Recent advances in understanding anorexia nervosa

Therapeutic ketogenic diet as treatment for anorexia nervosa

Anorexia nervosa (AN) is a severe psychiatric disorder. However, we lack neurobiological models and interventions to explain and treat the core characteristics of food restriction, feeling fat, and body size overestimation. Research has made progress in understanding brain function involved in the pathophysiology of AN, but translating those results into biological therapies has been challenging. Studies have suggested that metabolic factors could contribute to developing and maintaining AN pathophysiology. Here, we describe a neurobiological model for why using a therapeutic ketogenic diet could address key alterations in brain function in AN and prevent the desire for weight loss and associated eating disorder-specific symptoms. This translational model is based on animal studies and human data and integrates behavioral traits, brain neural energy metabolism, and neurotransmitter function. Pilot data indicate that the intervention can dramatically reduce eating and body-related fears, although larger studies across illness stages still need to be conducted.

Effects of Age-Dependent Hormonal Changes and Estrogen Supplementation on Voice in Girls with Anorexia Nervosa-Preliminary Report

INTRODUCTION

Human development includes lots of physical and emotional changes. The human voice depends on age. Voice production is a complex physiological and acoustic phenomenon that depends on many factors such as structure, hormone level, degree of fatigue or nutrition and hydration of the body, systemic diseases, and emotional state. All these factors can be present in anorexia nervosa (AN), such as excessive weight loss, generated hydro-electrolytic changes, nutritional deficiencies, hormonal disturbances in the function of the hypothalamic-pituitary-adrenal axis, the hypothalamic-pituitary-thyroid axis, the hypothalamic-pituitary-ovarian axis, and emotional distress. The prevalence of AN ranges between 0.3% and 3%, and it is the third most common chronic disease affecting adolescent girls. However, voice changes related to AN have not been fully investigated.

OBJECTIVE

The purpose of this study was to evaluate the impact of AN on age-related changes in the voice of adolescent women-before and after puberty, particularly through acoustic analysis. An additional objective was to evaluate estrogen substitution in female patients with AN in order to investigate their effect on voice condition.

MATERIALS AND METHODS

126 girls diagnosed with AN (15.32 ± 2.12 years, range 12-19, BMI = 14.38 ± 1.67), were assessed for the condition of the voice such as perceptual voice evaluation on the GRBAS scale, maximal phonation time (MPT), laryngoscopy, with special attention to voice acoustic analysis-Multi-Dimensional Voice Program (MDVP). The control group (B) included 93 girls without eating disturbances (aged 12-19, mean age 15.52 ± 2.40, BMI = 21.50 ± 1.54). Perceptual voice assessment, aerodynamic test MPT, and acoustic parameters were analyzed in age groups (≤16 years and >16 years). The human vocal tract is sensitive to sex hormones, so the analysis was carried out in the group up to the age of 16 and above 16 to check possible effects.

RESULTS

GRBAS scale was higher in girls with AN compared to the control group for breathiness (B) (P = 0.0002) and asthenia (A) (P < 0.05). The median GRBAS scale for the older group of anorexic women was the highest (2.0). The mean MPT for group A was significantly lower (15.40 ± 3.51 seconds). Comparing age subgroups there was a prolongation of MPT in the healthy group (in groups ≤16 years and >16 years respectively 21.13 seconds versus 25.40 seconds) and a shortening in the anorectic group (≤16 years versus >16 years: 17.06 seconds versus 14.17 seconds). There was no difference between groups A and C up to 16 years of age, but above 16 years of age appeared (14.17 seconds versus 25.40 seconds). Acoustic analysis revealed lower F0 values in group A and C in older subgroups (215,85 Hz versus 236,01 Hz-statistically significant), as well as between subgroups both groups (A: 251,38 Hz versus 215,85 Hz; C: 248,20 Hz versus 236,01 Hz). A narrowing of the vocal range in girls over 16 years in group A was observed. There were no statistically significant differences in F0 between subgroups ≤16 years in groups A and C (251.38 Hz versus 248.20 Hz). The ENT study found that more than half of the girls (54.55%) over the age of 16 who took hormone supplementation manifested laryngeal structure that was normal for their age, there was no effect of hormone supplementation on any of the MDVP parameters between the drug-taking and non-drug-taking groups.

CONCLUSIONS

The acoustic results of the voice in MDVP measurements in adolescent women with AN are not within the normal range and do not mimic the normal developmental changes of the voice. The most important acoustic characteristics of the voice are changes in the fundamental frequency F0 and the range of the voice tended to be more severe in anorectic women >16 years of age and to increase with age, indicating a possible cumulative effect of malnutrition-related disorders as well as hormonal dysfunctions. MDVP can be considered a simple, non-invasive method of assessing the voice organ in AN. MPT differentiated the study groups well: statistically significant differences were noted both between the groups, as well as between age groups. There was no significant effect of oral hormone supplementation on any parameters of the voice. In conclusion, body mass and fat volume in AN may be related to voice production/physiology, affecting voice quality, voice acoustic parameters, voice aerodynamics, and phonatory range in an age-dependent manner. Future studies are needed to assess the long-term efficacy of estrogen treatment in AN.

