Endocrinology-informed neuroimaging in eating disorders: GLP1, orexins, and psilocybin.

The neurobiology of eating disorders [EDs; anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED)] remains poorly understood. Here, I describe how neuroimaging, accompanied by peripheral endocrine measures, can provide insights into the neurobiological drivers of eating disorders. Orexins/hypocretins, glucagon-like peptide-1 receptor (GLP1R) agonists, and psilocybin are highlighted as avenues for investigation.

Elevated reward, emotion, and memory region response to thin models predicts eating disorder symptom persistence: A prospective functional magnetic resonance imaging study.

Because few studies have identified biological factors that predict the persistence of eating pathology, we tested the hypotheses that elevated responsivity of brain regions implicated in reward valuation to thin models and high-calorie binge foods would predict the persistence of eating pathology. We analyzed data from 146 women (Mage = 21.87 ± 3.81) with threshold or subthreshold anorexia nervosa, bulimia nervosa, binge eating disorder, or purging disorder who completed functional magnetic resonance imaging scans assessing neural response to thin models and binge foods at baseline, were randomized to two eating disorder treatments or a waitlist control condition and completed diagnostic interviews that assessed change in symptoms over 2.5-month follow-up. Elevated activation in regions associated with memory (parahippocampal gyrus r = .38; hippocampus r = .25) and with reward valuation and emotional salience (amygdala r = .35) in response to thin versus average-weight models predicted future persistence of an eating disorder symptom composite (all analyses controlled for treatment condition). Neural response to high-calorie binge foods did not predict the persistence of eating disorder symptoms. There was no evidence that either treatment moderated the relation of baseline neural responsivity to thin models to future persistence of eating disorder symptoms, though power for these post hoc analyses was limited. Results suggest that overvaluation of the thin ideal increases the risk for the persistence of eating disorder symptoms but provided no support for the hypothesis that overvaluation of high-calorie foods would predict symptom persistence. Results imply that treatments should seek to reduce the overvaluation of the thin ideal. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Neural correlates of Type A personality: Type A personality mediates the association of resting-state brain activity and connectivity with eating disorder symptoms.

BACKGROUND: Type A personality (TAP) was characterized by impatience, competitiveness, aggressiveness, and hostility. Higher TAP was proved to be associated with more eating disorder symptoms (EDS). While little is known about the underlying neural substrates of TAP and how TAP is linked to EDS at the neural level. METHODS: To investigate the neural basis of TAP, we adopted fractional amplitude of low-frequency fluctuations (fALFF) and resting-state functional connectivity (RSFC) via resting-state functional magnetic resonance imaging (rs-fMRI) (N = 1620). Mediation models were examined to explore the relationship between TAP, EDS, and brain activity. RESULTS: TAP was associated with decreased fALFF in the left middle frontal gyrus (MFG) and increased fALFF in the left precentral gyrus (PreCG). Furthermore, TAP was positively correlated to RSFC between the left MFG and left inferior temporal gyrus (ITG) and between the left PreCG and right middle temporal gyrus (MTG). Mediation analysis showed TAP fully mediated the association of the left MFG activity, MFG-ITG connectivity, and PreCG-MTG connectivity with EDS. LIMITATIONS: The cross-sectional design of this study precludes us from specifying the causal relationship in the associations we observed. CONCLUSIONS: Our results suggested spontaneous activity in the left MFG and PreCG is associated with TAP, and even in general sample, people with higher TAP showed more EDS. The present study is the first to investigate the neurobiological underpinnings of TAP in a large sample and further offered new insights into the relation between TAP and EDS from a neural basis perspective.

Altered anticipatory brain responses in eating disorders: A neuroimaging meta-analysis.

