounced in BED. We expect these abnormalities to be modifiable through state-of-the-art ER intervention, specifically in BED. To assess the role of NA transmission, we will quantify changes in NA transporter (NAT) availability using the highly NAT-specific [11 C]methylreboxetin (MRB) and positron emission tomography-magnetic resonance imaging (PET-MRI) that allows measuring molecular and neuronal changes before and after an ER intervention. Individual 12-session smartphone-supported acceptance-based behavioral therapy will be conducted to improve ER. Thirty individuals with OB and BED (OB + BED), 30 individuals with OB without BED (OB - BED), and 20 individuals with normal weight will undergo assessments of NAT availability and neuronal network activity under rest and stimulated conditions, clinical interviews, self-report questionnaires on eating behavior, ER, mental and physical health, and quality of life, and neuropsychological tests on executive function. Afterwards, in an experimental randomized-controlled design, individuals with OB + BED and OB - BED will be allocated to smartphone-supported ER intervention versus a waitlist and re-assessed after 10 weeks.

DISCUSSION

By obtaining biological and behavioral markers, the proposed study will disentangle the involvement of NAT and the central NA system in the modulation of emotion-supporting neuronal networks that influence eating behavior. Neurobehavioral mechanisms of change during an ER intervention will be determined.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS): DRKS00029367.

PUBLIC SIGNIFICANCE

This study investigates the central noradrenaline system by using hybrid brain imaging in conjunction with emotion regulation as a putative core biological mechanism in individuals with obesity with or without binge-eating disorder that is targeted by emotion regulation intervention. The results will provide a molecular signature beyond functional imaging biomarkers as a predictive biomarker toward precision medicine for tailoring treatments for individuals with binge-eating disorders and obesity.

Emotional food-cue-reactivity in anorexia nervosa and bulimia nervosa: An electroencephalography study

OBJECTIVE

Food-cue-reactivity entails neural and experiential responses to the sight and smell of attractive foods. Negative emotions can modulate such cue-reactivity and this might be central to the balance between restrictive versus bulimic symptomatology in Anorexia Nervosa (AN) and Bulimia Nervosa (BN).

METHOD

Pleasantness ratings and electrocortical responses to food images were measured in patients with AN (n = 35), BN (n = 32) and matched healthy controls (HC, n = 35) in a neutral state and after idiosyncratic negative emotion induction while electroencephalography (EEG) was recorded. The EEG data were analyzed using a mass testing approach.

RESULTS

Individuals with AN showed reduced pleasantness for foods compared to objects alongside elevated widespread occipito-central food-object discrimination between 170 and 535 ms, indicative of strong neural cue-reactivity. Food-object discrimination was further increased in the negative emotional condition between 690 and 1200 ms over centroparietal regions. Neither of these effects was seen in individuals with BN.

DISCUSSION

Emotion modulated food-cue-reactivity in AN might reflect a decreased appetitive response in negative mood. Such specific (emotion-)regulatory strategies require more theoretical work and clinical attention. The absence of any marked effects in BN suggests that emotional cue-reactivity might be less prominent in this group or quite specific to certain emotional contexts or food types.

PUBLIC SIGNIFICANCE

Negative affectivity is a risk factor for the development of eating disorders and individuals with eating disorders experience problems with emotion regulation. To better understand the effects of negative emotions, the present study investigated how they affected neural correlates of food perception in anorexia nervosa and bulimia nervosa.

Using Wearable Passive Sensing to Predict Binge Eating in Response to Negative Affect Among Individuals With Transdiagnostic Binge Eating: Protocol for an Observational Study

BACKGROUND

Binge eating (BE), characterized by eating a large amount of food accompanied by a sense of loss of control over eating, is a public health crisis. Negative affect is a well-established antecedent for BE. The affect regulation model of BE posits that elevated negative affect increases momentary risk for BE, as engaging in BE alleviates negative affect and reinforces the behavior. The eating disorder field's capacity to identify moments of elevated negative affect, and thus BE risk, has exclusively relied on ecological momentary assessment (EMA). EMA involves the completion of surveys in real time on one's smartphone to report behavioral, cognitive, and emotional symptoms throughout the day. Although EMA provides ecologically valid information, EMA surveys are often delivered only 5-6 times per day, involve self-report of affect intensity only, and are unable to assess affect-related physiological arousal. Wearable, psychophysiological sensors that measure markers of affect arousal including heart rate, heart rate variability, and electrodermal activity may augment EMA surveys to improve accurate real-time prediction of BE. These sensors can objectively and continuously measure biomarkers of nervous system arousal that coincide with affect, thus allowing them to measure affective trajectories on a continuous timescale, detect changes in negative affect before the individual is consciously aware of them, and reduce user burden to improve data completeness. However, it is unknown whether sensor features can distinguish between positive and negative affect states, given that physiological arousal may occur during both negative and positive affect states.

OBJECTIVE

The aims of this study are (1) to test the hypothesis that sensor features will distinguish positive and negative affect states in individuals with BE with >60% accuracy and (2) test the hypothesis that a machine learning algorithm using sensor data and EMA-reported negative affect to predict the occurrence of BE will predict BE with greater accuracy than an algorithm using EMA-reported negative affect alone.

METHODS

This study will recruit 30 individuals with BE who will wear Fitbit Sense 2 wristbands to passively measure heart rate and electrodermal activity and report affect and BE on EMA surveys for 4 weeks. Machine learning algorithms will be developed using sensor data to distinguish instances of high positive and high negative affect (aim 1) and to predict engagement in BE (aim 2).

RESULTS

This project will be funded from November 2022 to October 2024. Recruitment efforts will be conducted from January 2023 through March 2024. Data collection is anticipated to be completed in May 2024.

CONCLUSIONS

This study is anticipated to provide new insight into the relationship between negative affect and BE by integrating wearable sensor data to measure affective arousal. The findings from this study may set the stage for future development of more effective digital ecological momentary interventions for BE.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/47098.

Effect of stimulant medication on loss of control eating in youth with attention deficit/hyperactivity disorder: a prospective, observational case series study protocol

BACKGROUND

Loss of control eating (LOC-E) in youth predicts the later development of full-syndrome binge-eating disorder (BED), and therefore, could be a relevant target for prevention treatments. To develop these treatments, it is important to understand the underlying disease processes and mechanisms. Based on the putative role of neurocognitive impairments in the pathogenesis of LOC-E, treatments that modulate these neurocognitive factors warrant further exploration. For instance, stimulants are an effective treatment for impulsivity in youth with attention deficit/hyperactivity disorder (ADHD) and have been shown to improve symptoms of BED in adults. Notably, stimulants have not been examined as a treatment for LOC-E in youth. To explore this gap, we aim to measure change in LOC-E episodes and secondary outcomes in youth with comorbid ADHD and LOC-E who are being started on stimulants.