Habits and Persistent Food Restriction in Patients with Anorexia Nervosa: A Scoping Review

The aetiology of anorexia nervosa (AN) presents a puzzle for researchers. Recent research has sought to understand the behavioural and neural mechanisms of these patients' persistent choice of calorie restriction. This scoping review aims to map the literature on the contribution of habit-based learning to food restriction in AN. PRISMA-ScR guidelines were adopted. The search strategy was applied to seven databases and to grey literature. A total of 35 studies were included in this review. The results indicate that the habit-based learning model has gained substantial attention in current research, employing neuroimaging methods, scales, and behavioural techniques. Food choices were strongly associated with dorsal striatum activity, and habitual food restriction based on the self-report restriction index was associated with clinical impairment in people chronically ill with restricting AN. High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) and Regulating Emotions and Changing Habits (REaCH) have emerged as potential treatments. Future research should employ longitudinal studies to investigate the time required for habit-based learning and analyse how developmental status, such as adolescence, influences the role of habits in the progression and severity of diet-related illnesses. Ultimately, seeking effective strategies to modify persistent dietary restrictions controlled by habits remains essential.

Similarities and differences regarding acute anorexia nervosa and semi-starvation: does behavioral thermoregulation play a central role?

Objective

To clarify the association between acute anorexia nervosa (AN) and semi-starvation (SS) by focusing on similarities and differences in physiology, mood, and behavior.

Method

A comparison of published literature between these two groups.

Results

Both groups show similar hormonal and metabolic changes in response to caloric restriction and extreme weight loss (~25%). Associated changes result in a reduced body temperature (Tcore-low). Maintenance of body temperature within a specific range is crucial to survival. However, both groups cannot activate autonomic strategies to maintain their Tcore-low, such as increasing metabolic rate, constricting skin blood vessels, or shivering. Furthermore, Tcore-low increases the individuals' "coldness sensations" throughout the body, hence the frequent reports from ANs and SSs of "feeling cold." To eliminate these uncomfortable "coldness sensations" and, importantly, to maintain Tcore-low, ANs, and SSs "select" different thermoregulatory behavioral strategies. It is proposed that the primary differences between AN and SS, based on genetics, now manifest due to the "selection" of different thermo-regulatory behaviors. AN patients (ANs) "select" hyperactive behavior (HyAc), which increases internal metabolic heat and thus assists with maintaining Tcore-low; in harmony with hyperactive behavior is a lively mood. Also related to this elevated arousal pattern, ANs experience disrupted sleep. In contrast, SS individuals "select" a passive thermo-behavioral strategy, "shallow torpor," which includes reduced activity, resulting in energy conservation. In addition, this inactivity aids in the retention of generated metabolic heat. Corresponding to this lethargic behavior, SS individuals display a listless mood and increased sleep.

Conclusion

Initial similarities between the two are attributable to physiological changes related to extreme weight loss. Differences are most likely attributable to genetically programmed "selection" of alternate thermoregulatory strategies, primarily to maintain Tcore-low. However, if acute AN is prolonged and evolves into a chronic condition, AN will more closely align with starvation and more precisely reflect SS symptomology.

The relationship between cannabis and anorexia nervosa: a scoping review

BACKGROUND

Relapse rates in Anorexia Nervosa (AN) remain high, warranting exploration of further treatments. Cannabinoid agonists are of interest as they have shown successful outcomes in the treatment of associated conditions, such as post-traumatic stress disorder. This scoping review explores the endocannabinoid system (ECS), benefits/harms/null effects of cannabinoid treatment, and harms of cannabis use in AN.

METHODS

PubMed, PsycINFO, Cochrane, and Web of Science were searched for studies published between 2010 and August 2023, with human participants that explored the ECS, cannabinoid treatment, or cannabis use, and included 1 or more keywords for both cannabis and AN in the title and or abstract. Reports describing secondary anorexia, reports not available in English, grey literature, reports combining data from AN with other conditions, and reports only reporting the prevalence of cannabis abuse/dependence were excluded. Data were extracted from 17 reports (n = 15 studies). For the ECS, outcomes included genetics such as allele expression related to the ECS, cannabinoid receptor availability, and circulating levels of endocannabinoids. For benefits/harms/null effects of cannabinoid treatment, outcomes included changes in weight, eating disorder (ED) symptoms, physical activity (PA), and hormones. For harms of cannabis use, outcomes included genetics related to cannabis use disorder and associations between cannabis use and ED symptoms.

RESULTS

Eight studies (n = 8 reports) found abnormalities in the ECS in AN including expression of related alleles, genotypes, and haplotypes, availability of cannabinoid receptors, and levels of endocannabinoids. Three studies (n = 5 reports) found benefits/harms/null effects of cannabinoid treatment. Benefits included weight gain, improved ED symptoms and reduced PA, while null effects included no changes in weight or ED symptoms, and harms included increased PA and lowered adipose hormones. Four studies (n = 4 reports) expanded upon harms of cannabis use, including genetic predispositions to cannabis use disorder, and compensatory behaviors related to cannabis use.

