Significant Locus and Metabolic Genetic Correlations Revealed in Genome-Wide Association Study of Anorexia Nervosa

Genetics of Anorexia Nervosa: Translation to Future Personalized Therapies

Anorexia nervosa (AN) is a debilitating and often refractory eating disorder that is unique among psychiatric disorders insofar as nutrition is key to recovery. Treatment options and efficacy are limited with no approved medications for AN. Genetic studies are clarifying the etiology of AN, with the goal of eventually informing the development of innovative personalized pharmacologic, nutritional, microbial, and behavioral interventions. We present the current state of genome-wide and epigenome-wide association studies, gut microbiome research, and functional genomics investigations and discuss translating this knowledge into clinical practice.

Metabolome guided treasure hunt - learning from metabolic diversity

Metabolomics is a rapidly evolving field focused on the comprehensive identification and quantification of small molecules in biological systems. As the final layer of the biological hierarchy following of the genome, transcriptome and proteome, it presents a dynamic snapshot of phenotype, influenced by genetic, environmental and physiological factors. Whilst the metabolome sits downstream of genes and proteins, there are multiple higher levels-tissues, organs, the entire organism, and interactions with other organisms, which need to be considered in order to fully comprehend organismal biology. Advances in metabolomics continue to expand its applications in plant biology, biotechnology, and natural product discovery unlocking many of nature's most beneficial colors, tastes, nutrients and medicines. Flavonoids and other specialized metabolites are essential for plant defense against oxidative stress and function as key phytonutrients for human health. Recent advancements in gene-editing and metabolic engineering have significantly improved the nutritional value and flavor of crop plants. Here we highlight how advanced metabolic analysis is driving improvements in crops uncovering genes that influence nutrient and flavor profile and plant derived compounds with medicinal potential.

The association between disordered eating and psychosis in clinical and non-clinical populations: a systematic review and meta-analysis

BACKGROUND

Eating disorders and psychotic disorders represent two of the most serious psychiatric conditions. Emerging lines of evidence from genetic and epidemiological studies suggest that these disorders may commonly co-occur. This systematic review investigated the association between these disorders across community and clinical populations.

METHOD

A systematic review was preregistered (CRD42021231771) and conducted according to PRISMA guidelines. Web of Science, PsycINFO and Medline were searched for articles on the association and comorbidity between psychosis and eating disorders up to the 26th February 2024. A random effects meta-analysis was conducted for studies reporting comorbidity of eating disorders and psychotic disorders based on clinical diagnosis or interview measures, to estimate prevalence of the comorbidity between these disorders. A narrative synthesis was conducted for all other studies and grouped by sample (general population, eating disorders or psychotic disorders).

RESULTS

In total 43 studies met inclusion criteria for the systematic review and 16 were included in the meta-analysis. Findings suggest substantial comorbidity between eating disorders and psychotic disorders, with a pooled comorbidity prevalence of 8% (CI: 3, 14) based on clinical diagnosis or interview measures. Studies using self-report questionnaires also highlight the association between eating disorders and psychosis across clinical and community populations.

CONCLUSIONS

Eating disorders and psychotic disorders frequently co-occur. Further research should investigate the temporal order of symptom development and consider the need for novel interventions targeted at overlapping psychotic and eating disorder symptoms and associated phenomena.

Genome-wide association studies of binge eating behaviour and anorexia nervosa yield insights into the unique and shared biology of eating disorder phenotypes

Eating disorders -including anorexia nervosa (AN), bulimia nervosa, and binge eating disorder-are clinically distinct but exhibit symptom overlap and diagnostic crossover. Genomic analyses have mostly examined AN. We conducted the first genomic meta-analysis of binge eating behaviour (BE; 39,279 cases, 1,227,436 controls), alongside new analyses of AN (24,223 cases, 1,243,971 controls) and its subtypes (all European ancestries). We identified six loci associated with BE, including loci associated with higher body mass index (BMI) and impulse-control behaviours. AN GWAS yielded eight loci, validating six loci. Subsequent polygenic risk score analysis demonstrated an association with AN in two East Asian ancestry cohorts. BE and AN exhibited similar positive genetic correlations with psychiatric disorders, but opposing genetic correlations with anthropometric traits. Most of the genetic signal in BE and AN was not shared with BMI. We have extended eating disorder genomics beyond AN; future work will incorporate multiple diagnoses and global ancestries.

Genetic and functional analyses of CTBP2 in anorexia nervosa and body weight regulation

The C-terminal binding protein 2 (CTBP2) gene (translational isoforms: CTBP2-L/S, RIBEYE) had been identified by a cross-trait analysis of genome-wide association studies for anorexia nervosa (AN) and body mass index (BMI). Here, we did a mutation analysis in CTBP2 by performing polymerase chain reactions with subsequent Sanger-sequencing to identify variants relevant for AN and body weight regulation and ensued functional studies. Analysis of the coding regions of CTBP2 in 462 female patients with AN (acute or recovered), 490 children and adolescents with severe obesity, 445 healthy-lean adult individuals and 168 healthy adult individuals with normal body weight detected 24 variants located in the specific exon of RIBEYE. In the initial analysis, three of these were rare non-synonymous variants (NSVs) detected heterozygously in patients with AN (p.Arg72Trp - rs146900874; p.Val289Met -rs375685611 and p.Gly362Arg - rs202010294). Four NSVs and one heterozygous frameshift variant were exclusively detected in children and adolescents with severe obesity (p.Pro53Ser - rs150867595; p.Gln175ArgfsTer45 - rs141864737; p.Leu310Val - rs769811964; p.Pro397Ala - rs76134089 and p.Pro402Ser - rs113477585). Ribeye mRNA was detected in mouse hypothalamus. No effect of fasting or overfeeding on murine hypothalamic Ribeye expression was determined. Yet, increased Ribeye expression was detected in hypothalami of leptin-treated Lepob/ob mice. This increase was not related to reduced food intake and leptin-induced weight loss. We detected rare and frequent variants in the RIBEYE specific exon in both patients with AN and in children and adolescents with severe obesity. Our data suggest RIBEYE as a relevant gene for weight regulation.

Psychiatric genetics in the diverse landscape of Latin American populations

Psychiatric disorders are highly heritable and polygenic, influenced by environmental factors and often comorbid. Large-scale genome-wide association studies (GWASs) through consortium efforts have identified genetic risk loci and revealed the underlying biology of psychiatric disorders and traits. However, over 85% of psychiatric GWAS participants are of European ancestry, limiting the applicability of these findings to non-European populations. Latin America and the Caribbean, regions marked by diverse genetic admixture, distinct environments and healthcare disparities, remain critically understudied in psychiatric genomics. This threatens access to precision psychiatry, where diversity is crucial for innovation and equity. This Review evaluates the current state and advancements in psychiatric genomics within Latin America and the Caribbean, discusses the prevalence and burden of psychiatric disorders, explores contributions to psychiatric GWASs from these regions and highlights methods that account for genetic diversity. We also identify existing gaps and challenges and propose recommendations to promote equity in psychiatric genomics.

Suicidal behaviour in adolescents with affective disorders: A study in a crisis intervention unit (CIU)

BACKGROUND

Suicidal behaviour is a critical mental health issue in the adolescent population, often linked to serious emotional problems that leave survivors vulnerable to future risk. Psychological crises in adolescence are primarily associated with relational conflicts, with emotional crises involving depression or anxiety significantly increasing suicidal risk.

OBJECTIVE

This study aimed to evaluate the rates of suicidal behaviour in adolescents undergoing emotional crises and explore their association with psychiatric diagnoses and demographic factors in Ecuador.

METHODS

An observational, correlational study using a quantitative approach was conducted. Data from 252 adolescents admitted to the Crisis Intervention Unit at the Institute of Neurosciences in Guayaquil, Ecuador, between 2011 and 2023 were analysed. Hospitalisation frequencies by year, gender, and associated psychiatric diagnoses were assessed. Data were obtained from each patient's unified clinical history.

RESULTS

The study found that suicidal behaviour in adolescents hospitalised for emotional crises was most prevalent among females aged 16-18 years. Depressive episodes were the most common psychiatric diagnosis (73%), and cutting was the most frequent method of self-harm, followed by the ingestion of psychotropic substances. A combination of suicidal ideation and attempts was the most frequent presentation (64%), with family conflicts identified as the main source of distress.

CONCLUSIONS

The high frequency of suicidal behaviour in adolescent females aged 16-18 years underscores the need for targeted prevention programs addressing emotional crises and stress management in this high-risk group.