METHODS

We will collect prospective observational data on forty 8-to-13-year-old youth diagnosed with comorbid ADHD and LOC-E who are initiating a stimulant for ADHD. Prior to stimulant initiation, participants will complete baseline measures including LOC-E episode frequency in the last 3 months (primary outcome), and secondary outcomes including disordered eating cognitions, emotions and behaviors, ADHD symptom severity, parental LOC-E, impulsivity and reward sensitivity, and anxiety/mood severity. Outcome measurements will be gathered again at 3-months after initiating the stimulant. Within-patient standardized effect sizes with 95% confidence intervals will be calculated from baseline to 3-month follow-up for all outcomes.

DISCUSSION

Many individuals with LOC-E or binge eating do not fully remit over the course of psychotherapy. Whereas psychotherapy may address psychological and sociocultural domains associated with LOC-E, some individuals with neurocognitive impairments (e.g., ADHD) and neurobiological deficits (e.g., low intrasynaptic dopamine or norepinephrine) may benefit from adjunctive treatment that targets those factors. This will be the first study to provide pilot data for future studies that could examine both the effect of stimulants on LOC-E in youth and underlying mechanisms.

TRIAL REGISTRATION

Trial registration number: NCT05592119.

Meta-Analysis and Systematic Review of Resting-State High-Frequency Heart Rate Variability in Binge-Eating Disorder

Abstract. Binge-eating disorder (BED) is associated with a greater risk for cardiac problems and co-occurring health conditions. Resting-state measures of high-frequency heart rate variability (HF-HRV), which is a physiological proxy of self-regulatory neural functioning, may aid understanding of health risks. We systematically reviewed and meta-analyzed the literature on HF-HRV in individuals with BED and without BED. Six studies were reviewed in the qualitative synthesis, and five studies assessing HRV in individuals with BED ( n = 153) and without BED ( n = 124) were included in the meta-analysis. A non-significant effect size (Hedges’ g = .08, SE = 0.36, 95% CI [−0.62, 0.78]; z = 0.23, p = .82) was found, suggesting no difference in HF-HRV between groups. Age, BMI, and BMI-matched control status were not significant covariates. Synthesizing the five studies with available data, we found no difference in resting-state HF-HRV between individuals with and without BED. There was high heterogeneity in the sample, suggesting potential moderators. We discuss potential mechanisms, methodological and demographic confounds, and future directions for study.

Negative mood induction effects on problem-solving task in women with eating disorders: a multi-method examination

BACKGROUND

The effects of negative affect on problem-solving and its psychophysiological correlates are poorly understood in eating disorder populations.

METHODS

This study examined respiratory sinus arrhythmia (RSA) and skin conductance responses of women with Binge Eating Disorder (BED: n = 56), Anorexia Nervosa (AN: n = 12), Bulimia Nervosa (BN: n = 32), and 24 healthy controls (HCs) at baseline, and then during: a negative mood induction task, an adapted Means Ends Problem-Solving (MEPS) task, and recovery. The MEPS task included four interpersonal scenarios: (1) binge-eating as a solution to stress, (2) job loss, (3) rejection by friends, and (4) by a significant other.

RESULTS

We found that individuals with eating disorders reported less positive mood than HCs and individuals with BN and BED reported more negative mood and greater urges to binge than HCs. After a negative mood induction, women with BED provided significantly less effective problem-solving strategies compared to HCs and women with BN for the binge-eating MEPS scenario. Relative to baseline and the negative mood induction, all participants exhibited significantly higher skin conductance measures throughout the MEPS scenarios and recovery. BED showed significantly lower respiratory sinus arrhythmia (RSA) levels than individuals with BN and HCs throughout the protocol.

CONCLUSIONS

The multimethod findings suggest individuals with BED are likely to have disorder-specific problem-solving difficulties after a negative mood induction.

Sensor technology in eating disorders research: A systematic review

OBJECTIVE

Sensor technologies offer exciting potential to objectively measure psychopathological correlates of eating pathology and eating disorder (ED) research utilizing sensors has rapidly proliferated in the past several years. The aims of the present review are: (1) characterize the types of sensors that have been utilized in ED research, (2) identify the psychopathological factors relevant to EDs that have been assessed using sensors, (3) describe the data supporting the validity and reliability of these sensors, (4) discuss limitations associated with these sensors, and (5) identify gaps that persist within the ED literature with regard to use of sensor technologies.

METHOD

A systematic search was conducted of PubMed, PsycINFO, Web of Science, ProQuest, and "gray" literature sources. Eligible publications were empirical studies that utilized sensors to measure at least one psychological variable among clinical ED populations.

RESULTS

Sensors have been utilized with ED samples to measure eating behaviors, physical activity, sleep, autonomic nervous system activity, eyeblink startle response, visual attention, and visual-haptic object integration. The reliability and validity of these sensors varies widely and there are a number of significant gaps that remain in the literature with regard to the types of sensors utilized, context in which sensors have been used, and populations studied.

DISCUSSION

The existing literature utilizing sensors within ED research largely support the feasibility and acceptability of these tools. Sensors should continue to be utilized within the field, with a specific focus on examining the reliability and validity of these tools within ED samples and increasing the diversity of samples studied.

PUBLIC SIGNIFICANCE STATEMENT

Sensor technologies, such as those included in modern smartwatches, offer new opportunities to measure factors that may maintain or contribute to symptoms of eating disorders. This article describes the types of sensors that have been used in eating disorders research, challenges that may arise in using these sensors, and discusses new applications of these sensors that may be pursued in future research.

Social media exposure during COVID-19 lockdowns could lead to emotional overeating via anxiety: The moderating role of neuroticism

China was a major hotspot during the beginning of the COVID-19 pandemic. Several studies have reported changes in residents' eating behaviors and appetite during city wide lockdowns and home confinements. However, few have investigated how neuroticism interacts with the impact of COVID-19 to influence eating behaviors during city lockdowns. Thus, the current study aims to establish a pathway model to understand social media exposure, negative affect, neuroticism, and their interaction with eating behaviors during the COVID-19 lockdowns. We present data from 1,128 participants (Mage = 24.34 ± 10.48 years) who completed an online survey between February 17 and 27, 2020. The extent of respondents' social media exposure, negative affect, eating behaviors, and desire for high-calorie food during city lockdowns, as well as the personality trait of neuroticism, were measured. Results show that city lockdowns and home confinements had a negative impact on residents' eating behaviors and appetite. Forty-eight percent of respondents showed moderate to constant emotional overeating, and respondents' desire for high-calorie food significantly increased. Correlation analysis showed that emotional overeating is positively associated with social media exposure, neuroticism, and anxiety. Then, a moderated mediation model was established, showing that heavy social media exposure could lead to emotional overeating through anxiety, and the association between social media exposure and anxiety varies depending on the extent of neuroticism. The current study provides novel insight into how the interaction of a personality trait and the stressful situation of COVID-19 influence people's negative emotions and eating behaviors.

