The Neurobiology of Eating Disorders

The Inpatient Management of Adolescents with Eating Disorders

Eating disorders affect individuals of all ages, genders, sexual orientations, ethnicities, races, and socioeconomic statuses. They can lead to serious medical complications that require inpatient treatment. The eating disorders that are most likely to lead to medical complications requiring medical inpatient stabilization include anorexia nervosa, atypical anorexia nervosa, avoidant-restrictive food intake disorder, bulimia nervosa, and purging disorder. There are criteria that can help determine if a patient requires inpatient stabilization. Nearly all body systems may be affected. Patients are often treated by following a refeeding protocol that reduces the risk of developing refeeding syndrome, a dangerous and life-threatening state of metabolic derangements that can arise when a malnourished individual begins a renourishment process. Following stabilization, patients should receive further care through a number of different treatment options directed at their underlying eating disorder and by working with a multidisciplinary team. [Pediatr Ann. 2024;53(8):e283-e287.].

Cortical thickness and childhood eating behaviors: differences according to sex and age, and relevance for eating disorders

PURPOSE

This study investigated the association between childhood eating behaviors and cortical morphology, in relation to sex and age, in a community sample.

METHODS

Neuroimaging data of 71 children (mean age = 9.9 ± 1.4 years; 39 boys/32 girls) were obtained from the Nathan Kline Institute-Rockland Sample. Emotional overeating, food fussiness, and emotional undereating were assessed using the Children's Eating Behavior Questionnaire. Cortical thickness was obtained at 81,924 vertices covering the entire cortex. Generalized Linear Mixed Models were used for statistical analysis.

RESULTS

There was a significant effect of sex in the association between cortical thickness and emotional overeating (localized at the right postcentral and bilateral superior parietal gyri). Boys with more emotional overeating presented cortical thickening, whereas the opposite was observed in girls (p < 0.05). Different patterns of association were identified between food fussiness and cortical thickness (p < 0.05). The left rostral middle frontal gyrus displayed a positive correlation with food fussiness from 6 to 8 years, but a negative correlation from 12 to 14 years. Emotional undereating was associated with cortical thickening at the left precuneus, left middle temporal gyrus, and left insula (p < 0.05) with no effect of sex or age.

CONCLUSIONS

Leveraging on a community sample, findings support distinct patterns of associations between eating behaviors and cortical thickness, depending on sex and age.

Enhancing the Connection Between Basic and Applied Research in Eating Disorders: Steps Toward More Effective Translation

Translational research applies laboratory-generated scientific discoveries to real-world practice with the goal of potentiating more rapid solutions to health challenges. In 2023, the authors of this editorial (Hildebrandt and Goldschmidt) aimed to develop a special issue for the International Journal of Eating Disorders (IJED) focusing on translational eating disorder research. The goal for this issue was to begin closing the gap between basic and applied research by soliciting articles that improve our understanding of mechanisms that cause or maintain eating disorders, which could result in more robust research advances and dissemination of information to the public. Further goals for the issue included exposing IJED's readership to a wide range of translational research and inspiring new collaborative efforts. While strong submissions were received, challenges were encountered in soliciting enough articles, potentially reflecting long-standing communication barriers between basic and clinical scientists within the eating disorders field. In this editorial, we highlight work included in the special section, identify potential barriers in translational eating disorder research, and offer a multipronged approach to support more rapid progress across the translational spectrum. By improving how our field approaches translational research, we can promote better outcomes for those with or at risk for eating disorders.

Adverse childhood experiences, low self-esteem, and salient stimulus response in eating disorders

BACKGROUND

Adverse childhood experiences (ACEs) are elevated in individuals with eating disorders (EDs), but how the neurobiology of EDs and ACEs interact is unclear.

METHODS

Women 18-45 years old with anorexia nervosa (AN, n = 38), bulimia nervosa (BN, n = 32), or healthy controls (n = 60) were assessed for ACEs and ED behaviours and performed a taste-conditioning task during brain imaging. Mediation analyses tested relationships between ACE score, self-esteem, and ED behaviours.

RESULTS

ACE scores were elevated in EDs and correlated positively with body mass index (p = 0.001), drive for thinness (p = 0.001), and body dissatisfaction (p = 0.032); low self-esteem mediated the relationship between ACEs and body dissatisfaction, drive for thinness, and bulimia severity. ACE scores correlated negatively (FDR-corrected) with unexpected, salient stimulus receipt in AN (substantia nigra) and BN (anterior cingulate, frontal and insular cortex, ventral striatum, and substantia nigra). When ACE scores were included in the model, unexpected stimulus receipt brain response was elevated in EDs in the anterior cingulate and ventral striatum.

CONCLUSIONS

ACEs attenuate unexpected salient stimulus receipt response, which may be a biological marker for altered valence or hedonic tone perception in EDs. Low self-esteem mediates the relationships between ACEs and ED behaviours. Adverse childhood experiences should be assessed in biological studies, and their effects targeted in treatment.

Why Don't You Just Eat? Neuroscience and the Enigma of Eating Disorders

Eating disorders are severe psychiatric illnesses that are associated with high mortality. Research has identified environmental, psychological, and biological risk factors that could contribute to the psychopathology of eating disorders. Nevertheless, the patterns of self-starvation, binge eating, and purging behaviors are difficult to reconcile with the typical mechanisms that regulate appetite, hunger, and satiety. Here, the authors present a neuroscience and human brain imaging-based model to help explain the detrimental and often persistent behavioral patterns seen in individuals with eating disorders and why it is so difficult to overcome them. This model incorporates individual motivations to change eating, fear conditioning, biological adaptations of the brain and body, and the development of a vicious cycle that drives the individual to perpetuate those behaviors. This knowledge helps to explain these illnesses to patients and their families, and to develop more effective treatments, including biological interventions.

Achieved Weight Gain and Return to Work After Intervention With Traditional Japanese Acupuncture for Avoidant Restrictive Food Intake Disorder: A Case Report

Avoidant restrictive food intake disorder (ARFID) is newly established as a category of eating disorder (ED). Acupuncture is one treatment option for ED. However, no cases of acupuncture treatment of ARFID have been reported. A 28-year-old female presented with reduced food intake and weight, abdominal bloating, abnormal sense of taste, and tongue pain. Her body weight (BW) had been around 50 kg until four years previously. Three years before, her symptoms occurred, and her BW decreased to 36.5 kg after experiencing excessive mental stress at her workplace. She was diagnosed with ARFID by a psychosomatic physician and tended to refuse her prescribed antipsychotic drugs. She was treated weekly with the Hokushin-kai style, a traditional Japanese acupuncture, and the moxibustion method. After one month, the patient felt somewhat better and returned to work once a week for the first time in two years. Four months later, her BW started to increase. After 10 months, her BW had increased to 48 kg. Her acupuncture treatment continues. This case suggests acupuncture as an optional treatment for ARFID. Further studies, such as a combination of medications and acupuncture, would be desirable.

Are you how you eat? Aspects of self-awareness in eating disorders

Eating disorders (ED) are severe psychiatric disorders characterized by dysfunctional behaviors related to eating or weight control, with profound impacts on health, quality of life, and the financial burden of affected individuals and society at large. Given that these disorders involve disturbances in self-perception, it is crucial to comprehend the role of self-awareness in their prevalence and maintenance. This literature review presents different self-awareness processes, discussing their functioning across different levels of complexity. By deconstructing this concept, we can gain a better understanding of how each facet of self and personality relates to the symptoms of these disorders. Understanding the absence or impairment of self-awareness in ED holds significant implications for diagnosis, treatment, and overall management. By recognizing and comprehending the characteristics of self-awareness, clinicians can develop tailored interventions and evidence-based treatments for individuals with ED. Furthermore, this narrative review underscores the importance of considering temperament and personality factors in the context of ED, as temperament traits and personality characteristics may interact with self-awareness processes, influencing the development and maintenance of ED. Ultimately, the results highlight the pressing need for further research on the development of effective interventions and support strategies grounded in the aspects of self-awareness mechanisms for individuals affected by these disorders.