Enterobacterial caseinolytic protease B (ClpB) and ClpB antibodies in adolescents with anorexia nervosa

Caseinolytic protease B (ClpB) produced by the gut enterobacteria displays anorexigenic effects possibly due to its molecular mimicry with α-melanocyte-stimulating hormone (α-MSH), an anorexigenic neuropeptide. ClpB is known to induce α-MSH cross-reactive antibodies previously associated with eating disorders. In the present study we analyzed whether long-term changes of serum ClpB, anti-ClpB antibodies and fecal clpB gene content can be associated with disease progression in anorexia nervosa (AN). For this purpose, female adolescents diagnosed with the restrictive type of AN according to DSM-5 were studied at hospital admission, discharge, and at a 1-year follow up visit, while age-matched healthy female participants served as a control group. We found that ClpB protein was detected at variable levels in sera of all study participants without significant group differences. However, anti-ClpB IgG were low in adolescents with AN at the acute phase of disease and were characterized by increased affinity. Long-term individual dynamics of serum ClpB revealed that its increase after hospital discharge was associated with disease relapse. In healthy adolescents, serum ClpB correlated negatively with BMI-SDS. Fecal clpB DNA levels were low in patients at hospital admission and discharge correlating positively with the abundance of Enterobacteriaceae in gut microbiota. Thus, in healthy adolescents enterobacterial ClpB appears as a physiological microbiota-derived factor associated with lower body weight within the normal range. Low levels of anti-ClpB IgG in adolescents with AN may cause insufficient immune control of ClpB, possibly promoting ClpB anorexigenic effects which can be relevant to the pathophysiology of AN.

Identification of Six Cerebrospinal Fluid Metabolites Causally Associated with Anorexia Nervosa Risk: A Mendelian Randomization Analysis

Anorexia nervosa (AN) is a severe psychiatric disorder characterized by substantial heritability and a high mortality rate among psychiatric disorders. While cerebrospinal fluid (CSF) metabolomics has emerged as a novel approach to investigating central nervous system pathologies, its specific causal relationship with anorexia nervosa remains to be fully elucidated. Using genome-wide association study (GWAS) summary statistics for human CSF metabolites and AN information from publicly available datasets, we performed a two-sample Mendelian randomization (MR) analysis using the inverse-variance weighted (IVW) method as the primary approach, complemented by sensitivity analyses. Through a comprehensive analysis of 338 CSF metabolites, we identified six metabolites with significant causal relationships with AN risk. 1-stearoyl-2-linoleoyl-gpc (18:0/18:2) (OR = 1.09, 95% CI 1.00-1.18) and alpha-tocopherol (OR = 1.36, 95% CI 1.00-1.83) showed positive associations, increasing AN risk. Conversely, sphingomyelin (d18:1/20:0, d16:1/22:0) (OR = 0.86, 95% CI 0.77-0.95), 2,3-dihydroxy-2-methylbutyrate (OR = 0.92, 95% CI 0.86-0.98), N-acetylhistidine (OR = 0.92, 95% CI 0.86-0.98), and oxalate (ethanedioate) (OR = 0.83, 95% CI 0.73-0.94) had protective effects, reducing AN risk. Sensitivity analyses showed no evidence of horizontal pleiotropy or heterogeneity in the MR results. An MR directionality test and a Steiger filtering test confirmed the absence of reverse causality, thereby substantiating the robustness of our findings. These findings suggest that these CSF metabolites could serve as potential biomarkers for early AN detection and highlight novel therapeutic targets, potentially improving diagnosis and intervention strategies for this challenging disorder.

Differential Psychopathology Associations Found for Docosahexaenoic Acid versus Arachidonic Acid Oxylipins of the Cytochrome P450 Pathway in Anorexia Nervosa

Anorexia nervosa (AN) is one of the deadliest disorders in psychiatry. AN patients tend to avoid high-fat and high-calorie foods to maintain a pathologically low body weight. High-fat foods are major sources of polyunsaturated fatty acids (PUFAs), lipids that are crucial for health and brain development. PUFAs can be categorized into different omega classes (n-3, n-6) or into essential (ALA, LA) versus nonessential PUFAs (EPA, DHA, ARA). PUFAs are metabolized by Cytochrome P450 (CYP450) enzymes into bioactive oxylipins with inflammation-resolving properties termed epoxy-fatty acids (EpFAs). EpFAs are further hydrolyzed into pro-inflammatory diol-fatty acids (DiHFAs) by soluble epoxide hydrolase (sEH), the protein product of an AN risk gene, EPHX2 . Using a meal challenge study protocol, EpFA and DiHFA oxylipins and sEH were analyzed in age-matched AN and healthy women to determine if sEH-associated oxylipins affect AN risk and psychopathology. At the fasting timepoint, half of the oxylipins were lower in AN compared to controls (all p<0.050). After eating, all but one EpFAs increased in AN (p=0.091 to 0.697) whereas all EpFAs decreased in controls (p=0.0008 to 0.462). By contrast, essential PUFA-derived DiHFAs significantly increased, whereas nonessential PUFA-derived DiHFAs significantly decreased in both groups. DiHFA oxylipins associated with AN psychopathology displayed a PUFA-dependent directionally opposite pattern: n-3 DHA-derived DiHFAs (DiHDPEs) were associated with lower severity in eating disorder risk, global psychological maladjustment, shape and restraint concerns, and global Eating Disorder Examination score. By contrast, n-6 ARA-derived DiHFAs (DiHETrEs) were associated with more severe emotional dysregulation, bulimia, interoceptive deficits, asceticism, and overcontrol scores. On the other hand, EpFA oxylipins were not significantly associated with AN psychopathology. This study confirms lipid metabolic dysregulation as a risk factor for AN. CYP450 oxylipins associated with AN risk and symptoms are sEH- and PUFA class-dependent. Our findings reveal that gene-diet interactions contribute to metabolic dysregulation in AN, highlighting a need for additional research to develop precision medicine for AN management.

Preliminary Evidence That Shared Genetic Influences Underlie Comorbidity Between Self-Reported Eating and Internalizing Disorders and Gastrointestinal Disease in Adult Women and Men

INTRODUCTION

Accumulating research suggests both eating disorders (EDs) and internalizing disorders (e.g., anxiety, depression) are associated with gastrointestinal disease (e.g., irritable bowel syndrome, inflammatory bowel disease). However, the mechanisms underlying comorbidity with gastrointestinal disease-and whether they may differ for eating and internalizing disorders-remain poorly understood. Addressing these gaps is a critical first step to refining etiologic models of comorbidity and identifying potential targets for intervention.

METHOD

Participants included female and male twins ages 18-65 from the population-based MSU Twin Registry (N = 5883). Lifetime history of EDs, internalizing disorders, and gastrointestinal disease was assessed via questionnaire. We first examined whether EDs and internalizing disorders were independently associated with gastrointestinal disease phenotypically. We then used trivariate Cholesky decomposition twin models to investigate whether EDs and internalizing disorders were related to gastrointestinal disease through overlapping or distinct genetic/environmental pathways.

RESULTS

Eating (OR = 2.54, p = 0.009) and internalizing (OR = 2.14, p < 0.001) disorders were independently associated with gastrointestinal disease. Conclusions were unchanged after adjusting for important covariates (e.g., body mass index, age) and did not significantly differ across sex. Twin models suggested genetic influences shared by all three conditions explained their co-occurrence, with 31% of the variance in EDs and 12% of the variance in gastrointestinal disease attributable to genetic influences shared with internalizing disorders.

CONCLUSION

Shared genetic mechanisms may contribute to comorbidity between EDs, internalizing disorders, and gastrointestinal disease. Identifying overlapping molecular pathways could potentially lead to novel interventions that simultaneously address all three conditions.

Elevated plasma B12 and betaine levels in women with anorexia nervosa: possible role in illness pathophysiology and epigenetic regulation

BACKGROUND

Phenomenology in anorexia nervosa (AN) appears to be subject to epigenetic regulation via DNA methylation. The micronutrients B12 and betaine contribute directly to DNA methylation and have been shown to be abnormally elevated in blood samples from people with AN.

METHODS

We measured plasma B12 and betaine levels, as well as leukocyte DNA methylation levels, among women with active AN (AN-active group), those in 1-year remission from AN (AN-remitted group), and those who had never experienced an eating disorder (NED group). We compared the groups on micronutrient levels and on the strength of association between micronutrients and methylation.

RESULTS

We included 64 women in the AN-active group, 49 in the AN-remitted group, and 49 in the NED group. Relative to those with NED (B12: mean 339.6 [standard deviation (SD) 224.3] μmol/L; betaine: mean 33.74 [SD 17.10] μmol/L), participants with active AN showed high B12 and betaine (B12: mean 571.0 [SD 505.2] μmol/L; betaine: mean 43.73 [SD 22.50] μmol/L); AN-remitted participants had elevated B12 alone (B12: mean 588.2 [SD 379.9] μmol/L; betaine: mean 33.50 [SD 19.20] μmol/L). There were also group-based differences in the strength of association between B12 and site-specific DNA methylation at genes regulating insulin function, glucose metabolism, cell regulation, and neurotransmitter function. These associations between B12 and methylation levels were generally stronger among those without an ED than among those with either active or remitted AN.