OBJECTIVE: Functional neuroimaging studies have found differential neural activation patterns during anticipation-related paradigms in participants with eating disorders (EDs) compared to controls. However, publications reported conflicting results on the directionality and location of the abnormal activations. There is an urgent need to integrate our existing knowledge of anticipation, both rewarding and aversive, to elucidate these differences. METHOD: We conducted an activation likelihood estimation (ALE) meta-analysis to quantitatively review functional neuroimaging studies that evaluated differences between brain correlates of anticipation in participants with and without disordered eating. PubMed, Web of Sciences, PsycINFO, Medline and EMBASE were searched for studies published up to November 2022. Exploratory sub-analyses to check for differences between reward and non-reward anticipation among all anticipation paradigms. RESULTS: Twenty-one references met the inclusion criteria for meta-analysis. The meta-analysis across anticipation all tasks identified a significant hyperactivation cluster in the right putamen in participants with disordered eating (n = 17 experiments) and a significant hypoactivation cluster in the left inferior parietal lobule (n = 13 experiments), in participants with disordered eating compared to controls. CONCLUSIONS: These findings and sub-analyses of reward- and non-reward-related cues suggest potential pathophysiological mechanisms underlying anticipatory responses to rewarding and aversive cues in ED.

Childhood maltreatment is associated with cortical thinning in people with eating disorders.

Childhood maltreatment (CM) is a non-specific risk factor for eating disorders (ED) and is associated with a greater severity in their clinical presentation and poorer treatment outcome. These data suggest that maltreated people with ED may be biologically other than clinically different from non-maltreated people. The aim of the present study was to investigate cortical thickness (CT), a possible biomarker of neurodevelopment, in people with ED with or without history of CM and in healthy women. Twenty-four healthy women, 26 with anorexia nervosa and 24 with bulimia nervosa underwent a 3T MRI scan. All participants filled in the childhood trauma questionnaire. All neuroimaging data were processed by FreeSurfer. Twenty-four participants with ED were identified as maltreated and 26 participants with ED as non-maltreated. All healthy women were non-maltreated. Compared to healthy women, maltreated people with ED showed lower CT in the left rostral anterior cingulate gyrus, while compared to people with ED without history of CM showed lower CT values in the left superior frontal and in right caudal middle frontal and superior parietal gyri. No significant differences emerged in CT measures between healthy women and people with ED without history of CM. The present findings show for the first time that in adult people with ED childhood maltreatment is associated with cortical thinning in areas implicated in the modulation of brain processes that are acknowledged to play a role in the psychopathology of ED.

Trait anxiety is associated with amygdala expectation and caloric taste receipt response across eating disorders.

Anxious traits are elevated in eating disorders (EDs), are considered risk factors for ED development, and trait anxiety has been linked to ED psychopathology. How trait anxiety relates to ED neurobiology is not well understood. In this study 197 individuals across the ED spectrum (anorexia nervosa n = 91; other specified EDs n = 34; bulimia nervosa n = 56; binge ED n = 16), and 120 healthy controls were assessed for anxious traits and learned to expect and receive caloric or neutral taste stimuli during brain imaging. Amygdala sucrose expectation response differed across groups (Wilk's lambda = 0.945, p = 0.023), and was higher on the left in anorexia nervosa compared to healthy controls (p = 0.002). Expected sucrose receipt response across taste reward regions was not different between groups. In the ED sample, trait anxiety negatively moderated the relationship between amygdala expectation and right dorsal (p = 0.0062) and ventral (p = 0.0046) anterior insula receipt response. A subgroup analysis showed similar results for anorexia nervosa, and partially in bulimia nervosa. Across EDs, appetitive motivation correlated positively with bilateral orbitofrontal cortex, caudate head, and ventral striatal sucrose receipt response (r = 0.215 to 0.179, p = 0.002 to 0.012). Across the study sample, trait anxiety showed an inverted-U-shaped relationship with right (r = 0.147, p = 0.034) and left (r = 0.162, p = 0.016) amygdala expectation response. Amygdala sucrose expectation response is elevated in anorexia nervosa, correlates with sucrose receipt response, and this relationship is negatively moderated by trait anxiety across EDs. Trait anxiety may have an important role in how expectation drives taste stimulus receipt brain response and perhaps food approach in individuals with EDs.