Adult attachment style and salivary alpha-amylase and emotional responses to a psychosocial stressor in women with eating disorders

BACKGROUND

The fine-tuning of the endogenous stress response system, which includes the hypothalamus-pituitary-adrenal axis and the sympathetic nervous system (SNS), is influenced by early attachment relationships. A higher prevalence of insecure attachment has been detected in people with eating disorders (EDs). Thus, we investigated the emotional and the SNS reactivity to the Trier Social Stress Test (TSST) in women with EDs in relation to their attachment profiles.

METHODS

Fifty women with EDs and 20 healthy women participated into an experimental study. Attachment was evaluated by Experience in Close Relationship questionnaire. Salivary α-amylase (sAA) levels were measured to assess the SNS reactivity to TSST while the emotional response was measured by the STAI state scale.

RESULTS

Compared to women with EDs and low attachment anxiety and healthy controls, women with EDs and high attachment anxiety showed lower TSST-induced sAA production without difference in anxiety scores. Women with EDs and high attachment avoidance showed similar sAA response to TSST but higher levels of anxiety scores compared to those with low attachment avoidance and healthy controls.

CONCLUSIONS

Our findings corroborate the idea that adult attachment may be associated with variability in emotional and biological responses to a psychosocial stressor in women with EDs.

Volume and Connectivity Differences in Brain Networks Associated with Cognitive Constructs of Binge Eating

Bulimia nervosa (BN) and binge eating disorder (BED) are characterized by episodes of eating large amounts of food while experiencing a loss of control. Recent studies suggest that the underlying causes of BN/BED consist of a complex system of environmental cues, atypical processing of food stimuli, altered behavioral responding, and structural/functional brain differences compared with healthy controls (HC). In this narrative review, we provide an integrative account of the brain networks associated with the three cognitive constructs most integral to BN and BED, namely increased reward sensitivity, decreased cognitive control, and altered negative affect and stress responding. We show altered activity in BED/BN within several brain networks, specifically in the striatum, insula, prefrontal cortex (PFC) and orbitofrontal cortex (OFC), and cingulate gyrus. Numerous key nodes in these networks also differ in volume and connectivity compared with HC. We provide suggestions for how this integration may guide future research into these brain networks and cognitive constructs.

Stress appraisal prospectively predicts binge eating through increases in negative affect

PURPOSE

Ecological momentary assessment (EMA) studies preliminarily support the transactional model of emotion regulation in eating disorders, such that heightened stress appraisal (i.e., the cognitive evaluation of an event's demands) results in increased negative affect (NA) and subsequent binge eating (BE). However, the temporal relationships between these variables and the magnitude of stress appraisal that is clinically significant require clarification. The current study aimed to extend previous research by (1) examining the temporal relationship between stress appraisal, changes in NA, and BE using three timepoints, (2) exploring what magnitude of momentary stress appraisal results in clinically significant increases in NA and BE, and (3) characterizing what stressors are associated with clinically significant stress appraisal.

METHODS

37 adult females completed an EMA protocol assessing momentary stressors, stress appraisal, NA, and BE over 2 week duration. Multilevel mediation models were used to test the study aims.

RESULTS

Momentary increases in stress appraisal significantly predicted binge eating through increases in NA. Stress appraisal ratings of 0.50 SD higher relative to one's average stress appraisal began to significantly predict the likelihood of BE through increases in NA, and the likelihood of BE occurrence increased with every 0.25 increments in momentary stress appraisal. Work/school stressors and interpersonal stressors were the most commonly endorsed stressors of clinically significant stress appraisal.

CONCLUSION

The current study supported the transactional model of emotion dysregulation in a binge eating sample and supports the use of momentary interventions at times of clinically significant stress appraisal to reduce BE risk.

LEVEL OF EVIDENCE

Level II, controlled trial without randomization.

Emotion and Psychophysiological Responses During Emotion-Eliciting Film Clips in an Eating Disorders Sample

Background: Greater vulnerability to negative emotions appears associated with the development and maintenance of eating disorders (EDs). A systematic review of psychophysiological studies using emotion-eliciting film clips reveals that there are no studies examining the effect of standardized validated film clips on psychophysiological response across a range of EDs.

Methods: Using standardized validated film clips without ED-specific content, the present study examined self-reported emotions and psychophysiological responses of women with Binge-Eating Disorder (BED; n = 57), Anorexia Nervosa (AN; n = 16), Bulimia Nervosa (BN; n = 34), and Healthy Controls (HCs; n = 26) at Baseline, during Neutral, Sad, Happy, and Fear-inducing film clips, and at Recovery.

Results: Throughout the protocol, the ED groups reported significantly greater sadness and anxiety than HCs. Additionally, the AN group reported more fear, the BED group more frustration, and the BED and BN groups more tension than HCs. Compared to HCs, the BED group reported stronger urges to binge throughout the protocol, whereas BN group reported stronger urges to binge relative to the HC group only at Baseline and Recovery. The BN and BED groups experienced decreased urges to binge during all film clips compared to Baseline. Respiratory Sinus Arrhythmia levels were significantly lower in the BED group compared to HCs and the BN group throughout the protocol.

Discussion: Standardized validated film clips can be used to elicit expected self-reported emotion and skin conductance responses in ED groups, although individuals with EDs compared HCs report greater negative emotions. Interestingly, film clips appeared to reduce urges to binge in binge-eating groups.

Bad mood food? Increased versus decreased food cue reactivity in anorexia nervosa and bulimia nervosa during negative emotions

OBJECTIVE

Emotion regulation difficulties in anorexia nervosa (AN) and bulimia nervosa (BN) might underlie bingeing and purging in BN, extreme fasting in AN, or combinations of these symptoms in binge-purge type AN. In this study, we tested for decreased food cue reactivity in response to negative emotions in AN, and the opposite pattern for BN. Furthermore, we explored subgroup differences (restrictive vs. binge-purging AN; history of AN in BN).

METHOD

Patients with AN (n = 41), BN (n = 39), and matched controls (n = 70) completed an emotional eating questionnaire. In a laboratory experiment, we induced negative emotions and measured food cue reactivity (pleasantness, desire to eat (DTE), and corrugator muscle activity).

RESULTS

AN reported emotional undereating, while BN reported emotional overeating. In the laboratory task, BN showed increased DTE and an appetitive corrugator response during negative emotions, selectively towards high-calorie foods. AN showed generalized reduced cue reactivity to high-calorie food regardless of emotional state. This pattern appears to be characteristic of restrictive AN, while cue reactivity of both BN subgroups pointed towards emotional overeating.

CONCLUSIONS

The emotional over- versus undereating framework might help to explain bingeing and restricting along the anorectic-bulimic disorder spectrum, which calls for novel transdiagnostic theories and subgroup-specific treatments.

Mood-induced changes in the cortical processing of food images in bulimia nervosa

BACKGROUND

Negative mood often triggers binge eating in bulimia nervosa (BN). We investigated motivational salience as a possible underlying mechanism using event-related potentials (ERPs) as indicators of motivated attention allocation (P300) and sustained processing (LPP).