LIMITATIONS

The extent to which plasma nutrient levels provide a meaningful proxy to cellular processes affecting DNA methylation is uncertain and the sample size limits the stability of results. We included only biological females in this investigation.

CONCLUSION

Elevated B12 levels in AN resemble elevations reported among people with autoimmune, neoplastic, or other disorders. Such elevations imply that plasma B12 levels may misrepresent nutritional status among people with AN. Observed associations between levels of B12 and methylation at certain gene regions have ambiguous importance, but may indicate an influence of nutritional status on epigenetic mechanisms or may be the coincidence of separate processes that independently affect levels of micronutrients and DNA methylation.

Application of Genetic Testing for Anorexia Nervosa: An Ethical Analysis

OBJECTIVE

Anorexia Nervosa (AN) is a severe, debilitating disorder with a high mortality rate. Research indicates that genetics plays a significant role in AN manifestation and persistence. Genetic testing has the potential to transform how AN is treated, however, in clinical practice, care must be taken to consider the ethical complexities involved. Our objective was to perform an ethical analysis of genetic testing in AN.

METHODS

We applied the principlist approach, taking into consideration the stakeholders involved and the core ethical principles of autonomy, beneficence, non-maleficence, and justice to (1) evaluate the possible ethical implications of the use of genetic testing in the treatment of patients with AN, and (2) assess whether such testing is justified and if so, under what conditions.

RESULTS

Potential benefits of genetic testing identified include reduction of misdiagnosis and identification of treatable concurrent genetic conditions. The identified potential risks of genetic testing for possible AN-associated risk variants outside of a research setting, especially without more effective treatment options, include a false sense of reassurance for those testing negative and a reduced emphasis on the importance of behavioral-based therapies that may be of benefit.

DISCUSSION

Genetic testing for complex disorders, including AN, has tremendous potential, but is still primarily research-based. Currently, for those presenting with atypical AN, and severe and enduring AN who, by definition, have not benefited from traditional treatment, genetic testing to rule out or identify other genetic conditions could be of benefit.

Computational Approaches for Uncovering Interoceptive Mechanisms in Psychiatric Disorders and Their Biological Basis

Interoception, the process of detecting, perceiving, and interpreting signals from within the body, is essential for physiological regulation and adaptive behavior. A growing body of research underscores important potential links between interoceptive dysfunction and psychiatric disorders. Parallel advancements in the field of computational psychiatry have led to the development of biologically plausible models of information processing in the brain. This review surveys the current state of traditional and computational research approaches to study interoceptive processes in psychiatry. We also provide a foundational description of predominant computational approaches and theoretical models of interoception. Finally, we discuss the potential molecular foundations of interoceptive computation and consider future directions for incorporating computational models to enhance clinical insights and inform personalized treatments. We conclude that combining interoception and computational modeling approaches holds considerable promise in moving the field forward, both in addressing unresolved mechanistic questions and identifying novel potential therapeutic targets.

An evolutionary perspective on the genetics of anorexia nervosa

Anorexia nervosa (AN) typically emerges around adolescence and predominantly affects females. Recent progress has been made in identifying biological correlates of AN, but more research is needed to pinpoint the specific mechanisms that lead to its development and maintenance. There is a known phenotypic link between AN, growth and sexual maturation, yet the genetic overlap between these phenotypes remains enigmatic. One may hypothesize that shared factors between AN, energy metabolism and reproductive functions may have been under recent evolutionary selection. Here, we characterize the genetic overlap between AN, BMI and age at menarche, and aimed to reveal recent evolutionary factors that may help explain the origin of AN. We obtained publicly available GWAS summary statistics of AN, BMI and age at menarche and studied the polygenic overlap between them. Next, we used Neandertal Selective Sweep scores to explore recent evolutionary selection. We found 22 loci overlapping between AN and BMI, and 9 loci between AN and age at menarche, with 7 of these not previously associated with AN. We found that loci associated with AN may have been under particular evolutionary dynamic. Chronobiology appeared relevant to the studied genetic overlaps and prone to recent evolutionary selection, offering a promising avenue for future research. Taken together, our findings contribute to the understanding of the genetic underpinning of AN. Ultimately, better knowledge of the biological origins of AN may help to target specific biological processes and facilitate early intervention in individuals who are most at risk.

Ketogenic Food Ameliorates Activity-Based Anorexia of Adult Female Mice

OBJECTIVE

Genome-wide association studies implicate metabo-psychiatric origins for anorexia nervosa (AN). There are two case reports totaling six adult females who experienced complete remission of AN following a treatment comprised of ketogenic diet (targeting metabolism) with ketamine infusions (targeting psychiatric origins), but no study has determined the efficacy of ketogenic diet, alone. We addressed this gap in knowledge, with exploration of potential molecular mechanisms, using an animal model.

METHOD

Adult C57BL6 female mice underwent 2 or 3 cycles of activity-based anorexia (ABA1, ABA2, ABA3), an animal model of AN relapse, in which AN-like maladaptive behaviors of hyperactivity and voluntary food restriction are elicited when wheel access is combined with food restriction. ABA was categorized as severe, based on weight loss ≥ 20%, food restriction-evoked increase in wheel counts > 10,000/6 h, and crouching/grimace, and compared across two groups: (1) KG, fed ketogenic food continuously (N = 25); and (2) CON, fed standard diet (N = 28).

RESULTS

86% of CON versus none of the KG were crouching with grimace during ABA1. 93% of CON versus 11% of KG lost weight severely during ABA2 (p < 0.001, 8% difference of group mean weights). Severe hyperactivity was prevalent among CON (86%) and rare for KG (4%) during ABA2 (p < 0.001 on all food-restricted days). ABA up-regulated BDNF (brain-derived neurotrophic factor) in the hippocampus of both groups but ketone body, β-hydroxybutyrate, in urine was increased only among KG.

DISCUSSION

Ketogenic diet may reduce severity of AN relapse through reduction of compulsive exercise, via mechanisms that are in addition to BDNF up-regulation and involve β-hydroxybutyrate.

The current clinical approach to feeding and eating disorders aimed to increase personalization of management

Feeding and eating disorders (FEDs) are a heterogeneous grouping of disorders at the mind-body interface, with typical onset from childhood into emerging adulthood. They occur along a spectrum of disordered eating and compensatory weight management behaviors, and from low to high body weight. Psychiatric comorbidities are the norm. In contrast to other major psychiatric disorders, first-line treatments for FEDs are mainly psychological and/or nutrition-focused, with medications playing a minor adjunctive role. Patients, carers and clinicians all have identified personalization of treatment as a priority. Yet, for all FEDs, the evidence base supporting this personalization is limited. Importantly, disordered eating and related behaviors can have serious physical consequences and may put the patient's life at risk. In these cases, immediate safety and risk management considerations may at least for a period need to be prioritized over other efforts at personalization of care. This paper systematically reviews several key domains that may be relevant to the characterization of the individual patient with a FED aimed at personalization of management. These domains include symptom profile, clinical subtypes, severity, clinical staging, physical complications and consequences, antecedent and concomitant psychiatric conditions, social functioning and quality of life, neurocognition, social cognition and emotion, dysfunctional cognitive schemata, personality traits, family history, early environmental exposures, recent environmental exposures, stigma, and protective factors. Where possible, validated assessment measures for use in clinical practice are identified. The limitations of the current evidence are pointed out, and possible directions for future research are highlighted. These also include novel and emerging approaches aimed at providing more fine-grained and sophisticated ways to personalize treatment of FEDs, such as those that utilize neurobiological markers. We additionally outline remote measurement technologies designed to delineate patients' illness and recovery trajectories and facilitate development of novel intervention approaches.

Descriptives and Genetic Correlates of Eating Disorder Diagnostic Transitions and Presumed Remission in the Danish Registry

BACKGROUND

Eating disorders (EDs) are serious psychiatric disorders with an estimated 3.3 million healthy life-years lost worldwide yearly. Understanding the course of illness, diagnostic transitions and remission, and their associated genetic correlates could inform both ED etiology and treatment. We investigated occurrences of ED transitions and presumed remission and their genetic correlates as captured by polygenic scores (PGSs) in a large Danish register-based cohort.

METHODS

The sample comprised 10,565 individuals with a diagnosis of anorexia nervosa (AN), bulimia nervosa (BN), or eating disorder not otherwise specified (EDNOS) and with at least two registered hospital contacts between 1995 and 2018. Based on medical records, the occurrence of diagnostic transitions and periods of presumed remission were identified. Associations between 422 PGSs and diagnostic transitions and presumed remission were evaluated using Cox proportional hazard models.