Inpatient treatments for adults with anorexia nervosa: a systematic review of literature

PURPOSE

Anorexia nervosa (AN) is a mental disorder for which hospitalization is frequently needed in case of severe medical and psychiatric consequences. We aim to describe the state-of-the-art inpatient treatment of AN in real-world reports.

METHODS

A systematic review of the literature on the major medical databases, spanning from January 2011 to October 2023, was performed, using the keywords: "inpatient", "hospitalization" and "anorexia nervosa". Studies on pediatric populations and inpatients in residential facilities were excluded.

RESULTS

Twenty-seven studies (3501 subjects) were included, and nine themes related to the primary challenges faced in hospitalization settings were selected. About 81.48% of the studies detailed the clinical team, 51.85% cited the use of a psychotherapeutic model, 25.93% addressed motivation, 100% specified the treatment setting, 66.67% detailed nutrition and refeeding, 22.22% cited pharmacological therapy, 40.74% described admission or discharge criteria and 14.81% follow-up, and 51.85% used tests for assessment of the AN or psychopathology. Despite the factors defined by international guidelines, the data were not homogeneous and not adequately defined on admission/discharge criteria, pharmacological therapy, and motivation, while more comprehensive details were available for treatment settings, refeeding protocols, and psychometric assessments.

CONCLUSION

Though the heterogeneity among the included studies was considered, the existence of sparse criteria, objectives, and treatment modalities emerged, outlining a sometimes ambiguous report of hospitalization practices. Future studies must aim for a more comprehensive description of treatment approaches. This will enable uniform depictions of inpatient treatment, facilitating comparisons across different studies and establishing guidelines more grounded in scientific evidence.

LEVEL OF EVIDENCE

Level I, systematic review.

A framework for a brain-derived nosology of psychiatric disorders

Current psychiatric diagnoses are not defined by neurobiological measures which hinders the development of therapies targeting mechanisms underlying mental illness 1,2 . Research confined to diagnostic boundaries yields heterogeneous biological results, whereas transdiagnostic studies often investigate individual symptoms in isolation. There is currently no paradigm available to comprehensively investigate the relationship between different clinical symptoms, individual disorders, and the underlying neurobiological mechanisms. Here, we propose a framework that groups clinical symptoms derived from ICD-10/DSM-V according to shared brain mechanisms defined by brain structure, function, and connectivity. The reassembly of existing ICD-10/DSM-5 symptoms reveal six cross-diagnostic psychopathology scores related to mania symptoms, depressive symptoms, anxiety symptoms, stress symptoms, eating pathology, and fear symptoms. They were consistently associated with multimodal neuroimaging components in the training sample of young adults aged 23, the independent test sample aged 23, participants aged 14 and 19 years, and in psychiatric patients. The identification of symptom groups of mental illness robustly defined by precisely characterized brain mechanisms enables the development of a psychiatric nosology based upon quantifiable neurobiological measures. As the identified symptom groups align well with existing diagnostic categories, our framework is directly applicable to clinical research and patient care.

An adolescent case of ASXL3-related disorder with delayed onset of feeding difficulty

BACKGROUND

ASXL3-related disorder, first described in 2013, is a genetic disorder with an autosomal dominant inheritance that is caused by a heterozygous loss-of-function variant in ASXL3. The most characteristic feature is neurodevelopmental delay with consistently limited speech. Feeding difficulty is a main symptom observed in infancy. However, no adolescent case has been reported.

CASE PRESENTATION

A 14-year-old girl with ASXL3-related syndrome was referred to our hospital with subacute onset of emotional lability. Limbic encephalitis was ruled out by examination; however, the patient gradually showed a lack of interest in eating, with decreased diet volume. Consequently, she experienced significant weight loss. She experienced no symptoms of bulimia, or food allergy; therefore, avoidant/restrictive food intake disorder (ARFID) was clinically suspected.

CONCLUSIONS

We reported the first case of ASXL3-related disorder with adolescent onset of feeding difficulty. ARFID was considered a cause of the feeding difficulty.

Optimizing treatment environments for trait sensitivity in eating disorders

Research has identified trait sensitivity as a potential risk factor and treatment target of eating disorders. Conceptualizations of trait sensitivity have depicted individuals with high and low trait sensitivity metaphorically as orchids and dandelions, highlighting their responsiveness to environmental conditions and associated outcomes. While orchids require careful tending to survive, with such care, they emerge extraordinary. In contrast, dandelions can survive a broad range of environmental conditions. Within a scientific framework, trait sensitivity can be conceptualized as neurobiologically-based, with heightened sensory, interoceptive, interpersonal, and emotional processing. While trait sensitivity may increase susceptibility to eating disorders, when therapists view these traits through the lens of environmental responsiveness, they can facilitate their client's inherent resilience and potential. Incorporating a model of trait sensitivity into eating disorders treatment using psychoeducation, modifying environmental stimuli, and selecting optimal interventions has the potential to increase treatment engagement, deepen therapeutic collaboration, and improve outcomes.

A randomised controlled feasibility trial of intermittent theta burst stimulation with an open longer-term follow-up for young people with persistent anorexia nervosa (RaISE): Study protocol

OBJECTIVE

We present the protocol of a feasibility randomised controlled trial (RCT) of intermittent theta burst stimulation (iTBS) for young people with anorexia nervosa (AN). Effective first-line psychological therapies exist for young people with AN, but little is known about how to treat those who do not respond. Non-invasive neuromodulation, such as iTBS, could address unmet treatment needs by targeting neurocircuitry associated with the development and/or maintenance of AN.

DESIGN

Sixty-six young people (aged 13-30 years) with persistent AN will be randomly allocated to receive 20 sessions of real or sham iTBS over the left dorsolateral prefrontal cortex in addition to their usual treatment. Outcomes will be measured at baseline, post-treatment (1-month post-randomisation) and 4-months post-randomisation (when unblinding will occur). Additional open follow-ups will be conducted at 12- and 24-months post-randomisation. The primary feasibility outcome is the proportion of participants retained in the study at 4-months. Secondary outcomes include AN symptomatology, other psychopathology, quality of life, service utilisation, neurocognitive processes, and neuroimaging measures.

DISCUSSION

Findings will inform the development of a future large-scale RCT. They will also provide exploratory data on treatment efficacy, and neural and neurocognitive predictors and correlates of treatment response to iTBS in AN.

Dynamic Changes in Local Brain Connectivity and Activity: A Longitudinal Study in Adolescent Anorexia Nervosa

BACKGROUND

Resting-state functional connectivity analysis has been used to study disruptions in neural circuitries underlying eating disorder symptoms. Research has shown resting-state functional connectivity to be altered during the acute phase of anorexia nervosa (AN), but little is known about the biological mechanisms underlying neural changes associated with weight restoration. The goal of the current study was to investigate longitudinal changes in regional homogeneity (ReHo) among neighboring voxels, degree centrality (DC) (a voxelwise whole brain correlation coefficient), voxel-mirrored homotopic connectivity (VMHC) (measuring the synchronization between hemispheres), and the fractional amplitude of low-frequency fluctuations associated with weight gain during AN treatment.

