Disordered eating behaviours and autistic traits—Are there any associations in nonclinical populations? A systematic review

Camouflaging, not sensory processing or autistic identity, predicts eating disorder symptoms in autistic adults

LAY ABSTRACT

This study aimed to explore the impact of Autistic identity (i.e. feeling like you belong to the Autistic community), sensory profiles (e.g. being over or under responsive to sensations) and camouflaging behaviours (i.e. masking) on eating disorder symptoms in Autistic adults. 180 Autistic people were recruited from the community and NHS. The Autistic people completed online questionnaires measuring Autistic identity, sensory profiles, camouflaging behaviours, autistic traits and eating disorder symptoms. The analysis showed that higher levels of camouflaging behaviour predicted higher levels of eating disorder symptoms. Sensory profiles were related to but did not predict eating disorder symptoms and there was no relationship between level of Autistic identity and eating disorder symptoms. This shows that camouflaging is the most important predictor of eating disorder symptoms in Autistic people, and warrants further exploration.

Exploring the intersection of autism spectrum disorder and eating disorders: understanding the unique challenges and treatment considerations for autistic women with eating disorders

PURPOSE OF REVIEW

Autistic women struggle with high levels of both autistic eating behaviours and disordered eating behaviours , which might make them particularly vulnerable to develop eating disorders. Research investigating the presence and characteristics of eating disorders in autistic women is however limited, as is research examining the role of autism in the treatment and recovery of an eating disorder in autistic women.

RECENT FINDINGS

The link between autism and eating disorders has mainly been investigated from the field of eating disorder research, with studies finding an overrepresentation of autism or autistic traits in eating disorders populations. Findings also suggest that autism or autistic traits are associated with a more serious presentation of the eating disorders, including a higher chance of a chronic course of the eating disorders. Most studies however lack comprehensive autism assessments, making it difficult to determine the actual prevalence of autism and its role in women with eating disorders.

SUMMARY

Autistic women with an eating disorder seem to suffer from more complex eating disorders and seem to not benefit from current treatment modalities. This could be partly related to specific autism characteristics such as sensory sensitivities, which are not being considered by current treatment protocols. Future research needs to shed light on what underlies the eating behaviours of autistic women with an eating disorder, in order to help to adapt current treatment modalities to meet the unique needs of these women.

Exploring the role of autistic traits and eating disorder psychopathology on mentalising ability in the general population

BACKGROUND

This study evaluated the role of overlapping traits and characteristics related to autism spectrum disorder (autism) and anorexia nervosa (AN) in the general population, and the impact of these traits on mentalising ability.

METHODS

A sample of young adults (N = 306), aged 18-25 years, was recruited to complete an online study that consisted of 4 measures: the Autism-Spectrum Quotient, Eating Disorder Examination Questionnaire, the Mentalization Scale, and the Reading the Mind in the Eyes task.

RESULTS

Higher levels of autistic traits, particularly difficulty with attention switching, were associated with increased eating disorder psychopathology. Overall, autistic traits and eating disorder psychopathology were related among females, but not males. Difficulty with attention switching, however, was related to eating disorder psychopathology among both females and males. Autistic traits also appear to have a greater role in mentalising ability than does eating disorder psychopathology.

CONCLUSION

The role of attention switching in overlapping traits of autism and eating disorder psychopathology needs to be more comprehensively evaluated by future research, as does the role of biological sex. Expanded knowledge in this field will help to better understand and evaluate symptoms at presentation, leading to clearer diagnoses and potentially better treatment outcomes.

Sex-specific mechanisms for eating disorder risk in men and women with autistic traits: the role of alexithymia

BACKGROUND

A poorly understood relationship exists between eating disorders (ED) and autism spectrum conditions (ASC: henceforth 'autism'). ED are more prevalent in autistic people and people with high autistic traits, and autistic features are prognostic of longer illness. Aiming to understand what increases the risk of ED in relation to autism and autistic traits, previous research has implicated alexithymia as a causal mechanism in this relationship. These studies could not, however, disentangle whether alexithymia explains the relationship between ED pathology and autistic traits directly or through its impact on anxious/depressive symptoms, which in turn result in higher ED symptomatology. Moreover, despite evidence for sex differences in the aetiology of ED, little research has examined the impact of sex on these relationships.

