Ghrelin and PYY in low-weight females with avoidant/restrictive food intake disorder compared to anorexia nervosa and healthy controls

Lower region-specific gray matter volume in females with atypical anorexia nervosa and anorexia nervosa

OBJECTIVE

Few studies have focused on brain structure in atypical anorexia nervosa (atypical AN). This study investigates differences in gray matter volume (GMV) between females with anorexia nervosa (AN) and atypical AN, and healthy controls (HC).

METHOD

Structural magnetic resonance imaging data were acquired for 37 AN, 23 atypical AN, and 41 HC female participants. Freesurfer was used to extract GMV, cortical thickness, and surface area for six brain lobes and associated cortical regions of interest (ROI). Primary analyses employed linear mixed-effects models to compare group differences in lobar GMV, followed by secondary analyses on ROIs within significant lobes. We also explored relationships between cortical gray matter and both body mass index (BMI) and symptom severity.

RESULTS

Our primary analyses revealed significant lower GMV in frontal, temporal and parietal areas (FDR < .05) in AN and atypical AN when compared to HC. Lobar GMV comparisons were non-significant between atypical AN and AN. The parietal lobe exhibited the greatest proportion of affected cortical ROIs in both AN versus HC and atypical AN versus HC. BMI, but not symptom severity, was found to be associated with cortical GMV in the parietal, frontal, temporal, and cingulate lobes. No significant differences were observed in cortical thickness or surface area.

DISCUSSION

We observed lower GMV in frontal, temporal, and parietal areas, when compared to HC, but no differences between AN and atypical AN. This indicates potentially overlapping structural phenotypes between these disorders and evidence of brain changes among those who are not below the clinical underweight threshold.

PUBLIC SIGNIFICANCE

Despite individuals with atypical anorexia nervosa presenting above the clinical weight threshold, lower cortical gray matter volume was observed in partial, temporal, and frontal cortices, compared to healthy individuals. No significant differences were found in cortical gray matter volume between anorexia nervosa and atypical anorexia nervosa. This underscores the importance of continuing to assess and target weight gain in clinical care, even for those who are presenting above the low-weight clinical criteria.

Co-existing mental and somatic conditions in Swedish children with the avoidant restrictive food intake disorder phenotype

Background

Avoidant restrictive food intake disorder (ARFID) is a feeding and eating disorder, characterized by limited variety and/or quantity of food intake impacting physical health and psychosocial functioning. Children with ARFID often present with a range of psychiatric and somatic symptoms, and therefore consult various pediatric subspecialties; large-scale studies mapping comorbidities are however lacking. To characterize health care needs of people with ARFID, we systematically investigated ARFID-related mental and somatic conditions in 616 children with ARFID and >30,000 children without ARFID.

Methods

In a Swedish twin cohort, we identified the ARFID phenotype in 6-12-year-old children based on parent-reports and register data. From >1,000 diagnostic ICD-codes, we specified mental and somatic conditions within/across ICD-chapters, number of distinct per-person diagnoses, and inpatient treatment days between birth and 18th birthday (90 outcomes). Hazard ratios (HR) and incidence rate ratios (IRR) were calculated.

Findings

Relative risks of neurodevelopmental, gastrointestinal, endocrine/metabolic, respiratory, neurological, and allergic disorders were substantially increased in ARFID (e.g., autism HR[CI95%]=9.7[7.5-12.5], intellectual disability 10.3[7.6-13.9], gastroesophageal reflux disease 6.7[4.6-9.9], pituitary conditions 5.6[2.7-11.3], chronic lower respiratory diseases 4.9[2.4-10.1], epilepsy 5.8[4.1-8.2]). ARFID was not associated with elevated risks of autoimmune illnesses and obsessive-compulsive disorder. Children with ARFID had a significantly higher number of distinct mental diagnoses (IRR[CI95%]=4.7[4.0-5.4]) and longer duration of hospitalizations (IRR[CI95%]=5.5[1.7-17.6]) compared with children without ARFID. Children with ARFID were diagnosed earlier with a mental condition than children without ARFID. No sex-specific differences emerged.

