Estimating the Prevalence and Genetic Risk Mechanisms of ARFID in a Large Autism Cohort

Social communication and restricted, repetitive behavior as assessed with a diagnostic tool for autism (ADOS-2) in women with anorexia nervosa

OBJECTIVE

In anorexia nervosa (AN), the traits of autism spectrum disorder (ASD) are associated with poor outcomes. However, the subtle nature of these characteristics remains poorly understood. We investigated the in-depth patterns of ASD traits using Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) in women with AN.

METHODS

Of 28 women with ICD-10 AN, 16 (age 19-30 years) participated in the ADOS-2, a video-recorded, semistructured diagnostic assessment for social communication and interaction and restricted, repetitive behaviors and interests related to ASD. None of the participants had previously been diagnosed with ASD. Other measurements included the Eating Disorder Examination Questionnaire and the Wechsler Abbreviated Scale of Intelligence-IV.

RESULTS

Five individuals (18% of all, 31% of those assessed) scored above the cutoff for autism in ADOS-2. They had challenges in social communication and interaction, manifesting as sustained difficulties in social relationships and deficits in conversation skills. Few described being frequently misunderstood by others, including in the eating disorder treatment settings. Three individuals showed prominent restricted and repetitive behaviors such as ritual seeking, eating-related routines, sensory sensitivity related to food texture and selective eating, and intense interest in specific topics. The mean duration of AN in women above the cutoff was twice as long compared with those below (12.3 vs. 6.2 years).

DISCUSSION

The ASD-related characteristics and behavior appear to contribute to the manifestation and duration of AN in a subgroup of women. Among these women, the traits of ASD appear to be mixed with eating disorder symptoms, which should be taken into account in the treatment.

Avoidant/Restrictive Food Intake Disorder: Review and Recent Advances

Avoidant/restrictive food intake disorder (ARFID) is an eating disorder recently codified in DSM-5 that affects individuals of all ages. A proliferation of ARFID research has emerged over the years, and this review provides a brief overview of the current understanding of ARFID epidemiology, symptoms, comorbid conditions, assessment, and treatment. The review highlights recent research updates regarding ARFID among adults, putative neurobiological mechanisms underlying ARFID, and new treatment trials. Findings from this review demonstrate that ARFID is as prevalent as other eating disorders, even among adults, and is associated with significant medical and psychiatric comorbid conditions. New, promising treatments for children, adolescents, and adults are in the early stages of development. Several assessments are now available to aid in the screening and diagnosis of ARFID and have demonstrated cross-cultural validity. Areas for future research and clinical guidance, including unresolved questions regarding ARFID categorization and differential diagnosis, are discussed.

Potential mechanisms underlying the association between feeding and eating disorders and autism

There is a reliable association between autism and Feeding and Eating Disorders. Concerningly, where these two conditions co-occur, clinical outcomes of Feeding and Eating Disorders are significantly worse, and treatment less effective, than when the Feeding and Eating Disorders occur in neurotypical individuals. Problematically, the reason for the association between autism and Feeding and Eating Disorders is poorly understood, which constrains advances in clinical care. This paper outlines several possible mechanisms that may underlie the observed association and suggests ways in which they may be empirically tested. Mechanisms are split into those producing an artefactual association, and those reflecting a genuine link between conditions. Artefactual associations may be due to conceptual overlap in both diagnostic criteria and measurement, Feeding and Eating Disorders causing transient autistic traits, or the association being non-specific in nature. A genuine association between autism and Feeding and Eating Disorders may be due to common causal factors, autism directly or indirectly causing Feeding and Eating Disorders, and Feeding and Eating Disorders being a female manifestation of autism.

Analysis of feeding and eating disorders in 191 children according to psychiatric or gastroenterological recruitment: The PEDIAFED cohort study

OBJECTIVE

The DSM-5 classification introduced new Feeding and Eating Disorders (FED) diagnostic categories, notably Avoidant and Restrictive Food Intake Disorder (ARFID), which, like other FED, can present psychiatric and gastrointestinal symptoms. However, paediatric clinical research that focuses on children below the age of 12 years remains scarce. The aim of this study was first to investigate the clinical features of FED in a cohort of children, second to compare them according to their recruitment (gastroenterology or psychiatry unit).