METHODS

Focusing on the association between autistic traits and ED psychopathology, we examined independent mediating effects of alexithymia and anxious/depressive symptoms, as well as sequential mediation effects where alexithymia affects ED psychopathology via its impact on anxious/depressive symptoms. Participants were 198 men and 265 women with formally diagnosed and suspected ED, who completed an online survey of standardised scales.

RESULTS

In men, higher autistic traits were associated with ED psychopathology sequentially via greater alexithymia and through that, greater depressive/anxious symptoms. In women, alexithymia mediated the relationship between autistic traits and ED psychopathology both directly and sequentially through its impact on anxious/depressive symptoms. Interestingly, depressive/anxious symptoms also mediated that relationship independently from alexithymia.

CONCLUSIONS

While cross-sectional, these findings suggest that the relationship between autistic traits and ED symptomatology is mediated by other variables. In support of its proposed role in the aetiology of ED, alexithymia was directly associated with ED symptoms in women. It also affected ED symptoms indirectly, in all participants, via its effect on depressive/anxious symptoms. Interventions focusing on alexithymia may facilitate recovery not only via their effect on ED, but via their effect on other forms of state psychopathology which contribute to the maintenance and development of ED. Sex differences, however, reflect that alternative therapeutic targets for men and women may be beneficial.

The associations between autistic traits and disordered eating/drive for muscularity are independent of anxiety and depression in females but not males

Previous research has shown a positive correlation between autistic traits and eating disorder symptoms, and this relationship appears to be independent of co-occurring mental health status. The current study followed a pre-registered analysis plan with the aim to investigate a previously unconsidered factor in the relationship between autistic traits and disorders of eating and body image: the drive for muscularity. Participants (N = 1068) completed the Autism Spectrum Quotient (AQ), Hospital Anxiety and Depression Scale (HADS), Eating Attitudes Test-26 (EAT-26) and Drive for Muscularity Scale (DMS). Positive correlations between AQ and EAT-26 and AQ and DMS were observed. In females, AQ remained significantly correlated with EAT-26 and DMS when controlling for co-occurring anxiety and depression symptoms, but this was not the case in males. These findings demonstrate the moderating role of sex, and the need to consider autistic traits in individuals diagnosed with, or at a heightened risk for, disorders of eating and body image.

Problematic eating behaviours of autistic women-A scoping review

Aim

Eating and feeding behaviours of autistic individuals and related consequences have been mainly investigated in autistic children or in autistic adults with intellectual disabilities. Behaviours such as food selectivity or food neophobia have been shown to persist into adolescence and adulthood and are associated with aversive consequences. However, much less is known about the eating behaviours of autistic adults without intellectual disabilities, especially those of women. By means of a scoping review, we aim to assess the extent of the scientific literature on what is known about the eating behaviours of these women and the possible consequences of such eating behaviour.

Method

Medline, Cochrane, PubMed and PsycInfo databases were searched according to Preferred Reporting Items for Systematic reviews and Meta‐Analyses (PRISMA) guidelines.

Results

Five studies met the eligibility criteria and were included in this review. Autistic women not only reported high levels of eating behaviour frequently seen in autism spectrum disorders (ASD), but also high levels of disordered eating behaviour, similar to that of women with eating disorders.

Conclusions

Autistic women seem to exhibit high levels of eating behaviour frequently seen in ASD as well as disordered eating behaviour. Future research needs to shed light on what underlies these problematic eating behaviours, in order to help to adapt current treatment modalities to meet the unique needs of these women.