Interpretation

This study yields the broadest and most detailed evidence of co-existing mental and somatic conditions in the largest sample of children with ARFID to date. Findings suggest a complex pattern of health needs in youth with ARFID, underscoring the critical importance of attention to the illness across all pediatric specialties.

Funding

Fredrik and Ingrid Thurings Foundation, Mental Health Foundation.

Clinical characteristics, treatment course and outcome of adults treated for avoidant/restrictive food intake disorder (ARFID) at a tertiary care eating disorders program

BACKGROUND

Avoidant/restrictive food intake disorder (ARFID) is now recognized as a feeding/eating disorder that affects individuals across the lifespan, but research on ARFID in general and particularly in adults remains limited. The purpose of this study was to describe the demographic and clinical characteristics of adults with ARFID seeking treatment at a tertiary care eating disorders program, and to describe the course and outcomes of treatment at three levels of care-inpatient, intensive outpatient, and outpatient individual therapy.

METHOD

This retrospective chart review study examined the charts of 42 patients who received treatment for ARFID between April 2020 and March 2023. Following diagnostic assessment, patients were referred to either inpatient treatment, intensive outpatient treatment, or outpatient individual therapy. All three levels of care involved individual cognitive behaviour therapy. Inpatients typically transitioned to one of the outpatient treatments as part of a continuous care plan. We examined demographic and clinical characteristics, treatment length and completion, and changes in key indicators during treatment.

RESULTS

Patients were diverse with respect to demographics (e.g., 62% cisgender women; 21% cisgender men; 17% transgender, non-binary, or other gender) and comorbid concerns (e.g., 43% had neurodevelopmental disorders; > 50% had mood and anxiety disorders; 40% had posttraumatic stress disorder [PTSD]; 35% had medical conditions impacting eating/digestion). Most patients presented with more than one ARFID maintaining mechanism (i.e., lack of appetite/interest, sensory sensitivities, and/or fear of aversive consequences of eating). Treatment completion rates and outcomes were good. On average, patients showed significant improvement in impairment related to their eating disorder, and those who were underweight significantly improved on BMI and were not underweight at end of treatment.

DISCUSSION

These findings add to the literature by indicating that ARFID patients are commonly male or have diverse gender identities, and have high rates of neurodevelopmental, mood, anxiety, and gastrointestinal disorders. We also found high rates of PTSD. The findings show promise for treatment outcomes across the continuum of care. Next steps in ARFID treatment and research include incorporating ARFID-specific assessments into routine care, and ongoing research investigating the efficacy and effectiveness of treatments such as CBT-AR.

The buffet challenge: a behavioral assessment of eating behavior in adolescents with an eating disorder

OBJECTIVE

Eating disorders are characterized by disturbances in nutritional intake and abnormal mealtime behaviors. Laboratory eating paradigms offer a unique opportunity to accurately measure dietary intake and eating behaviors, however, these studies have predominantly occurred in adults. This paper describes the development and preliminary psychometric examination of the Buffet Challenge, a laboratory-based meal task for youths with an eating disorder.

METHOD

We recruited and assessed 56 participants as part of a randomized controlled trial of Family-Based Treatment for adolescents with anorexia nervosa. Adolescents completed the Buffet Challenge at baseline, midway through treatment (~ week 16 of a 6 months course), and end of treatment. Participants and their parents also reported eating disorder symptomatology and treatment related variables of interest were recorded.

RESULTS

All adolescents were willing to complete the Buffet Challenge at all time points, although one refused to give up their cellphone, and there were no significant adverse events recorded. Preliminary results are presented.

CONCLUSIONS

Our initial pilot of this task in adolescents with anorexia nervosa demonstrates its acceptability, although investigation of our hypotheses was hindered by significant missing data due to COVID-related research shutdowns. Future studies should replicate procedures in a larger sample to ensure analyses are adequately powered.

Prevalence, characteristics, and correlates of probable avoidant/restrictive food intake disorder among adult respondents to the National Eating Disorders Association online screen: a cross-sectional study

BACKGROUND

Avoidant/restrictive food intake disorder (ARFID) is a serious, albeit under-researched, feeding or eating disorder. This exploratory study utilized data from adult respondents to the National Eating Disorders Association online eating disorder screen to validate items assessing the presence of ARFID and examine the prevalence, clinical characteristics, and correlates of a positive ARFID screen.

