Processing of food stimuli in anorexia nervosa: An ERP-study comparing adolescents and adults.

BACKGROUND: Anorexia nervosa (AN) is associated with altered processing of disorder-relevant stimuli. Event-related potentials (ERP) - such as the Late Positive Potential (LPP) - give information about the underlying mechanisms of central nervous stimulus processing. METHODS: Patients with AN (22 adolescents, 23 adults) and healthy controls (HCs; 17 adolescents, 24 adults) were included. Neutral, low, and high calorie food-images were rated for valence and arousal; EEG activity was recorded and LPPs (early: 350-700 ms; late: 800-1200 ms) were extracted. Effects of patient status, age group, and stimulus category were analyzed via mixed 2 × 2 × 3-AN(C)OVAs. RESULTS: Patients with AN rated high calorie stimuli lower in valence and higher in arousal than HCs. Controlling for hunger, food stimuli elicited higher early LPPs than neutral ones in patients and HCs. For the late LPP, patients with AN showed larger amplitudes. CONCLUSION: Results suggest a highly automatic attentional bias towards low-calorie foods. Patients with AN seem to have more intense cognitive processing independent of stimulus material. More research is needed to validate and clarify differences between early and late LPP measures as well as the operationalization and relevance of hunger status.

A 10-Year-Old Girl's Dysfunctional 'Self-Help' in ADHD: Suppression of Hyperkinetic Symptoms via Self-Induced Weight Loss in the Context of Anorexia Nervosa-A Case Report.

Anorexia Nervosa (AN) and Attention Deficit Hyperactivity Disorder (ADHD) are frequent mental disorders in child and adolescent psychiatry. Comorbidity of these disorders is, however, rare among minors. Thus, little is known about their mutual impact on illness development as well as diagnostic and therapeutic influencing factors. We report the case of a 10-year old girl with AN and massive underweight. At the age of 5, ADHD had been diagnosed. Application of ADHD-specific medication had been refused by her caregiver. As of 3rd grade, hyperkinetic symptoms were significantly reduced, which was later linked to beginning AN-induced weight loss. At inpatient admission, no clinically relevant ADHD-related symptoms were present. Accompanying weight gain, rather 'sudden' appearance of attention difficulties, motoric hyperactivity and impulsivity were reported, widely impairing our patient's schoolwork and further daily life. Methylphenidate medication showed good clinical response and tolerability. We hypothesize that the former massive underweight had suppressed ADHD-specific behaviour. AN with significant weight loss could possibly mask hyperkinetic symptoms in children. Thus, sufficient clinical diagnostics and intense monitoring during ED treatment are required. Physicians and therapists should be sensitized for interactions in the joint occurrence of these mental disorders among minors.

Heart Rate as a Correlate for the Emotional Processing of Body Stimuli in Anorexia Nervosa.

In anorexia nervosa, aberrant emotional reactions toward body stimuli have been discussed. We investigated heart rate as a physiological marker when viewing body stimuli and hypothesized altered HR reactions toward those highly significant and emotional stimuli in anorexia nervosa. In total, 37 anorexia nervosa patients and 43 control participants viewed pictures of women of five different weight categories, while their cardiac activity was recorded. R-R intervals following picture onset were determined, and means were calculated for three distinct time periods. The overall change in HR relative to baseline across all picture categories was greater in the patient group than in the control group (significant effect of "group", p = 0.002, partial η2 = 0.120). A significant decrease in HR 2 to 8 s after picture presentation was found for pictures of women of extreme weight in both participant groups (significant "category ∗ time segment interaction", p = 0.01, partial η2 = 0.037) and correlated with scores of sociocultural attitudes toward the appearance for the extremely underweight category (r = -0.33, p = 0.005). Therefore, differential HR reactions for anorexia nervosa patients and control participants were found for body stimuli in general. The highest HR decelerations in response to pictures of strongly underweight and overweight women may reflect emotional processes such as anxiety due to social comparison.

Brain Structure in Acutely Underweight and Partially Weight-Restored Individuals With Anorexia Nervosa: A Coordinated Analysis by the ENIGMA Eating Disorders Working Group.