METHODS

Resting-state functional connectivity data were acquired and analyzed from a sample of 174 female volunteers: 87 underweight patients with AN that were scanned before treatment and again after at least 12% body mass index increase, as well as 87 age-matched healthy control participants.

RESULTS

Longitudinal changes in ReHo, DC, VMHC, and the fractional amplitude of low-frequency fluctuations were observed in most regions identified to differ between patients with AN before treatment and healthy control participants. However, the degree of normalization varied for each parameter, ranging from 9% of all clusters in DC to 66% in VMHC. Longitudinal changes in ReHo and VMHC showed a linear association weight gain.

CONCLUSIONS

Resting-state functional magnetic resonance imaging measures, including ReHo, DC, VMHC, and the fractional amplitude of low-frequency fluctuations, show varying degrees of recovery after short-term weight restoration. Although only some of these changes were related to weight gain, our results provide an overall positive message, suggesting that weight restoration is associated with changes in functional brain measures that point toward normalization.

Reduction in eating disorder symptoms among adults in different weight loss interventions

Restriction of food intake and counting calories as part of weight loss programs are thought to trigger eating behaviors and attitudes which can lead to eating disorders. We have developed a treatment model, Regulation of Cues (ROC), that targets appetitive traits, including food responsiveness and satiety responsiveness, which could address overeating at an implicit level and reduce risk of detrimental behaviors and attitudes. This manuscript evaluates eating disorder symptoms, attitudes, and behaviors among adults with overweight or obesity randomized to ROC, behavioral weight loss (BWL), a combination of ROC + BWL (ROC+) and an active comparator (AC). Participants included 271 adults with a body mass index of 25 to 45, age 18 to 65 years, and a lack of comorbidities that could interfere with participation. Assessments occurred at baseline, mid-treatment (6 months), post-treatment (12-months) and 6- and 12-month follow-up. During treatment, participants in all four arms showed decreases in Eating, Weight, and Shape concerns on the Eating Disorder Examination-Questionnaire and binge eating symptoms on the Binge Eating Scale which were maintained at 6-month follow-up but increased at the 12-month follow-up. Both the ROC+ and BWL arms showed increases in Restraint during treatment which dissipated after treatment ended. This study contributes to a growing body of literature demonstrating that weight loss programs are not associated with increases in eating disorder symptoms. Future studies should evaluate interventions to maintain improvements in eating disorder symptoms following weight loss programs.

Predicting long-term outcome in anorexia nervosa: a machine learning analysis of brain structure at different stages of weight recovery

BACKGROUND

Anorexia nervosa (AN) is characterized by sizable, widespread gray matter (GM) reductions in the acutely underweight state. However, evidence for persistent alterations after weight-restoration has been surprisingly scarce despite high relapse rates, frequent transitions to other psychiatric disorders, and generally unfavorable outcome. While most studies investigated brain regions separately (univariate analysis), psychiatric disorders can be conceptualized as brain network disorders characterized by multivariate alterations with only subtle local effects. We tested for persistent multivariate structural brain alterations in weight-restored individuals with a history of AN, investigated their putative biological substrate and relation with 1-year treatment outcome.

METHODS

We trained machine learning models on regional GM measures to classify healthy controls (HC) (N = 289) from individuals at three stages of AN: underweight patients starting intensive treatment (N = 165, used as baseline), patients after partial weight-restoration (N = 115), and former patients after stable and full weight-restoration (N = 89). Alterations after weight-restoration were related to treatment outcome and characterized both anatomically and functionally.

RESULTS

Patients could be classified from HC when underweight (ROC-AUC = 0.90) but also after partial weight-restoration (ROC-AUC = 0.64). Alterations after partial weight-restoration were more pronounced in patients with worse outcome and were not detected in long-term weight-recovered individuals, i.e. those with favorable outcome. These alterations were more pronounced in regions with greater functional connectivity, not merely explained by body mass index, and even increases in cortical thickness were observed (insula, lateral orbitofrontal, temporal pole).

CONCLUSIONS

Analyzing persistent multivariate brain structural alterations after weight-restoration might help to develop personalized interventions after discharge from inpatient treatment.

Psychedelics in the treatment of eating disorders: Rationale and potential mechanisms

Eating disorders are serious illnesses showing high rates of mortality and comorbidity with other mental health problems. Psychedelic-assisted therapy has recently shown potential in the treatment of several common comorbidities of eating disorders, including mood disorders, post-traumatic stress disorder, and substance use disorders. The theorized therapeutic mechanisms of psychedelic-assisted therapy suggest that it could be beneficial in the treatment of eating disorders as well. In this review, we summarize preliminary data on the efficacy of psychedelic-assisted therapy in people with anorexia nervosa, bulimia nervosa, and binge eating disorder, which include studies and case reports of psychedelic-assisted therapy with ketamine, MDMA, psilocybin, and ayahuasca. We then discuss the potential therapeutic mechanisms of psychedelic-assisted therapy in these three eating disorders, including both general therapeutic mechanisms and those which are relatively specific to eating disorders. We find preliminary evidence that psychedelic-assisted therapy may be effective in the treatment of anorexia nervosa and bulimia nervosa, with very little data available on binge eating disorder. Regarding mechanisms, psychedelic-assisted therapy may be able to improve beliefs about body image, normalize reward processing, promote cognitive flexibility, and facilitate trauma processing. Just as importantly, it appears to promote general therapeutic factors relevant to both eating disorders and many of their common comorbidities. Lastly, we discuss potential safety concerns which may be associated with these treatments and present recommendations for future research.

Systematic review of prospective studies assessing risk factors to predict anorexia nervosa onset

BACKGROUND

According to case‒control studies, a multitude of factors contribute to the emergence of anorexia nervosa (AN). The present systematic review examines prospective studies specifically designed to evaluate the prediction of AN onset.

METHODS

According to the ARMSTAR 2 and PRISMA 2020 checklists, the PubMed, PsycINFO and Cochrane databases were searched. The methodological quality of the studies was assessed with the Downs and Black checklist.

RESULTS

Three articles concerning prospective studies of the general population were ultimately included in the review. The methodological quality of these studies was not optimal. Bidirectional amplification effects were observed between risk factors, some of which could have a relative predictive force as low bodyweight or body dissatisfaction. Even if not included according to specified criteria for this systematic review 11 longitudinal studies, with retrospective analysis of AN onset' prediction, were also discussed. None of these studies asserted the predictive value of particular risk factors as low body weight, anxiety disorders or childhood aggression.

CONCLUSIONS

To date there are insufficient established data to propose predictive markers of AN onset for predictive actions in pre-adolescent or adolescent populations. Future work should further evaluate potential risk factors previously identified in case‒control/retrospective studies within larger prospective investigations in preadolescent populations. It is important to clearly distinguish predisposing factors from precipitating factors in subjects at risk of developing AN.

Neural effects of deep brain stimulation on reward and loss anticipation and food viewing in anorexia nervosa: a pilot study

BACKGROUND

Anorexia nervosa (AN) is a severe and life-threatening psychiatric disorder. Initial studies on deep brain stimulation (DBS) in severe, treatment-refractory AN have shown clinical effects. However, the working mechanisms of DBS in AN remain largely unknown. Here, we used a task-based functional MRI approach to understand the pathophysiology of AN.

METHODS

We performed functional MRI on four AN patients that participated in a pilot study on the efficacy, safety, and functional effects of DBS targeted at the ventral limb of the capsula interna (vALIC). The patients and six gender-matched healthy controls (HC) were investigated at three different time points. We used an adapted version of the monetary incentive delay task to probe generic reward processing in patients and controls, and a food-specific task in patients only.