METHODS

Among 50,082 adult screen respondents between January 2022 and January 2023, the prevalence of a positive ARFID screen was calculated. Chi-square tests and t-tests compared demographics, eating disorder attitudes and behaviors, suicidal ideation, current eating disorder treatment status, and eating disorder treatment-seeking intentions between respondents with possible ARFID and other eating disorder diagnostic and risk categories. Clinical characteristics of respondents with possible ARFID were also examined.

RESULTS

2378 (4.7%) adult respondents screened positive for ARFID. Respondents with possible ARFID tended to be younger, male, and have lower household income, and were less likely to be White and more likely to be Hispanic/Latino than most other diagnostic/risk groups. They had lower weight/shape concerns and eating disorder behaviors than most other diagnoses and higher BMI than those with AN. 35% reported suicidal ideation, 47% reported intentions to seek treatment for an eating disorder, and 2% reported currently being in treatment. The most common clinical feature of ARFID was lack of interest in eating (80%), followed by food sensory avoidance (55%) and avoidance of food due to fear of aversive consequences (31%).

CONCLUSIONS

Findings from this study indicated that ARFID was prevalent among adult screen respondents and more common among individuals who were younger, male, non-White, Hispanic, and lower income relative to those with other eating disorders, at risk for an eating disorder, or at low risk. Individuals with possible ARFID frequently reported suicidal ideation and were rarely in treatment for an eating disorder. Further research is urgently needed to improve advances in the assessment and treatment of ARFID and improve access to care in order to prevent prolonged illness duration.

Endocrinology of Underweight and Anorexia Nervosa

More than any other mental illness, the course, prognosis, and therapy of anorexia nervosa are shaped by the physical changes associated with being underweight. This article provides an overview of the endocrine changes associated with malnutrition and underweight. This overview serves as a basis for understanding the other articles in this special issue, which deal with the health risks associated with being underweight. In this context, the differences between underweight in anorexia nervosa and in constitutional thinness are of particular importance in assessing the impact of intentional weight loss. In this context, the regulation of hunger and satiety deserves special interest, as this is the area in which the intentional influence on body weight comes into play. Clinical consequences on, for example, fertility, bone metabolism, the homeostasis of, for example, serum glucose levels, or body temperature have been observed for a long time; nonetheless, the medical responses, apart from vitamin supplementations and advice to gain weight, are still limited. Therefore, emphasis was placed on the potential improvement of outcomes through the administration of central or peripheral hormones. Studies were identified on PubMed via a selection of relevant keywords; original texts that were cited in reviews were studied where it was advantageous. This review found some promising data on bone health and the administration of transdermal oestrogen, which is not yet widely used, as well as distinct hormonal markers to differentiate between CT and AN. We concluded that the continuous efforts to investigate the role of endocrinology in underweight and/or anorexia nervosa lead to outcome benefits and that more and higher-powered studies are needed.

Oxytocin response to food intake in avoidant/restrictive food intake disorder

OBJECTIVE

To investigate the response of anorexigenic oxytocin to food intake among adolescents and young adults with avoidant/restrictive food intake disorder (ARFID), a restrictive eating disorder characterized by lack of interest in food or eating, sensory sensitivity to food, and/or fear of aversive consequences of eating, compared with healthy controls (HC).

DESIGN

Cross-sectional.

METHODS

A total of 109 participants (54 with ARFID spectrum and 55 HC) were instructed to eat a ∼400-kcal standardized mixed meal. We sampled serum oxytocin at fasting and at 30-, 60-, and 120-min postmeal. We tested the hypothesis that ARFID would show higher mean oxytocin levels across time points compared with HC using a mixed model ANOVA. We then used multivariate regression analysis to identify the impact of clinical characteristics (sex, age, and body mass index [BMI] percentile) on oxytocin levels in individuals with ARFID.

RESULTS

Participants with ARFID exhibited greater mean oxytocin levels at all time points compared with HC, and these differences remained significant even after controlling for sex and BMI percentile (P = .004). Clinical variables (sex, age, and BMI percentile) did not show any impact on fasting and postprandial oxytocin levels among individuals with ARFID.