This scoping review indicates that autistic women exhibit both eating behaviours frequently seen in autism spectrum disorders (ASD) and disordered eating behaviours, similar to those of women with eating disorders.

The review also indicates that studies investigating these eating behaviours of autistic women are still very scarce, and those that are available often lack a comprehensive assessment of the ASD diagnosis.

Future studies are needed to confirm the findings and to further explore how and why autistic women eat the way they eat, in order to help to adapt current treatment modalities to meet the unique needs of these women.

Avoidant/restrictive food intake disorder and severe food selectivity in children and young people with autism: A scoping review

AIM

To assess the extent of the scientific literature on avoidant/restrictive food intake disorder (ARFID) in children and young people with autism in order to evaluate and synthesize the evidence on (a) the nature of feeding and eating difficulties in children and young people with autism; (b) the consequences of a severely restricted diet; and (c) what is known about effective treatment approaches.

METHOD

PubMed and PsycInfo databases were searched, identifying 56 studies and a narrative synthesis was effected.

RESULTS

The literature suggested that ARFID-like presentations are common in children and young people with autism, with severe consequences for physical and mental health. The three drivers mentioned in the DSM-5 criteria, namely a sensory-based avoidance, fear- or phobia-based restriction, and a lack of interest in eating, are present in this population, although sensory sensitivities are currently the most commonly described. Research suggests that ARFID symptoms in children and young people with autism can be amenable to treatment, with evidence that behavioural interventions are feasible and potentially effective in this population.

INTERPRETATION

ARFID is a common and impactful problem among young people with autism but is currently under researched. Work is required to (a) identify the prevalence of ARFID in children and young people with autism; (b) uncover the key drivers of ARFID in this population; (c) adapt currently available interventions for use with children and young people with autism; and (d) rigorously test these interventions in clinical trials.

WHAT THIS PAPER ADDS

Significant food restriction is common in children and young people with autism. Sensory sensitivities are frequently cited as a reason for food restriction. The prevalence and causes of avoidant/restrictive food disorders in children and young people with autism need further research.

Do orthorexia and intolerance of uncertainty mediate the relationship between autism spectrum traits and disordered eating symptoms?

PURPOSE

Autism spectrum disorder traits have been implicated in the psychopathology of eating disorders and may also be relevant for the development of orthorexia symptoms. Further, intolerance of uncertainty (IUS) may indirectly contribute to the development of disordered eating, as the displacement of anxiety onto food may help achieve a sense of control and maximise certainty. We examined a new cognitive model of eating pathology which assessed the role of IU and orthorexia symptoms as potential mediators of the relationship between autistic traits and disordered eating in a community sample.

METHODS

Three-hundred-and-ninety-six female participants (M = 20.07, SD = 4.52 years old) completed an online self-report questionnaire which assessed the variables of interest.

RESULTS

Despite finding significant bivariate correlations, our model results showed that autistic traits did not directly predict disordered eating or orthorexia symptoms. Significant indirect relationships were found between autistic traits and eating disorder symptoms through both IU and orthorexia symptoms.

CONCLUSION

The findings provide partial support for our proposed model suggesting that autistic traits may increase the vulnerability for disordered eating, not directly, but through their associations with mechanisms such as IU and the development of problematic eating behaviours typical of orthorexia. Future research should focus on whether targeting IU may assist in preventing the development of disordered eating.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

The Association Between Autistic Traits and Disordered Eating is Moderated by Sex/Gender and Independent of Anxiety and Depression

Previous studies have reported positive correlations between autistic traits and disordered eating, though it is unclear whether the association is moderated by sex/gender or whether it is independent of anxiety or depression. We present the findings of an online survey of 691 participants who completed the Autism Spectrum Quotient (AQ), Hospital Anxiety and Depression Scale (HADS), and Eating Attitudes Test-26 (EAT-26). Following a pre-registered analysis plan, we observed positive correlations between AQ and EAT-26 in males and females, with the association being significantly stronger in females. AQ also remained a significant predictor of EAT-26 when anxiety and depression were controlled for statistically. These findings may be relevant when considering therapeutic interventions in disordered eating populations that exhibit autistic traits.