BACKGROUND: The pattern of structural brain abnormalities in anorexia nervosa (AN) is still not well understood. While several studies report substantial deficits in gray matter volume and cortical thickness in acutely underweight patients, others find no differences, or even increases in patients compared with healthy control subjects. Recent weight regain before scanning may explain some of this heterogeneity. To clarify the extent, magnitude, and dependencies of gray matter changes in AN, we conducted a prospective, coordinated meta-analysis of multicenter neuroimaging data. METHODS: We analyzed T1-weighted structural magnetic resonance imaging scans assessed with standardized methods from 685 female patients with AN and 963 female healthy control subjects across 22 sites worldwide. In addition to a case-control comparison, we conducted a 3-group analysis comparing healthy control subjects with acutely underweight AN patients (n = 466) and partially weight-restored patients in treatment (n = 251). RESULTS: In AN, reductions in cortical thickness, subcortical volumes, and, to a lesser extent, cortical surface area were sizable (Cohen's d up to 0.95), widespread, and colocalized with hub regions. Highlighting the effects of undernutrition, these deficits were associated with lower body mass index in the AN sample and were less pronounced in partially weight-restored patients. CONCLUSIONS: The effect sizes observed for cortical thickness deficits in acute AN are the largest of any psychiatric disorder investigated in the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) Consortium to date. These results confirm the importance of considering weight loss and renutrition in biomedical research on AN and underscore the importance of treatment engagement to prevent potentially long-lasting structural brain changes in this population.

Effects of the COVID-19 Restrictions on Eating Behaviour and Eating Disorder Symptomology in Female Adolescents.

Confinement due to the COVID-19 pandemic imposes a burden on adolescents worldwide and may seriously impact patients with an eating disorder (ED). The current FRanconian Anorexia Nervosa during COVID-19 (FRANCO) study explored (1) perceived change of depressive and ED symptomology during lockdown, (2) the role of social media, and (3) coping strategies of anorexia nervosa (AN) patients and clinical as well as healthy comparison groups. From June 2021 to September 2021, 222 female adolescents (19 with AN, 20 with depression, 45 with a self-reported psychiatric disorder (SRPD), and 138 controls) aged 11.2 to 18.9 years completed a one-time anonymous survey retrospectively reporting back on ED and depressive symptomology before and during the pandemic, the impact of social media, and coping strategies. A reduced quality of life (QoL) due to confinement was observed in almost half of female adolescents. All groups reported a significant perceived increase of disordered eating, overeating, anxiety, and depressive symptoms and emotion-regulation problems. In AN patients, significantly higher percentual deterioration of disordered eating and anxiety and depressive symptoms was found. For controls, a younger age and higher susceptibility of the sociocultural body image significantly correlated with increased disordered eating. Large-scale media literacy interventions are recommended.

Computer Based Body Exposure in Adolescents With Anorexia Nervosa: A Study Protocol.

Body dissatisfaction is a core feature of eating disorders (EDs) and plays an essential role in the development and maintenance of anorexia nervosa (AN). In the current study, a computer based body exposure intervention is conducted and evaluated regarding short-term effects on body dissatisfaction, psychopathology, viewing patterns, and stress reactivity. Within a randomized controlled trial (RCT) female adolescents and young women with AN are either receiving the intervention or treatment as usual (TAU). Furthermore, in a transdiagnostic approach, a highly body-dissatisfied group of clinical control participants obtaining the intervention will be surveyed to identify AN-specific processes. The standardized four-session body exposure intervention using photographs of the own body is adapted from a manualized body image treatment program for computer use. Psychopathology (body dissatisfaction, body image avoidance, body checking, depression, anxiety) is assessed via standardized questionnaires before and after the intervention. During each session, attentional biases regarding one's own body are measured via eye tracking, stress levels are measured via subjective ratings, heart rate variability, as well as salivary cortisol and alpha amylase. Between- and within-subject effects will be assessed. The pilot study aims to identify short-term effects of the intervention on body dissatisfaction and attentional bias, as well as to investigate the potential underlying mechanism of physiological habituation.

Attention towards food: Conflicting mechanisms in anorexia nervosa.

In Anorexia nervosa (AN) attentional biases towards, as well as away from, food cues have been found using different paradigms. In the current study, adult and adolescent AN patients and control participants performed two tasks while their eye movements were recorded. The tasks involved viewing and rating: 1. Single photographs of food items; 2. Pairs of pictures consisting of one picture of high calorie and one of low calorie food. Girls and women suffering from AN rated pictures of high calorie food as more negative than control participants. In the task showing single food pictures, reduced fixation times within Regions of Interest of low calorie food were seen in AN; during the task using picture pairs, a visual attentional bias towards low calorie and away from high calorie stimuli for AN was demonstrated. There is evidence for heightened visual attentional capture by high calorie stimuli when presented alone as well as attraction of attention by low calorie stimuli when shown next to high calorie stimuli, possibly facilitated by avoidance of the latter. Different attentional mechanisms seem to be activated when only one stimulus is shown compared to when two stimuli are competing for the viewer's attention.