CONCLUSION

Limited evidence suggests that abnormalities in the ECS in AN may render cannabis a potential treatment for weight restoration and associated symptoms. Future research may wish to investigate individualized dosing approaches to maximize beneficial effects while minimizing harms. Level II Evidence: Scoping Review.

Induction of Activity-Regulated Cytoskeleton-Associated Protein and c-Fos Expression in an Animal Model of Anorexia Nervosa

Anorexia nervosa (AN) is a complex eating disorder characterized by reduced caloric intake to achieve body-weight loss. Furthermore, over-exercise is commonly reported. In recent years, animal models of AN have provided evidence for neuroplasticity changes in specific brain areas of the mesocorticolimbic circuit, which controls a multitude of functions including reward, emotion, motivation, and cognition. The activity-regulated cytoskeleton-associated protein (Arc) is an immediate early gene that modulates several forms of synaptic plasticity and has been linked to neuropsychiatric illness. Since the role of Arc in AN has never been investigated, in this study we evaluated whether the anorexic-like phenotype reproduced by the activity-based anorexia (ABA) model may impact its expression in selected brain regions that belong to the mesocorticolimbic circuit (i.e., prefrontal cortex, nucleus accumbens, and hippocampus). The marker of neuronal activation c-Fos was also assessed. We found that the expression of both markers increased in all the analyzed brain areas of ABA rats in comparison to the control groups. Moreover, a negative correlation between the density of Arc-positive cells and body-weight loss was found. Together, our findings suggest the importance of Arc and neuroplasticity changes within the brain circuits involved in dysfunctional behaviors associated with AN.

Acoustics Features of Voice in Adolescent Females With Anorexia Nervosa

INTRODUCTION

The process of human voice production is a complex physiological and acoustic phenomenon that depends on many structural, physical, and hormonal factors, systemic diseases as well as emotional states. All these factors can be present in eating disorders. However, studies on eating disorders and voice problems have usually been evaluated in terms of bulimia. Chronic starvation and emotional problems in the course of anorexia nervosa (AN) appear to be under-researched, despite various biochemical, metabolic, and hormonal changes.

OBJECTIVE

The purpose of this study was to evaluate voice quality, specifically acoustic analysis, in adolescent female with AN from the point of view of the possible influence on the function and structure of the larynx, low body mass accompanying AN, as well as energy deficiency, hormonal and emotional disturbances.

MATERIALS AND METHODS

A total of 84 girls diagnosed with AN (Gr.A) (15.32 years, SD = 2.12; range 12-19, BMI = 14.11 ± 1.72) were assessed for the condition of the voice such as perceptual voice evaluation on the GRBAS scale, maximal phonation time (MPT), laryngoscopy, with special attention to voice acoustic analysis - Multi-Dimensional Voice Program (MDVP). The control group (Gr.C) included 62 girls without eating disturbances (aged 12-19, mean age 15.41 ± 2.40, BMI = 21.60 ± 1.92). Perceptual voice assessment, aerodynamic test MPT, and acoustic parameters were analyzed according to girls' age.

RESULTS

Total GRBAS scale was higher in girls with AN compared to the control group mainly for two parameters: breathiness (B) (P = 0.00015) and asthenia (A) (P < 0.05). The MPT for Gr.A was significantly shorter compared to Gr.C (15.40 ± 3.51 seconds vs. 23.19 ± 5.17 seconds) (P < 0.001), and a correlation of MPT values with the age of the adolescent female was observed: Spearman's coefficient for Gr.A = (-)0.5378, for Gr.C = 0.5516 (P = 0.0012). Acoustic analysis revealed the decrease in the basic frequency F0 in Gr.A compared to Gr.C (231.08 Hz vs. 242.30 Hz), and narrowing of the voice scale was observed, resulting mainly from a reduction in the upper limit. Significant differences were found for measures of frequency perturbations (Jita, Jitter, RPA, PPQ, sPPR), with Gr.A scoring significantly higher than Gr.C (P < 0.05 for all). Significant changes in voice acoustic analysis parameters were found with age. Negative correlations were found for measures of F0 for Gr.A to a much greater extent compared to Gr.C. Positive correlations were found with measures of tremor assessment (SPI, FTRI, ATRI) for Gr.A.

Disordered eating symptoms as a function of perceived weight status and race: An intersectional examination

Disordered eating (DE) exhibited by individuals with intersecting marginalized identities may be less likely to be perceived as pathological compared to DE exhibited by individuals with non-marginalized identities. The present experiment tested the intersectional impact of weight status and race stimuli on responses to DE in a college sample. Undergraduate students (N = 193, M_age = 18.57, SD = 1.88, 71 % female) read a fictional account from a female target with DE who was described as "underweight," "average weight," or "overweight," and "White" or "Black." Participants completed an in-lab survey assessing detection of and responses to DE. Three 2 (race: Black, White) x 3 (weight status: underweight, average weight, overweight) ANCOVAs revealed a main effect of weight status. DE was more likely to be detected in "underweight" than "average" and "overweight" targets (p < .001). Participants encouraged weight loss for "average" and "overweight" targets compared to "underweight" targets (p < .001) and encouraged weight restoration for "underweight" targets compared to "average weight" and "overweight" targets (p < .001). No significant effects for target race or interaction between weight status and race emerged. These findings underscore the salience of weight status in shaping perceptions of DE.