Prevalence of autism spectrum disorder and autistic traits in children with anorexia nervosa and avoidant/restrictive food intake disorder

BACKGROUND

Autism spectrum disorder (ASD) and feeding and eating disorders (FEDs) such as anorexia nervosa (AN) are strongly linked as evidenced by frequent comorbidity and overlapping traits. However, eating and social behaviors are shaped by culture, so it is critical to examine these associations in different populations. Moreover, FEDs are heterogeneous, and there has been no examination of autistic traits in avoidant/restrictive food intake disorder (ARFID).

METHODS

Therefore, we investigated the prevalence of ASD and autistic traits among Japanese children with AN (n = 92) or ARFID (n = 32) from a prospective multicenter cohort study using the Autism Spectrum Quotient Children's version (AQC) and Children's Eating Attitudes Test (ChEAT26).

RESULTS

ASD prevalence was high in both AN and ARFID (16.3 and 12.5%, respectively). The AN group exhibited significantly higher scores on all AQC subscales than an age-matched healthy control (HC) group, but there were no significant correlations between AQC scores and ChEAT26 scores. In the AFRID group, AQC scores did not differ from HCs, but significant correlations were found between total AQC and ChEAT26 scores and between several AQC and ChEAT26 subscales.

CONCLUSIONS

Both the AN and ARFID groups had high prevalence rates of ASD. The AN group showed a significantly higher degree of autistic traits than the HC group; however, no difference was found between the ARFID and HC groups. Clinicians need to be aware of these rates when working with children with ED.

The relationship between tendency to attend to detail, sensory sensitivity, and affective response to food cues - A registered report

Understanding the underlying drivers of food choice remains a challenge and has highlighted the need for measures that capture data over and above that offered by self-reporting tools. Consequently, a growing body of research has set out to interpret facial responses to food cues to offer a greater insight into the emotional responses that may drive food acceptance. However, interpreting facial responses is challenging, as there are numerous factors that may influence affective response to foods, including expectation, context, and individual differences. Existing findings suggest there is a link between autistic traits and sensory sensitivities; research highlights further links between sensory sensitivities and eating behaviour, and autistic traits and eating behaviour, with a body of research focusing on the autistic trait attention to detail (ATD). As such, the current study aimed to examine rapid facial activity in response to foods cues while capturing these individual differences present in the general population. This study found no evidence to suggest facial responses to food pictures were linked with attention to detail or hyper-sensitivity. The findings did support a general link between self-reported pleasantness ratings of viewed foods and activity of facial muscles. Post-hoc analyses suggested scoring on the social skills sub-scale of the Autism Quotient (AQ) was associated with levator activity while viewing pictures low in pleasantness. This study offers a greater understanding of variations, at the individual level, which are associated with affective response to foods, and may help to inform the development of tools that set out to predict food acceptance.

Perceptions of non-successful families attending a weight-management clinic

OBJECTIVE

This study seeks to understand family's perceptions of their care at a paediatric weight management service, with a view to informing service improvement.

DESIGN

A qualitative service review conducted via semistructured interviews with parents (n=11) and children (n=3) who attended the clinic. The recruitment was open to all, but those who were not succeeding in their weight-loss goals self-selected to participate. Self-Determination Theory was used as a framework to explore families' experiences of the clinic.

SETTING

Recruitment occurred during clinical appointments and interviews were conducted over the phone in the days following the appointments.

PATIENTS

The service sees paediatric patients with a body mass index >99th percentile, with comorbidities or safeguarding concerns.

INTERVENTIONS

The clinic's service includes appointments typically every 2 months, with a multidisciplinary team including consultant endocrinologists, a dietician, a clinical psychologist, a social worker and a clinical nurse specialist.