RESULTS

A minority of ED cases (14.1%-23.1%) experienced a diagnostic transition. Rates of presumed remission ranged between 86.9% and 89.8%. Higher (1 SD increase) PGSs for major depressive disorder and multisite chronic pain were positively associated with transitioning from AN to either BN or EDNOS. Higher PGSs for a measure of body fat percentage and financial difficulties were positively associated with presumed remission from AN. Having a higher PGS for mood swings was positively associated with presumed remission from EDNOS whereas higher PGS for overall health rating showed the opposite.

CONCLUSIONS

We found that most patients with an ED did not experience diagnostic transitions but were more likely to experience a period of presumed remission. Both diagnostic transitions and presumed remission have a significant polygenic component.

Elevating the Field of Eating Disorders Through Scholarship and Thoughtfulness: Honoring the Legacy of Dr. Michael Strober

This Virtual Issue of the International Journal of Eating Disorders honors the legacy of the late Dr. Michael Strober in the eating disorders and child psychiatry fields. Having served as Editor-in-Chief of the International Journal of Eating Disorders from 1983 to 2012, Dr. Strober elevated the quality of science conducted in the eating disorders field. His frank feedback and encouraging words inspired many junior researchers to sharpen their work and to think deeply about their results. An incisive thinker, eloquent writer, and gifted clinician, Dr. Strober was a role model for psychologists in clinical leadership positions and demonstrated that it is indeed possible to be a highly effective all-rounder. In this issue, we present an annotated selection of Dr. Strober's publications in the journal over the past decades to illustrate the evolution of his thinking and the seeds of what have become major directions in the field, including fear conditioning and genetics. By presenting this collection of his work, we encourage all investigators to read broadly and deeply and to identify and acknowledge those incisive scholars who have built the foundation upon which our work today stands.

Systemic Lupus Erythematosus Presenting as Anorexia Nervosa in a Middle-Aged Woman: A Rare Case Report and Literature Review

BACKGROUND

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with multisystemic involvement and unclear etiology. Although SLE could be linked to multiple neuropsychiatric manifestations, the co-occurrence of anorexia nervosa was only described through a few case reports that mainly affected children and adolescents.

CASE PRESENTATION

a 40-year-old Filipina woman presented to hospital with a 3-day history of agitation, anorexia and auditory hallucinations. She also had restrictive dietary habits with substantial weight loss and excessive fear of weight gain for the past several months. Her medical history was also noticeable for a 3-month history of erythematous non-itchy skin rash. On examination, the patient was pale and underweight. She had angular stomatitis, bilateral exophthalmos, and diffuse goiter. Skin examination revealed diffuse scaly and erythematous rash over the neck and upper torso with post-inflammatory skin discoloration. Laboratory investigations showed pancytopenia, high serum creatinine, and +1 proteinuria. Further workup confirmed thyrotoxicosis due to Graves disease as well as having multiple positive autoantibodies including antinuclear antibody (ANA) which were suggestive for SLE. A subsequent kidney biopsy demonstrated class IV diffuse lupus nephritis. The patient was treated successfully with intravenous pulse steroid therapy, rituximab, and antithyroid medications with no residual symptoms or laboratory abnormalities.

CONCLUSIONS

The concurrence of anorexia nervosa with SLE and the complete resolution of anorexia nervosa symptoms with immunosuppressive therapy suggest common autoinflammatory pathogenesis for both conditions. Further research is needed to elucidate any potential association between SLE and anorexia nervosa.

Predisposing Potential Risk Factors for Severe Anorexia Nervosa in Adolescents

BACKGROUND

Anorexia nervosa is a serious eating disorder that mainly affects children and adolescents. Most patients present with extreme body dissatisfaction and an obsessive focus on body weight and food. Anorexia nervosa is a complex and multifactorial condition characterised by biological, psychological, and social factors. However, studies that have explored the cumulative risk that predisposes to anorexia nervosa are limited. This study aims to explore the potential risk factors for a severe form of the disease in patients affected by anorexia nervosa and to identify whether they may interact and reinforce each other, contributing to the severity of the disorder.

METHODS

For this study, we enrolled children and adolescents under 18 years of age hospitalised at IRCCS Bambino Gesù Pediatric Hospital, Rome, Italy, for anorexia nervosa from 1 December 2022 to 31 August 2024, identifying and analysing potential risk factors. Elevated shape and weight concerns were found in all patients. Psychiatric and neurodevelopment comorbidities were identified in 76 patients (51.35%), life stress events in 69 (46.62%), and a family history of eating and weight control behaviours in 39 (26.35%). Out of the sample size, 20.27% of patients did not live in a traditionally structured family. This study used the Kiddie-SADS-Present and Lifetime Version interview, the Coddington Life Events Scales, and the Trauma Symptom Checklist for Children questionnaires.

RESULTS

Patients with an extreme or severe index of anorexia nervosa are more likely to have multiple predisposing factors. In detail, four predisposing factors were found in 18.6% of patients with an extreme severity index, in 15.5% of those with a severe score, and in 10.3 and 10.6% of those with a moderate and mild score, respectively.

CONCLUSIONS

Cumulative potential risk factors are more likely to be found in cases of severe course disease and patients hospitalised for anorexia. Prompt identification of predisposing factors and an effective plan of action are required to avoid a severe course disorder.

Causal relationship between genetically predicted mental disorders and frailty: a bidirectional and multivariable mendelian randomization study

BACKGROUND

In observational studies, frailty has been strongly associated with mental disorders. However, the mechanisms underlying the association between frailty and mental disorders remain unclear.

METHODS

We conducted a two-sample Mendelian randomization (MR) study to assess the causal relationship between frailty, as measured by the frailty index (FI), and ten common mental disorders. The datasets involved European ancestry individuals and included measurements of the FI (N = 175,226), schizophrenia (SCZ; N = 320,404), major depressive disorder (MDD; N = 143,265), bipolar disorder (N = 337,199), insomnia (N = 462,341), obsessive-compulsive disorder (N = 33,925), anxiety disorders (N = 463,010), autism spectrum disorder (N = 46,351), anorexia nervosa (N = 14,477), opioid-related mental and behavioral disorders (N = 215,650), and mental and behavioral disorders due to use of other stimulants including caffeine (N = 215,570).

RESULTS

Two-sample MR analyses were performed using inverse variance weighting followed by various sensitivity and validation analyses. Genetically predicted SCZ (odds ratio [OR] = 1.019, 95% confidence interval [CI] 1.005-1.033) and MDD (OR = 1.211, 95% CI 1.092-1.343) had significant causal effects on FI. In the reverse MR analysis, we discovered that MDD was significantly and causally affected by FI (OR = 1.290, 95% CI 1.133-1.469). No causal links were identified between the FI and the other eight common mental disorders. In the Multivariable MR, the estimated MDD effect on FI is comparable to the univariate IVW estimate (OR = 1.298; 95% CI, 1.175 to 1.435), while the estimated SCZ effect on FI fails to be significant compared to the univariate estimate. The results of the sensitivity and validation analyses confirmed stabilization.

CONCLUSIONS

Our study found evidence of a causal relationship between SCZ, MDD, and frailty and explored the underlying mechanisms.

Epigenetic alterations in patients with anorexia nervosa-a systematic review

Anorexia nervosa (AN) is a complex metabolic and psychological disorder that is influenced by both heritable genetic components and environmental factors. Exposure to various environmental influences can lead to epigenetically induced changes in gene expression. Epigenetic research in AN is still in its infancy, and studies to date are limited in determining clear, valid links to disease onset and progression are limited. Therefore, the aim of this systematic review was to compile and critically evaluate the available results of epigenetic studies specifically in AN and to provide recommendations for future studies. In accordance with the PRISMA guidelines, a systematic literature search was performed in three different databases (PubMed, Embase, and Web of Science) through May 2023. Twenty-three original papers or conference abstracts on epigenetic studies in AN were collected. Epigenome-wide association studies (EWASs), which analyze DNA methylation across the genome in patients with AN and identify potential disease-relevant changes in promoter/regulatory regions of genes, are the most promising for future research. To date, five EWASs on AN have been published, suggesting a potential reversibility of malnutrition-induced epigenetic changes once patients recover. Hence, determining differential DNA methylation levels could serve as a biomarker for disease status or early diagnosis and might be involved in disease progression or chronification. For future research, EWASs with a larger sample size, longitudinal study design and uniform methods should be performed to contribute to the understanding of the pathophysiology of AN, the development of individual interventions and a better prognosis for affected patients.