Social Processing in Eating Disorders: Neuroimaging Paradigms and Research Domain Organizational Constructs.

PURPOSE OF REVIEW: Social and environmental factors have been related to both symptom expression of disordered eating in individuals and changes in the prevalence of eating disorders (EDs) in populations. Neural differences in processing social information may contribute to EDs. This review assesses the evidence for aberrant neural responses during social processing in EDs. RECENT FINDINGS: This review examines how constructs within the social processing domain have been evaluated by neuroimaging paradigms in EDs, including communication, affiliation, and understanding of both oneself and others. Differences related to social processing in EDs include altered processing for self-relevant stimuli, in the context of identity, valence, expectations, and affiliative relationships. Future work is needed to integrate how differences in processing social stimuli relate to alterations in cognitive control and reward as well as specific disordered eating symptoms.

Sequelae of Eating Disorders at Imaging.

Although eating disorders are common, they tend to be underdiagnosed and undertreated because social stigma tends to make patients less likely to seek medical attention and less compliant with medical treatment. Diagnosis is crucial because these disorders can affect any organ system and are associated with the highest mortality rate of any psychiatric disorder. Because of this, imaging findings, when recognized, can be vital to the diagnosis and management of eating disorders and their related complications. The authors familiarize the radiologist with the pathophysiology and sequelae of eating disorders and provide an overview of the related imaging findings. Some imaging findings associated with eating disorders are nonspecific, and others are subtle. The presence of these findings should alert the radiologist to correlate them with the patient's medical history and laboratory results and the clinical team's findings at the physical examination. The combination of these findings may suggest a diagnosis that might otherwise be missed. Topics addressed include (a) the pathophysiology of eating disorders, (b) the clinical presentation of patients with eating disorders and their medical complications and sequelae, (c) the imaging features associated with common and uncommon sequelae of eating disorders, (d) an overview of management and treatment of eating disorders, and (e) conditions that can mimic eating disorders (eg, substance abuse, medically induced eating disorders, and malnourishment in patients with cancer). Online supplemental material is available for this article. ©RSNA, 2022.

Striatal volumes as potential biomarkers in Eating Disorders: A pilot study.

INTRODUCTION: Differences in bulimic and impulsive behaviours in Eating Disorders (ED) have been associated with cortico-striatal circuit dysfunction at a neurobiological level. We sought to investigate neo-striatal volume as a biomarker in ED subgroups as well as the possible relationship with trauma history. MATERIAL AND METHODS: We studied 24 female patients: Anorexia Nervosa AN (n=8), Bulimia Nervosa BN (n=9), comorbid ED with borderline personality disorder (EDc; n=7), and a group of Healthy Controls (n=19). Binge eating behaviours and impulsivity scales were used to characterize our sample as well as Trauma Questionnaires and Magnetic resonance imaging (MRI) volumetric manual measurements of caudate and putamen nuclei (striatum). RESULTS: Our preliminary results showed a significantly larger left putaminal volume in AN compared to the other three groups [C (p=0.008), BN (p<.001) and EDc (p=.001)] and a smaller right putaminal volume in EDc compared to controls (p=.045) and AN (p=.039). Some negative correlations were found between bilateral putaminal volumes and self-reported general and early traumatization scores. CONCLUSION: This pilot study suggested that striatal volumes might differentiate AN from BN and EDc at a neurobiological level with implications for treatment strategies. Larger scale studies should be carried out that allow replication of these data.

Affecting Explicit and Implicit Body Image with Thin-Idealized Avatars in Virtual Reality: The Role of Sense of Embodiment.