RESULTS

At baseline, no significant differences for reward anticipation were found between AN and HC. Significant group (AN and HC) by time (pre- and post-DBS) interactions were found in the right precuneus, right putamen, right ventral and medial orbitofrontal cortex (mOFC). No significant interactions were found in the food viewing task, neither between the conditions high-calorie and low-calorie food images nor between the different time points. This could possibly be due to the small sample size and the lack of a control group.

CONCLUSION

The results showed a difference in the response of reward-related brain areas post-DBS. This supports the hypotheses that the reward circuitry is involved in the pathogenesis of AN and that DBS affects responsivity of reward-related brain areas. Trial registration Registered in the Netherlands Trial Register ( https://www.trialregister.nl/trial/3322 ): NL3322 (NTR3469).

Disentangling the role of NAc D1 and D2 cells in hedonic eating

Overeating is driven by both the hedonic component ('liking') of food, and the motivation ('wanting') to eat it. The nucleus accumbens (NAc) is a key brain center implicated in these processes, but how distinct NAc cell populations encode 'liking' and 'wanting' to shape overconsumption remains unclear. Here, we probed the roles of NAc D1 and D2 cells in these processes using cell-specific recording and optogenetic manipulation in diverse behavioral paradigms that disentangle reward traits of 'liking' and 'wanting' related to food choice and overeating in healthy mice. Medial NAc shell D2 cells encoded experience-dependent development of 'liking', while D1 cells encoded innate 'liking' during the first food taste. Optogenetic control confirmed causal links of D1 and D2 cells to these aspects of 'liking'. In relation to 'wanting', D1 and D2 cells encoded and promoted distinct aspects of food approach: D1 cells interpreted food cues while D2 cells also sustained food-visit-length that facilitates consumption. Finally, at the level of food choice, D1, but not D2, cell activity was sufficient to switch food preference, programming subsequent long-lasting overconsumption. By revealing complementary roles of D1 and D2 cells in consumption, these findings assign neural bases to 'liking' and 'wanting' in a unifying framework of D1 and D2 cell activity.

Binge-Eating Precursors in Children and Adolescents: Neurodevelopment, and the Potential Contribution of Ultra-Processed Foods

Binge-eating disorder (BED) is a highly prevalent disorder. Subthreshold BED conditions (sBED) are even more frequent in youth, but their significance regarding BED etiology and long-term prognosis is unclear. A better understanding of brain findings associated with BED and sBED, in the context of critical periods for neurodevelopment, is relevant to answer such questions. The present narrative review starts from the knowledge of the development of emotional self-regulation in youth, and the brain circuits supporting emotion-regulation and eating behaviour. Next, neuroimaging studies with sBED and BED samples will be reviewed, and their brain-circuitry overlap will be examined. Deficits in inhibition control systems are observed to precede, and hyperactivity of reward regions to characterize, sBED, with overlapping findings in BED. The imbalance between reward/inhibition systems, and the implication of interoception/homeostatic processing brain systems should be further examined. Recent knowledge of the potential impact that the high consumption of ultra-processed foods in paediatric samples may have on these sBED/BED-associated brain systems is then discussed. There is a need to identify, early on, those sBED individuals at risk of developing BED at neurodevelopmental stages when there is a great possibility of prevention. However, more neuroimaging studies with sBED/BED pediatric samples are needed.

The complex interplay between psychosocial and biological factors in pregorexia nervosa - a rapid review

The importance of detecting eating disorders (EDs) during pregnancy cannot be overemphasized, because of the major negative effects this pathology has on both maternal and fetal health. Based on a rapid review including primary and secondary reports, PN may still be considered an elusive diagnosis entity, that partially overlaps with other EDs, either well-defined, like anorexia nervosa, or still in search of their own diagnosis criteria, like orthorexia nervosa. Neurochemical and hormonal factors, psychological and social mechanisms, along with lifestyle changes create a very complex framework for clinicians interested in defining the typical features of pregorexia nervosa (PN). The personal history of EDs is considered one of the most important risk factors for PN. The core diagnostic criteria for this entity are, so far, lack of gaining weight during pregnancy, an excessive focus on counting calories and/or intense physical exercising with a secondary decrease of interest in the fetus's health, lack of acceptance of the change in body shape during pregnancy, and pathological attention for own body image. Regarding the treatment of PN, nutritional and psychosocial interventions are recommended but no specific therapeutic strategies for this disorder have been detected in the literature. Psychotherapy is considered the main intervention for pregnant women with associated EDs and mood disorders, as the pharmacological agents could have teratogenic effects or insufficient data to support their safety in this population. In conclusion, taking into consideration the methodological limitations of a rapid review, data supporting the existence of PN were found, mainly regarding tentative diagnostic criteria, risk factors, and pathophysiological aspects. These data, corroborated with the importance of preserving optimal mental health in a vulnerable population, e.g., pregnant women, justify the need for further research focused on finding specific diagnostic criteria and targeted therapeutic approaches.

Food restriction and hyperactivity induce changes in corticolimbic brain dopamine and serotonin levels in female rats

Compelling data support altered dopamine (DA) and serotonin (5-HT) signaling in anorexia nervosa (AN). However, their exact role in the etiopathogenesis of AN has yet to be elucidated. Here, we evaluated the corticolimbic brain levels of DA and 5-HT in the induction and recovery phases of the activity-based anorexia (ABA) model of AN. We exposed female rats to the ABA paradigm and measured the levels of DA, 5-HT, the metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and the dopaminergic type 2 (D2) receptors density in feeding- and reward-implicated brain regions (i.e., cerebral cortex, Cx; prefrontal cortex, PFC; caudate putamen, CPu; nucleus accumbens, NAcc; amygdala, Amy; hypothalamus, Hyp; hippocampus, Hipp). DA levels were significantly increased in the Cx, PFC and NAcc, while 5-HT was significantly enhanced in the NAcc and Hipp of ABA rats. Following recovery, DA was still elevated in the NAcc, while 5-HT was increased in the Hyp of recovered ABA rats. DA and 5-HT turnover were impaired at both ABA induction and recovery. D2 receptors density was increased in the NAcc shell. These results provide further proof of the impairment of the dopaminergic and serotoninergic systems in the brain of ABA rats and support the knowledge of the involvement of these two important neurotransmitter systems in the development and progression of AN. Thus, providing new insights on the corticolimbic regions involved in the monoamine dysregulations in the ABA model of AN.

Longitudinal study in adolescent anorexia nervosa: evaluation of cortico-striatal and default mode network resting-state brain circuits

Anorexia nervosa (AN) typically emerges in adolescence. The cortico-striatal system (CSTS) and the default mode network (DMN) are brain circuits with a crucial development during this period. These circuits underlie cognitive functions that are impaired in AN, such as cognitive flexibility and inhibition, among others. Little is known about their involvement in adolescent AN and how weight and symptom improvement might modulate potential alterations in these circuits. Forty-seven adolescent females (30 AN, 17 healthy control) were clinically/neuropsychologically evaluated and scanned during a 3T-MRI resting-state session on two occasions, before and after a 6-month multidisciplinary treatment of the AN patients. Baseline and baseline-to-follow-up between-group differences in CSTS and DMN resting-state connectivity were evaluated, as well as their association with clinical/neuropsychological variables. Increased connectivity between the left dorsal putamen and the left precuneus was found in AN at baseline. At follow-up, body mass index and clinical symptoms had improved in the AN group. An interaction effect was found in the connectivity between the right dorsal caudate to right mid-anterior insular cortex, with lower baseline AN connectivity that improved at follow-up; this improvement was weakly associated with changes in neuropsychological (Stroop test) performance. These results support the presence of CSTS connectivity alterations in adolescents with AN, which improve with weight and symptom improvement. In addition, at the level of caudate-insula connectivity, they might be associated with inhibitory processing performance. Alterations in CSTS pathways might be involved in AN from the early stages of the disorder.