METHODS

We collected ERPs (P300: 350-400 ms; LPP: 600-1000 ms) from 21 women with full-syndrome or partially remitted BN and 21 healthy women (HC), matched for age and body mass index. Idiosyncratic negative and neutral situations were used to induce corresponding mood states (counterbalanced), before participants viewed images of high- and low-calorie foods and neutral objects, and provided ratings for pleasantness and desire to eat.

RESULTS

P300 was larger for foods than objects; LPP was largest for high-calorie foods, followed by low-calorie foods, then objects. The BN group showed an increased desire to eat high-calorie foods under negative mood and stronger mood induction effects on ERPs than the HC group, with generally reduced P300 and a small increase in LPP for high-calorie foods. Effects were limited to circumscribed electrode positions. Exploratory analyses showed clearer effects when comparing high vs. low emotional eaters.

CONCLUSION

We argue that negative mood decreased the availability of cognitive resources (decreased P300) in BN, thereby facilitating disinhibition and food cravings (increased desire-to-eat ratings). Increased sustained processing might be linked to emotional eating tendencies rather than BN pathology per se, and reflect approach motivation, conflict, or regulatory processes. Negative mood appears to induce complex changes in food image processing, whose understanding may contribute to the development of tailored interventions in the future.

A Critical Review of Studies Assessing Interpretation Bias Towards Social Stimuli in People With Eating Disorders and the Development and Pilot Testing of Novel Stimuli for a Cognitive Bias Modification Training

People with eating disorders display a negative interpretation bias towards ambiguous social stimuli. This bias may be particularly relevant to young people with the illness due to the developmental salience of social acceptance and rejection. The overall aim of this study was to systematically develop and validate stimuli for a cognitive bias modification training to reduce a social rejection-related negative interpretation bias in young people with eating disorders. A mixed-methods design was used to achieve this aim. A review of the literature was conducted using EMBASE, MEDLINE, PsycINFO, Web of Science, and PubMed. Six studies were included in the review. Focus groups were held with patients with eating disorders, carers and healthcare professionals. Content analysis was used to identify key themes from the qualitative data. Based on these themes, a total of 339 scenarios were generated by the researchers. Salient themes identified from the focus group data included virtual rejection/exclusion, rejection associated with an aspect of the eating disorder, rejection triggered by ambiguous/benign comments or behaviors of others and rejection perceived when confiding in others. Patients rated these scenarios in terms of their age-relevance and emotional salience and 301 scenarios were included in the final stimulus set. These materials may be used by researchers conducting future experimental research into the potential benefits of interpretation bias training for young people with eating disorders.

Emotional reactivity and eating disorder related attitudes in response to the trier social stress test: An experimental study in people with anorexia nervosa and with bulimia nervosa

BACKGROUND

In order to experimentally asses the role of socio-emotional problems in Eating Disorder (ED) psychopathology, we have measured affective states and ED-related attitudes in response to an acute psychosocial stress and their relationships with interpersonal sensitivity in people with Anorexia Nervosa (AN) and Bulimia Nervosa (BN).

METHODS

Twenty-one women with AN, 21 with BN and 27 healthy women underwent an acute psycho-social challenge, the Trier Social Stress Test. Anxiety feelings, hunger perception, amount of desired food and body dissatisfaction were measured throughout the experimental procedure. The relationships between these variables and with interpersonal sensitivity measures were explored through Pearson's correlation and mediation analyses.

RESULTS

Stress-induced anxiety was increased in people with EDs. People with AN showed reduced hunger perception, decreased desire for food and a negative association between anxiety feelings and desire for food. In people with EDs, baseline ineffectiveness predicted post-stress body dissatisfaction through the mediation of post-stress anxiety levels.

LIMITATIONS

The relatively low sample size and the lack of an experimental control condition are the main limitations of the study.

CONCLUSIONS

The present findings show, for the first time, the relationships between socio-emotional distress and ED-related attitudes in people with EDs, providing experimental support to the interpersonal model of EDs. This gives empirical evidence to treatments targeting interpersonal problems in 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.

Fight, Flight, - Or Grab a Bite! Trait Emotional and Restrained Eating Style Predicts Food Cue Responding Under Negative Emotions

In today's society, obesity rates are rising as food intake is no longer only a response to physiological hunger signals that ensure survival. Eating can represent a reward, a response to boredom, or stress reduction and emotion regulation. While most people decrease food intake in response to stress or negative emotions, some do the opposite. Yet, it is unclear who shows emotional overeating under which circumstances. Emotion regulation theories describe emotional overeating as a learned strategy to down-regulate negative emotions. Cognitive theories, by contrast, attribute emotional overeating to perceived diet breaches in individuals who chronically attempt to diet. After consuming "forbidden foods", they eat more than individuals who do not restrict their food intake. This laboratory study investigated emotional overeating by exposing individuals to a personalized emotion induction while showing images of palatable foods. Outcome variables indexed cue reactivity to food images through picture ratings (valence, desire to eat), facial expressions (electromyography of the corrugator supercilii muscle), and brain reactivity by detecting event-related potentials (ERPs) by means of electroencephalography (EEG). The influence of emotion condition (negative, neutral) and individual differences (self-reported trait emotional and restrained eating) on outcome variables was assessed. Valence ratings and appetitive reactions of the corrugator muscle to food pictures showed a relative increase in the negative condition for individuals with higher emotional eating scores, with the opposite pattern in lower scores. Desire to eat ratings showed a similar pattern in individuals who showed a strong response to the emotion induction manipulation, indicative of a dose-response relationship. Although no differences between conditions were found for ratings or corrugator activity with restrained eating as a predictor, an ERP at P300 showed increased activation when viewing food compared to objects in the negative condition. Findings support emotion regulation theories: Emotional eaters showed an appetitive reaction in rating patterns and corrugator activity. EEG findings (increased P300) suggest a motivated attention toward food in restrained eaters, which supports cognitive theories. However, this did not translate to other variables, which might demonstrate successful restraint. Future studies may follow up on these findings by investigating eating disorders with emotion regulation difficulties.

Emotional eating in healthy individuals and patients with an eating disorder: evidence from psychometric, experimental and naturalistic studies

Emotional eating has traditionally been defined as (over)eating in response to negative emotions. Such overeating can impact general health because of excess energy intake and mental health, due to the risks of developing binge eating. Yet, there is still significant controversy on the validity of the emotional eating concept and several theories compete in explaining its mechanisms. The present paper examines the emotional eating construct by reviewing and integrating recent evidence from psychometric, experimental and naturalistic research. Several psychometric questionnaires are available and some suggest that emotions differ fundamentally in how they affect eating (i.e. overeating, undereating). However, the general validity of such questionnaires in predicting actual food intake in experimental studies is questioned and other eating styles such as restrained eating seem to be better predictors of increased food intake under negative emotions. Also, naturalistic studies, involving the repeated assessment of momentary emotions and eating behaviour in daily life, are split between studies supporting and studies contradicting emotional eating in healthy individuals. Individuals with clinical forms of overeating (i.e. binge eating) consistently show positive relationships between negative emotions and eating in daily life. We will conclude with a summary of the controversies around the emotional eating construct and provide recommendations for future research and treatment development.