A large number of previous studies have examined the effects of thin-ideal avatars on body image in virtual reality (VR), reporting mixed results. A possible explanation is that individuals' sense of embodiment (SoE) can influence the effects of avatars. Using the body discontinuity paradigm, a paradigm rarely used in prior studies, this study explores how SoE affects users' body image when using thin-ideal avatars in VR. A group of 77 female participants were randomly assigned to one of the SoE conditions to complete a VR task using a thin-ideal avatar. The body image was assessed not only using explicit but also with implicit measures. The result shows that participants in a high SoE condition were more likely to have a more positive actual body image than others in a low SoE condition, regardless of whether implicit or explicit measures were used. Furthermore, the ownership subcomponent of the SoE significantly mediated the relationship between thin-ideal avatars exposure and the actual body image using implicit measures. However, no substantial difference in ideal body image was found. These findings extend our understanding of avatar effects in VR, thereby providing additional evidence for using avatars to explore body image-related phenomena and to use them in psychotherapeutic applications such as treatments for eating disorders.

Restrictive eating across a spectrum from healthy to unhealthy: behavioral and neural mechanisms.

BACKGROUND: Restriction of food intake is a central feature of anorexia nervosa (AN) and other eating disorders, yet also occurs in the absence of psychopathology. The neural mechanisms of restrictive eating in health and disease are unclear. METHODS: This study examined behavioral and neural mechanisms associated with restrictive eating among individuals with and without eating disorders. Dietary restriction was examined in four groups of women (n = 110): healthy controls, dieting healthy controls, patients with subthreshold (non-low weight) AN, and patients with AN. A Food Choice Task was administered during fMRI scanning to examine neural activation associated with food choices, and a laboratory meal was conducted. RESULTS: Behavioral findings distinguished between healthy and ill participants. Healthy individuals, both dieting and non-dieting, chose significantly more high-fat foods than patients with AN or subthreshold AN. Among healthy individuals, choice was primarily influenced by tastiness, whereas, among both patient groups, healthiness played a larger role. Dorsal striatal activation associated with choice was most pronounced among individuals with AN and was significantly associated with selecting fewer high-fat choices in the task and lower caloric intake in the meal the following day. CONCLUSIONS: A continuous spectrum of behavior was suggested by the increasing amount of weight loss across groups. Yet, data from this Food Choice Task with fMRI suggest there is a behavioral distinction between illness and health, and that the neural mechanisms underlying food choice in AN are distinct. These behavioral and neural mechanisms of restrictive eating may be useful targets for treatment development.

The Role of the Noradrenergic System in Eating Disorders: A Systematic Review.

Noradrenaline (NE) is a catecholamine acting as both a neurotransmitter and a hormone, with relevant effects in modulating feeding behavior and satiety. Several studies have assessed the relationship between the noradrenergic system and Eating Disorders (EDs). This systematic review aims to report the existing literature on the role of the noradrenergic system in the development and treatment of EDs. A total of 35 studies were included. Preclinical studies demonstrated an involvement of the noradrenergic pathways in binge-like behaviors. Genetic studies on polymorphisms in genes coding for NE transporters and regulating enzymes have shown conflicting evidence. Clinical studies have reported non-unanimous evidence for the existence of absolute alterations in plasma NE values in patients with Anorexia Nervosa (AN) and Bulimia Nervosa (BN). Pharmacological studies have documented the efficacy of noradrenaline-modulating therapies in the treatment of BN and Binge Eating Disorder (BED). Insufficient evidence was found concerning the noradrenergic-mediated genetics of BED and BN, and psychopharmacological treatments targeting the noradrenergic system in AN. According to these data, further studies are required to expand the existing knowledge on the noradrenergic system as a potential target for treatments of EDs.

Association of Brain Reward Response With Body Mass Index and Ventral Striatal-Hypothalamic Circuitry Among Young Women With Eating Disorders.