New insight on the mechanism of eating disorder in females based on metabolic differences of bisphenol S in female and male zebrafish

The different capacity of glucuronic acid metabolism might lead to the difference of bisphenol S (BPS) residual in tissues of male and female zebrafish. This may be the fundamental reason why BPS causes different effects in females and males. Here, adult zebrafish are exposed to 1, 10 and 100 μg/L BPS for 35 days to explore the main effect on females. After exposure, the liver of females showed stronger BPS metabolism ability than males, resulting in the accumulation of BPS in the gut of females. The results of neurotransmitters in gut of females revealed that the content of serotonin was decreased by BPS treatments. In addition, the mRNA expression levels of tryptophan 5-monooxygenase (Tph1) that regulated serotonin synthesis was reduced in gut of females in all BPS groups, and Tph1 protein has very high affinity with BPS molecule. Adult females treated with BPS exhibited symptoms including overeating, a decrease of serotonin in the gut, hypoglycemia and hyperlipidemia, a similar effect of Tph1 protein inhibitor LP533401 on adult females. This hypoglycemia stimulates brain agrp/pomc and orexin neurons to induce overfeeding behavior, causing intestinal homeostasis imbalance and hyperlipidemia. Our data elucidate a potential pathogenesis of eating disorder under pollutant stress.

Does NUCB2/Nesfatin-1 Influence Eating Behaviors in Obese Patients with Binge Eating Disorder? Toward a Neurobiological Pathway

Nesfatin-1 is a new anorexigenic neuropeptide involved in the regulation of hunger/satiety, eating, and affective disorders. We aimed to investigate nesfatin-1 secretion in vitro, in murine adipose cells, and in human adipose fat samples, as well as to assess the link between circulating nesfatin-1 levels, NUCB2 and Fat Mass and Obesity Gene (FTO) polymorphisms, BMI, Eating Disorders (EDs), and pathological behaviors. Nesfatin-1 secretion was evaluated both in normoxic fully differentiated 3T3-L1 mouse adipocytes and after incubation under hypoxic conditions for 24 h. Omental Visceral Adipose tissue (VAT) specimens of 11 obese subjects, and nesfatin-1 serum levels' evaluation, eating behaviors, NUCB2 rs757081, and FTO rs9939609 polymorphisms of 71 outpatients seeking treatment for EDs with different Body Mass Index (BMI) were studied. Significantly higher levels of nesfatin-1 were detected in hypoxic 3T3-L1 cultured adipocytes compared to normoxic ones. Nesfatin-1 was highly detectable in the VAT of obese compared to normal-weight subjects. Nesfatin-1 serum levels did not vary according to BMI, sex, and EDs diagnosis, but correlations with grazing; emotional, sweet, and binge eating; hyperphagia; social eating; childhood obesity were evident. Obese subjects with CG genotype NUCB2 rs757081 and AT genotype FTO rs9939609 polymorphisms had higher nesfatin-1 levels. It could represent a new biomarker of EDs comorbidity among obese patients.

Ethical tensions in the treatment of youth with severe anorexia nervosa

Treatment of anorexia nervosa poses a moral quandary for clinicians, particularly in paediatrics. The challenges of appropriately individualising treatment while balancing prospective benefits against concomitant harms are best highlighted through exploration and discussion of the ethical issues. The purpose of this Viewpoint is to explore the ethical tensions in treating young patients (around ages 10-18 years) with severe anorexia nervosa who are not capable of making treatment-based decisions and describe how harm reduction can reasonably be applied. We propose the term AN-PLUS to refer to the subset of patients with a particularly concerning clinical presentation-poor quality of life, lack of treatment response, medically severe and unstable, and severe symptomatology-who might benefit from a harm reduction approach. From ethics literature, qualitative studies, and our clinical experience, we identify three core ethical themes in making treatment decisions for young people with AN-PLUS: capacity and autonomy, best interests, and person-centred care. Finally, we consider how a harm reduction approach can provide direction for developing a personalised treatment plan that retains a focus on best interests while attempting to mitigate the harms of involuntary treatment. We conclude with recommendations to operationalise a harm reduction approach in young people with AN-PLUS.

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.

Brain reward response in adolescents and young adults with anorexia nervosa is moderated by changes in body weight and sweetness perception

OBJECTIVE

Anorexia nervosa (AN) is a severe psychiatric illness with complex etiology. Recently, we found elevated striatal brain response to sweet taste stimuli in adolescents and young adults with AN. Here, we tested the hypothesis that nutritional rehabilitation normalizes prediction error activation, a measure for dopamine-related reward circuit response, to salient caloric taste stimuli in AN.

METHODS

A total of 28 individuals with AN (age = 16 ± 2 years; body mass index [BMI] = 16 ± 1) who previously underwent brain imaging while performing a taste prediction error task using sucrose as salient caloric stimulus, participated in a second brain imaging scan (BMI = 18 ± 1) after intensive specialized eating disorder treatment (41 ± 15 days). A total of 31 healthy controls (age = 16 ± 3 years; BMI = 21 ± 2) were also studied on two occasions.

RESULTS

At baseline, individuals with AN demonstrated an elevated salience response in bilateral caudate head and nucleus accumbens, and right ventral striatum. At the second scan, elevated response was only found in the right nucleus accumbens. A moderator analysis indicated that greater increase in BMI and greater decrease in sweetness perception predicted lesser prediction error response at the second scan in AN.

CONCLUSION

Consistent with the previously reported monetary stimulus-response, elevated taste prediction error response in AN was largely absent after weight restoration. This study indicates that changes in BMI and sweet taste perception are independent moderators of change of brain salience response in adolescents and young adults with AN. The study points toward dynamic changes in the brain reward circuitry in AN and highlights the importance of nutrition and weight restoration in that process.

PUBLIC SIGNIFICANCE STATEMENT

AN is a severe psychiatric illness. Biological factors that integrate neurobiology and behavior could become important targets to improve treatment outcome. This study highlights the importance of weight normalization and taste perception the normalization of brain function, and food type or taste-specific interventions could help in the recovery process. Furthermore, the study suggests that food-related and nonfood-related reward processing adapts to illness state in AN.

The prevalence and risk factors of screen-based disordered eating among university students: a global systematic review, meta-analysis, and meta-regression

PURPOSE

The purpose of this review was to estimate the prevalence of screen-based disordered eating (SBDE) and several potential risk factors in university undergraduate students around the world.

METHODS

An electronic search of nine data bases was conducted from the inception of the databases until 1st October 2021. Disordered eating was defined as the percentage of students scoring at or above established cut-offs on validated screening measures. Global data were also analyzed by country, research measure, and culture. Other confounders in this review were age, BMI, and sex.

RESULTS

Using random-effects meta-analysis, the mean estimate of the distribution of effects for the prevalence of SBDE among university students (K = 105, N = 145,629) was [95% CI] = 19.7% [17.9%; 21.6%], I2 = 98.2%, Cochran's Q p value = 0.001. Bayesian meta-analysis produced an estimate of 0.24, 95% credible intervals [0.20, 0.30], τ = 92%. Whether the country in which the students were studying was Western or non-Western did not moderate these effects, but as either the mean BMI of the sample or the percentage of the sample that was female increased, the prevalence of SBDE increased.