METHOD

This non-interventional retrospective cohort study analysed 191 patients in a French paediatric tertiary care centre (gastroenterology n = 100, psychiatry n = 91). The main outcome variables were clinical data (type of FED, BMI, nutritional support, chronic diseases, psychiatric comorbidities, sensory, sleep, language disorders, gastrointestinal complaints, adverse life events, family history). The outcome was defined by a Clinical Global Impression of Change-score.

RESULTS

FED diagnoses were ARFID (n = 100), Unspecified FED (UFED, n = 57), anorexia nervosa (AN, n = 33) and one pica/rumination. Mean follow-up was 3.28 years (SD 1.91). ARFID was associated with selective and sensory disorders (p < 0.001); they had more anxiety disorders than patients with UFED (p < 0.001). Patients with UFED had more chewing difficulties, language disorder (p < 0.001), and more FED related to chronic disease (p < 0.05) than patients with ARFID and AN. Patients with AN were female, underweight, referred exclusively to the psychiatrist, and had more depression than patients with ARFID and UFED (p < 0.001). The gastroenterology cohort included more UFED, while the psychiatry cohort included more psychiatric comorbidities (p < 0.001). A worse clinical outcome was associated with ARFID, a younger age at onset (p < 0.001), selective/sensory disorders and nutritional support (p < 0.05).

CONCLUSION

ARFID and UFED children were diagnosed either by gastroenterologists or psychiatrists. Due to frequently associated somatic and psychiatric comorbidities, children with FED should benefit from a multidisciplinary assessment and care.

Pediatric hospital utilization for patients with avoidant restrictive food intake disorder

BACKGROUND

Avoidant restrictive food intake disorder (ARFID) is a relatively new feeding and eating disorder added to the DSM-5 in 2013 and ICD-10 in 2018. Few studies have examined hospital utilization for patients with ARFID specifically, and none to date have used large administrative cohorts. We examined inpatient admission volume over time and hospital utilization and 30-day readmissions for patients with ARFID at pediatric hospitals in the United States.

METHODS

Using data from the Pediatric Health Information System (PHIS), we identified inpatient admissions for patients with ARFID (by principal International Classification of Diseases, 10th Revision, ICD-10 diagnosis code) discharged October 2017-June 2022. We examined the change over time in ARFID volume and associations between patient-level factors (e.g., sociodemographic characteristics, co-morbid conditions including anxiety and depressive disorders and malnutrition), hospital ARFID volume, and hospital utilization including length of stay (LOS), costs, use of enteral tube feeding or GI imaging during admission, and 30-day readmissions. Adjusted regression models were used to examine associations between sociodemographic and clinical factors on LOS, costs, and 30-day readmissions.

RESULTS

Inpatient ARFID volume across n = 44 pediatric hospitals has increased over time (β = 0.36 per month; 95% CI 0.26-0.46; p < 0.001). Among N = 1288 inpatient admissions for patients with ARFID, median LOS was 7 days (IQR = 8) with median costs of $16,583 (IQR = $18,115). LOS and costs were highest in hospitals with higher volumes of ARFID patients. Younger age, co-morbid conditions, enteral feeding, and GI imaging were also associated with LOS. 8.5% of patients were readmitted within 30 days. In adjusted models, there were differences in the likelihood of readmission by age, insurance, malnutrition diagnosis at index visit, and GI imaging procedures during index visit.

CONCLUSIONS

Our results indicate that the volume of inpatient admissions for patients with ARFID has increased at pediatric hospitals in the U.S. since ARFID was added to ICD-10. Inpatient stays for ARFID are long and costly and associated with readmissions. It is important to identify effective and efficient treatment strategies for ARFID in the future.