Neural mechanisms of perceptive and affective processing of body stimuli in anorexia nervosa - are there developmental effects?

Different components of body image processing seem to be reflected by different neural mechanisms. A core symptom of Anorexia nervosa (AN) is a disturbance of body image with correlates found on a neural level. The present study focuses on the neural processing of visual body stimuli of different weight categories in adolescent and adult AN patients. Thirty-three adolescents aged 12-18 years (15 AN patients, 18 control participants) and 36 adult women (19 AN patients, 17 control participants) underwent functional magnetic resonance imaging (fMRI) while performing a perceptive and an affective body image task involving photographic stimuli of women belonging to different BMI categories. Differential effects on activation, depending on the BMI of the women shown in the pictures, were found in frontal brain regions, the thalamus, the caudate and the fusiform gyrus. Group effects differentiating between AN patients and control participants were seen mainly in the caudate and insula. No significant developmental effect was seen. During a perceptive task, diminished activation of regions involved in perceptive and evaluative functions as well as emotional reasoning was seen in AN. During an affective task there was a tendency towards activation differences reflecting reduced ability of size estimation and impaired integration of visual and body perception with emotions.

Pavlovian-to-instrumental transfer in Anorexia Nervosa: A pilot study on conditioned learning and instrumental responding to low- and high-calorie food stimuli.

Anorexia Nervosa is characterized by persistent restraint eating despite severe negative consequences and often a chronic course of the disease. Recent theoretical models suggest that abnormalities in reward processing and incentive salience of disorder-compatible stimuli as observed in addictive behaviours contribute to the development and maintenance of Anorexia Nervosa. The aim of the present study was to investigate the process of the acquisition of food-related conditioned responses and the influence of conditioned low-calorie and high-calorie food stimuli on instrumental responding for different foods. A Pavlovian-to-instrumental transfer paradigm and questionnaires on eating disorder psychopathology (EDE-Q, EDI-2) were administered to patients with Anorexia Nervosa (n = 39) and healthy controls (n = 41). Results indicated that patients with Anorexia Nervosa showed deficits of the acquisition of knowledge of the experimental contingencies. Nevertheless, in patients with Anorexia Nervosa and healthy controls instrumental responding for low- and high-calorie food rewards was affected by stimuli conditioned to these rewards; no group differences were observed. Importantly, in Anorexia Nervosa, instrumental responding for low-calorie food increased with increasing severity of eating disorder psychopathology suggesting weight-loss directed behaviour. Future studies are warranted to enhance our understanding of deficits of reward-associated learning and to replicate and extend findings with regard to the impact of conditioned stimuli on instrumental responding. At present, our findings suggest that cognitive treatment interventions might be warranted that challenge dysfunctional beliefs about weight loss.

Snack food as a modulator of human resting-state functional connectivity.

OBJECTIVE: To elucidate the mechanisms of how snack foods may induce non-homeostatic food intake, we used resting state functional magnetic resonance imaging (fMRI), as resting state networks can individually adapt to experience after short time exposures. In addition, we used graph theoretical analysis together with machine learning techniques (support vector machine) to identifying biomarkers that can categorize between high-caloric (potato chips) vs. low-caloric (zucchini) food stimulation. METHODS: Seventeen healthy human subjects with body mass index (BMI) 19 to 27 underwent 2 different fMRI sessions where an initial resting state scan was acquired, followed by visual presentation of different images of potato chips and zucchini. There was then a 5-minute pause to ingest food (day 1=potato chips, day 3=zucchini), followed by a second resting state scan. fMRI data were further analyzed using graph theory analysis and support vector machine techniques. RESULTS: Potato chips vs. zucchini stimulation led to significant connectivity changes. The support vector machine was able to accurately categorize the 2 types of food stimuli with 100% accuracy. Visual, auditory, and somatosensory structures, as well as thalamus, insula, and basal ganglia were found to be important for food classification. After potato chips consumption, the BMI was associated with the path length and degree in nucleus accumbens, middle temporal gyrus, and thalamus. CONCLUSION: The results suggest that high vs. low caloric food stimulation in healthy individuals can induce significant changes in resting state networks. These changes can be detected using graph theory measures in conjunction with support vector machine. Additionally, we found that the BMI affects the response of the nucleus accumbens when high caloric food is consumed.