CONCLUSIONS

These findings support previous studies indicating that many undergraduate students are struggling with disordered eating or a diagnosable eating disorder, but are neither receiver effective prevention nor accessing accurate diagnosis and available treatment. It is particularly important to develop ever more valid ways of identifying students with high levels of disordered eating and offering them original or culturally appropriate and effective prevention or early treatment.

LEVEL OF EVIDENCE

I, systematic review and meta-analysis.

Anticipatory and consummatory pleasure in eating disorders

BACKGROUND

Recent research suggests that anhedonia, or the inability to experience pleasure, is elevated in individuals with eating disorders (EDs). However, past literature has only studied anhedonia in EDs as a unidimensional construct rather than separately examining anticipatory (i.e., prediction of pleasure for a future event) and consummatory (i.e., enjoyment of a present event) pleasure. Given that these subcomponents of pleasure have distinct neurobiological correlates, studying pleasure as a multifaceted construct may yield important insights into the underlying mechanisms of binge eating or food restriction.

METHODS

A sample of 124 women with anorexia nervosa, bulimia nervosa, or other specified feeding or eating disorder and 84 control women (CW) completed self-report measures of anticipatory pleasure, consummatory pleasure, ED symptoms, depression, harm avoidance, and anxiety.

RESULTS

Individuals with EDs endorsed significantly lower anticipatory pleasure than CW, but there were no significant group differences in consummatory pleasure. Further, there were no significant differences in self-reported pleasure among ED diagnostic groups. Within the ED sample, anticipatory pleasure but not consummatory pleasure was positively related to binge eating frequency and significantly negatively correlated with cognitive ED symptoms, state and trait anxiety, and harm avoidance. Both anticipatory and consummatory pleasure was negatively associated with depression.

CONCLUSION

The results of the current study suggest that lower pleasure across the ED spectrum may be due to deficits in anticipatory, but not consummatory, pleasure. Future research should continue to explore the behavioral, affective, and neural correlates of anticipatory pleasure in EDs to characterize better how it relates to the onset and maintenance of binge eating and other eating disorder pathology.

The emotional-behavioral state of Israeli adolescent and young adult females with anorexia nervosa during the COVID19 pandemic

BACKGROUND

During the COVID-19 pandemic in Israel, the number of patients with eating disorders (EDs) seeking treatment increased significantly. The present study sought to evaluate whether, during the pandemic (2020-21), patients with anorexia nervosa (AN) would show more ED-related, comorbid, and COVID-19-related symptoms in comparison to a naturalistic control group, and whether differences would be found between adult and adolescent patients with AN. We also examined attitudes to telemedicine use during the pandemic in patients receiving long-distance interventions.

METHODS

Using online self-report questionnaires, we assessed general and COVID-19-specific symptoms with a secure digital platform (REDCap^®) in 36 female adolescents with AN, 35 female adults with AN, and 25 female controls.

RESULTS

Compared with controls, patients with AN showed more symptoms of EDs, anxiety, depression, and post-traumatic stress disorder (PTSD), elevated suicidal ideation, more COVID-related emotional-behavioral disturbances, and lower resilience. Adult patients with AN fared worse than adolescent patients on most of these measures. Adult patients using telemedicine during the COVID-19 pandemic showed fewer positive attitudes toward this treatment than adolescents (telemedicine was offered to all, but used by 18/35 adolescents and 21/36 adults with AN). Last, elevated COVID-19-related symptomatology was correlated with more symptoms of ED, anxiety, depression and PTSD, and with lower resilience.

CONCLUSIONS

Our findings suggest that the emotional-behavioral state of Israeli females with AN, particularly adults, was worse during the COVID-19 pandemic in comparison to controls. Many patients did not use telemedicine for their treatment. Adult patients using telemedicine were less satisfied with it than adolescent patients.

A network approach can improve eating disorder conceptualization and treatment

Eating disorders are severe mental illnesses with the second highest mortality rate of all psychiatric illnesses. Eating disorders are exceedingly deadly because of their complexity. Specifically, eating disorders are highly comorbid with other psychiatric illnesses (up to 95% of individuals with an eating disorder have at least one additional psychiatric illness), have extremely heterogeneous presentations, and individuals often migrate from one specific eating disorder diagnosis to another. In this Perspective, we propose that understanding eating disorder comorbidity and heterogeneity via a network theory approach offers substantial benefits for both conceptualization and treatment. Such a conceptualization, strongly based on theory, can identify specific pathways that maintain psychiatric comorbidity, how diagnoses vary across individuals, and how specific symptoms and comorbidities maintain illness for one individual, thereby paving the way for personalized treatment.

Impulsivity and eating disorders: The relationship between serum 25-hydroxyvitamin D and different impulsivity facets in a transdiagnostic sample

OBJECTIVES

Eating disorders (EDs) are severe psychiatric conditions characterised by malnutrition, dysfunctional behaviours, and hypovitaminosis D. In various psychiatric conditions, including EDs, preliminary evidence has correlated impulsivity to a low level of 25-hydroxyvitamin D [25(OH)D]. This study aims to reinforce this evidence by examining different facets, both behavioural and psychological, of the impulsivity construct in patients with ED.

METHODS

A sample of 119 women was evaluated with a validated questionnaire and computerised neuropsychological tasks: the UPPS-P impulsive behaviour scale, a go/no-go task, and the Balloon Analogue Risk Task (BART). A clinical evaluation for EDs and blood sample collection were also performed to assess specific psychopathology and determine the serum level of 25(OH)D.

RESULTS

Significant correlations were found between serum levels of 25(OH)D and BART scores (p = 0.012) and lack of perseverance (p = 0.034). Moreover, regression analyses showed that higher BART scores may be explained by hypovitaminosis D and higher levels of lack of perseverance in patients with EDs.

CONCLUSIONS

The specific aspect of impulsivity linked to goal strategy and behaviours may be explained in patients with EDs by hypovitaminosis D. A possible connection to the brain inflammatory system is also discussed, along with possible directions for future research.

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.

Eating and Control Styles Axis in Mentalisation-Based Psychotherapy in Eating Disorders: A Randomised Clinical Trial

Background

Clinicians need an instrument that helps their patients with eating disorders (ED) to explore their agent's inner intentions and confront negative behaviour and control styles.

Objectives

To assess the feasibility and impact of an eating and control styles axis (ECOSA) during the first 8 months of mentalisation-based psychotherapy with a community-based sample of ED patients.

Methods

Six experienced therapists and their consecutively admitted patients were randomly allocated to the intervention and control groups. A total of 94 women, M age = 24 were recruited between June 2020 and October 2021. Ninety completed it. Both groups received mentalisation-based psychotherapy, but only the intervention group used the ECOSA repeatedly. Therapists and participants were blinded to the study aims and hypothesis. Fidelity assessment was applied to ensure that the two groups differed mainly in terms of ECOSA usage.

Results

The use of ECOSA, although less than advised, was reported as feasible. The effect size of the improvement in reflective functioning was larger than that of the control group and correlated significantly only in the intervention group with EDE-Q score (r = 0.46; p = 0.001).

Conclusion

Although the study limitations: selective population, relatively small sample size and the lack of controlled confounder, the combined quantitative and qualitative results lend preliminary evidence for the validity and contribution of ECOSA as a possible instrument that may upgrade the clinician's toolbox in the treatment of ED. A more rigorous study design is needed to explore the potential usage of ECOSA as a clinical tool to enhance mentalisation among people with ED.