Family-related non-abuse adverse life experiences occurring for adults diagnosed with eating disorders: a systematic review

BACKGROUND

Although previous reviews suggest a strong association between abuse and eating disorders, less is known about non-abuse adverse life experiences, such as parental mental illness or family discord, which occur frequently for this population. The aim of the current study was to identify family-related non-abuse adverse life experiences occurring for adults with eating disorders, and to establish whether they occur for people with anorexia nervosa, bulimia nervosa or binge-eating disorder more than the general population and other psychiatric populations.

METHOD

A systematic review of studies focusing on family-related non-abuse adverse life experiences and eating disorders was conducted in accordance with PRISMA guidelines. The search string was applied to four electronic databases including Psycinfo, PubMed/Medline, CINAHL Plus and EMBASE.

RESULTS

Of the 26 studies selected for inclusion, six types of family-related non-abuse adverse life experiences were identified: adverse parenting style; family disharmony; loss of a family member, relative or close person; familial mental health issues; family comments about eating, or shape, weight and appearance; and family disruptions. Findings provided tentative evidence for eating disorder specific (i.e. parental demands and criticism) and non-specific (i.e. familial loss and family disruptions) non-abuse adversities, with findings also suggesting that those with bulimia nervosa and binge-eating disorder were more impacted by loss, family separations and negative parent-child interactions compared to those with anorexia nervosa.

CONCLUSIONS

This review provides a clear synthesis of previous findings relating to family-related non-abuse adverse life experiences and eating disorders in adults. Implications for trauma-informed care in clinical practice were discussed (e.g. considering the impact of past life events, understanding the function of ED behaviours, reducing the risk of potential re-traumatisation).

Negative affect amplifies the relation between appetitive-food-related neural responses and weight gain over three-year follow-up among adolescents

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Interaction of negative affect and hippocampal food-image response predicts BMI gain.

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Interaction of negative affect, vermis and precuneus food response predicts BMI gain.

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Interaction of stress and middle occipital gyrus milkshake response predicts BMI gain.

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Weight gain associated with restrained eating and eating-disorder related behavior.

Obesity is a major public health concern that is associated with disruption in food reward-related brain function. This study examined if negative affect and stressful events enhance the relation between the food reward-related neural response and future weight gain. Initially healthy weight adolescents (N = 135) completed fMRI paradigms in which they tasted milkshakes and viewed palatable food images, and reported on negative affect and stressful events at baseline; BMI was measured annually over 3-year follow-up. Whole-brain analyses revealed that among participants with higher negative affect, weight gain over 3-year follow-up was predicted by elevated response to appetitive versus unappetitive food images in the left hippocampus, and elevated response in the vermis and the bilateral precuneus to tastes of milkshake versus tasteless solution. Among participants who experienced more stressful events, elevated right middle occipital gyrus response to milkshakes predicted future weight gain. Profiling analyses suggested that participants with higher negative affect or more stressful events who later gained weight reported engaging in more restrained eating and eating disorder-related behaviors. Results suggest that negative affect or stressful events may amplify the relation of neural response to food and the risk for future weight gain.

Interpersonal difficulties in obesity: A systematic review and meta-analysis to inform a rejection sensitivity-based model

Obesity is associated with difficulties due to stigma and loneliness. These impact negatively on individuals' quality of life and behaviour change efforts. Increased sensitivity to others' negative feedback might play a role in the maintenance of these difficulties and could be addressed in psychological interventions. We conducted a systematic review of interpersonal difficulties in individuals with obesity, across the lifespan. We investigated early interpersonal adversity (i.e. frequency of teasing/bullying), perceived interpersonal stress and quality of social life, based on a rejection sensitivity model. The databases PubMed, Web of Knowledge and AGRIS, Embase, Medline and PsychINFO were searched for published peer-reviewed journal articles (1980-June 2018). Thirty-two studies met inclusion criteria. Results from the meta-analyses (n = 16 studies) indicated that overweight/obese individuals reported more frequent experiences of teasing/bullying, greater interpersonal stress and poorer quality of social life than healthy weight individuals. Findings in the systematic review aligned to this evidence. Psychological interventions targeting increased sensitivity to negative interpersonal feedback could improve interpersonal functioning and, in turn, eating behaviours in individuals with obesity.

Toward Quantifying the Psychopathology of Eating Disorders From the Autonomic Nervous System Perspective: A Methodological Approach

The phenomenology of Eating Disorders (ED) relates with altered functioning of the Autonomic Nervous System (ANS). The lack of agreement in what comes to the direction and significance of such alterations is possibly due to the variability in the ED spectrum. As the stress response system is an integral part of the ANS, we propose to investigate ANS tonic variations and phasic activations in response to stressors. We hypothesize that, while using stress as a test probe, characteristic ANS dysregulations in ED may be found when considering several physiological signals measured over time, and weighted by the individual psychological profiles. In this article we describe a novel methodological approach to investigate this hypothesis with the aim of providing further clarification on the ED spectrum conceptualization. The proposed methodology has been designed to be easily integrated in clinical practice and, eventually, in daily life. The population under observation includes both patients in treatment for ED, and matched controls. The study session has the duration of 1 day, including: (1) the administration of a stress task in a controlled environment and (2) naturalistic data collection. The stress task is designed to elicit both mentally and physically driven ANS activation. The naturalistic component intends to illustrate the psychophysiology in everyday life. We use wearable devices to continuously and non-invasively measure bio-signals related to ANS functioning. This information is complemented with psychometric information from validated stress and ED scales and ecological momentary assessments. The protocol has received ethical approval and has been implemented in practice, currently accounting for 37 patients (out of 120) and 16 controls (out of 60). Ongoing work focus on the definition and implementation of a data processing pipeline to quantitatively test our hypothesis, both standard statistical methods and more exploratory machine learning approaches will be considered.

Distress tolerance across self-report, behavioral and psychophysiological domains in women with eating disorders, and healthy controls

BACKGROUND AND OBJECTIVES

The tendency to engage in impulsive behaviors when distressed is linked to disordered eating. The current study comprehensively examines emotional responses to a distress tolerance task by utilizing self-report, psychophysiological measures (respiratory sinus arrhythmia [RSA], skin conductance responses [SCRs] and tonic skin conductance levels [SCLs]), and behavioral measures (i.e., termination of task, latency to quit task).

METHODS

26 healthy controls (HCs) and a sample of treatment-seeking women with Bulimia Nervosa (BN), Binge Eating Disorder (BED) and Anorexia Nervosa (AN) (N = 106) completed the Paced Auditory Serial Addition Task- Computerized (PASAT-C). Psychophysiological measurements were collected during baseline, PASAT-C, and recovery, then averaged for each time period. Self-reported emotions were collected at baseline, post-PASAT-C and post-recovery.

RESULTS

Overall, we found an effect of Time, with all participants reporting greater negative emotions, less happiness, lower RSA, more SCRs and higher tonic SCLs after completion of the PASAT-C relative to baseline. There were no differences in PASAT-C performance between groups. There was an effect of Group for negative emotions, with women with BN, BED and AN reporting overall higher levels of negative emotions relative to HCs. Furthermore, we found an effect of Group for greater urges to binge eat and lower RSA values among BED, relative to individuals with BN, AN and HCs.