Convergent molecular signatures across eating disorders and obsessive-compulsive disorder in the human brain

Eating disorders (ED) and obsessive-compulsive disorder (OCD) exhibit significant clinical and genetic overlap, yet their shared molecular mechanisms remain unclear. We conducted a transcriptomic investigation of the dorsolateral prefrontal cortex (DLPFC) and caudate from 86 controls, 57 ED, and 27 OCD cases. ED was associated with robust differentially expressed genes (DEGs): 102 DEGs the DLPFC and 222 in the caudate (FDR < 1%) and replicated in an independent cohort. For OCD, no DEGs reached significance; however, meta-analysis with extant data identified 57 DEGs in the caudate. High concordance in transcriptomic changes was observed between ED and OCD in both regions (DLPFC r=0.67, caudate r=0.75). A combined ED+OCD analysis uncovered 233 DEGs in the DLPFC and 816 in the caudate, implicating disrupted GABAergic neuron function, neuroendocrine pathways, metabolism, and synaptic processes. Genetically regulated expression analysis identified nine genes with strong evidence for increasing ED risk, further validating these pathways. These findings reveal a shared molecular basis for ED and OCD, offering new insights into their pathobiology and potential therapeutic targets.

Comorbidity between internalizing symptoms and disordered eating is primarily driven by genetic influences on emotion regulation in adult female twins

Internalizing (e.g., anxiety, depression) and disordered eating (DE; e.g., binge eating, dietary restraint) are highly comorbid, but the mechanisms underlying their comorbidity remain unknown. This was the first twin study to examine whether their co-occurrence may be driven by genetic and/or environmental influences on emotion regulation (ER; ability to modulate duration/intensity of emotions). Analyses included 688 adult female twins from the MSU Twin Registry. Cholesky decomposition twin models showed comorbidity between dimensionally-modeled internalizing and DE was due to overlapping genetic (r = .55; 69.3% of shared variance) and nonshared environmental influences (r = .26; 30.7% of shared variance). When ER was added into the model, all genetic influences shared between internalizing and DE were attributable to ER, suggesting genetic influences on ER are the primary driver of comorbidity between internalizing and DE. Shared genes may shape affective processing, interoceptive sensitivity, or other brain-based processes (e.g., cognitive control) implicated in ER.

[Therapy of Food Refusal and Anorexia Nervosa in German-Language Psychiatry Textbooks of the Past 200 Years]

The aim of this study was to describe how the therapy of anorexia nervosa (AN) and food refusal have been discussed in leading textbooks used in German-speaking academic psychiatry over the past 200 years. For this purpose, 18 textbooks of important school psychiatrists were selected. These were analyzed in a structured way to determine the content of the subject taught at universities in German-speaking countries at a given period. We found that AN was not taught as a distinct disorder until the end of the 20th century, although great attention had been paid to food refusal as a symptom and manifold therapeutic concepts had been developed much earlier. Whereas at the beginning of the 19th century forced feeding using feeding tubes was established, in the following years pharmacotherapies and special diets were developed. It is noteworthy that since the beginnings of academic psychiatry, some early forms of psychotherapy have been developed; for instance, special kinds of behavior were recommended when dealing with the patient, as the therapist was supposed to serve as a role model to encourage patients to eat. Treatment of food refusal by means of structured psychotherapeutic approaches were not established before AN was generally accepted as a distinct disease entity. The understanding of etiological factors that might lead to AN as well as potential psychotherapeutic interventions have changed fundamentally over the past decades.

Inhibitory neuron links the causal relationship from air pollution to psychiatric disorders: a large multi-omics analysis

Psychiatric disorders are severe health challenges that exert a heavy public burden. Air pollution has been widely reported as related to psychiatric disorder risk, but their casual association and pathological mechanism remained unclear. Herein, we systematically investigated the large genome-wide association studies (6 cohorts with 1,357,645 samples), single-cell RNA (26 samples with 157,488 cells), and bulk-RNAseq (1595 samples) datasets to reveal the genetic causality and biological link between four air pollutants and nine psychiatric disorders. As a result, we identified ten positive genetic correlations between air pollution and psychiatric disorders. Besides, PM2.5 and NO2 presented significant causal effects on schizophrenia risk which was robust with adjustment of potential confounders. Besides, transcriptome-wide association studies identified the shared genes between PM2.5/NO2 and schizophrenia. We then discovered a schizophrenia-derived inhibitory neuron subtype with highly expressed shared genes and abnormal synaptic and metabolic pathways by scRNA analyses and confirmed their abnormal level and correlations with the shared genes in schizophrenia patients in a large RNA-seq cohort. Comprehensively, we discovered robust genetic causality between PM2.5, NO2, and schizophrenia and identified an abnormal inhibitory neuron subtype that links schizophrenia pathology and PM2.5/NO2 exposure. These discoveries highlight the schizophrenia risk under air pollutants exposure and provide novel mechanical insights into schizophrenia pathology, contributing to pollutant-related schizophrenia risk control and therapeutic strategies development.

Graphical Abstract

Descriptives and genetic correlates of eating disorder diagnostic transitions and presumed remission in the Danish registry

Objective

Eating disorders (EDs) are serious psychiatric disorders with an estimated 3.3 million healthy life-years lost worldwide yearly. Understanding the course of illness, diagnostic transitions and remission, and their associated genetic correlates could inform both ED etiology and treatment. The authors investigated occurrences of ED transitions and presumed remission and their genetic correlates as captured by polygenic scores (PGSs) in a large Danish register-based cohort.

Methods

The sample compromised of 10,565 individuals with a diagnosis of anorexia nervosa (AN), bulimia nervosa (BN), or eating disorder not otherwise specified (EDNOS) with at least two registered hospital contacts between 1995 and 2018. Based on medical records, occurrence of diagnostic transitions and periods of presumed remission were identified. Associations between 422 PGS and diagnostic transitions and presumed remission were evaluated using Cox proportional hazard models.

Results

A minority of ED cases (14.1%-23.1%) experienced a diagnostic transition. Presumed remission ranged between 86.9%-89.8%. Higher (one SD increase) PGS for major depressive disorder and multisite chronic pain were positively associated with transitioning from AN to either BN or EDNOS. Higher PGS on a measure of body fat percentage and financial difficulties were positively associated with presumed remission from AN. Higher PGS for mood swings was positively associated with presumed remission from EDNOS whereas higher PGS for health rating showed the opposite.

Conclusions

The authors found that most ED patients did not experience diagnostic transitions but were more likely to experience a period of presumed remission. Both diagnostic transitions and presumed remission have significant polygenic component.

Cognitive processing speed and accuracy are intrinsically different in genetic architecture and brain phenotypes

Since the birth of cognitive science, researchers have used reaction time and accuracy to measure cognitive ability. Although recognition of these two measures is often based on empirical observations, the underlying consensus is that most cognitive behaviors may be along two fundamental dimensions: cognitive processing speed (CPS) and cognitive processing accuracy (CPA). In this study, we used genomic-wide association studies (GWAS) data from 14 cognitive traits to show the presence of those two factors and revealed the specific neurobiological basis underlying them. We identified that CPS and CPA had distinct brain phenotypes (e.g. white matter microstructure), neurobiological bases (e.g. postsynaptic membrane), and developmental periods (i.e. late infancy). Moreover, those two factors showed differential associations with other health-related traits such as screen exposure and sleep status, and a significant causal relationship with psychiatric disorders such as major depressive disorder and schizophrenia. Utilizing an independent cohort from the Adolescent Brain Cognitive Development (ABCD) study, we also uncovered the distinct contributions of those two factors on the cognitive development of young adolescents. These findings reveal two fundamental factors underlying various cognitive abilities, elucidate the distinct brain structural fingerprint and genetic architecture of CPS and CPA, and hint at the complex interrelationship between cognitive ability, lifestyle, and mental health.

Identification of State Markers in Anorexia Nervosa: Replication and Extension of Inflammation-Associated Biomarkers Using Multiplex Profiling

Background

Proteomics offers potential for detecting and monitoring anorexia nervosa (AN) and its variant, atypical AN (atyp-AN). However, research has been limited by small protein panels, a focus on adult AN, and lack of replication.

Methods

In this study, we performed Olink multiplex profiling of 92 inflammation-related proteins in females with AN/atyp-AN (n = 64), all of whom were ≤90% of expected body weight, and age-matched healthy control individuals (n = 44).

Results

Five proteins differed significantly between the primary AN/atyp-AN group and the healthy control group (lower levels: HGF, IL-18R1, TRANCE; higher levels: CCL23, LIF-R). The expression levels of 3 proteins (lower IL-18R1, TRANCE; higher LIF-R) were uniquely disrupted in participants with AN in our primary model. No unique expression levels emerged for atyp-AN. In the total sample, 12 proteins (ADA, CD5, CD6, CXCL1, FGF-21, HGF, IL-12B, IL18, IL-18R1, SIRT2, TNFSF14, TRANCE) were positively correlated with body mass index and 5 proteins (CCL11, FGF-19, IL8, LIF-R, OPG) were negatively correlated with body mass index in our primary models.