Ketamine as a Novel Psychopharmacotherapy for Eating Disorders: Evidence and Future Directions

Eating disorders (EDs) are serious, life-threatening psychiatric conditions associated with physical and psychosocial impairment, as well as high morbidity and mortality. Given the chronic refractory nature of EDs and the paucity of evidence-based treatments, there is a pressing need to identify novel approaches for this population. The noncompetitive N-methyl-D-aspartate receptor (NMDAr) antagonist, ketamine, has recently been approved for treatment-resistant depression, exerting rapid and robust antidepressant effects. It is now being investigated for several new indications, including obsessive–compulsive, post-traumatic, and substance use disorder, and shows transdiagnostic potential for EDs, particularly among clinical nonresponders. Hence, the aim of this review is to examine contemporary findings on the treatment of EDs with ketamine, whether used as a primary, adjunctive, or combination psychopharmacotherapy. Avenues for future research are also discussed. Overall, results are encouraging and point to therapeutic value; however, are limited to case series and reports on anorexia nervosa. Further empirical research is thus needed to explore ketamine efficacy across ED subgroups, establish safety profiles and optimize dosing, and develop theory-driven, targeted treatment strategies at the individual patient level.

Urinary free cortisol and childhood maltreatments in eating disorder patients: New evidence for an ecophenotype subgroup

Introduction

Increasing neurobiological evidence has suggested the presence of a specific ecophenotype in people with eating disorders (EDs) linked to early maltreatment. Urinary‐free cortisol could strengthen the data and show specific relationships between maltreated subtypes and the hormonal profiles of patients with EDs. This study aims to evaluate the presence of different urinary cortisol in drug‐free patients in the acute phase of the disorder and its relationship with childhood maltreatment.

Methods

A sample of 78 female patients with ED is included in the study. Childhood maltreatment history and 24‐h urinary free cortisol (24‐h UFC) are evaluated at a specialised ED ward admission.

Results

Patients with a maltreatment history show more blunted 24‐h UFC levels than peers without childhood maltreatment (p = 0.001). Regression analysis showed that child abuse is a predictor of the reduction of 24‐h UFC (p < 0.001), with physical abuse (p = 0.011) and sexual abuse (p = 0.050) that could have a more specific impact than other maltreatment subtypes.

Discussion

Childhood maltreatment should be evaluated in ED patients due to its biological impact on the hormonal stress axis, which could impair the ability of patients to respond to standardized ED treatment.

Eating disorder patients with history of maltreatment showed a reduced 24‐h urinary free cortisol.

New data support the evidence about the presence of an ecophenotype ED subgroup.

Reduced 24‐h urinary free cortisol is significantly correlated with child abuses.

Initial evidence of abnormal brain plasticity in anorexia nervosa: an ultra-high field study

Anorexia Nervosa has been associated with white matter abnormalities implicating subcortical abnormal myelination. Extending these findings to intracortical myelin has been challenging but ultra-high field neuroimaging offers new methodological opportunities. To test the integrity of intracortical myelin in AN we used 7 T neuroimaging to acquire T1-weighted images optimized for intracortical myelin from seven females with AN (age range: 18-33) and 11 healthy females (age range: 23-32). Intracortical T₁ values (inverse index of myelin concentration) were extracted from 148 cortical regions at ten depth-levels across the cortical ribbon. Across all cortical regions, these levels were averaged to generate estimates of total intracortical myelin concentration and were clustered using principal component analyses into two clusters; the outer cluster comprised T₁ values across depth-levels ranging from the CSF boundary to the middle of the cortical regions and the inner cluster comprised T₁ values across depth-levels ranging from the middle of the cortical regions to the gray/white matter boundary. Individuals with AN exhibited higher T₁ values (i.e., decreased intracortical myelin concentration) in all three metrics. It remains to be established if these abnormalities result from undernutrition or specific lipid nutritional imbalances, or are trait markers; and whether they may contribute to neurobiological deficits seen in AN.

Taste of Fat and Obesity: Different Hypotheses and Our Point of View

Obesity results from a temporary or prolonged positive energy balance due to an alteration in the homeostatic feedback of energy balance. Food, with its discriminative and hedonic qualities, is a key element of reward-based energy intake. An alteration in the brain reward system for highly palatable energy-rich foods, comprised of fat and carbohydrates, could be one of the main factors involved in the development of obesity by increasing the attractiveness and consumption of fat-rich foods. This would induce, in turn, a decrease in the taste of fat. A better understanding of the altered reward system in obesity may open the door to a new era for the diagnosis, management and treatment of this disease.

Psychopathological and Neurobiological Overlap Between Anorexia Nervosa and Self-Injurious Behavior: A Narrative Review and Conceptual Hypotheses

Empirical evidence and clinical observations suggest a strong -yet under acknowledged-link between anorexia nervosa (AN) and non-suicidal self-injurious behavior (NSSI). By reviewing the literature on the psychopathology and neurobiology of AN and NSSI, we shed light on their relationship. Both AN and NSSI are characterized by disturbances in affect regulation, dysregulation of the reward circuitry and the opioid system. By formulating a reward-centered hypothesis, we explain the overlap between AN and NSSI. We propose three approaches understanding the relationship between AN and NSSI, which integrate psychopathology and neurobiology from the perspective of self-destructiveness: (1) a nosographical approach, (2) a research domain (RDoC) approach and (3) a network analysis approach. These approaches will enhance our knowledge of the underlying neurobiological substrates and may provide groundwork for the development of new treatment options for disorders of self-destructiveness, like AN and NSSI. In conclusion, we hypothesize that self-destructiveness is a new, DSM-5-transcending concept or psychopathological entity that is reward-driven, and that both AN and NSSI could be conceptualized as disorders of self-destructiveness.

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.

A Comprehensive Review of Complications and New Findings Associated with Anorexia Nervosa

Anorexia nervosa is a complex and deadly psychiatric disorder. It is characterized by a significant degree of both co-occurring psychiatric diseases and widespread physiological changes which affect nearly every organ system. It is important for clinicians to be aware of the varied consequences of this disorder. Given the high rate of mortality due to AN, there is a need for early recognition so that patients can be referred for appropriate medical and psychiatric care early in the course of the disorder. In this study, we present a comprehensive review of the recent literature describing medical findings commonly encountered in patients with AN. The varied and overlapping complications of AN affect pregnancy, psychological well-being, as well as bone, endocrine, gastrointestinal, cardiovascular, and pulmonary systems.

Neurobiological and Psychological Maintenance Mechanisms Associated with Anticipatory Reward in Bulimia Nervosa

The purpose of this investigation is to identify the anticipatory reward mechanisms that maintain binge eating and purging in bulimia nervosa. Emerging data indicate the importance of reward and anticipatory processes as maintenance mechanisms of bulimia nervosa that can be targeted in treatment. The proposed research will identify neurobiological and psychological anticipatory mechanisms of binge eating and purging using functional magnetic resonance imaging (fMRI), and ecological momentary assessment (EMA) in the natural environment. In this investigation, 60 adults (30 with bulimia nervosa and 30 matched comparison participants) will undergo negative and positive mood inductions followed by an fMRI food selection task (and a comparison shopping task) to examine neurobiological and affective responses to food and non-food reward anticipation. Participants with bulimia nervosa will complete two weeks of EMA examining real-time affect changes in relation to the anticipation of binge eating and purging. These methods will facilitate rigorous assessment of the links between neurobiological (fMRI) and naturalistic (EMA) data in anticipatory reward processes. Findings from this investigation will inform the conceptualization and treatment of bulimia nervosa by identifying the role of reward anticipation in symptom maintenance, providing a crucial framework for targeting these anticipatory processes in existing and novel interventions.