CONCLUSIONS

Consistently high oxytocin levels might be involved in low appetite and sensory aversions to food, contributing to food avoidance in individuals with ARFID.

Low bone mineral density is found in low weight female youth with avoidant/restrictive food intake disorder and associated with higher PYY levels

BACKGROUND

Avoidant/restrictive food intake disorder (ARFID) is a restrictive eating disorder commonly associated with medical complications of undernutrition and low weight. In adolescence, a critical time for bone accrual, the impact of ARFID on bone health is uncertain. We aimed to study bone health in low-weight females with ARFID, as well as the association between peptide YY (PYY), an anorexigenic hormone with a role in regulation of bone metabolism, and bone mineral density (BMD) in these individuals. We hypothesized that BMD would be lower in low-weight females with ARFID than healthy controls (HC), and that PYY levels would be negatively associated with BMD.

METHODS

We performed a cross-sectional study in 14 adolescent low-weight females with ARFID and 20 HC 10-23 years old. We assessed BMD (total body, total body less head and lumbar spine) using dual x-ray absorptiometry (DXA) and assessed fasting total PYY concentration in blood.

RESULTS

Total body BMD Z-scores were significantly lower in ARFID than in HC (- 1.41 ± 0.28 vs. - 0.50 ± 0.25, p = 0.021). Mean PYY levels trended higher in ARFID vs. HC (98.18 ± 13.55 pg/ml vs. 71.40 ± 5.61 pg/ml, p = 0.055). In multivariate analysis within the ARFID group, PYY was negatively associated with lumbar BMD adjusted for age (β = -0.481, p = 0.032).

CONCLUSION

Our findings suggest that female adolescents with low-weight ARFID may have lower BMD than healthy controls and that higher PYY levels may be associated with lower BMD at some, but not all, sites in ARFID. Further research with larger samples will be important to investigate whether high PYY drives bone loss in ARFID.

Neural activation of regions involved in food reward and cognitive control in young females with anorexia nervosa and atypical anorexia nervosa versus healthy controls

Anorexia nervosa (AN) and atypical AN (AtypAN) are complex neurobiological illnesses that typically onset in adolescence with an often treatment-refractory and chronic illness trajectory. Aberrant eating behaviors in this population have been linked to abnormalities in food reward and cognitive control, but prior studies have not examined respective contributions of clinical characteristics and metabolic state. Research is needed to identify specific disruptions and inform novel intervention targets to improve outcomes. Fifty-nine females with AN (n = 34) or AtypAN (n = 25), ages 10-22 years, all ≤90% expected body weight, and 34 age-matched healthy controls (HC) completed a well-established neuroimaging food cue paradigm fasting and after a standardized meal, and we used ANCOVA models to investigate main and interaction effects of Group and Appetitive State on blood oxygenation level-dependent (BOLD) activation for the contrast of exposure to high-calorie food images minus objects. We found main effects of Group with greater BOLD activation in the dorsal anterior cingulate cortex (dACC), dorsolateral prefrontal cortex (DLPFC), hippocampus, caudate, and putamen for AN/AtypAN versus HC groups, and in the three-group model including AN, AtypAN, and HC (sub-)groups, where differences were primarily driven by greater activation in the AtypAN subgroup versus HC group. We found a main effect of Appetitive State with increased premeal BOLD activation in the hypothalamus, amygdala, nucleus accumbens, and caudate for models that included AN/AtypAN and HC groups, and in BOLD activation in the nucleus accumbens for the model that included AN, AtypAN, and HC (sub-)groups. There were no interaction effects of Group with Appetitive State for any of the models. Our findings demonstrate robust feeding-state independent group effects reflecting greater neural activation of specific regions typically associated with reward and cognitive control processing across AN and AtypAN relative to healthy individuals in this food cue paradigm. Differential activation of specific brain regions in response to the passive viewing of high-calorie food images may underlie restrictive eating behavior in this clinical population.

Prevalence, Characteristics, and Correlates of Avoidant/Restrictive Food Intake Disorder among Adult Respondents to the National Eating Disorders Association Online Screen: A Cross-Sectional Study

Background

Avoidant/restrictive food intake disorder (ARFID) is a serious, albeit under-researched, feeding or eating disorder. This exploratory study utilized data from adult respondents to the National Eating Disorders Association (NEDA) online eating disorder screen to validate items assessing the presence of ARFID and examine the prevalence, clinical characteristics, and correlates of a positive ARFID screen compared to other probable eating disorder/risk categories.