The Sensory Profiles, Eating Behaviors, and Quality of Life of Children with Autism Spectrum Disorder and Avoidant/Restrictive Food Intake Disorder

Eating disorders frequently accompany autism spectrum disorder (ASD). One such novel eating disorder is avoidant/restrictive food intake disorder (ARFID). This study compares the eating attitudes, quality of life, and sensory processing of typically developing children (TDC), autistic children, and autistic children with ARFID. A total of 111 children aged 4-10 with a diagnosis of ASD and ARFID (n = 37), ASD without ARFID (n = 37), and typical development (n = 37) were recruited. After an interview in which Childhood Autism Rating Scale (CARS) was administered, Child Eating Behavior Questionnaire (CEBQ), Pediatric Quality of Life Inventory (PedsQL), Social Responsiveness Scale (SRS) and Sensory Profile (SP) were completed by caregivers. Autistic children with ARFID had higher scores in CEBQ subscales relating to low appetite and lower scores on the subscales associated with weight gain. Both groups of autistic children scored lower than TDC on all PedsQL subscales and autistic children with ARFID had lower social QL scores than both groups. SRS scores were highest in autistic children with ARFID, followed by autistic and typically developing children. CARS scores were similar in both groups of autistic children, but higher than TDC. Auditory, vision, touch, multi-sensory, oral processing scores; as well as all quadrant scores, were significantly lower in autistic children with ARFID. Oral sensory processing scores were found to be the most significant predictor of ARFID comorbidity in ASD and reliably predicted ARFID in autistic children in the clinical setting. Autistic children with ARFID demonstrate differences in social functioning, sensory processing, eating attitudes, and quality of life compared to autistic and TD children.

Off-label psychopharmacological interventions for autism spectrum disorders: strategic pathways for clinicians

The prevalence of autism spectrum disorder (ASD) continues to see a trend upward with a noticeable increase to 1 in 36 children less than 8 years of age in the recent MMWR. There are many factors linked to the substantially increased burden of seeking mental health services, and clinically these individuals are likely to present for impairments associated with co-occurring conditions. The advances in cutting-edge research and the understanding of co-occurring conditions in addition to psychosocial interventions have provided a window of opportunity for psychopharmacological interventions given the limited availability of therapeutics for core symptomatology. The off-label psychopharmacological treatments for these co-occurring conditions are central to clinical practice. However, the scattered evidence remains an impediment for practitioners to systematically utilize these options. The review collates the crucial scientific literature to provide stepwise treatment alternatives for individuals with ASD; with an aim to lead practitioners in making informed and shared decisions. There are many questions about the safety and tolerability of off-label medications; however, it is considered the best practice to utilize the available empirical data in providing psychoeducation for patients, families, and caregivers. The review also covers experimental medications and theoretical underpinnings to enhance further experimental studies. In summary, amidst the growing clinical needs for individuals with ASD and the lack of approved clinical treatments, the review addresses these gaps with a practical guide to appraise the risk and benefits of off-label medications.

Avoidant-restrictive food intake disorder and autism: epidemiology, etiology, complications, treatment, and outcome

PURPOSE OF REVIEW

There is considerable overlap between the features of avoidant-restrictive food intake disorder (ARFID) and autism. The purpose of this scoping review is to provide an overview of studies published on ARFID and autism in 2022 and the first half of 2023.

RECENT FINDINGS

ARFID and autism are highly heritable conditions that often co-occur. In a large autism cohort, 21% of participants and 17% of their parents presented with avoidant-restrictive features. Of children diagnosed with ARFID, 8.2-54.8% are autistic. More than half of individuals with ARFID also have other neurodevelopmental, psychiatric, or somatic diagnoses. Anxiety, depression, sleep disorders, and learning difficulties are particularly common co-occurring issues. Various strategies have been developed to support autistic children with feeding difficulties. It appears that their feeding difficulties, particularly sensory sensitivities, food preferences, and mealtime rituals and routines frequently persist into adolescence and adulthood, but research on optimal support for adults and adolescents is still scarce. Untreated ARFID in autistic individuals may lead to serious complications.