LIMITATIONS

This study is cross-sectional and lacked an overweight healthy control group.

CONCLUSION

During the PASAT-C, individuals with eating disorders (EDs) compared to HCs report higher levels of negative emotions, despite similar physiological and behavioral manifestations of distress.

Heart rate variability and emotion regulation among individuals with obesity and loss of control eating

Autonomic nervous system functioning, measured with heart rate variability (HRV), is associated with emotion regulation and likely contributes to binge eating. This study examined the link between HRV and binge eating severity and analyzed changes in HRV as a marker of emotion regulation in individuals with binge eating. Participants (n = 28) with obesity and loss of control eating reported overeating and loss of control episodes and completed an HRV assessment at rest and during a mental stressor. At rest, lower time-domain HRV was linked to more severe loss of control (SDNN B = -0.18, p = 0.03). Frequency-domain HRV was associated with more severe overeating (LFn B = 14.92, p = 0.03; HFn B = -14.81, p = 0.04). Frequency-domain HRV differed between resting and stressed conditions (p's < 0.001). Findings contribute to understanding emotion regulation in binge eating and guide future research and novel intervention development.

A pilot open trial of UNITE-BED: A couple-based intervention for binge-eating disorder

OBJECTIVE

To evaluate the feasibility, acceptability, and preliminary efficacy of a couple-based intervention for binge-eating disorder (BED), called UNiting couples In the Treatment of Eating disorders-BED edition (UNITE-BED).

METHOD

In an open pilot trial, 11 couples in which one or both adult partners had a diagnosis of DSM-5 threshold or sub-threshold BED participated in 22 weekly sessions of UNITE-BED. Patients also received individual treatment, outside of the context of the trial. Couples completed measures on treatment satisfaction, eating disorder symptom severity, depression, anxiety, emotion regulation, and relational functioning at post-treatment and 3-month follow-up. Statistical analyses were conducted to identify change over the course of treatment.

RESULTS

UNITE was feasible and acceptable to the majority of couples (9% dropout; high satisfaction ratings). Objective binge abstinence was 81.8% and subjective binge abstinence was 45.5% by post-treatment. Patient binge-eating symptomatology reduced over the course of treatment with results maintained at follow up. Patients' depression symptoms decreased and patients' emotion regulation improved at both time points.

DISCUSSION

Including partners in treatment for BED may be beneficial. Results support further evaluation of the efficacy of couple-based interventions for BED in larger randomized-controlled trials.

Perceived Discrimination and Binge Eating Disorder; Gender Difference in African Americans

Environmental stressors, such as perceived discrimination (PD), are linked to Binge Eating Disorder (BED). The current study investigated the association between PD and BED among African Americans, and the variation in such an association based on gender. Data of the National Survey of American Life (NSAL), 2001⁻2003, with a nationally-representative sample of African American adults, were used (n = 3516). The independent variable in the study was PD. The dependent variable was BED, measured using the Composite International Diagnostic Interview (CIDI). Socio-demographics (age, education, employment, and marital status) were covariates, and gender was the moderator variable. Survey logistic regressions with and without gender × PD interaction terms were used for data analysis. In the pooled sample, PD was associated with higher odds of BED, net of socio-demographic factors. Models also showed a significant gender × PD interaction term suggesting a stronger association between PD and BED for women, compared to men. Gender specific models showed an association between PD and BED among female, but not male, African Americans. Although a link may exist between PD and BED among African Americans, the magnitude of this association depends on gender, with a stronger association among females than males. This finding is in line with the literature that has shown gender-specific consequences of environmental stress for African Americans.

Cue reactivity, habituation, and eating in the absence of hunger in children with loss of control eating and attention-deficit/hyperactivity disorder

OBJECTIVE

Childhood loss of control (LOC) eating and attention-deficit/hyperactivity disorder (ADHD) are highly comorbid conditions and present with disordered eating behaviors, such as overeating. This study sought to delineate shared and specific abnormalities in physiological, cognitive-motivational, and behavioral components of food-specific impulsivity in children with LOC eating and ADHD. Specifically, children's reactivity and habituation to food and eating in the absence of hunger were examined.

METHODS

Within this community-based study, four groups of 8-13-year-old children with LOC eating (n = 24), ADHD (n = 32), comorbid LOC eating/ADHD (n = 9), and matched controls (n = 34) received a standard laboratory test meal to establish satiety and were then exposed to their favorite snack food in a cue exposure/reactivity trial, while salivation and desire to eat were repeatedly assessed. Subsequently, they were offered a variety of snack foods ad libitum.

RESULTS

Children with LOC eating, ADHD, and LOC/ADHD did not differ from controls in salivary reactivity and habituation to food cues. Children with LOC eating and ADHD showed greater cue reactivity of the desire to eat than controls, but groups did not differ in its longer-term increments. At free access, only children with LOC/ADHD consumed significantly more energy than controls. Longer-term increments of desire to eat predicted greater energy intake beyond LOC/ADHD group status.

DISCUSSION

Desire to eat among children with comorbid LOC eating and ADHD was associated with overeating in the absence of hunger, which may contribute to excess weight gain. Delineation of the specific features of childhood LOC eating versus ADHD warrants further study.

Obesity is associated with lack of inhibitory control and impaired heart rate variability reactivity and recovery in response to food stimuli

Recent theories compare obesity with addiction in terms of lack of inhibitory control in both clinical populations. The present study hypothesized impaired inhibition in obese patients reflected both in executive functions and reduced vagal tone (indexed by a decrease in heart rate variability; HRV) in response to food stimuli. Twenty-four inpatients with obesity (19 women) and 37 controls (24 women) underwent ECG monitoring during baseline, food stimuli viewing, and a recovery phase. Tests and questionnaires assessing inhibitory control and psychopathological dispositions were also administered. As hypothesized, patients were characterized by deficits in all the tests measuring inhibitory capacities. Results also show greater HRV reduction and impaired HRV recovery in response to food stimuli in obese patients compared to controls. The drive to eat experienced by obese patients in the absence of caloric need may rely on impairments in inhibitory and vagal functioning. Results are discussed in terms of implications for therapy.

A systematic review of the association between emotions and eating behaviour in normal and overweight adult populations

A systematic review was completed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search of four electronic databases (2004–2015) yielded 60,017 articles, of which 29 met inclusion criteria. Included studies performed poorly on data quality analysis in terms of randomisation and controlling for confounding factors. Participant’s body mass index scores range from 19.73 (standard deviation = 1.54) to 28.4 (standard deviation = 1.4) kg/m2. Where positive and negative affects were compared, food was more likely to be consumed in response to positive affect. With regard to discrete emotions; stress, depression and sadness consistently elicited eating behaviours that fall outside of nutritional recommendations (e.g. increased food intake or poor nutritional food choices). The role of moderators including individual differences in dietary restraint and emotional eating, as well as methodological considerations, such as means of eliciting and measuring emotions, may account for equivocality with regard to some emotion and eating associations. This article concludes with recommendations for future research and implications for practice.