Conclusions

Our results replicate the results of a previous study that demonstrated a dysregulated inflammatory status in AN and extend those results to atyp-AN. Of the 17 proteins correlated with body mass index, 11 were replicated from a previous study that used similar methods, highlighting the promise of inflammatory protein expression levels as biomarkers of AN disease monitoring. Our findings underscore the complexity of AN and atyp-AN by highlighting the inability of the identified proteins to differentiate between these 2 subtypes, thereby emphasizing the heterogeneous nature of these disorders.

Shared Genetic Architecture Between Schizophrenia and Anorexia Nervosa: A Cross-trait Genome-Wide Analysis

BACKGROUND AND HYPOTHESIS

Schizophrenia (SCZ) and anorexia nervosa (AN) are 2 severe and highly heterogeneous disorders showing substantial familial co-aggregation. Genetic factors play a significant role in both disorders, but the shared genetic etiology between them is yet to be investigated.

STUDY DESIGN

Using summary statistics from recent large genome-wide association studies on SCZ (Ncases = 53 386) and AN (Ncases = 16 992), a 2-sample Mendelian randomization analysis was conducted to explore the causal relationship between SCZ and AN. MiXeR was employed to quantify their polygenic overlap. A conditional/conjunctional false discovery rate (condFDR/conjFDR) framework was adopted to identify loci jointly associated with both disorders. Functional annotation and enrichment analyses were performed on the shared loci.

STUDY RESULTS

We observed a cross-trait genetic enrichment, a suggestive bidirectional causal relationship, and a considerable polygenic overlap (Dice coefficient = 62.2%) between SCZ and AN. The proportion of variants with concordant effect directions among all shared variants was 69.9%. Leveraging overlapping genetic associations, we identified 6 novel loci for AN and 33 novel loci for SCZ at condFDR <0.01. At conjFDR <0.05, we identified 10 loci jointly associated with both disorders, implicating multiple genes highly expressed in the cerebellum and pituitary and involved in synapse organization. Particularly, high expression of the shared genes was observed in the hippocampus in adolescence and orbitofrontal cortex during infancy.

CONCLUSIONS

This study provides novel insights into the relationship between SCZ and AN by revealing a shared genetic component and offers a window into their complex etiology.

Dynamic convergence of autism disorder risk genes across neurodevelopment

Over a hundred risk genes underlie risk for autism spectrum disorder (ASD) but the extent to which they converge on shared downstream targets to increase ASD risk is unknown. To test the hypothesis that cellular context impacts the nature of convergence, here we apply a pooled CRISPR approach to target 29 ASD loss-of-function genes in human induced pluripotent stem cell (hiPSC)-derived neural progenitor cells, glutamatergic neurons, and GABAergic neurons. Two distinct approaches (gene-level and network-level analyses) demonstrate that convergence is greatest in mature glutamatergic neurons. Convergent effects are dynamic, varying in strength, composition, and biological role between cell types, increasing with functional similarity of the ASD genes examined, and driven by cell-type-specific gene co-expression patterns. Stratification of ASD genes yield targeted drug predictions capable of reversing gene-specific convergent signatures in human cells and ASD-related behaviors in zebrafish. Altogether, convergent networks downstream of ASD risk genes represent novel points of individualized therapeutic intervention.

Causal Relationship between Aging and Anorexia Nervosa: A White-Matter-Microstructure-Mediated Mendelian Randomization Analysis

This study employed a two-step Mendelian randomization analysis to explore the causal relationship between telomere length, as a marker of aging, and anorexia nervosa and to evaluate the mediating role of changes in the white matter microstructure across different brain regions. We selected genetic variants associated with 675 diffusion magnetic resonance imaging phenotypes representing changes in brain white matter. F-statistics confirmed the validity of the instruments, ensuring robust causal inference. Sensitivity analyses, including heterogeneity tests, horizontal pleiotropy tests, and leave-one-out tests, validated the results. The results show that telomere length is significantly negatively correlated with anorexia nervosa in a unidirectional manner (p = 0.017). Additionally, changes in specific white matter structures, such as the internal capsule, corona radiata, posterior thalamic radiation, left cingulate gyrus, left longitudinal fasciculus, and left forceps minor (p < 0.05), were identified as mediators. These findings enhance our understanding of the neural mechanisms, underlying the exacerbation of anorexia nervosa with aging; emphasize the role of brain functional networks in disease progression; and provide potential biological targets for future therapeutic interventions.

An advanced Artificial Intelligence platform for a personalised treatment of Eating Disorders

Introduction

Eating Disorders (EDs) affect individuals globally and are associated with significant physical and mental health challenges. However, access to adequate treatment is often hindered by societal stigma, limited awareness, and resource constraints.

Methods

The project aims to utilize the power of Artificial Intelligence (AI), particularly Machine Learning (ML) and Deep Learning (DL), to improve EDs diagnosis and treatment. The Master Data Plan (MDP) will collect and analyze data from diverse sources, utilize AI algorithms for risk factor identificat io n, treatment planning, and relapse prediction, and provide a patient-facing chatbot for information and support. This platform will integrate patient data, support healthcare professionals, and empower patients, thereby enhancing care accessibility, personalizing treatment plans, and optimizing care pathways. Robust data governance measures will ensure ethical and secure data management.

Results

Anticipated outcomes include enhanced care accessibility and efficiency, personalized treatment plans leading to improved patient outcomes, reduced waiting lists, heightened patient engagement, and increased awareness of EDs with improved resource allocation.

Discussion

This project signifies a pivotal shift towards data-driven, patient-centered ED care in Italy. By integrat ing AI and promoting collaboration, it seeks to redefine mental healthcare standards and foster better well- being among individuals with EDs.

Building Confidence in Discussing Genetics With Patients With Eating Disorders and Their Families

Many individuals with eating disorders and their family members are well-informed about advances in science that could affect the treatment and outcome of these illnesses. They appropriately apply this knowledge to evaluate available treatments and advocate for the best possible evidence-based care. They ask hard questions that many clinicians are often ill-prepared to answer. Genetics has advanced our understanding of eating disorders and provides a novel lens through which to understand these pernicious illnesses. Clinicians can now update their understanding of the etiology of eating disorders and abandon outdated etiological theories, some of which have done harm to patients and their families. Without becoming expert in psychiatric genetics, psychiatrists and other mental health care professionals can develop a general overview of the science, understand what it can and cannot offer, incorporate genetic factors into their case conceptualizations, and boost their confidence in discussing these topics with patients and families.

Discrimination between healthy participants and people with panic disorder based on polygenic scores for psychiatric disorders and for intermediate phenotypes using machine learning

OBJECTIVE

Panic disorder is a modestly heritable condition. Currently, diagnosis is based only on clinical symptoms; identifying objective biomarkers and a more reliable diagnostic procedure is desirable. We investigated whether people with panic disorder can be reliably diagnosed utilizing combinations of multiple polygenic scores for psychiatric disorders and their intermediate phenotypes, compared with single polygenic score approaches, by applying specific machine learning techniques.

METHODS

Polygenic scores for 48 psychiatric disorders and intermediate phenotypes based on large-scale genome-wide association studies (n = 7556-1,131,881) were calculated for people with panic disorder (n = 718) and healthy controls (n = 1717). Discrimination between people with panic disorder and healthy controls was based on the 48 polygenic scores using five methods for classification: logistic regression, neural networks, quadratic discriminant analysis, random forests and a support vector machine. Differences in discrimination accuracy (area under the curve) due to an increased number of polygenic score combinations and differences in the accuracy across five classifiers were investigated.

RESULTS

All five classifiers performed relatively well for distinguishing people with panic disorder from healthy controls by increasing the number of polygenic scores. Of the 48 polygenic scores, the polygenic score for anxiety UK Biobank was the most useful for discrimination by the classifiers. In combinations of two or three polygenic scores, the polygenic score for anxiety UK Biobank was included as one of polygenic scores in all classifiers. When all 48 polygenic scores were used in combination, the greatest areas under the curve significantly differed among the five classifiers. Support vector machine and logistic regression had higher accuracy than quadratic discriminant analysis and random forests. For each classifier, the greatest area under the curve was 0.600 ± 0.030 for logistic regression (polygenic score combinations N = 14), 0.591 ± 0.039 for neural networks (N = 9), 0.603 ± 0.033 for quadratic discriminant analysis (N = 10), 0.572 ± 0.039 for random forests (N = 25) and 0.617 ± 0.041 for support vector machine (N = 11). The greatest areas under the curve at the best polygenic score combination significantly differed among the five classifiers. Random forests had the lowest accuracy among classifiers. Support vector machine had higher accuracy than neural networks.

CONCLUSIONS

These findings suggest that increasing the number of polygenic score combinations up to approximately 10 effectively improved the discrimination accuracy and that support vector machine exhibited greater accuracy among classifiers. However, the discrimination accuracy for panic disorder, when based solely on polygenic score combinations, was found to be modest.