Emotional imagination of negative situations: Functional neuroimaging in anorexia and bulimia

Aim

The present study aims to extend the knowledge of the neural correlates of emotion processing in first episode subjects affected by anorexia nervosa (AN) or bulimia nervosa (BN). We applied an emotional distress paradigm targeting negative emotions thought to be relevant for interpersonal difficulties and therapeutic resistance mechanisms.

Methods

The current study applied to 44 female participants with newly diagnosed AN or BN and 20 matched controls a neuroimaging paradigm eliciting affective responses. The measurements also included an extensive assessment comprising clinical scales, neuropsychological tests, measures of emotion processing and empathy.

Results

AN and BN did not differ from controls in terms of emotional response, emotion matching, self-reported empathy and cognitive performance. However, eating disorder and psychopathological clinical scores, as well as alexithymia levels, were increased in AN and BN. On a neural level, no significant group differences emerged, even when focusing on a region of interest selected a priori: the amygdala. Some interesting findings put in relation the hippocampal activity with the level of Body Dissatisfaction of the participants, the relative importance of the key nodes for the common network in the decoding of different emotions (BN = right amygdala, AN = anterior cingulate area), and the qualitative profile of the deactivations.

Conclusions

Our data do not support the hypothesis that participants with AN or BN display reduced emotional responsiveness. However, peculiar characteristics in emotion processing could be associated to the three different groups. Therefore, relational difficulties in eating disorders, as well as therapeutic resistance, could be not secondary to a simple difficulty in feeling and identifying basic negative emotions in AN and BN participants.

Academy of Nutrition and Dietetics: Revised 2020 Standards of Practice and Standards of Professional Performance for Registered Dietitian Nutritionists (Competent, Proficient, and Expert) in Eating Disorders

Eating disorders (ED) are complex mental illnesses and are not a result of personal choice. Full recovery from an ED is possible. The severity and inherent lethality of an ED is undisputed, and the role of the registered dietitian nutritionist (RDN) is essential. Clinical symptomology presents at varying developmental milestones and is perpetuated through a sociocultural evaluation of beauty and drive for ascetic idealism. ED are globally prevalent in 4.4% of the population aged 5 to 17 years, yet affect individuals across the entire lifespan, including all cultures and genders. The Behavioral Health Nutrition Dietetic Practice Group, along with the Academy of Nutrition and Dietetics Quality Management Committee, revised the Standards of Practice (SOP) and Standards of Professional Performance (SOPP) for RDNs in Eating Disorders. Including the RDN in ED treatment is vital for all levels of care. The RDN must be perceptive to negative symptoms indicative of psychological triggers when exploring food belief systems, patterns of disinhibition, and nutrition misinformation with clients. Through a conscious awareness of medical, psychological, and behavioral strategies, the implementation of the SOP and SOPP supports a dynamic and holistic view of ED treatment by the RDN. The SOP and SOPP are complementary resources for RDNs and are intended to be used as self-evaluation tools for assuring competent practice in ED and for determining potential education, training, supervision, and mentorship needs for advancement to a higher practice level in a variety of settings.

Case Report: Repeated Transcranial Magnetic Stimulation Improves Comorbid Binge Eating Disorder in Two Female Patients With Treatment-Resistant Bipolar Depression

Introduction: Binge eating disorder (BED) is the most common eating disorder, affecting a large population worldwide. It is characterized by recurrent episodes of binge eating, with no compensatory behaviors. BED is often associated with psychiatric comorbidities, and still represents a challenge in terms of treatment strategies. In the last years, neuromodulation has represented a promising approach in the treatment of BED. We report the cases of two women, affected by Bipolar Disorder Type II (BD-II) and comorbid BED, whose BED symptoms improved after a course of accelerated intermittent Theta Burst Stimulation (iTBS). Methods: We carried out a clinical study, involving neurostimulation on six patients with a treatment-resistant depressive episode. The trial consisted of a 3-week accelerated iTBS treatment, delivered to the left dorsolateral pre-frontal cortex. Clinical evaluation scales (Hamilton Rating Scale for Depression, Montgomery-Åsberg Depression Rating Scale, and Young Mania Rating Scale) were administered at baseline, after 2 weeks, and at the end of the stimulation cycle. Pharmacotherapy was maintained unchanged during iTBS treatment. Patients gave their informed consent both for the protocol and for the publication. Results: The treatment was well-tolerated. Depressive symptoms only slightly improved; however, patients' binge episodes remitted completely, which was a serendipitous finding. BED symptomatology complete remission lasted up to 12 weeks follow-up. Discussion: This is the first study regarding iTBS use in BED in comorbidity with BD-II. Further research is still needed to assess the efficacy of this technique in BED treatment.

Activity-Based Anorexia Induces Browning of Adipose Tissue Independent of Hypothalamic AMPK

Anorexia nervosa (AN) is an eating disorder leading to malnutrition and, ultimately, to energy wasting and cachexia. Rodents develop activity-based anorexia (ABA) when simultaneously exposed to a restricted feeding schedule and allowed free access to running wheels. These conditions lead to a life-threatening reduction in body weight, resembling AN in human patients. Here, we investigate the effect of ABA on whole body energy homeostasis at different housing temperatures. Our data show that ABA rats develop hyperactivity and hypophagia, which account for a massive body weight loss and muscle cachexia, as well as reduced uncoupling protein 1 (UCP1) expression in brown adipose tissue (BAT), but increased browning of white adipose tissue (WAT). Increased housing temperature reverses not only the hyperactivity and weight loss of animals exposed to the ABA model, but also hypothermia and loss of body and muscle mass. Notably, despite the major metabolic impact of ABA, none of the changes observed are associated to changes in key hypothalamic pathways modulating energy metabolism, such as AMP-activated protein kinase (AMPK) or endoplasmic reticulum (ER) stress. Overall, this evidence indicates that although temperature control may account for an improvement of AN, key hypothalamic pathways regulating thermogenesis, such as AMPK and ER stress, are unlikely involved in later stages of the pathophysiology of this devastating disease.

Evaluation of spontaneous regional brain activity in weight-recovered anorexia nervosa

Whereas research using structural magnetic resonance imaging (sMRI) reports sizable grey matter reductions in patients suffering from acute anorexia nervosa (AN) to be largely reversible already after short-term weight gain, many task-based and resting-state functional connectivity (RSFC) studies suggest persistent brain alterations even after long-term weight rehabilitation. First investigations into spontaneous regional brain activity using voxel-wise resting-state measures found widespread abnormalities in acute AN, but no studies have compared intrinsic brain activity properties in weight-recovered individuals with a history of AN (recAN) with healthy controls (HCs). SMRI and RSFC data were analysed from a sample of 130 female volunteers: 65 recAN and 65 pairwise age-matched HC. Cortical grey matter thickness was assessed using FreeSurfer software. Fractional amplitude of low-frequency fluctuations (fALFFs), mean-square successive difference (MSSD), regional homogeneity (ReHo), voxel-mirrored homotopic connectivity (VHMC), and degree centrality (DC) were calculated. SMRI and RSFC data were analysed from a sample of 130 female volunteers: 65 recAN and 65 pairwise age-matched HCs. Cortical grey matter thickness was assessed using FreeSurfer software. Fractional amplitude of low-frequency fluctuations (fALFF), mean-square successive difference (MSSD), regional homogeneity (ReHo), voxel-mirrored homotopic connectivity (VHMC), and degree centrality (DC) were calculated. Abnormal regional homogeneity found in acute AN seems to normalize in recAN, supporting assumptions of a state rather than a trait marker. Aberrant fALFF values in the cerebellum and the infertior temporal gyrus could possibly hint towards trait factors or a scar (the latter, e.g., from prolonged periods of undernutrition), warranting further longitudinal research.