Affective cognition in eating disorders: a systematic review and meta-analysis of the performance on the "Reading the Mind in the Eyes" Test

BACKGROUND

The Reading the Mind in the Eyes Test (RMET) is listed in the National Institute of Mental Health's Research Domain Criteria as a tool apt to measure the understanding of others' mental states. People diagnosed with anorexia nervosa (AN) showed poorer performances on the RMET than healthy controls. Less data are available concerning other eating disorders.

METHODS

Systematic review of four major databases from inception to July 15, 2021 following the PRISMA guidelines. Meta-analysis of cross-sectional observational studies comparing the scores of the RMET between patients with eating disorders and age- and-gender matched control groups.

RESULTS

Out of 21 studies, we retrieved 29 independent samples of patients diagnosed with an eating disorder. Patients with active AN (n = 580) showed worse performances on the RMET than controls (n = 1019). Year of publication accounted for 61% of the (substantial: I2 = 81%) heterogeneity in the meta-analysis. Earlier studies were more likely to find worse performances on the RMET of patients with active AN than later studies. Patients with bulimia nervosa (n = 185) performed poorly as compared to controls (n = 249), but the results were not statistically significant on the random-effect model. Obese patients with binge-eating disorder (n = 54) did not differ on the RMET from obese controls (n = 52). Patients with eating disorder not otherwise specified (n = 57) showed minimal differences compared to controls (n = 96). Study quality was good in six studies only.

CONCLUSIONS

Patients with eating disorders do not suffer from an impaired understanding of others' mental states, except for a still-to-be-identified subgroup of patients with active AN.

LEVEL OF EVIDENCE

I, systematic review and meta-analysis.

Emergency Department Utilization by Patients With Eating Disorders: A National Population-Based Study

Background There is a scarcity of national United States (U.S) data on emergency department (ED) utilization by patients with eating disorders. This study aims to determine the most common reasons for ED visits of patients with eating disorders, as well as baseline characteristics of patients who present due to eating disorders. Methods We obtained data from the Nationwide Emergency Department Sample (NEDS), the largest all-payer ED database in the United States. Each ED visit in NEDS 2018 can have only one "principal" diagnosis, which is the main reason for the visit and up to 34 "secondary" diagnoses. We abstracted data for all ED visits with "any" diagnosis of an eating disorder, using the ICD-10 code "F50". We highlighted the 10 most common "principal" diagnoses based on the organ system involved and the 10 most specific "principal" diagnoses for all ED visits by patients with any diagnosis of eating disorder. We then highlighted baseline characteristics of ED visits with a "principal" diagnosis of an eating disorder. Results There were a total of 56,901 ED visits for patients with eating disorders in 2018. Among these, 7,979 had an eating disorder as the "principal" diagnosis. Patients who visited the ED principally for eating disorders were more likely to be young females and came from higher-income households; about a third were admitted with 22.1 million U.S. dollars in aggregate ED charges. Mental disorders, and injuries and poisoning were the most common principal diagnosis by organ system categories, while eating disorders, major depression disorder (MDD), hypokalemia, and dehydration are common specific reasons for ED visits among patients with eating disorders. Conclusions Eating disorders, and its medical complications and psychiatric comorbidities such as MDD are common reasons for ED visits among patients with eating disorders. Management of the underlying eating disorder and their psychiatric comorbidities through a multidisciplinary approach in the outpatient setting is invaluable in reducing ED utilization by these patients.

Efficacy and safety of antipsychotics and antidepressants in the treatment of anorexia nervosa: a systematic review

INTRODUCTION

The recommendations of the current guidelines are based on low quality evidence. Periodic updating is required, taking recent evidence into consideration.

OBJECTIVE

To synthesise the best available clinical evidence on the efficacy and safety of second-generation antidepressants and antipsychotics in patients with anorexia nervosa.

METHODS

Systematic review (CRD42020150577). We searched PubMed, SCOPUS, Ovid(Cochrane), EMBASE and LILACS for randomised clinical trials performed in patients with anorexia nervosa that evaluated the use of second-generation antipsychotics or oral antidepressants, at any dose and for any length of time, in outpatient and/or hospital treatment, taking weight (body mass index), psychopathological entities and safety as results.

RESULTS

Five studies were included, with four assessed as having a high risk of bias. The evidence indicates that patients receiving treatment with olanzapine or fluoxetine tend to stay in treatment programmes for longer. Olanzapine showed favourable results (one study) in terms of weight gain, but did not show the same results in psychopathology, where the evidence is contradictory.