SUMMARY

Individuals seeking specialist care for autism, eating disorders, or gender dysphoria should be screened for ARFID. More research is needed on how to support autistic adolescents and adults with features of ARFID.

Birth-related, medical, and diagnostic characteristics in younger versus older children with avoidant/restrictive food intake disorder (ARFID)

BACKGROUND

Although avoidant/restrictive food intake disorder (ARFID) presents the replacement and extension of feeding disorders of infancy and childhood, previous research into ARFID concentrated mainly on older patients. While birth-related characteristics play an etiologic role in feeding disorders, virtually nothing is known so far in ARFID. Therefore, the first aim of the study was to identify differences in birth-related characteristics in younger vs. older children with ARFID. Second, differences in physical and mental comorbidities, and third, diagnostic features between age groups were analysed.

METHODS

Among N = 51 in- and outpatient treatment-seeking patients, n = 23 patients aged 0-5 years (30% girls) and n = 28 patients aged 6-17 years (57% girls), with an interview-based diagnosis of ARFID were included. Data on the pre- and perinatal period and mental and physical comorbidities were derived from patients' medical records, while diagnostic criteria, main ARFID presentation, and sociodemographic variables were collected through diagnostic interview.

RESULTS

Significantly, younger patients with ARFID were born more often preterm and had more pre- and perinatal complications and a higher incidence of postnatal invasive procedures. Patients with ARFID aged 0-5 years presented significantly more physical comorbidities and conditions, especially congenital anomalies, while mental comorbidities, especially mood disorders, were significantly more common in patients with ARFID aged 6-17 years. No age differences were found for the distribution of diagnostic criteria and main ARFID presentation.

CONCLUSION

This is the first study which aimed to identify age-specific characteristics in patients with ARFID with potential relevance for diagnosis and treatment. Especially birth-related complications, including invasive procedures postnatally, may be associated with developing ARFID, highlighting the importance of a closer view on these potential risk factors of the disorder. Future research with longitudinal design and larger samples may allow more detailed information on further age-specific associations, symptom trajectories, and age-specific risk factors for ARFID.

Current evidence for avoidant restrictive food intake disorder: Implications for clinical practice and future directions

Background

ARFID (avoidant restrictive food intake disorder) is a relatively new diagnostic term covering a number of well-recognised, clinically significant disturbances in eating behaviour unrelated to body weight/shape concerns. Its phenotypic heterogeneity combined with much about the condition remaining unknown, can contribute to uncertainties about best practice. While other reviews of the evidence base for ARFID exist, few specifically target health care professionals and implications for clinical practice.

Methods

A narrative review was conducted to synthesise the findings of ARFID papers in scientific journals focussing on four key areas relevant to clinical practice: prevalence, assessment and characterisation of clinical presentations, treatment, and service delivery. Freely available online databases were searched for case studies and series, research reports, review articles, and meta-analyses. Findings were reviewed and practice implications considered, resulting in proposed clinical recommendations and future research directions.

Results

We discuss what is currently known about the four key areas included in this review. Based on available evidence as well as gaps identified in the literature, recommendations for clinical practice are derived and practice-related research priorities are proposed for each of the four of the areas explored.

Conclusion

Prevalence studies highlight the need for referral and care pathways to be embedded across a range of health care services. While research into ARFID is increasing, further studies across all areas of ARFID are required and there remains a pressing need for guidance on systematic assessment, evidence-based management, and optimal service delivery models. Informed clinical practice is currently predominantly reliant on expert consensus and small-scale studies, with ongoing routine clinical data capture, robust treatment trials and evaluation of clinical pathways all required. Despite this, a number a positive practice points emerge.