Importance: Eating disorders are severe psychiatric disorders; however, disease models that cross subtypes and integrate behavior and neurobiologic factors are lacking. Objective: To assess brain response during unexpected receipt or omission of a salient sweet stimulus across a large sample of individuals with eating disorders and healthy controls and test for evidence of whether this brain response is associated with the ventral striatal-hypothalamic circuitry, which has been associated with food intake control, and whether salient stimulus response and eating disorder related behaviors are associated. Design, Setting, and Participants: In this cross-sectional functional brain imaging study, young adults across the eating disorder spectrum were matched with healthy controls at a university brain imaging facility and eating disorder treatment program. During a sucrose taste classic conditioning paradigm, violations of learned associations between conditioned visual and unconditioned taste stimuli evoked the dopamine-related prediction error. Dynamic effective connectivity during expected sweet taste receipt was studied to investigate hierarchical brain activation between food intake relevant brain regions. The study was conducted from June 2014 to November 2019. Data were analyzed from December 2019 to February 2020. Main Outcomes and Measures: Prediction error brain reward response across insula and striatum; dynamic effective connectivity between hypothalamus and ventral striatum; and demographic and behavior variables and their correlations with prediction error brain response and connectivity edge coefficients. Results: Of 317 female participants (197 with eating disorders and 120 healthy controls), the mean (SD) age was 23.8 (5.6) years and mean (SD) body mass index was 20.8 (5.4). Prediction error response was elevated in participants with anorexia nervosa (Wilks λ, 0.843; P = .001) and in participants with eating disorders inversely correlated with body mass index (left nucleus accumbens: r = -0.291; 95% CI, -0.413 to -0.167; P < .001; right dorsal anterior insula: r = -0.228; 95% CI, -0.366 to -0.089; P = .001), eating disorder inventory-3 binge eating tendency (left nucleus accumbens: r = -0.207; 95% CI, -0.333 to -0.073; P = .004; right dorsal anterior insula: r = -0.220; 95% CI, -0.354 to -0.073; P = .002), and trait anxiety (left nucleus accumbens: r = -0.148; 95% CI, -0.288 to -0.003; P = .04; right dorsal anterior insula: r = -0.221; 95% CI, -0.357 to -0.076; P = .002). Ventral striatal to hypothalamus directed connectivity was positively correlated with ventral striatal prediction error in eating disorders (r = 0.189; 95% CI, 0.045-0.324; P = .01) and negatively correlated with feeling out of control after eating (right side: r = -0.328; 95% CI, -0.480 to -0.164; P < .001; left side: r = -0.297; 95% CI, -0.439 to -0.142; P = .001). Conclusions and Relevance: The results of this cross-sectional imaging study support that body mass index modulates prediction error and food intake control circuitry in the brain. Once altered, this circuitry may reinforce eating disorder behaviors when paired with behavioral traits associated with overeating or undereating.

Resting-state functional network connectivity underlying eating disorder symptoms in healthy young adults.

Previous neuroimaging research of eating disorders such as anorexia nervosa and bulimia nervosa has mainly focused on clinical patients, indicating the crucial role of intrinsic connectivity networks involved in aberrant behavioral control (i.e., executive control network), reward reactivity (i.e., basal ganglia network), and excessive self-focused and body-focused ruminations (i.e., default mode network) in the onset and maintenance of eating disturbances. However, examinations of large-scale resting-state networks that support the role of cognitive control, reward sensitivity, and self-directed thinking in disordered eating have rarely involved non-clinical samples from the general population. This study, involving a total of 693 healthy young adults (68.69% females; mean age, 18.37 years), investigated these issues by using pre-defined functional regions of interest from the executive control network, basal ganglia network, default mode network, and a seed-based region of interest-to-region of interest approach. After statistically controlling for differences in age, sex, body mass index, and head motion, we observed significant associations of higher levels of eating disorder symptoms, especially bulimia-type eating (i.e., binge eating and a combination of binge eating and compensatory behaviors, such as purging via self-induced vomiting or laxative use, and compulsive exercise), with weaker intra-network and inter-network functional synchrony. These results remained significant after excluding underweight, overweight, and obese participants. These findings suggest that these neural circuits may play a key role in the symptoms of disordered eating in healthy adults. They further reveal that the less efficient information exchange within and between intrinsic networks associated with self-referential thinking, inhibitory control, and reward sensitivity are strongly related to eating disorder symptoms.