Methods

Among 47,705 adult screen respondents between January 2022 and January 2023, the prevalence of a positive ARFID screen was calculated. Chi-square tests and t-tests compared demographics, eating disorder attitudes and behaviors, suicidal ideation, current eating disorder treatment status, and eating disorder treatment-seeking intentions between respondents with possible ARFID and other eating disorder diagnostic and risk categories. Clinical characteristics of respondents with possible ARFID were also examined.

Results

2,378 (5.0%) adult respondents screened positive for ARFID. Respondents with possible ARFID tended to be younger, male, and have lower household income, and were less likely to be White and more likely to be Hispanic/Latino than most other diagnostic/risk groups. They had lower weight/shape concerns and eating disorder behaviors than all other diagnoses but higher BMI than those with AN. 35% reported suicidal ideation, 47% reported intentions to seek treatment for an eating disorder, and 2% reported currently being in treatment. The most common clinical feature of ARFID was lack of interest in eating (80%), followed by food sensory avoidance (55%) and avoidance of food due to fear of aversive consequences (31%).

Conclusions

Findings from this study indicated that ARFID was prevalent among adult screen respondents and more common among individuals who were younger, male, non-White, Hispanic, and lower income relative to those with other eating disorders or at risk for an eating disorder. Individuals with possible ARFID frequently reported suicidal ideation and were rarely in treatment for an eating disorder. Further research is urgently needed to improve advances in the assessment and treatment of ARFID and improve access to care in order to prevent prolonged illness duration.

Lower Ghrelin Levels Are Associated With Higher Anxiety Symptoms in Adolescents and Young Adults With Avoidant/Restrictive Food Intake Disorder

Objective: Avoidant/restrictive food intake disorder (ARFID) is associated with increased risk for anxiety, which may adversely affect prognosis. The appetite-stimulating hormone, ghrelin, increases in response to stress, and exogenous ghrelin decreases anxiety-like behaviors in animal models. The aim of this study was to evaluate the relationship between ghrelin levels and measures of anxiety in youth with ARFID. We hypothesized that lower ghrelin levels would be associated with increased anxiety symptoms.

Methods: We studied a cross-sectional sample of 80 subjects with full and subthreshold ARFID diagnosed by DSM-5 criteria, aged 10-23 years (female, n = 39; male, n = 41). Subjects were enrolled in a study of the neurobiology of avoidant/restrictive eating conducted from August 2016 to January 2021. We assessed fasting ghrelin levels and anxiety symptoms (State-Trait Anxiety Inventory [STAI] and STAI for Children [STAI-C] measuring general trait anxiety; Beck Anxiety Inventory [BAI] and BAI for youth [BAI-Y] assessing cognitive, emotional, and somatic symptoms of anxiety; and Liebowitz Social Anxiety Scale [LSAS] assessing symptoms of social anxiety).

Results: Consistent with our hypothesis, ghrelin levels were inversely associated with anxiety symptoms as assessed by STAI/STAI-C T scores (r = -0.28, P = .012), BAI/BAI-Y T scores (r = -0.28, P = .010), and LSAS scores (r = -0.3, P = .027), all with medium effect sizes. Findings held in the full threshold ARFID group when adjusting for body mass index z scores (STAI/STAI-C T scores, β = -0.27, P = .024; BAI/BAI-Y T scores, β = -0.26, P = .034; LSAS, β = -0.34, P = .024).

Conclusions: These findings demonstrate that lower levels of ghrelin are associated with more severe anxiety symptoms in youth with ARFID and raise the question of whether ghrelin pathways could be targeted in the treatment of ARFID.