Psychoeducational and motivational treatment for low-weight Avoidant/Restrictive Food Intake Disorder (ARFID): Three case reports in school-aged children

BACKGROUND

Individuals with Avoidant/Restrictive Food Intake Disorder (ARFID) experience restrictive or highly selective eating problems that interfere with growth and development. Despite the increasing number of referrals for ARFID, no evidence-based treatments exist. This compilation of case composites describes a novel manualized treatment, Psychoeducational and Motivational Treatment (PMT) for children with ARFID, focusing on exploring motivation to change eating behaviors. This approach is based on motivational non-directive psychotherapy models, psychoeducational interventions, and the usefulness of play to support psychotherapeutic learning in school-age children.

CASE PRESENTATIONS

Three cases of children with ARFID treated using PMT are presented: a 7-year-old, a 10-year-old, and a 12-year-old. These cases illustrate how a clinician delivers PMT interventions in the context of developmental abilities and common comorbidities associated with ARFID.

CONCLUSION

PMT is a promising therapy for ARFID in school-age children. Challenges and strategies are discussed, including ways to address obstacles such as young age, comorbidities, and use of the virtual environment.

Interactions between the lipidome and genetic and environmental factors in autism

Autism omics research has historically been reductionist and diagnosis centric, with little attention paid to common co-occurring conditions (for example, sleep and feeding disorders) and the complex interplay between molecular profiles and neurodevelopment, genetics, environmental factors and health. Here we explored the plasma lipidome (783 lipid species) in 765 children (485 diagnosed with autism spectrum disorder (ASD)) within the Australian Autism Biobank. We identified lipids associated with ASD diagnosis (n = 8), sleep disturbances (n = 20) and cognitive function (n = 8) and found that long-chain polyunsaturated fatty acids may causally contribute to sleep disturbances mediated by the FADS gene cluster. We explored the interplay of environmental factors with neurodevelopment and the lipidome, finding that sleep disturbances and unhealthy diet have a convergent lipidome profile (with potential mediation by the microbiome) that is also independently associated with poorer adaptive function. In contrast, ASD lipidome differences were accounted for by dietary differences and sleep disturbances. We identified a large chr19p13.2 copy number variant genetic deletion spanning the LDLR gene and two high-confidence ASD genes (ELAVL3 and SMARCA4) in one child with an ASD diagnosis and widespread low-density lipoprotein-related lipidome derangements. Lipidomics captures the complexity of neurodevelopment, as well as the biological effects of conditions that commonly affect quality of life among autistic people.

What do we know about the epidemiology of avoidant/restrictive food intake disorder in children and adolescents? A systematic review of the literature

BACKGROUND

Avoidant/restrictive food intake disorder (ARFID) was a new diagnosis in DSM-5. This systematic review explores what is known to date about the epidemiology of ARFID in children and adolescents.

METHOD

Embase, Medline and PsycInfo were used to identify studies meeting inclusion criteria. PRISMA guidelines were followed.

RESULTS

Thirty studies met inclusion criteria, with most coming from specialised eating disorder services where prevalence rates were 5%-22.5%. Three studies from specialist feeding clinics showed the highest prevalence rates, ranging from 32% to 64%. Studies from non-clinical samples reported ARFID prevalence estimates ranging from 0.3% to 15.5%. One study, using national surveillance methodology, reported the incidence of ARFID in children and adolescents reaching clinical care to be 2.02 per 100,000 patients. Psychiatric comorbidity was common, especially anxiety disorders (9.1%-72%) and autism spectrum disorder (8.2%-54.75%).

CONCLUSION

The current literature on the epidemiology of ARFID in children and adolescents is limited. Studies are heterogeneous with regard to setting and sample characteristics, with a wide range of prevalence estimates. Further studies, especially using surveillance methodology, will help to better understand the nature of this disorder and estimate clinical service needs.

Etiology of the Broad Avoidant Restrictive Food Intake Disorder Phenotype in Swedish Twins Aged 6 to 12 Years

Importance

Avoidant restrictive food intake disorder (ARFID) is characterized by an extremely limited range and/or amount of food eaten, resulting in the persistent failure to meet nutritional and/or energy needs. Its etiology is poorly understood, and knowledge of genetic and environmental contributions to ARFID is needed to guide future research.