Exploring the mind's eye: Contents and characteristics of mental images in overweight individuals with binge eating behaviour

Mental images play a role in various mental disorders and are strongly associated with emotions. Negative emotions and their regulation are important in eating disorders. However, research on mental imagery in eating disorders is still scarce. We investigated mental images and their relation to distress and eating disorder psychopathology in individuals with binge eating behaviour. Content and characteristics of mental images and their relation to psychopathology of 21 individuals with binge eating behaviour, 19 mixed patient controls and 21 healthy controls have been assessed with a semi-structured interview. Occurrence and vividness of food-related images did not differ between groups. However they were experienced as more distressing and distracting and more difficult to control by eating disordered patients. Body-related mental images were less associated with desire to eat than expected. Mental images of social rejection were experienced as more vivid by both clinical groups and caused desire to eat in individuals with binge eating behaviour. Mental images are relevant in binge eating behaviour, but with different patterns regarding concomitant distress and eating disorder psychopathology. As transdiagnostic mental images of social rejection are relevant for individuals with binge eating behaviour, research on imagery based techniques in eating disorders seems promising.

Does habituation really happen? Investigation of psycho-biological responses to body exposure in bulimia nervosa

BACKGROUND

Body exposure is a common and effective treatment for body image disturbance in bulimia nervosa (BN). However, little is known about treatment mechanisms. Based on models of emotional processing and neurovisceral integration, we expected to observe a) initial activation and b) habituation of cognitive-affective and autonomic responding within one and between two standardized body exposure sessions.

METHODS

A group of 13 women with BN and 13 healthy controls (HC) were repeatedly exposed to their bodies. Prior to and after treatment with three individualized mirror exposure sessions participants received a session of standardized exposure to videographic recordings of their body. Subjective ratings of body-related emotions and thoughts were assessed repeatedly throughout the standardized exposure sessions and autonomic responses were recorded continuously.

RESULTS

Subjective and sympathetic responses were activated initially in both groups. Cognitive-affective responses habituated within the standardized sessions in both groups, whereas between the standardized sessions habituation was only found in women with BN. Increasing sympathetic responses were found within the sessions in both groups.

CONCLUSIONS

The results support cognitive-affective habituation during body exposure in BN and to a lesser extent in HC. Autonomic responses however did not show a corresponding pattern and did not distinguish between groups. Implications for body exposure research and practice are discussed.

A Meta-analysis on Resting State High-frequency Heart Rate Variability in Bulimia Nervosa

OBJECTIVE

Autonomic nervous system function is altered in eating disorders. We aimed to quantify differences in resting state vagal activity, indexed by high-frequency heart rate variability comparing patients with bulimia nervosa (BN) and healthy controls.

METHODS

A systematic search of the literature to identify studies eligible for inclusion and meta-analytical methods were applied. Meta-regression was used to identify potential covariates.

RESULTS

Eight studies reporting measures of resting high-frequency heart rate variability in individuals with BN (n = 137) and controls (n = 190) were included. Random-effects meta-analysis revealed a sizeable main effect (Z = 2.22, p = .03; Hedge's g = 0.52, 95% CI [0.06;0.98]) indicating higher resting state vagal activity in individuals with BN. Meta-regression showed that body mass index and medication intake are significant covariates.

DISCUSSION

Findings suggest higher vagal activity in BN at rest, particularly in unmedicated samples with lower body mass index. Potential mechanisms underlying these findings and implications for routine clinical care are discussed. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

The neurobiological basis of binge-eating disorder

Relatively little is known about the neuropathophysiology of binge-eating disorder (BED). Here, the evidence from neuroimaging, neurocognitive, genetics, and animal studies are reviewed to synthesize our current understanding of the pathophysiology of BED. Binge-eating disorder may be conceptualized as an impulsive/compulsive disorder, with altered reward sensitivity and food-related attentional biases. Neuroimaging studies suggest there are corticostriatal circuitry alterations in BED similar to those observed in substance abuse, including altered function of prefrontal, insular, and orbitofrontal cortices and the striatum. Human genetics and animal studies suggest that there are changes in neurotransmitter networks, including dopaminergic and opioidergic systems, associated with binge-eating behaviors. Overall, the current evidence suggests that BED may be related to maladaptation of the corticostriatal circuitry regulating motivation and impulse control similar to that found in other impulsive/compulsive disorders. Further studies are needed to understand the genetics of BED and how neurotransmitter activity and neurocircuitry function are altered in BED and how pharmacotherapies may influence these systems to reduce BED symptoms.

Behavioral and neurodevelopmental precursors to binge-type eating disorders: support for the role of negative valence systems

BACKGROUND

Pediatric loss-of-control (LOC) eating is a robust behavioral precursor to binge-type eating disorders. Elucidating precursors to LOC eating and binge-type eating disorders may refine developmental risk models of eating disorders and inform interventions.

METHOD

We review evidence within constructs of the Negative Valence Systems (NVS) domain, as specified by the Research Domain Criteria framework. Based on published studies, we propose an integrated NVS model of binge-type eating-disorder risk.

RESULTS

Data implicate altered corticolimbic functioning, neuroendocrine dysregulation, and self-reported negative affect as possible risk factors. However, neuroimaging and physiological data in children and adolescents are sparse, and most prospective studies are limited to self-report measures.

CONCLUSIONS

We discuss a broad NVS framework for conceptualizing early risk for binge-type eating disorders. Future neural and behavioral research on the developmental trajectory of LOC and binge-type eating disorders is required.

Blunted neuroendocrine stress reactivity in young women with eating disorders

OBJECTIVE

Stress is known to influence risk and progression of eating disorders (EDs). However, studies investigating physiological and psychological stress responses under laboratory conditions in patients with Anorexia nervosa or Bulimia nervosa are scarce and often produce conflicting findings. We therefore aimed to compare the neuroendocrine and affective stress response in ED inpatients and healthy controls.

METHODS

Twenty-eight female inpatients with Anorexia or Bulimia nervosa and 26 healthy women were exposed to the Trier Social Stress Test (TSST). Salivary cortisol and alpha-amylase (sAA) levels were assessed before as well as repeatedly after stress exposure, while heart rate and heart rate variability were determined before and during the TSST. Negative affective state was assessed at baseline and post-TSST.

RESULTS

Compared to healthy controls, ED patients showed blunted cortisol stress responses combined with overall attenuated sAA levels. The latter was reflected in generally enhanced parasympathetic activity indicated by lower heart rate and stronger high-frequency heart rate variability throughout the TSST. Although patients reported more negative affect overall, they did not differ in their affective stress response.

CONCLUSIONS

In summary, patients suffering from eating disorders show a blunted HPA axis reactivity to stress exposure and a generally reduced sympathetic/exaggerated parasympathetic nervous system activity. This combination may contribute to elevated health risks seen in eating disorder patients, such as enhanced inflammatory activity, and thus provide insight into the underlying stress-related mechanisms.