Eating Disorders in Frontotemporal Dementia and Alzheimer's Disease: Evaluation of Brain Perfusion Correlates Using 99mTc-HMPAO SPECT with Brodmann Areas Analysis.

BACKGROUND: Eating disorders (ED) in dementia represent a significant impairment affecting patients' and caregivers' lives. In frontotemporal dementia (FTD), ED include overeating, sweet food preference, stereotypical eating, and hyperorality, while in Alzheimer's disease (AD), anorexia and appetite loss are the most common ED. OBJECTIVE: The aim of our study was to highlight Brodmann areas (BAs) implicated specifically in the appearance of ED in FTD and AD. METHODS: We studied 141 patients, 75 with FTD and 66 with AD. We used the NeuroGamTM software on the reconstructed single photon emission computed tomography-SPECT data for the automated comparison of BAs perfusion on the left (L) and right (R) hemisphere with perfusion in corresponding BAs of a normal database. RESULTS: The FTD group included 27 men and 48 women, age (mean±SD) 65.8±8.5 years, duration of disease 3.4±3.3 years, Mini-Mental State Examination (MMSE) 17.9±8.6, ED score on Neuropsychiatric Inventory (NPI) 4.7±8.5. ED in FTD were correlated with hypoperfusion in right anterior and dorsolateral prefrontal cortices (BAs 10R, 46R), left orbitofrontal cortex (BA 12L), orbital part of the right inferior frontal gyrus (BA 47R), and left parahippocampal gyrus (BA 36L). The AD group included 21 men and 45 women, age (mean±SD) 70.2±8.0 years, duration of disease 3.3±2.4 years, MMSE 20.2±6, ED-NPI score 2.7±3.9. ED in AD were correlated with hypoperfusion in left inferior temporal cortex (BA 20L). CONCLUSION: SPECT imaging with automated mapping of brain cortex could contribute to the understanding of the neural networks involved in the manifestation of ED in dementia.

Processing of emotionally ambiguous stimuli in eating disorders: an fMRI pilot study.

PURPOSE: People with eating disorders (EDs) have difficulties understanding their own emotions and recognizing the emotions of others, especially in ambiguous settings. We examined the neuronal mechanisms underlying the emotion processing of ambiguous interpersonal stimuli in EDs and healthy controls (HCs). METHODS: The fMRI data were acquired by a blocked experimental design with 28 women (14 EDs) during the visual presentation of a modified Thematic Apperception Test. RESULTS: EDs showed very strong associations between experienced and inferred emotions evoked by the stimuli; no such relationship was found in HCs. HCs displayed elevated left anterior insula activity during the mentalizing condition; EDs showed increased activity in the right supramarginal gyrus and medial prefrontal cortex. CONCLUSION: The two groups seem to apply different strategies for judging emotionally ambiguous stimuli, albeit resulting in equivalent judgments. We assume that activity in the supramarginal gyrus and insula in EDs is linked with suppressing their own perspective while considering emotional states, probably due to alexithymia and the lack of awareness of their own mental states. We hypothesize that the strong correlation between experienced and inferred emotions in EDs could reflect their tendency to use others as a reference point for perceiving themselves and gaining information about their affective state. LEVEL OF EVIDENCE: No level of evidence, this is a basic science study.

The role of body composition assessment in obesity and eating disorders.

Lack of a balanced diet can have a significant impact on most organs of the body. Traditionally, evaluation of these conditions relied heavily upon body mass index "BMI" measurements, which are limited and open to inaccurate interpretation or omission of critical data. Advances in imaging allow better recognition of these conditions using accurate qualitative and quantitative data and correlation with any morphological changes in organs. Body composition evaluations include the assessment of the bone mineral density (BMD), visceral fat, subcutaneous fat, liver fat and iron overload and muscle fat (including the lean muscle ratio), with differential evaluation of specific muscle groups when required. Such measurements are important as a baseline and for monitoring the effect of therapies and various interventions. In addition, they may predict and help alleviate any potential complications, allowing counselling of patients in a relatable manner. This positively influences patient compliance and outcomes during early counselling, monitoring and modulation of therapy. This encourages patients suffering from obesity and eating disorders to better understand their often chronic but reversible condition. We present a review of current literature with reflection on our own practices. We discuss the importance of monitoring the reversibility of certain parameters in specific cohorts of patients. We consider the role of artificial intelligence and deep learning in developing software algorithms that can help the reading radiologist evaluate large volumes of data and present the results in a format that is easier to interpret, thereby reducing interobserver and intraobserver variabilities.