Endocrine complications of anorexia nervosa

An important component in the treatment of anorexia nervosa (AN) is the evaluation and management of its endocrine complications, including functional hypogonadotropic hypogonadism and increased fracture risk. The body's adaptive response to chronic starvation results in many endocrine abnormalities, most of which are reversible upon weight restoration. A multidisciplinary team with experience in treating patients with AN is critical to improving endocrine outcomes in patients with this disorder, including in women with AN who are interested in fertility. Much less is understood about endocrine abnormalities in men, as well as sexual and gender minorities, with AN. In this article, we review the pathophysiology and evidence-based recommendations for the treatment of endocrine complications in AN, as well as discuss the status of clinical research in this area.

Clinical features of adult patients with avoidant/restrictive food intake disorder presenting for medical stabilization: A descriptive study

OBJECTIVE

The purpose of this study is to describe the clinical features of adult patients with avoidant/restrictive food intake disorder (ARFID) to better understand the medical findings, psychological comorbidities, and laboratory abnormalities in this population.

METHOD

We completed a retrospective chart review of all adult patients with a diagnosis of ARFID, admitted for medical stabilization, between April 2016 and June 2021, to an inpatient hospital unit, which specializes in severe eating disorders. Information collected included anthropomorphic data, laboratory assessments, and medical history at time of admission.

RESULTS

One hundred and twenty-two adult patients with ARFID were identified as meeting inclusion criteria for the study. The most common ARFID presentation was "fear of adverse consequences." The majority were female (70%), with an average age of 32.7 ± 13.7 years and mean percent of ideal body weight (m%IBW) of 68.2 ± 10.9. The most common laboratory abnormalities were low serum prealbumin and vitamin D, hypokalemia, leukopenia, and elevated serum bicarbonate. The most common psychiatric diagnoses were anxiety and depressive disorders, and the most common medical diagnoses were disorders of gut-brain interaction (DGBI).

DISCUSSION

This is the largest study to the authors' knowledge of medical presentations in adult patients with ARFID. Our results reflect that the adult patient with ARFID may, in some aspects, present differently than pediatric and adolescent patients with ARFID, or from ARFID patients requiring less intensive care. This study highlights the need for further investigation of adult patients with ARFID.

PUBLIC SIGNIFICANCE

ARFID is a restrictive eating disorder first defined in 2013. This study explores the medical presentations of adult patients (>18 years old) with ARFID presenting for specialized eating disorder treatment and identifies unique features of the adult presentation for treatment, compared to pediatric and adolescent peers.

Differential comorbidity profiles in avoidant/restrictive food intake disorder and anorexia nervosa: Does age play a role?

OBJECTIVE

Research comparing psychiatric comorbidities between individuals with avoidant/restrictive food intake disorder (ARFID) and anorexia nervosa (AN) is limited. ARFID often develops in childhood, whereas AN typically develops in adolescence or young adulthood. Understanding how age may impact differential psychological comorbidity profiles is important to inform etiological conceptualization, differential diagnosis, and treatment planning. We aimed to compare the lifetime frequency of psychiatric comorbidities and suicidality between females with ARFID (n = 51) and AN (n = 40), investigating the role of age as a covariate.

METHOD

We used structured interviews to assess the comparative frequency of psychiatric comorbidities/suicidality.

RESULTS

When age was omitted from analyses, females with ARFID had a lower frequency of depressive disorders and suicidality compared to AN. Adjusting for age, only suicidality differed between groups.

DISCUSSION

This is the first study to compare comorbidities in a similar number of individuals with ARFID and AN, and a structured clinical interview to confer ARFID and comorbidities, covarying for age, and the first to compare suicidality. Although suicidality is at least three times less common in ARFID than AN, observed differences in other psychiatric comorbidities may reflect ARFID's relatively younger age of presentation compared to AN.

PUBLIC SIGNIFICANCE

Our results highlight that, with the exception of suicidality, which was three times less common in ARFID than AN irrespective of age, observed differences in psychiatric comorbidities in clinical practice may reflect ARFID's younger age at clinical presentation compared to AN.

Psychiatric and medical comorbidities of eating disorders: findings from a rapid review of the literature

BACKGROUND

Eating disorders (EDs) are potentially severe, complex, and life-threatening illnesses. The mortality rate of EDs is significantly elevated compared to other psychiatric conditions, primarily due to medical complications and suicide. The current rapid review aimed to summarise the literature and identify gaps in knowledge relating to any psychiatric and medical comorbidities of eating disorders.