Neural processing of food and emotional stimuli in adolescent and adult anorexia nervosa patients.

BACKGROUND: A constant preoccupation with food and restrictive eating are main symptoms of anorexia nervosa (AN). Imaging studies revealed aberrant neural activation patterns in brain regions processing hedonic and reward reactions as well as-potentially aversive-emotions. An imbalance between so called "bottom-up" and "top-down" control areas is discussed. The present study is focusing on neural processing of disease-specific food stimuli and emotional stimuli and its developmental course in adolescent and adult AN patients and could offer new insight into differential mechanisms underlying shorter or more chronic disease. METHODS: 33 adolescents aged 12-18 years (15 AN patients, 18 control participants) and 32 adult women (16 AN patients, 16 control participants) underwent functional magnetic resonance imaging (fMRI, 3T high-field scanner) while watching pictures of high and low-calorie food and affective stimuli. Afterwards, they rated subjective valence of each picture. FMRI data analysis was performed using a region of interest based approach. RESULTS: Pictures of high-calorie food items were rated more negatively by AN patients. Differences in activation between patients and controls were found in "bottom up" and "top down" control areas for food stimuli and in several emotion processing regions for affective stimuli which were more pronounced in adolescents than in adults. CONCLUSION: A differential pattern was seen for food stimuli compared to generally emotion eliciting stimuli. Adolescents with AN show reduced processing of affective stimuli and enhanced activation of regions involved in "bottom up" reward processing and "top down" control as well as the insula with regard to food stimuli with a focus on brain regions which underlie changes during adolescent development. In adults less clear and less specific activation differences were present, pointing towards a high impact that regions undergoing maturation might have on AN symptoms.

Visual selective attention in body dysmorphic disorder, bulimia nervosa and healthy controls.

OBJECTIVE: Cognitive behavioral models postulate that selective attention plays an important role in the maintenance of body dysmorphic disorder (BDD). It is suggested that individuals with BDD overfocus on perceived defects in their appearance, which may contribute to the excessive preoccupation with their appearance. METHODS: The present study used eye tracking to examine visual selective attention in individuals with BDD (n=19), as compared to individuals with bulimia nervosa (BN) (n=21) and healthy controls (HCs) (n=21). Participants completed interviews, questionnaires, rating scales and an eye tracking task: Eye movements were recorded while participants viewed photographs of their own face and attractive as well as unattractive other faces. RESULTS: Eye tracking data showed that BDD and BN participants focused less on their self-rated most attractive facial part than HCs. Scanning patterns in own and other faces showed that BDD and BN participants paid as much attention to attractive as to unattractive features in their own face, whereas they focused more on attractive features in attractive other faces. HCs paid more attention to attractive features in their own face and did the same in attractive other faces. CONCLUSION: Results indicate an attentional bias in BDD and BN participants manifesting itself in a neglect of positive features compared to HCs. Perceptual retraining may be an important aspect to focus on in therapy in order to overcome the neglect of positive facial aspects. Future research should aim to disentangle attentional processes in BDD by examining the time course of attentional processing.

Theta/beta neurofeedback in children with ADHD: Feasibility of a short-term setting and plasticity effects.

Neurofeedback (NF) is increasingly used as a therapy for attention-deficit/hyperactivity disorder (ADHD), however behavioral improvements require 20 plus training sessions. More economic evaluation strategies are needed to test methodological optimizations and mechanisms of action. In healthy adults, neuroplastic effects have been demonstrated directly after a single session of NF training. The aim of our study was to test the feasibility of short-term theta/beta NF in children with ADHD and to learn more about the mechanisms underlying this protocol. Children with ADHD conducted two theta/beta NF sessions. In the first half of the sessions, three NF trials (puzzles as feedback animations) were run with pre- and post-reading and picture search tasks. A significant decrease of the theta/beta ratio (TBR), driven by a decrease of theta activity, was found in the NF trials of the second session demonstrating rapid and successful neuroregulation by children with ADHD. For pre-post comparisons, children were split into good vs. poor regulator groups based on the slope of their TBR over the NF trials. For the reading task, significant EEG changes were seen for the theta band from pre- to post-NF depending on individual neuroregulation ability. This neuroplastic effect was not restricted to the feedback electrode Cz, but appeared as a generalized pattern, maximal over midline and right-hemisphere electrodes. Our findings indicate that short-term NF may be a valuable and economical tool to study the neuroplastic mechanisms of targeted NF protocols in clinical disorders, such as theta/beta training in children with ADHD.