MAIN OUTCOME MEASURES

Families' feedback on the multi-disciplinary team (MDT) clinic, and their perceptions of how improvements could be made.

RESULTS

Families perceive a lack of autonomy, competency and feel a lack of connectivity both in their lives broadly and within their experience at the clinic.

CONCLUSIONS

Interventions in families struggling with weight improvements should see the clinical team placing more emphasis on working alongside parents to develop young people's sense of self-determination. Expectations must be set that success originates from changes outside of clinical appointments and that the clinical team is in place to support the family's development of sustainable, self-determined lifestyle habits.

Eating disturbances in adults with autism spectrum disorder without intellectual disabilities

There is a growing interest in the relationship between autism spectrum disorders (ASDs) and eating disorders (EDs), two relatively common conditions lying on a spectrum from mild to severe clinical features. However, only limited data are available about pathological eating behaviors throughout adults on the autistic spectrum. The aim of the present study is to assess dysfunctional eating behaviors, including EDs manifestations and ASDs-related eating disturbances, in a population of adults with ASDs without intellectual disabilities. We recruited 106 adults on the autistic spectrum, without intellectual disability and 103 neurotypical adults (NAs). Participants completed the "Eating Attitude Test" (EAT-26), to measure symptoms and concerns characteristic of EDs, and the "Swedish Eating Assessment for Autism Spectrum Disorders" (SWEAA), to assess eating behaviors frequently observed within the autistic spectrum. Participants with ASDs scored significantly higher than NA at the EAT-26 and at the SWEAA. Moreover, participants with ASDs scored higher than NA at the EAT-26 subscales Dieting and Bulimia. The difference between groups remained significant after controlling for the effect of age, biological sex, and BMI. These results suggest that adults with ASDs without intellectual disability presented not only a higher prevalence of eating disturbances typical of the autistic spectrum, but also other symptoms of EDs in comparison to NA. LAY SUMMARY: For both scales assessing eating disturbances (EAT-26 and SWEAA), participants with ASDs scored higher than NA, presenting a higher prevalence both of eating disturbances typical of ASDs and of ED symptoms (distorted body image, tendency toward bulimic behaviors, and self-control of eating).

Central coherence and set-shifting between nonunderweight eating disorders and anorexia nervosa: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis compared previously documented inefficiencies in central coherence and set-shifting between people with nonunderweight eating disorders (bulimia nervosa and binge-eating disorder) and people with anorexia nervosa.

METHOD

We performed random-effects meta-analyses on 16 studies (1,112 participants) for central coherence and 38 studies (3,505 participants) for set-shifting. Random effects meta-regressions were used to test whether the effect sizes for people with nonunderweight eating disorders were significantly different from the effect sizes for people with anorexia nervosa.

RESULTS

People with anorexia nervosa (Hedge's g = -0.53, 95% CIs: -0.80, -0.27, p < .001) and bulimia nervosa (Hedge's g = -0.70, 95% CIs: -1.14, -0.25, p = .002), but not binge-eating disorder, had significantly poorer central coherence than healthy controls. Similarly, people with anorexia nervosa (Hedge's g = -0.38, 95% CIs: -0.50, -0.26, p < .001) and bulimia nervosa (Hedge's g = -0.55, 95% CIs: -0.81, -0.29, p < .001), but not binge-eating disorder, had significantly poorer set-shifting than healthy controls. The effect sizes for people with nonunderweight eating disorders did not significantly differ from those for people with anorexia nervosa.

DISCUSSION

Our meta-analysis was underpowered to make definitive judgments about people with binge-eating disorder. However, we found that people with bulimia nervosa clearly have central coherence and set-shifting inefficiencies which do not significantly differ from those observed in people with anorexia nervosa. Clinically, this suggests that people with bulimia nervosa might benefit from adjunctive approaches to address these inefficiencies, such as cognitive remediation therapy.