METHODS

This paper forms part of a rapid review) series scoping the evidence base for the field of EDs, conducted to inform the Australian National Eating Disorders Research and Translation Strategy 2021-2031, funded and released by the Australian Government. ScienceDirect, PubMed and Ovid/Medline were searched for English-language studies focused on the psychiatric and medical comorbidities of EDs, published between 2009 and 2021. High-level evidence such as meta-analyses, large population studies and Randomised Control Trials were prioritised.

RESULTS

A total of 202 studies were included in this review, with 58% pertaining to psychiatric comorbidities and 42% to medical comorbidities. For EDs in general, the most prevalent psychiatric comorbidities were anxiety (up to 62%), mood (up to 54%) and substance use and post-traumatic stress disorders (similar comorbidity rates up to 27%). The review also noted associations between specific EDs and non-suicidal self-injury, personality disorders, and neurodevelopmental disorders. EDs were complicated by medical comorbidities across the neuroendocrine, skeletal, nutritional, gastrointestinal, dental, and reproductive systems. Medical comorbidities can precede, occur alongside or emerge as a complication of the ED.

CONCLUSIONS

This review provides a thorough overview of the comorbid psychiatric and medical conditions co-occurring with EDs. High psychiatric and medical comorbidity rates were observed in people with EDs, with comorbidities contributing to increased ED symptom severity, maintenance of some ED behaviours, and poorer functioning as well as treatment outcomes. Early identification and management of psychiatric and medical comorbidities in people with an ED may improve response to treatment and overall outcomes.

Eighteen-month Course and Outcome of Adolescent Restrictive Eating Disorders: Persistence, Crossover, and Recovery

OBJECTIVE

In adults, low-weight restrictive eating disorders, including anorexia nervosa (AN), are marked by chronicity and diagnostic crossover from restricting to binge-eating/purging. Less is known about the naturalistic course of these eating disorders in adolescents, particularly atypical AN (atyp-AN) and avoidant/restrictive food intake disorder (ARFID). To inform nosology of low-weight restrictive eating disorders in adolescents, we examined outcomes including persistence, crossover, and recovery in an 18-month observational study.

METHOD

We assessed 82 women (ages 10-23 years) with low-weight eating disorders including AN (n = 40; 29 restricting, 11 binge-eating/purging), atyp-AN (n = 26; 19 restricting, seven binge-eating/purging), and ARFID (n = 16) at baseline, nine months (9 M; 75% retention), and 18 months (18 M; 73% retention) via semi-structured interviews. First-order Markov modeling was used to determine diagnostic persistence, crossover, and recovery occurring at 9 M or 18 M.

RESULTS

Among all diagnoses, the likelihood of remaining stable within a given diagnosis was greater than that of transitioning, with the greatest probability among ARFID (0.84) and AN-R (0.62). Persistence of BP and atypical presentations at follow-up periods was less stable (AN-BP probability 0.40; atyp-AN-R probability 0.48; atyp-AN-BP probability, 0.50). Crossover from binge-eating/purging to restricting occurred 72% of the time; crossover from restricting to binge-eating/purging occurred 23% of the time. The likelihood of stable recovery (e.g., recovery at both 9 M and 18 M) was between 0.00 and 0.36.

CONCLUSION

Across groups, intake diagnosis persisted in about two-thirds, and recovery was infrequent, underscoring the urgent need for innovative treatment approaches to these illnesses. Frequent crossover between AN and atyp-AN supports continuity between typical and atypical presentations, whereas no crossover to ARFID supports its distinction.

Elevated Fasting Satiety-Promoting Cholecystokinin (CCK) in Avoidant/Restrictive Food Intake Disorder Compared to Healthy Controls