Increased anticipatory but decreased consummatory brain responses to food in sisters of anorexia nervosa patients.

BACKGROUND: We have previously shown increased anticipatory and consummatory neural responses to rewarding and aversive food stimuli in women recovered from anorexia nervosa (AN). AIMS: To determine whether these differences are trait markers for AN, we examined the neural response in those with a familial history but no personal history of AN. METHOD: Thirty-six volunteers were recruited: 15 who had a sister with anorexia nervosa (family history) and 21 control participants. Using fMRI we examined the neural response during an anticipatory phase (food cues, rewarding and aversive), an effort phase and a consummatory phase (rewarding and aversive tastes). RESULTS: Family history (FH) volunteers showed increased activity in the caudate during the anticipation of both reward and aversive food and in the thalamus and amygdala during anticipation of aversive only. FH had decreased activity in the dorsal anterior cingulate cortex, the pallidum and the superior frontal gyrus during taste consumption. CONCLUSIONS: Increased neural anticipatory but decreased consummatory responses to food might be a biomarker for AN. Interventions that could normalise these differences may help to prevent disorder onset. DECLARATION OF INTEREST: C.M. has acted as a consultant to P1VITAL, Givaudan, GWPharma, the British Broadcasting Corporation (BBC) and Channel 4. COPYRIGHT AND USAGE: © The Royal College of Psychiatrists 2016. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.

Perception and evaluation of women's bodies in adolescents and adults with anorexia nervosa.

Body image disturbance in anorexia nervosa (AN) has been widely studied with regard to the patient's own body, but little is known about perception of or attitude towards other women's bodies in AN. The aim of the present study was to investigate how 20 girls aged 12-18 years and 19 adult women suffering from AN compared to 37 healthy adolescent girls and women estimate weight and attractiveness of women's bodies belonging to different BMI categories (BMI 13.8-61.3 kg/m²). Weight and attractiveness ratings of the participant's own body and information on physical comparisons were obtained, and effects on others' weight and attractiveness ratings investigated. Differential evaluation processes were found: AN patients estimated other women's weight higher than control participants. Patients showed a bias towards assessing extremely underweight women as more attractive and normal weight and overweight women as less attractive than healthy girls and women. These effects were more pronounced in adult than in adolescent AN patients. The tendency to engage in physical comparison with others significantly correlated with weight as well as attractiveness ratings in patients. A logistic regression model encompassing own attractiveness ratings, attractiveness bias towards strongly underweight others' bodies and the interaction of this bias with age as predictors differentiated best between AN patients and controls. Our results indicate that females suffering from AN and healthy girls and women perceive other women's bodies differently. Assessment of others' weight and attractiveness may contribute to the maintenance of dysfunctional physical comparison processes.

The late positive potential as a marker of motivated attention to underweight bodies in girls with anorexia nervosa.

OBJECTIVE: In anorexia nervosa (AN), aspects of motivational salience and reward are increasingly discussed. Event related potentials, particularly the late positive potential (LPP), have been investigated as a marker for motivational salience of stimuli, for example in addictive disorders. The aim of this study was to assess the LPP as a possible indicator of motivated attention towards disease-specific pictures of underweight female bodies in adolescents with AN in comparison to typically developing (TD) adolescent girls. METHOD: 13 girls with AN and 18 TD adolescent girls (aged 12 to 18 years) viewed pictures of underweight, normal-weight and overweight women while EEG activity was recorded. An earlier (450-680 ms after stimulus onset) as well as a later time window (850-1250 ms after stimulus onset) of the LPP were examined for the different picture categories. Participants were also asked to rate subjective emotions (fear, disgust, happiness) elicited by the pictures. RESULTS: Subjective ratings showed no differential experience of emotions for the two groups. For AN patients, highest LPP amplitudes were found for underweight women in the earlier as well as in the later time window. In TD girls, highest amplitudes for pictures of overweight women were observed in the earlier time window. CONCLUSION: A differential LPP pattern for girls with AN and TD girls when viewing pictures of women's bodies of different weight categories was obtained. Highest amplitudes in AN patients for pictures of underweight women may reflect motivational significance of strongly underweight body shapes.

"Looks do matter"--visual attentional biases in adolescent girls with eating disorders viewing body images.

Visual attention allocation of adolescent girls with and without an eating disorder while viewing body images of underweight, normal-weight and overweight women was studied using eye tracking. While all girls attended more to specific body parts (e.g. hips, upper legs), eating-disordered girls showed an attentional bias towards unclothed body parts.