Objective

To estimate the extent to which genetic and environmental factors contribute to the liability to the broad ARFID phenotype.

Design, Setting, and Participants

This nationwide Swedish twin study includes 16 951 twin pairs born between 1992 and 2010 whose parents participated in the Child and Adolescent Twin Study in Sweden (CATSS) at twin age 9 or 12 years. CATSS was linked to the National Patient Register (NPR) and the Prescribed Drug Register (PDR). Data were collected from July 2004 to April 2020, and data were analyzed from October 2021 to October 2022.

Main Outcomes and Measures

From CATSS, NPR, and PDR, all parent reports, diagnoses, procedures, and prescribed drugs that were relevant to the DSM-5 ARFID criteria were extracted when twin pairs were aged 6 to 12 years and integrated into a composite measure for the ARFID phenotype (ie, avoidant/restrictive eating with clinically significant impact, such as low weight or nutritional deficiency, and with fear of weight gain as an exclusion). In sensitivity analyses, autism and medical conditions that could account for the eating disturbance were controlled for. Univariate liability threshold models were fitted to estimate the relative contribution of genetic and environmental variation to the liability to the ARFID phenotype.

Results

Of 33 902 included children, 17 151 (50.6%) were male. A total of 682 children (2.0%) with the ARFID phenotype were identified. The heritability of ARFID was 0.79 (95% CI, 0.70-0.85), with significant contributions from nonshared environmental factors (0.21; 95% CI, 0.15-0.30). Heritability was very similar when excluding children with autism (0.77; 95% CI, 0.67-0.84) or medical illnesses that could account for the eating disturbance (0.79; 95% CI, 0.70-0.86).

Conclusions and Relevance

Prevalence and sex distribution of the broad ARFID phenotype were similar to previous studies, supporting the use of existing epidemiological data to identify children with ARFID. This study of the estimated genetic and environmental etiology of ARFID suggests that ARFID is highly heritable, encouraging future twin and molecular genetic studies.

Self-reported expertise and confidence in diagnosing and treating avoidant restrictive food intake disorder among Swedish clinicians

OBJECTIVE

To assess self-reported knowledge and confidence regarding avoidant restrictive food intake disorder (ARFID) diagnosis and treatment in Swedish clinicians from various disciplines.

METHOD

The study included 489 clinicians who attended educational lectures about ARFID. Participants responded to 20 ARFID-related questions and statements using the online audience engagement platform Mentimeter. Items assessed ARFID-related knowledge, education, and experience, as well as treatment methods offered to ARFID patients at clinicians' healthcare units.

RESULTS

We found predominantly correct responses to three basic knowledge-based items about ARFID. However, most participants (64.0%) reported never having received education about ARFID, and few participants reported feeling confident in their ability to diagnose (13.4%) and treat (10.7%) ARFID. Nearly half the sample reported either not knowing which ARFID treatments their unit offered (22.3%) or that no treatment was offered (21.3%).

CONCLUSION

Experience and confidence in diagnosing and treating ARFID are generally low in Swedish clinicians, and many individuals with ARFID do not receive treatment. We identify a pressing need for resources, clearer organisation, and structure, and for additional education and training opportunities for clinicians meeting individuals with ARFID.

Symptoms of Avoidant/Restrictive Food Intake Disorder (ARFID) in the Orthodox and Secular Jewish Communities in Israel

Symptoms related to avoidant/restrictive food intake disorder (ARFID) are not well defined in the general population. The aim of this study was to determine whether differences exist in the presentation of ARFID-related eating disturbances between healthy, religious and secular Jewish children in Israel. Sixty-four families participated in this study. Parents completed standardized questionnaires to assess ARFID behaviors of children, parental feeding problems and overall functioning, anxiety and sensory-aversion. No significant between-group differences were found for almost all assessments. However, sensory-related pleasure and sensory-seeking behavior was greater in secular children. Overall, religious and non-religious Israeli children do not differ in parental-reported ARFID-related feeding and eating behaviors.