Shared molecular mechanisms and transdiagnostic potential of neurodevelopmental disorders and immune disorders

The co-occurrence and familial clustering of neurodevelopmental disorders and immune disorders suggest shared genetic risk factors. Based on genome-wide association summary statistics from five neurodevelopmental disorders and four immune disorders, we conducted genome-wide, local genetic correlation and polygenic overlap analysis. We further performed a cross-trait GWAS meta-analysis. Pleotropic loci shared between the two categories of diseases were mapped to candidate genes using multiple algorithms and approaches. Significant genetic correlations were observed between neurodevelopmental disorders and immune disorders, including both positive and negative correlations. Neurodevelopmental disorders exhibited higher polygenicity compared to immune disorders. Around 50%-90% of genetic variants of the immune disorders were shared with neurodevelopmental disorders. The cross-trait meta-analysis revealed 154 genome-wide significant loci, including 8 novel pleiotropic loci. Significant associations were observed for 30 loci with both types of diseases. Pathway analysis on the candidate genes at these loci revealed common pathways shared by the two types of diseases, including neural signaling, inflammatory response, and PI3K-Akt signaling pathway. In addition, 26 of the 30 lead SNPs were associated with blood cell traits. Neurodevelopmental disorders exhibit complex polygenic architecture, with a subset of individuals being at a heightened genetic risk for both neurodevelopmental and immune disorders. The identification of pleiotropic loci has important implications for exploring opportunities for drug repurposing, enabling more accurate patient stratification, and advancing genomics-informed precision in the medical field of neurodevelopmental disorders.

Clinical characterization of Co-morbid autoimmune disease and eating disorders: a retrospective chart review

Research suggests a link between autoimmune illnesses (AI) and eating disorders (ED). We retrospectively reviewed charts of adolescent patients presenting for eating disorder treatment. We compared the presentation and treatment course for those with an ED and comorbid AI [with (GI-AI, N = 59) or without (non-GI, N = 21) gastrointestinal inflammation] with matched ED-only cases. The sample was overwhelmingly female, with an average age of 15.40. Weight gain trajectories differed across groups, with similar rates of weight gain between controls and non GI-AI cases and with a lower rate of weight gain for individuals with comorbid GI-AI. Over half (56%) of patients reported an AI diagnosis prior to ED; 38% reported an AI diagnosis following ED, and 6% reported ED and AI simultaneous diagnosis. On presentation, ED-only controls had higher rates of comorbid anxiety than cases in either AI group, while those with non-GI AI were more likely to report depression. Mean total GI symptoms, % goal weight at presentation, vital sign instability, and markers of refeeding syndrome did not differ across groups. Health care professionals treating patients with either condition should have a low threshold for asking additional questions to identify the presence of the other condition.

Interplay of polygenic liability with birth-related, somatic, and psychosocial factors in anorexia nervosa risk: a nationwide study

BACKGROUND

Although several types of risk factors for anorexia nervosa (AN) have been identified, including birth-related factors, somatic, and psychosocial risk factors, their interplay with genetic susceptibility remains unclear. Genetic and epidemiological interplay in AN risk were examined using data from Danish nationwide registers. AN polygenic risk score (PRS) and risk factor associations, confounding from AN PRS and/or parental psychiatric history on the association between the risk factors and AN risk, and interactions between AN PRS and each level of target risk factor on AN risk were estimated.

METHODS

Participants were individuals born in Denmark between 1981 and 2008 including nationwide-representative data from the iPSYCH2015, and Danish AN cases from the Anorexia Nervosa Genetics Initiative and Eating Disorder Genetics Initiative cohorts. A total of 7003 individuals with AN and 45 229 individuals without a registered AN diagnosis were included. We included 22 AN risk factors from Danish registers.

RESULTS

Risk factors showing association with PRS for AN included urbanicity, parental ages, genitourinary tract infection, and parental socioeconomic factors. Risk factors showed the expected association to AN risk, and this association was only slightly attenuated when adjusted for parental history of psychiatric disorders or/and for the AN PRS. The interaction analyses revealed a differential effect of AN PRS according to the level of the following risk factors: sex, maternal age, genitourinary tract infection, C-section, parental socioeconomic factors and psychiatric history.

CONCLUSIONS

Our findings provide evidence for interactions between AN PRS and certain risk-factors, illustrating potential diverse risk pathways to AN diagnosis.

Toward a memory perspective on eating psychopathology: An investigation of the types of childhood and adolescence memories that are associated with eating disorder symptoms

The cognitive mechanisms through which specific life events affect the development and maintenance of eating disorders (ED) have received limited attention in the scientific literature. The present research aims to address this gap by adopting a memory perspective to explore the type of life events associated with eating psychopathology and how these events are encoded and reconstructed as memories. Two studies (n = 208 and n = 193) were conducted to investigate the relationship between specific memories and eating disorder psychopathology. Study 1 focused on parent-related memories, while Study 2 examined childhood/adolescence memories. Results from both studies revealed that need thwarting and shame in memories were associated with eating disorder symptoms, but only when individuals drew symbolic connections between these memories and food or eating behavior. Moreover, need thwarting and shame in such memories were associated with other eating and body image outcomes, including uncontrolled eating and body esteem. These results also held after controlling for a host of known predictors of eating disorder psychopathology, such as BMI, perfectionism, or thin ideal internalization. Overall, the present findings suggest that the reprocessing of memories symbolically and idiosyncratically linked to food and eating behavior might be a fruitful clinical intervention.

Examining the role of artificial intelligence to advance knowledge and address barriers to research in eating disorders

OBJECTIVE

To provide a brief overview of artificial intelligence (AI) application within the field of eating disorders (EDs) and propose focused solutions for research.

METHOD

An overview and summary of AI application pertinent to EDs with focus on AI's ability to address issues relating to data sharing and pooling (and associated privacy concerns), data augmentation, as well as bias within datasets is provided.

RESULTS

In addition to clinical applications, AI can utilize useful tools to help combat commonly encountered challenges in ED research, including issues relating to low prevalence of specific subpopulations of patients, small overall sample sizes, and bias within datasets.

DISCUSSION

There is tremendous potential to embed and utilize various facets of artificial intelligence (AI) to help improve our understanding of EDs and further evaluate and investigate questions that ultimately seek to improve outcomes. Beyond the technology, issues relating to regulation of AI, establishing ethical guidelines for its application, and the trust of providers and patients are all needed for ultimate adoption and acceptance into ED practice.

PUBLIC SIGNIFICANCE

Artificial intelligence (AI) offers a promise of significant potential within the realm of eating disorders (EDs) and encompasses a broad set of techniques that offer utility in various facets of ED research and by extension delivery of clinical care. Beyond the technology, issues relating to regulation, establishing ethical guidelines for application, and the trust of providers and patients are needed for the ultimate adoption and acceptance of AI into ED practice.

Sustained insulin treatment restoring metabolic status, body weight, and cognition in an anorexia nervosa-like animal model in mice

INTRODUCTION

Anorexia Nervosa (AN) is a psycho-socio-biological disease characterized by severe weight loss as result of dieting and hyperactivity. Effective treatments are scarce, despite its significant prevalence and mortality. AN patients show lower basal insulin levels and increased metabolic clearance, leading to weight loss, cognitive deficits, and hormonal imbalances. Low-dose polymer insulin could potentially reverse these effects by restoring brain function, reducing fear of weight gain, encouraging food intake, and restoring fat depots. This study evaluates an insulin delivery system designed for sustained release and AN treatment.

METHODS

AN-like model was established through dietary restriction (DR). On days 1-25, mice were on DR, and on days 26-31 they were on ad libitum regimen. An insulin-loaded delivery system was administered subcutaneously (1% w/w insulin). The impact of insulin treatment on gene expression in the hippocampus (cognition, regulation of stress, neurogenesis) and hypothalamus (eating behavior, mood) was assessed. Behavioral assays were conducted to evaluate motor activity and cognitive function.

RESULTS

The delivery system demonstrated sustained insulin release, maintaining therapeutic plasma levels. Diet restriction mice treated with the insulin delivery system showed body weight restoration. Gene expression analysis revealed enhanced expression of CB1 and CB2 genes associated with improved eating behavior and cognition, while POMC expression was reduced. Insulin-polymer treatment restored cognitive function and decreased hyperactivity in the AN-like model.

CONCLUSION

The PSA-RA-based insulin delivery system effectively restores metabolic balance, body weight, and cognitive function in the AN model. Its ability to steadily release insulin makes it a promising candidate for AN treatment."