Subclinical eating disorder traits are correlated with cortical thickness in regions associated with food reward and perception.

Behavioral traits associated with various forms of psychopathology are conceptualized as dimensional, varying from those present in a frank disorder to subclinical expression. Demonstrating links between these behavioral traits and neurobiological indicators, such as brain structure, provides one form of validation for this view. However, unlike behavioral dimensions associated with other forms of psychopathology (e.g., autism spectrum disorder, attention deficit hyperactivity disorder, antisocial disorders), eating disorder traits have not been investigated in this manner in spite of the potential that such an approach has to elucidate etiological mechanisms. Therefore, we examined for the first time neural endophenotypes of Anorexia Nervosa and Bulimia via dimensional traits (measured using the Eating Disorders Inventory-3) in a large subclinical sample of young adults (n = 456 and n = 247, respectively; ages = 18-22 years) who each provided a structural magnetic resonance imaging scan. Cortical thickness was quantified at 81,924 vertices across the cortical surface. We found: 1) increasing eating disorder traits correlated with thinner cortex in the insula and orbitofrontal cortex, among other regions, and 2) using these regions as seeds, increasing eating disorder trait scores negatively modulated structural covariance between these seed regions and other cortical regions linked to regulatory and sensorimotor functions (e.g., frontal and temporal cortices). These findings parallel those found in the clinical literature (i.e., thinner cortex in these food-related regions in individuals with eating disorders) and therefore provide evidence supporting the dimensional view of behavioral traits associated with eating disorders. Extending this approach to genetic and neuroimaging genetics studies holds promise to inform etiology.

Randomized trial of a dissonance-based transdiagnostic group treatment for eating disorders: An evaluation of target engagement.

OBJECTIVE: Test whether a dissonance-based transdiagnostic eating disorder treatment reduces valuation of the thin beauty ideal and high-calorie binge foods, the intervention targets, and eating pathology relative to waitlist controls. METHOD: Women with Diagnostic and Statistical Manual of Mental Disorders-5 eating disorders (N = 100) were randomized to an 8-week group-implemented Body Project Treatment (BPT) redesigned to encourage rapid symptom reduction or a waitlist control condition, completing functional MRI paradigms assessing neural response to thin models and binge foods, questionnaires, and diagnostic interviews at pretest and posttest. RESULTS: Compared to controls, BPT participants showed greater reductions in responsivity of regions involved in reward valuation (ventromedial prefrontal cortex, dorsolateral prefrontal cortex, caudate) to thin models but not binge foods, pursuit of the thin ideal (d = .72), palatability ratings of binge foods (d = .78), and greater increases in attractiveness ratings of average-weight models (d = .44), the intervention targets. BPT participants also showed significantly greater reductions in body dissatisfaction (d = .83), negative affect (d = .76), and eating disorder symptoms (d = .59), and marginally greater abstinence from binge eating and compensatory behaviors (39% vs. 21%) than controls. CONCLUSIONS: Results provide novel evidence that BPT affected the hypothesized intervention targets and reduced variables that are putatively secondary to pursuit of the thin ideal, including body dissatisfaction, negative affect, and eating disorder symptoms. Symptom reductions were smaller than in past trials, suggesting that it may be optimal to reduce valuation of the thin ideal before asking participants to reduce disordered eating behaviors that are used to pursue this ideal. (PsycINFO Database Record (c) 2019 APA, all rights reserved).