[Triggers of bulimia and compulsion attacks: validation of the "Start" questionnaire]

AIM

There are few published studies on the triggers of binge eating in anorexia nervosa of binge/purging subtype (BPAN), bulimia nervosa (BN) and binge eating disorder (BED).

PATIENTS AND METHODS

We validated in 29 patients (10 BPAN, 10 BN and 9 BED) the perspicuity, the clarity and the intra- (doubles) and inter- (test-retest) reproducibility of a 24-item Start questionnaire on the triggers of binge eating. Then the Start questionnaire was administered to 176 patients (65 BPAN, 62 BN and 59 BED patients) being 27.5+9.1 yr old, having 15+9 binge eating (BE) episodes/week, with a mean binge duration of 1 hr 36min (+ 38min)/day.

RESULTS

BE episodes occurred mainly during the second part of the day: afternoon after work (67% of the patients), "tea" time (55%), evening after dinner (42%) and at night (22%). The principal place for BE episodes was at home (96%). The BED patients avoided binges at the parents' home (89%) more often than the BPAN (62%, P<0.02). The binges occurred mainly in the living room (44%), in the kitchen (43%), and less in the bedroom (31%). Hunger pangs seemed to be a trigger of binges in 31% of the patients, and a stronger trigger in BED (42%) than in the BPAN and BN patients (24%; P=0.04). Binge eating episodes could occur despite a high satiety level (just after lunch or dinner) in 29% of the BN and in 16% of the BED patients (P<0.02). Concerning food, the major triggers were high energy-density food (77%) and comfort food (60%), such as chocolate, cakes, bread and pasta. The food consumed for binge episodes (in-binge food) was more often a strong trigger than the other food (not used for binges): olfaction (19% versus 10%), sight (52% versus 25%) and placing in the mouth (71% versus 26%; P<0.02 for all, in the 3 groups). Being tired could be a strong trigger in 37% of the patients, but "being aroused" in the other 38 % of the patients. Stressful events (65%), anxiety (74%), "being under pressure" or irritated (51% and 55%) were of course major triggers in a majority of the patients, as well as sadness (61%), feeling of powerlessness (62%), inefficiency (73%) and depressive state (71%). Flashback from traumatism (sexual trauma in 17% of the patients) was a strong trigger of binges more often in BPAN and BED (44%) than in BN (23%; P<0.05). The binge eating was painful (and "not at all a pleasure") in 69% of the patients, but could also be a relaxing behavior in 31% of the patients, more often in the BED (43%) than in the BPAN patients (20%; P<0.05). The binge eating behavior was quoted as obsessive in 63% of BPAN, 92% of BN and only 34% of BED patients (P<0.001). The patients said that they were unable to avoid the binge (76% of the patients), more often in BPAN and BN than in BED patients (P<0.01). As a whole, 62% of BPAN, 89% of BN and only 4 % of BED patients (P<0.05) were unable to avoid purging (vomiting). In 12% of the cases, there was a pleasure felt when binging. For the other patients, shame, filth and incapacity were the feelings related to binges in 58% of the BPAN, 45% of BN and 43% of BED patients (P<0.04). The global score of addiction (zero=not addicted, 10=very addicted) was 8.56+1.2 in BPAN, 8.42+1.5 in BN and 6.74+1.1 in BED patients (NS between BPAN and BN; P<0.01 between BPAN and BN on the one hand and BED on the other).

CONCLUSION

The present study has demonstrated the usefulness of the Start questionnaire. It also evidences the key role of intrinsic factors, both metabolic and emotional, as strong triggers for binge eating episodes in BPAN, BN and BED. It has also demonstrated the role of environmental determinants.

From passive overeating to "food addiction": a spectrum of compulsion and severity

A psychobiological dimension of eating behaviour is proposed, which is anchored at the low end by energy intake that is relatively well matched to energy output and is reflected by a stable body mass index (BMI) in the healthy range. Further along the continuum are increasing degrees of overeating (and BMI) characterized by more severe and more compulsive ingestive behaviours. In light of the many similarities between chronic binge eating and drug abuse, several authorities have adopted the perspective that an apparent dependence on highly palatable food-accompanied by emotional and social distress-can be best conceptualized as an addiction disorder. Therefore, this review also considers the overlapping symptoms and characteristics of binge eating disorder (BED) and models of food addiction, both in preclinical animal studies and in human research. It also presents this work in the context of the modern and "toxic" food environment and therein the ubiquitous triggers for over-consumption. We complete the review by providing evidence that what we have come to call "food addiction" may simply be a more acute and pathologically dense form of BED.

A systematic review of obstetric complications as risk factors for eating disorder and a meta-analysis of delivery method and prematurity

OBJECTIVE

The aim of this study was to systematically review the literature on obstetric factors at birth and their role as risk factors for a subsequent eating disorder (ED) and where possible to perform a meta-analysis of case-control studies of EDs and obstetric complications (OCs).

METHOD

Studies were ascertained by computer searches of electronic databases (Medline, PsycINFO, Web of Science and CINAHL), searches of reference lists and from raw data obtained upon request from the authors. A total of 14 studies were identified for the systematic review, of which 6 were eligible for the subsequent meta-analysis. Of the selected 6 studies, 5 reported on the same OCs, namely vaginal instrumental delivery and prematurity. Accordingly, meta-analyses were run on these two variables. Both analyses were conducted on anorexia nervosa (AN) patients.

RESULTS

Findings from the systematic review were conflicting, with some studies reporting a significant relationship between OCs and ED diagnoses and/or ED symptomatology and others refuting it. A non-significant association of instrumental delivery [pooled odds ratio (OR) 1.06, 95%CI: 0.69, 1.65] and prematurity [pooled OR 1.17, 95%CI: 0.91, 1.52] with AN was revealed in our meta-analysis.

CONCLUSION

The current literature on OCs as risk factors for a later ED is contradictory. The range of different occurrences considered as OCs and methodological limitations hinder ultimate conclusions. Upcoming studies should pool datasets together to obtain sufficient power to assess OCs and EDs in combination.

Self-reported dieting success is associated with cardiac autonomic regulation in current dieters

Restrained eating, eating disorders and obesity have been associated with cardiac autonomic dysregulation. The current study investigated cardiac autonomic regulation in current dieters. Female students (N=50) indicated if they were currently trying to control their weight and completed the Perceived Self-Regulatory Success in Dieting Scale (PSRS). Heart beat intervals were recorded during two 10 min relaxation periods from which parameters of vagal-cardiac control (high frequency power in normalized units, HF n.u.) and sympathovagal balance (ratio of low and high frequency power, LF/HF) were calculated. In current dieters, self-reported dieting success was positively associated with HF and negatively associated with LF/HF. These associations were independent of current body-mass and food deprivation (i.e. hours since the last meal). We conclude that vagal-cardiac control reflects self-regulatory strength, rather than nutritional status, in current dieters.