CONCLUSIONS

In accordance with previous reviews, our work allows us to conclude that there is contradictory information on the efficacy of psychotropic drugs in the treatment of anorexia nervosa. Future work should focus on developing clinical trials of high methodological quality.

Genetics and neurobiology of eating disorders

Eating disorders (anorexia nervosa, bulimia nervosa and binge-eating disorder) are a heterogeneous class of complex illnesses marked by weight and appetite dysregulation coupled with distinctive behavioral and psychological features. Our understanding of their genetics and neurobiology is evolving thanks to global cooperation on genome-wide association studies, neuroimaging, and animal models. Until now, however, these approaches have advanced the field in parallel, with inadequate cross-talk. This review covers overlapping advances in these key domains and encourages greater integration of hypotheses and findings to create a more unified science of eating disorders. We highlight ongoing and future work designed to identify implicated biological pathways that will inform staging models based on biology as well as targeted prevention and tailored intervention, and will galvanize interest in the development of pharmacologic agents that target the core biology of the illnesses, for which we currently have few effective pharmacotherapeutics.

Brain networks in eating disorders: a systematic review of graph theory studies

PURPOSE

Recent evidence from neuroimaging research has shown that eating disorders (EDs) are characterized by alterations in interconnected neural systems, whose characteristics can be usefully described by connectomics tools. The present paper aimed to review the neuroimaging literature in EDs employing connectomic tools, and, specifically, graph theory analysis.

METHODS

A systematic review of the literature was conducted to identify studies employing graph theory analysis on patients with eating disorders published before the 22nd of June 2020.

RESULTS

Twelve studies were included in the systematic review. Ten of them address anorexia nervosa (AN) (AN = 199; acute AN = 85, weight recovered AN with acute diagnosis = 24; fully recovered AN = 90). The remaining two articles address patients with bulimia nervosa (BN) (BN = 48). Global and regional unbalance in segregation and integration properties were described in both disorders.

DISCUSSION

The literature concerning the use of connectomics tools in EDs evidenced the presence of alterations in the topological characteristics of brain networks at a global and at a regional level. Changes in local characteristics involve areas that have been demonstrated to be crucial in the neurobiology and pathophysiology of EDs. Regional imbalances in network properties seem to reflect on global patterns.

LEVEL OF EVIDENCE

Level I, systematic review.

Subjective Experience of Antidepressant Prescription Among Adolescents With Anorexia Nervosa

INTRODUCTION

Major depressive disorder is considered the most common comorbidity of anorexianervosa in adolescence. Some evidence argues against antidepressant use in this population. Moreover, the fear of being threatened with autonomy and of becoming dependent specific to this adolescent population and at the very core of the anorexic disease, make the proposal of such a treatment difficult to accept. This qualitative research aimed to explore the perspectives of view of adolescents with anorexia nervosa about antidepressants.

METHODS

We conducted interviews with adolescents suffering from anorexia nervosa who had been treated with an antidepressant agent during their inpatient or outpatient care at Cochin Hospital. Adolescents were chosen by convenience sampling. Both verbal and written questions were asked to elicit their lived experiences. Interpretative Phenomenological Analysis was used to examine the data.

RESULTS

Fifteen adolescents (13 girls and two boys) were interviewed. We have reached total data saturation. The analysis found two meta-themes, each with two separate themes. (I) Reactions to the proposal of antidepressant with (i) an opposition phase (about the existence of depressive symptoms and about negative preconceptions) and (ii) need to share with family and other teenagers. (II) Reactions to antidepressant use with (iii) ambivalence and an initial perception of coercion, and (iv) effects of antidepressants (psychological effects, effects on the body and on anorexia nervosa and effects perceived through the eyes of others).

DISCUSSION

Despite positive effects, ambivalence toward the treatment remained present throughout the interviews: these adolescents still worry greatly about loss of control and weight gain. Depression as comorbidity seems to be entangled in the denial of disease, cognitive distortion and acquired fearlessness specific to AN. Its existence in adolescence can uncover transgenerational issues, sometimes previously hidden. An orodispersible/drinkable form of antidepressants would facilitate adherence to treatment in this specific population. The intervention of a "patient-expert" could reduce adolescents' anxiety about loss of control. A latency period seems necessary to allow them to understand the prescription at their own level and in the complexity of their anorexic illness.

Temperament-based treatment for young adults with eating disorders: acceptability and initial efficacy of an intensive, multi-family, parent-involved treatment

BACKGROUND

Adult eating disorder treatments are hampered by lack of access and limited efficacy. This open-trial study evaluated the acceptability and preliminary efficacy of a novel intervention for adults with eating disorders delivered to young adults and parent-supports in an intensive, multi-family format (Young Adult Temperament-Based Treatment with Supports; YA-TBT-S).

METHODS

38 YA-TBT-S participants (m age = 19.58; SD 2.13) with anorexia nervosa (AN)-spectrum disorders, bulimia nervosa (BN)-spectrum disorders, and avoidant/restrictive food intake disorder (ARFID) completed self-report assessments at admission, discharge, and 12-month follow-up. Assessments measured program satisfaction, eating disorder psychopathology and impairment, body mass index (BMI), and trait anxiety. Outcomes were analyzed using linear mixed effects models to examine changes in outcome variables over time.