Eggs, sugar, grated bones: colour-based food preferences in autism, eating disorders, and beyond

In 1913, eccentric French composer Erik Satie wrote a fragmentary, diary-like essay where he depicted a strikingly rigid diet consisting solely of white foods: eggs, sugar, coconuts, rice, cream cheese, fuchsia juice and so on. Satie's brief essay has later been used as one of many puzzle pieces in attempts to retrospectively diagnose him with autism spectrum disorder. With Satie's white meal as a starting point, this paper explores colour-based food preferences and selective eating in clinical and non-clinical populations, with a special focus on autism spectrum disorder and avoidant/restrictive food intake disorder (ARFID). General colour preferences and their causes as well as the impact of colour on taste and food identification are also explored. Selective eating during childhood is immensely common and does not generally lead to disordered eating in the long run, although subgroups may experience rigidity around food of a more enduring nature. Problems related to eating were repeatedly described in Kanner's original 1943 autism case series and continue to be common in autism. Most studies on eating and sensory sensitivity in autism show that the texture and consistency of the food are the most common factors behind selective eating. In contrast, colour-based food preferences appear to be relatively rare, although numerous anecdotal reports exist. Foods that are white or colourless may be particularly appealing or tolerable for individuals with sensory hypersensitivity, which can occur in autism or ARFID. Ultimately, in the case of Erik Satie, this paper concludes that his description of a strictly white diet should not be read as an autobiographical account but rather as an ironic take on contemporary symbolist literature, with the famously decadent all-black dinner party in French novelist Joris-Karl Huysmans' À Rebours (1884; also known as Against Nature) as an obvious source of inspiration.

Trajectories of autistic social traits in childhood and adolescence and disordered eating behaviours at age 14 years: A UK general population cohort study

BACKGROUND

Some people with eating disorders have difficulties with social communication. However, no longitudinal evidence regarding the direction of this association exists. We investigated trajectories of autistic social traits across childhood and adolescence in adolescents with and without disordered eating behaviours in early adolescence.

METHODS

We used data from the Avon Longitudinal Study of Parents and Children. Our disordered eating measure indicated presence of any, monthly and weekly disordered eating (fasting, purging, dieting, binge eating) at age 14 years. Autistic social traits were reported by mothers using the Social and Communication Disorders Checklist (SCDC) at age seven, 11, 14 and 16 years. We modelled SCDC score trajectories using multilevel negative binomial models adjusting for a number of child- and maternal-level confounders.

RESULTS

Of the 5,381 adolescents included in our sample, 421 (7.8%) experienced one or more disordered eating behaviours, and 148 (2.8%) weekly episodes. Adolescents with disordered eating had a 20% increase in SCDC scores (relative risk (RR) 1.23, 95% confidence interval (CI):1.14, 1.32) compared to those without disordered eating. This association was particularly apparent for those reporting weekly (RR 1.43, 95%CI: 1.27, 1.61) as opposed to monthly disordered eating (RR 1.12, 95%CI: 1.01, 1.22).

CONCLUSIONS

Greater autistic social traits in childhood could represent a risk factor for the development of disordered eating in adolescence. Although mechanisms of this association need to be elucidated, clinicians should be aware that autistic social traits could have predated the eating disorder when managing people with these conditions.

Nutritional Deficiency Disease Secondary to ARFID Symptoms Associated with Autism and the Broad Autism Phenotype: A Qualitative Systematic Review of Case Reports and Case Series

BACKGROUND

The demographics, weight statuses, and dietary patterns of people with autism or the broad autism phenotype who experience a severe nutrient deficiency disease due to symptoms of avoidant/restrictive food intake disorder have not been well established.

OBJECTIVE

The primary objective of this review was to examine the relationship between the demographics, weight statuses, dietary patterns, and nutrient deficiency diseases that characterize the most severe manifestations of avoidant/restrictive food intake disorder symptomology associated with autism or the broad autism phenotype.