Clinical autism subscales have common genetic liabilities that are heritable, pleiotropic, and generalizable to the general population

The complexity of autism's phenotypic spectra is well-known, yet most genetic research uses case-control status as the target trait. It is undetermined if autistic symptom domain severity underlying this heterogeneity is heritable and pleiotropic with other psychiatric and behavior traits in the same manner as autism case-control status. In N = 6064 autistic children in the SPARK cohort, we investigated the common genetic properties of twelve subscales from three clinical autism instruments measuring autistic traits: the Social Communication Questionnaire (SCQ), the Repetitive Behavior Scale-Revised (RBS-R), and the Developmental Coordination Disorder Questionnaire (DCDQ). Educational attainment polygenic scores (PGS) were significantly negatively correlated with eleven subscales, while ADHD and major depression PGS were positively correlated with ten and eight of the autism subscales, respectively. Loneliness and neuroticism PGS were also positively correlated with many subscales. Significant PGS by sex interactions were found-surprisingly, the autism case-control PGS was negatively correlated in females and had no strong correlation in males. SNP-heritability of the DCDQ subscales ranged from 0.04 to 0.08, RBS-R subscales ranged from 0.09 to 0.24, and SCQ subscales ranged from 0 to 0.12. GWAS in SPARK followed by estimation of polygenic scores (PGS) in the typically-developing ABCD cohort (N = 5285), revealed significant associations of RBS-R subscale PGS with autism-related behavioral traits, with several subscale PGS more strongly correlated than the autism case-control PGS. Overall, our analyses suggest that the clinical autism subscale traits show variability in SNP-heritability, PGS associations, and significant PGS by sex interactions, underscoring the heterogeneity in autistic traits at a genetic level. Furthermore, of the three instruments investigated, the RBS-R shows the greatest evidence of genetic signal in both (1) autistic samples (greater heritability) and (2) general population samples (strongest PGS associations).

How genetic analysis may contribute to the understanding of avoidant/restrictive food intake disorder (ARFID)

Avoidant/restrictive food intake disorder (ARFID) was introduced in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Unlike anorexia nervosa, ARFID is characterised by avoidant or restricted food intake that is not driven by weight or body shape-related concerns. As with other eating disorders, it is expected that ARFID will have a significant genetic risk component; however, sufficiently large-scale genetic investigations are yet to be performed in this group of patients. This narrative review considers the current literature on the diagnosis, presentation, and course of ARFID, including evidence for different presentations, and identifies fundamental questions about how ARFID might fit into the fluid landscape of other eating and mental disorders. In the absence of large ARFID GWAS, we consider genetic research on related conditions to point to possible features or mechanisms relevant to future ARFID investigations, and discuss the theoretical and clinical implications an ARFID GWAS. An argument for a collaborative approach to recruit ARFID participants for genome-wide association study is presented, as understanding the underlying genomic architecture of ARFID will be a key step in clarifying the biological mechanisms involved, and the development of interventions and treatments for this serious, and often debilitating disorder.

Associations between childhood autistic traits and adolescent eating disorder behaviours are partially mediated by fussy eating

Objective

Previous literature shows an increased risk for eating disorders in autistic individuals. This study tested whether fussy eating contributes to the association between childhood autistic traits and adolescent eating disorder behaviours.

Method

Using data from the Avon Longitudinal Study of Parents and Children, we estimated the intercept and slope of parent‐rated autistic traits and fussy eating between 7 and 14 years (N = 8982) and their association with self‐reported eating disorder behaviours at age 14 years, including the indirect path from autistic traits to eating disorder behaviours via fussy eating. Analyses were adjusted for child sex, maternal age at delivery, maternal body mass index and maternal education.

Results

Analyses found a small indirect pathway from autistic traits intercept to eating disorder behaviours via fussy eating slope (b = 0.017, 95% CI = 0.002–0.032, p = 0.026), with higher levels of autistic traits at age 7 years being associated with a shallower decline in fussy eating, which in turn was associated with greater eating disorder behaviours.