Genetic variants for head size share genes and pathways with cancer

The size of the human head is highly heritable, but genetic drivers of its variation within the general population remain unmapped. We perform a genome-wide association study on head size (N = 80,890) and identify 67 genetic loci, of which 50 are novel. Neuroimaging studies show that 17 variants affect specific brain areas, but most have widespread effects. Gene set enrichment is observed for various cancers and the p53, Wnt, and ErbB signaling pathways. Genes harboring lead variants are enriched for macrocephaly syndrome genes (37-fold) and high-fidelity cancer genes (9-fold), which is not seen for human height variants. Head size variants are also near genes preferentially expressed in intermediate progenitor cells, neural cells linked to evolutionary brain expansion. Our results indicate that genes regulating early brain and cranial growth incline to neoplasia later in life, irrespective of height. This warrants investigation of clinical implications of the link between head size and cancer.

Fatty Acids and Their Lipogenic Enzymes in Anorexia Nervosa Clinical Subtypes

Disordered eating behavior differs between the restricting subtype (AN-R) and the binging and purging subtype (AN-BP) of anorexia nervosa (AN). Yet, little is known about how these differences impact fatty acid (FA) dysregulation in AN. To address this question, we analyzed 26 FAs and 7 FA lipogenic enzymes (4 desaturases and 3 elongases) in 96 women: 25 AN-R, 25 AN-BP, and 46 healthy control women. Our goal was to assess subtype-specific patterns. Lauric acid was significantly higher in AN-BP than in AN-R at the fasting timepoint (p = 0.038) and displayed significantly different postprandial changes 2 h after eating. AN-R displayed significantly higher levels of n-3 alpha-linolenic acid, stearidonic acid, eicosapentaenoic acid (EPA), docosapentaenoic acid, and n-6 linoleic acid and gamma-linolenic acid compared to controls. AN-BP showed elevated EPA and saturated lauric acid compared to controls. Higher EPA was associated with elevated anxiety in AN-R (p = 0.035) but was linked to lower anxiety in AN-BP (p = 0.043). These findings suggest distinct disordered eating behaviors in AN subtypes contribute to lipid dysregulation and eating disorder comorbidities. A personalized dietary intervention may improve lipid dysregulation and enhance treatment effectiveness for AN.

Association of mental disorders with sepsis: a bidirectional Mendelian randomization study

Background

Substantial research evidence supports the correlation between mental disorders and sepsis. Nevertheless, the causal connection between a particular psychological disorder and sepsis remains unclear.

Methods

For investigating the causal relationships between mental disorders and sepsis, genetic variants correlated with mental disorders, including anorexia nervosa (AN), attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), bipolar disorder (BD), major depressive disorder (MDD), obsessive-compulsive disorder (OCD), panic disorder (PD), posttraumatic stress disorder (PTSD), schizophrenia (SCZ), and tourette syndrome (TS), were all extracted from the Psychiatric Genomics Consortium (PGC). The causal estimates and direction between these mental disorders and sepsis were evaluated employing a two-sample bidirectional MR strategy. The inverse variance weighted (IVW) method was the primary approach utilized. Various sensitivity analyses were performed to confirm the validity of the causal effect. Meta-analysis, multivariable MR, and mediation MR were conducted to ensure the credibility and depth of this research.

Results

The presence of AN was in relation to a greater likelihood of sepsis (OR 1.08, 95% CI 1.02-1.14; p = 0.013). A meta-analysis including validation cohorts supported this observation (OR 1.06, 95% CI 1.02-1.09). None of the investigated mental disorders appeared to be impacted when sepsis was set as the exposure factor. Even after adjusting for confounding factors, AN remained statistically significant (OR 1.08, 95% CI 1.02-1.15; p = 0.013). Mediation analysis indicated N-formylmethionine levels (with a mediated proportion of 7.47%), cystatin D levels (2.97%), ketogluconate Metabolism (17.41%) and N10-formyl-tetrahydrofolate biosynthesis (20.06%) might serve as mediators in the pathogenesis of AN-sepsis.

Conclusion

At the gene prediction level, two-sample bidirectional MR analysis revealed that mental disorder AN had a causal association with an increased likelihood of sepsis. In addition, N-formylmethionine levels, cystatin D levels, ketogluconate metabolism and N10-formyl-tetrahydrofolate biosynthesis may function as potential mediators in the pathophysiology of AN-sepsis. Our research may contribute to the investigation of novel therapeutic strategies for mental illness and sepsis.

Anorexia nervosa and bulimia nervosa: a Mendelian randomization study of gut microbiota

Background

Anorexia nervosa (AN) and bulimia nervosa (BN) poses a significant challenge to global public health. Despite extensive research, conclusive evidence regarding the association between gut microbes and the risk of AN and BN remains elusive. Mendelian randomization (MR) methods offer a promising avenue for elucidating potential causal relationships.

Materials and methods

Genome-wide association studies (GWAS) datasets of AN and BN were retrieved from the OpenGWAS database for analysis. Independent single nucleotide polymorphisms closely associated with 196 gut bacterial taxa from the MiBioGen consortium were identified as instrumental variables. MR analysis was conducted utilizing R software, with outlier exclusion performed using the MR-PRESSO method. Causal effect estimation was undertaken employing four methods, including Inverse variance weighted. Sensitivity analysis, heterogeneity analysis, horizontal multivariate analysis, and assessment of causal directionality were carried out to assess the robustness of the findings.

Results

A total of 196 bacterial taxa spanning six taxonomic levels were subjected to analysis. Nine taxa demonstrating potential causal relationships with AN were identified. Among these, five taxa, including Peptostreptococcaceae, were implicated as exerting a causal effect on AN risk, while four taxa, including Gammaproteobacteria, were associated with a reduced risk of AN. Similarly, nine taxa exhibiting potential causal relationships with BN were identified. Of these, six taxa, including Clostridiales, were identified as risk factors for increased BN risk, while three taxa, including Oxalobacteraceae, were deemed protective factors. Lachnospiraceae emerged as a common influence on both AN and BN, albeit with opposing effects. No evidence of heterogeneity or horizontal pleiotropy was detected for significant estimates.

Conclusion

Through MR analysis, we revealed the potential causal role of 18 intestinal bacterial taxa in AN and BN, including Lachnospiraceae. It provides new insights into the mechanistic basis and intervention targets of gut microbiota-mediated AN and BN.

The impact of assortative mating, participation bias and socioeconomic status on the polygenic risk of behavioural and psychiatric traits

To investigate assortative mating (AM), participation bias and socioeconomic status (SES) with respect to the genetics of behavioural and psychiatric traits, we estimated AM signatures using gametic phase disequilibrium and within-spouses and within-siblings polygenic risk score correlation analyses, also performing a SES conditional analysis. The cross-method meta-analysis identified AM genetic signatures for multiple alcohol-related phenotypes, bipolar disorder, major depressive disorder, schizophrenia and Tourette syndrome. Here, after SES conditioning, we observed changes in the AM genetic signatures for maximum habitual alcohol intake, frequency of drinking alcohol and Tourette syndrome. We also observed significant gametic phase disequilibrium differences between UK Biobank mental health questionnaire responders versus non-responders for major depressive disorder and alcohol use disorder. These results highlight the impact of AM, participation bias and SES on the polygenic risk of behavioural and psychiatric traits, particularly in alcohol-related traits.

Inclusion of the severe and enduring anorexia nervosa phenotype in genetics research: a scoping review

BACKGROUND

Anorexia nervosa has one of the highest mortality rates of all mental illnesses. For those who survive, less than 70% fully recover, with many going on to develop a more severe and enduring phenotype. Research now suggests that genetics plays a role in the development and persistence of anorexia nervosa. Inclusion of participants with more severe and enduring illness in genetics studies of anorexia nervosa is critical.

OBJECTIVE

The primary goal of this review was to assess the inclusion of participants meeting the criteria for the severe enduring anorexia nervosa phenotype in genetics research by (1) identifying the most widely used defining criteria for severe enduring anorexia nervosa and (2) performing a review of the genetics literature to assess the inclusion of participants meeting the identified criteria.

METHODS

Searches of the genetics literature from 2012 to 2023 were performed in the PubMed, PsycINFO, and Web of Science databases. Publications were selected per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The criteria used to define the severe and enduring anorexia nervosa phenotype were derived by how often they were used in the literature since 2017. The publications identified through the literature search were then assessed for inclusion of participants meeting these criteria.

RESULTS

most prevalent criteria used to define severe enduring anorexia nervosa in the literature were an illness duration of ≥ 7 years, lack of positive response to at least two previous evidence-based treatments, a body mass index meeting the Diagnostic and Statistical Manual of Mental Disorders-5 for extreme anorexia nervosa, and an assessment of psychological and/or behavioral severity indicating a significant impact on quality of life. There was a lack of consistent identification and inclusion of those meeting the criteria for severe enduring anorexia nervosa in the genetics literature.

DISCUSSION

This lack of consistent identification and inclusion of patients with severe enduring anorexia nervosa in genetics research has the potential to hamper the isolation of risk loci and the development of new, more effective treatment options for patients with anorexia nervosa.