Objective: Avoidant/restrictive food intake disorder (ARFID) is characterized by food avoidance or dietary restriction not primarily motivated by body weight/shape concerns. Individuals with ARFID can report early satiation, post-prandial fullness, and high intermeal satiety, but whether these symptoms are related to differences in the biology underlying appetite regulation is unknown. In male and female children and adolescents, we hypothesized that fasting levels of cholecystokinin (CCK), a satiety hormone, would be elevated in participants with ARFID (full or subthreshold) versus healthy controls (HCs). Within the ARFID group, we also explored the relations of CCK with weight status, subjective appetite ratings, and ARFID severity and phenotypes. Methods: A total of 125 participants (83 with full/subthreshold ARFID (per DSM-5) and 42 HCs, aged 10.2-23.7 years; 61% female; July 2014-December 2019) underwent fasting blood draws for CCK, completed self-report measures assessing subjective state and trait appetite ratings, and completed a semistructured interview assessing ARFID severity. Results: Fasting CCK was higher in those with full/subthreshold ARFID versus HCs with a large effect (F₁ = 25.0, P < .001, η_p² = 0.17), controlling for age, sex, and body mass index (BMI) percentile. Within the ARFID group, CCK was not significantly related to BMI percentile, subjective appetite ratings, or ARFID characteristic measures. Conclusions: CCK may contribute to etiology and/or maintenance of ARFID, as children and adolescents with heterogeneous presentations of avoidant/restrictive eating appear to show elevated fasting levels compared to healthy youth. Further research is needed to understand relations between CCK and appetite, weight, and eating behavior in ARFID.

Evaluating the predictive validity of purging disorder by comparison to bulimia nervosa at long-term follow-up

OBJECTIVE

The current study sought to examine the predictive validity of the purging disorder diagnosis at long-term follow-up by comparing naturalistic outcomes with bulimia nervosa.

METHOD

Women with purging disorder (N = 84) or bulimia nervosa (N = 133) who had completed comprehensive baseline assessments as part of one of three studies between 2000 and 2012 were sought for follow-up assessment. Nearly all (94.5%) responded to recruitment materials and 150 (69% of sought sample; 83.3% non-Hispanic white; 33.40 [7.63] years old) participated at an average of 10.59 (3.71) years follow-up. Participants completed the Eating Disorder Examination, the Structured Clinical Interview for DSM-IV, and a questionnaire battery. Diagnostic groups were compared on eating disorder (illness status, recovery status, and eating pathology) and related outcomes. Group differences in predictors of outcome were explored.

RESULTS

There were no significant differences in eating disorder presence (p = .70), recovery status (p = .87), and level of eating pathology (p = .17) between diagnostic groups at follow-up. Post hoc equivalence tests indicated group differences were smaller than a medium effect size (p's ≤ .005). Groups differed in diagnosis at follow-up (p = .002); diagnostic stability was more likely than cross-over to bulimia nervosa for women with baseline purging disorder (p = .004).

DISCUSSION

Although purging disorder and bulimia nervosa do not differ in long-term outcomes, the relative stability in clinical presentation suggests baseline group differences in clinical presentation may be useful in augmenting treatments for purging disorder.

PUBLIC SIGNIFICANCE STATEMENT

While purging disorder is classified as an "other specified" eating disorder, individuals who experience this disorder have comparable negative long-term outcomes as those with bulimia nervosa. This highlights the importance of screening for and treating purging disorder as a full-threshold eating disorder.

Biased Ghrelin Receptor Signaling and the Dopaminergic System as Potential Targets for Metabolic and Psychological Symptoms of Anorexia Nervosa

Anorexia Nervosa (AN) is a complex disease that impairs the metabolic, mental and physiological health of affected individuals in a severe and sometimes lethal way. Many of the common symptoms in AN patients, such as reduced food intake, anxiety, impaired gut motility or overexercising are connected to both the orexigenic gut hormone ghrelin and the dopaminergic system. Targeting the ghrelin receptor (GhrR) to treat AN seems a promising possibility in current research. However, GhrR signaling is highly complex. First, the GhrR can activate four known intracellular pathways Gαq, Gαi/o, Gα12/13 and the recruitment of β-arrestin. Biased signaling provides the possibility to activate or inhibit only one or a subset of the intracellular pathways of a pleiotropic receptor. This allows specific targeting of physiological functions without adverse effects. Currently little is known on how biased signaling could specifically modulate GhrR effects. Second, GhrR signaling has been shown to be interconnected with the dopaminergic system, particularly in the context of AN symptoms. This review highlights that a biased agonist for the GhrR may be a promising target for the treatment of AN, however extensive and systematic translational studies are still needed and the connection to the dopaminergic system has to be taken into account.