RESULTS

Treatment was rated as highly satisfactory. 53.33% were in partial or full remission at 12-month follow-up. 56% of participants received other treatment within the 12-month follow-up period, suggesting that YA-TBT-S may be an adjunctive treatment. Participants reported reductions in ED symptomatology (AN and BN), increases in BMI (AN and ARFID), and reductions in clinical impairment (AN and ARFID) at 12-month follow-up.

CONCLUSIONS

YA-TBT-S is a feasible and acceptable adjunctive treatment for young adults with a broad range of ED diagnoses and may be a method for involving parents in ED treatment in ways that are acceptable to both parents and YA. Further evaluation of efficacy is needed in larger samples, and to compare YA-TBT-S to other ED treatment approaches. Plain English summary Eating disorders are costly and dangerous psychiatric disorders that affect millions of individuals each year. Despite their risks and societal costs, currently available treatments are limited. This study examined the acceptability and efficacy of Young Adult, Temperament-Based Treatment with Supports (YA-TBT-S), a new treatment program for adults with eating disorders. YA-TBT-S was rated highly, and a significant portion of participants improved based on ratings collected 12 months after program participation. Those with anorexia nervosa (AN) and bulimia nervosa (BN) showed significant reductions in eating disorder pathology, and those with AN and avoidant/restrictive food intake disorder (ARFID) showed increases in BMI over time.

Prevention of diet restriction induced hyperactivity but not body-weight reduction in rats co-treated with tryptophan: relationship with striatal serotonin and dopamine metabolism and serotonin-1A auto-receptor expression

Anorexia Nervosa (AN) is an eating and behavioral disorder characterized with anxiety/depression, hyperactivity, behavioral impulsivity and psychosis. Most of the associated symptoms are related to the deficiency of serotonin (5-hydroxytryptamine: 5-HT) stores. A deficiency of 5-HT can modulate dopamine neurotransmission in the striatum to elicit hyperactivity and psychosis in AN patients. Also, the release and availability of 5-HT are modulated by serotonin-1A (5-HT1A) auto-receptor. The present study investigates the role of striatal metabolism of 5-HT and dopamine in precipitating hyperactivity in the rat model of diet restriction (DR) induced AN. The role of tryptophan (Trp) in influencing the 5-HT metabolism and the mRNA expression of 5-HT1A auto-receptor is also investigated. We find that long-term DR for 38 days reduces body-weight in rats and produces hyperactivity, similar to AN. This hyperactivity is characterized by declined striatal metabolism of both, dopamine and 5-HT. The mRNA expression of 5-HT1A auto-receptor in the raphe nuclei is also decreased. Trp co-treatment improves these deficiencies in monoamine metabolism and alleviates hyperactivity. Interestingly, DR-induced changes in body-weights are not effected by Trp co-treatment. The study suggests that the striatal metabolism of 5-HT and dopamine and mRNA expression of 5-HT1A auto-receptor has an important role in the pathogenesis of AN. The finding suggests that co-use of Trp can prevent precipitation of AN by normalizing 5-HT metabolism.

Cortical thinning and associated connectivity changes in patients with anorexia nervosa

Structural brain abnormalities are a consistent finding in anorexia nervosa (AN) and proposed as a state biomarker of the disorder. Yet little is known about how regional structural changes affect intrinsic resting-state functional brain connectivity (rsFC). Using a cross-sectional, multimodal imaging approach, we investigated the association between regional cortical thickness abnormalities and rsFC in AN. Twenty-two acute AN patients and twenty-six age- and gender-matched healthy controls underwent a resting-state functional magnetic resonance imaging scan and cognitive tests. We performed group comparisons of whole-brain cortical thickness, seed-based rsFC, and network-based statistical (NBS) analyses. AN patients showed cortical thinning in the precuneus and inferior parietal lobules, regions involved in visuospatial memory and imagery. Cortical thickness in the precuneus correlated with nutritional state and cognitive functions in AN, strengthening the evidence for a critical role of this region in the disorder. Cortical thinning was accompanied by functional connectivity reductions in major brain networks, namely default mode, sensorimotor and visual networks. Similar to the seed-based approach, the NBS analysis revealed a single network of reduced functional connectivity in patients, comprising mainly sensorimotor- occipital regions. Our findings provide evidence that structural and functional brain abnormalities in AN are confined to specific regions and networks involved in visuospatial and somatosensory processing. We show that structural changes of the precuneus are linked to nutritional and functional states in AN, and future longitudinal research should assess how precuneus changes might be related to the evolution of the disorder.

Altered habenula to locus coeruleus functional connectivity in past anorexia nervosa suggests correlation with suicidality: a pilot study

PURPOSE

Despite anorexia nervosa having the highest mortality rate of mental illnesses, little is known regarding the brain mechanisms involved. Given that lack of interest for food in anorexic patients is related to alterations in the reward system, we tested the hypothesis that patients with past anorexia nervosa (pAN) have altered resting state functional connectivity (RSFC) between the habenula (a major component of the reward system) and its targets.