Conclusion

Findings point towards fussy eating as a potential link between childhood autistic traits and later disordered eating. Addressing fussy eating patterns before they become entrenched may decrease risk for eating disorders later in development.

There is evidence that high levels of autistic traits are associated with an increased likelihood of experiencing an eating disorder.

The current study sought to test whether the link between autism and eating disorders could in part be explained by variation in fussy eating.

In a large prospective cohort study, we found a significant indirect effect of fussy eating, such that higher childhood autistic traits were associated with a shallower decline in fussy eating between childhood and adolescence, which in turn was associated with higher levels of eating disorder behaviours in adolescence.

Orexin/Hypocretin System Dysfunction in ESSENCE (Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations)

Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations (ESSENCE) is an umbrella term covering a wide range of neurodevelopmental difficulties and disorders. Thus, ESSENCE includes attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and other neurodevelopmental disorders (NDDs) and difficulties, with a variety of symptoms in cognitive, motor, sensory, social, arousal, regulatory, emotional, and behavioral developmental domains, frequently co-occurring and likely having partly common neurobiological substrates. The ESSENCE concept is a clinical paradigm that promotes organizing NDDs in everyday clinical practice according to their coexistence, symptom dimensions overlapping, and treatment possibilities. Despite increased knowledge regarding NDDs, the neurobiological mechanisms that underlie them and other ESSENCE-related problems, are not well understood. With its wide range of neural circuits and interactions with numerous neurotransmitters, the orexin/hypocretin system (Orx-S) is possibly associated with a variety of neurocognitive, psychobiological, neuroendocrine, and physiological functions and behaviors. Dysfunction of Orx-S has been implicated in various psychiatric and neurological disorders. This article provides an overview of Orx-S dysfunctions' possible involvement in the development, presentation, and maintenance of ESSENCE. We provide a focused review of current research evidence linking orexin neuropeptides with specific clinical NDDs symptoms, mostly in ADHD and ASD, within the Research Domain Criteria (RDoC) framework. We propose that Orx-S dysfunction might have an important role in some of these neurodevelopmental symptom domains, such as arousal, wakefulness, sleep, motor and sensory processing, mood and emotional regulation, fear processing, reward, feeding, attention, executive functions, and sociability. Our perspective is presented from a clinical point of view. Further, more thorough systematic reviews are needed as well as planning of extensive new research into the Orx-S's role in ESSENCE, especially considering RDoC elements.

Feeding Problems Including Avoidant Restrictive Food Intake Disorder in Young Children With Autism Spectrum Disorder in a Multiethnic Population

We examined feeding problems, including Avoidant Restrictive Food Intake Disorder (ARFID), in preschool children with Autism Spectrum Disorder (ASD). Data were collected from a prospective longitudinal study of 46 children with ASD in a multiethnic, low resource area in Gothenburg, Sweden. Feeding problems were found in 76% of the children with ASD, and in 28%, the criteria for ARFID were met. The study highlights early onset age, the heterogeneity of feeding problems, and the need for multidisciplinary assessments in ASD as well as in feeding problems, and also the need for further elaboration of feeding disorder classifications in children.

Autism-related dietary preferences mediate autism-gut microbiome associations

There is increasing interest in the potential contribution of the gut microbiome to autism spectrum disorder (ASD). However, previous studies have been underpowered and have not been designed to address potential confounding factors in a comprehensive way. We performed a large autism stool metagenomics study (n = 247) based on participants from the Australian Autism Biobank and the Queensland Twin Adolescent Brain project. We found negligible direct associations between ASD diagnosis and the gut microbiome. Instead, our data support a model whereby ASD-related restricted interests are associated with less-diverse diet, and in turn reduced microbial taxonomic diversity and looser stool consistency. In contrast to ASD diagnosis, our dataset was well powered to detect microbiome associations with traits such as age, dietary intake, and stool consistency. Overall, microbiome differences in ASD may reflect dietary preferences that relate to diagnostic features, and we caution against claims that the microbiome has a driving role in ASD.