METHODS

RSFC between the habenula and major targets (locus coeruleus, median and dorsal raphe nuclei, substantia nigra, and ventral tegmental area) was studied in 14 psychiatric inpatients with pAN and 14 psychiatric inpatient controls (PC, never-anorexic patients in same clinic, matched for comorbidities). Next, we tested possible correlations between RSFC and suicidal ideation, depression, and anxiety as determined by self-report questionnaires.

RESULTS

Left habenula/locus coeruleus RSFC was lower in pAN patients compared to PC. The left habenula/locus coeruleus RSFC was positively correlated with suicidal ideation (past 2 months) in pAN patients, but not in controls.

CONCLUSIONS

pAN patients showed long lasting alterations in habenular connectivity. This may have clinical implications, possibly including future evaluation of the habenula as a therapeutic target and the need to carefully monitor suicidality in pAN patients.

NO LEVEL OF EVIDENCE

Basic science.

Development and evaluation of an adapted physical activity program in anorexia nervosa inpatients: A pilot study

BACKGROUND AND CONTEXT

Problematic use of physical activity is frequent in subjects with anorexia nervosa (AN). Although it increases resistance to therapeutic treatment, paradoxically, physical activity in AN can also improve mental and physical health. Based on the literature review we hypothesized that adding an adapted physical activity (APA) program to treatment programs could be more beneficial than a total suppression of physical activities. We designed this open study to evaluate the outcome of AN inpatients after an APA program implementation as well as the perceived effect of APA.

METHOD

Forty-one women with AN (17.2 (±2.5) years old, BMI of 16.86 (±2.0)) were included. An eight-session (1 h30/session/week) standardized APA program was delivered and evaluated by structured questionnaires assessing exercise dependence, perceived physical activity, eating disorder (ED) symptoms, body mass index (BMI), along with an interview before and after the APA program.

RESULTS

Twenty-nine women complete the PA program and evaluation. BMI and perceived PA score significantly increased, ED and exercise dependence scores significantly decreased (p < .01). Participants appreciated the program.

DISCUSSION/CONCLUSION

The inpatient program which included APA program helped AN inpatients in decreasing their ED symptoms and their dependence to PA, without any deleterious effect on BMI. Furthermore, APA was appreciated by participants.

A virtual issue highlighting animal studies of eating disorders as valuable tools for examining neurobiological underpinnings and treatment of eating disorders

While studies in humans suggest a role for psychosocial factors as well as biological and genetic processes in the development of eating disorders, the specific etiologic mechanisms remain largely unknown. In this virtual issue, we present a collection of 14 archived articles from the International Journal of Eating Disorders to highlight the utility of animal studies of eating disorders to advance our understanding of eating disorder etiology. Selected articles establish animal studies as valid tools to study disordered eating behavior, offer insight into potential neurobiological mechanisms, and highlight novel targets for future pharmacological treatments. Clinical implications of each article's findings are included to demonstrate the translational value of animal studies for the eating disorders field. We hope that the exciting concepts and findings in this issue inspire future animal studies of eating disorders.

Integrative Genomic Enrichment Analysis Identified the Brain Regions and Development Stages Related to Anorexia Nervosa and Obsessive-Compulsive Disorder

Our aim is to explore the spatial and temporal features of anorexia nervosa (AN) and obsessive-compulsive disorder (OCD) considering different brain regions and development stages. The gene sets related to 16 brain regions and nine development stages were obtained from a brain spatial and temporal transcriptomic dataset. Using the genome-wide association study data, transcriptome-wide association study (TWAS) was conducted to identify the genes whose imputed expressions were associated with AN and OCD, respectively. The mRNA expression profiles were analyzed by GEO2R to obtain differentially expressed genes. Gene set enrichment analysis was conducted to detect the spatial and temporal features related to AN and OCD using the TWAS and mRNA expression analysis results. We observed multiple common association signals shared by TWAS and mRNA expression analysis of AN, such as the primary auditory cortex vs. cerebellar cortex in fetal development and earlier vs. later fetal development in the somatosensory cortex. For OCD, we also detected multiple common association signals, such as medial prefrontal cortex vs. amygdala in adulthood and fetal development vs. infancy in mediodorsal nucleus of thalamus. Our study provides novel clues for describing the spatial and temporal features of brain development in the pathogenesis of AN and OCD.

The effect of repetitive transcranial magnetic stimulation on food choice-related self-control in patients with severe, enduring anorexia nervosa

OBJECTIVE

Individuals with anorexia nervosa (AN) pursue low-fat, low-calorie diets even when in a state of emaciation. These maladaptive food choices may involve fronto-limbic circuitry associated with cognitive control, habit, and reward. We assessed whether high-frequency repetitive transcranial magnetic stimulation (rTMS) to the left dorsolateral prefrontal cortex (DLPFC) influenced food-related choice behavior in patients with severe, enduring (SE)-AN.

METHOD

Thirty-four females with SE-AN completed a Food Choice Task before and after 20 sessions of real or sham rTMS treatment and at a 4-month follow-up. During the task, participants rated high- and low-fat food items for healthiness and tastiness and then made a series of choices between a neutral-rated food and high- and low-fat foods. Outcomes included the proportion of high-fat and self-controlled choices made. A comparison group of 30 healthy women completed the task at baseline only.

RESULTS

Baseline data were consistent with previous findings: relative to healthy controls, SE-AN participants showed a preference for low-fat foods and exercised self-control on a greater proportion of trials. There was no significant effect of rTMS treatment nor time on food choices related to fat content. However, among SE-AN participants who received real rTMS, there was a decrease in self-controlled food choices at post-treatment, relative to baseline. Specifically, there was an increase in the selection of tasty-unhealthy foods.

DISCUSSION

In SE-AN, rTMS may promote more flexibility in relation to food choice. This may result from neuroplastic changes in the DLPFC and/or in associated brain areas.

Genetic and epigenetic findings in anorexia nervosa

Polygenic factors are relevant for the genetic predispositions to the eating disorder anorexia nervosa (AN). The most recent genome-wide association study (GWAS) for AN comprised almost 17,000 patients with AN and controls. A total of eight genome-wide significant polygenic loci associated with AN have been identified. Each single polygenic locus makes only a small contribution to the development of AN. Analyses across different traits successfully identified regions/genes for AN that had not been detected by analyses of the single traits. Functional studies of the genes derived by GWAS studies aim to improve the understanding of the biological mechanisms involved in eating disorders. Epigenetic studies have not yet successfully contributed to the understanding of AN.

Moving towards specificity: A systematic review of cue features associated with reward and punishment in anorexia nervosa

Models of anorexia nervosa (AN) posit that symptoms are maintained through deficient reward and enhanced punishment processing. However, theoretical and empirical inconsistencies highlight the need for a more nuanced conceptualization of this literature. Our goal was to comprehensively review the research on reward and punishment responding in AN from a cue-specific lens to determine which stimuli evoke or discourage reward and punishment responses in this population, and, ultimately, what properties these rewarding and punishing cues might share. A systematic review interrogating reward and punishment responses to specific cues yielded articles (n = 92) that examined responses to disorder relevant (e.g., food) and irrelevant (e.g., money) stimuli across self-report, behavioral, and biological indices. Overall, in most studies individuals with AN exhibited aversive responses to cues signaling higher body weights, social contexts, and monetary losses, and appetitive responses to cues for weight loss behaviors and thinness. Findings were more mixed on responses to palatable food and monetary gains. Results highlight that reward and punishment responding in AN are context specific and may be affected by varied stimulus qualities (e.g., predictability, controllability, delay, effort). Increasing specificity in future research on reward and punishment mechanisms in AN will better inform development of precisely-targeted interventions.

Functional Connectivity Patterns and the Role of 5-HTTLPR Polymorphism on Network Architecture in Female Patients With Anorexia Nervosa

Introduction

Recent neuroimaging studies suggest that anorexia nervosa (AN) symptoms emerge from failures in the relationships between spatially distributed networks that support different cognitive, emotional, and somatosensory functions. The 5-HTTLPR genotype has been shown to modulate all these abilities in AN, as well as the connectivity patterns between brain regions that support their functioning. This study aims at exploring the presence of any difference in functional connectome properties between AN patients and healthy controls (HC) by means of graph theory tools. The effect of 5-HTTLPR genotype on regional and global network characteristics in AN and HC was also explored.

Methods

A sample of 74 subjects (38 HC, 36 AN) underwent a resting state functional magnetic resonance imaging and was genotyped for 5-HTTLPR polymorphism. Comparisons of network properties were made between the AN and HC groups and, within each group, between 5-HTTLPR carriers of low-functioning alleles and carriers of the long–long genotype.

Results

Patients with AN displayed lower network clustering than HC (p = 0.04 at Mann–Whitney U test). Based on both degree and betweenness, a different distribution of network hubs emerged in the two groups. In particular, the anterior part of the anterior cingulate cortex was a hub only in the patient group. A correlation emerged between differences in brain volumes between patients and HC and differences in degree values of basal ganglia, nodes in the insula, and those in the parietal cortex. Carriers of the short allele of the 5-HTTLPR polymorphism were characterized by lower small-world properties (p = 0.027) and modularity (p = 0.031) in the patient group, and a trend toward higher modularity (p = 0.033) and small-world values (p = 0.123) in the HC group.

Discussion

Patients with AN showed differences in hubs distribution, providing evidence of the presence of a different functional architectural backbone in this group. Since some correlation emerged between different degree values of nodes and differences in volumes, further longitudinal studies are warranted to better understand the role of malnutrition on brain network architecture. The opposite effects of 5-HTTLPR polymorphism on global network characteristics in the two groups suggest an interaction of the short allele and malnutrition in modulating brain network properties.