METHODS

A systematic review of English and non-English articles published up to August 29, 2019, on the Scopus, PubMed, and Cumulative Index to Nursing and Allied Health Literature Plus electronic databases was conducted. Additional cases were identified through the reference list of all included articles. The search terms used were "autis^∗ AND (deficiency OR scurvy)". Only case reports or case series in which a person of any age who had been identified as having a formal diagnosis of autism or autism symptoms and a disease of nutritional deficiency due to self-imposed dietary restrictions were included. Data were independently extracted by 8 authors using predefined data fields.

RESULTS

A total of 76 cases (patients were aged 2.5 to 17 years) from 63 articles that were published from 1993 through 2019 were found. More than 85% cases (65 of 76 patients) were from articles published in the past 10 years. The largest percentage of published cases (69.7% [53 of 76]) involved scurvy, a vitamin C deficiency. The second-largest percentage of published cases (17.1% [13 of 76]) involved eye disorders secondary to vitamin A deficiency. Other primary nutrient deficiencies reported were thiamin, vitamin B-12, and vitamin D. In 62.9% (22 of 35) of the patients for which a body mass index or a weight percentile for age was provided, the patient was within normal weight parameters, per Centers for Disease Control weight status categories.

CONCLUSIONS

Based on the 63 articles extracted for this systematic review, nutritional deficiency diseases related to inadequate intakes of vitamin A, thiamin, vitamin B-12, vitamin C, and vitamin D were found in individuals with autism and the broad autism phenotype who had severe self-imposed dietary restrictions. When weight information was provided, most of the youth in these cases were not reported to be underweight. Individuals of any weight who present with symptoms of avoidant/restrictive food intake disorder can benefit from early and frequent screening for adequacy of micronutrient intake, regardless of whether they have a clinical diagnosis of autism.

Alexithymia may explain the relationship between autistic traits and eating disorder psychopathology

BACKGROUND

Autistic people are disproportionately vulnerable to anorexia nervosa and other eating disorders (ED), and within the general population, autistic traits correlate with ED psychopathology. A putative mechanism which may underpin this heightened risk is alexithymia, a difficulty identifying and describing emotional states which is observed in both autism and ED. In two experiments with independent non-clinical samples, we explored whether alexithymia might mediate the heightened risk of eating psychopathology in individuals high in autistic traits.

METHODS

Our first experiment used the PROCESS macro for SPSS to examine relationships between alexithymia (measured by the Toronto Alexithymia Scale (TAS-20)), autistic traits (autism quotient (AQ)), and eating psychopathology (Eating Attitudes Test (EAT-26)) in 121 participants. Our second experiment (n = 300) replicated and furthered this analysis by examining moderating effects of sex and controlling for anxiety and depression as covariates. We also included an additional performance-based measure of alexithymia, the Levels of Emotional Awareness Scale (LEAS).

RESULTS

Study 1 suggested that TAS-20 scores mediated the relationship between heightened autistic traits and eating psychopathology. Replication and further scrutiny of this finding, in study 2, revealed that this mediation effect was partial and specific to the female participants in this sample. The mediation effect appeared to be carried by the difficulty identifying feelings subscale of the TAS-20, even when depression and anxiety were controlled for. LEAS scores, however, were not significantly related to autistic traits or eating psychopathology.

LIMITATIONS

Cross-sectional data prevents any conclusions around the direction and causality of relationships between alexithymia, autistic traits, and eating psychopathology (alongside depression and anxiety), necessitating longitudinal research. Our non-clinical sample was predominantly Caucasian undergraduate students, so it remains to be seen if these results would extrapolate to clinical and/or autistic samples. Divergence between the TAS-20 and LEAS raises crucial questions regarding the construct validity of these measures.

CONCLUSIONS

Our findings with respect to autistic traits suggest that alexithymia could partially explain the prevalence of ED in autistic people and may as such be an important consideration in the pathogenesis and treatment of ED in autistic and non-autistic people alike. Further research with clinical samples is critical to explore these ideas. Differences between men and women, furthermore, emphasize the importance of looking for sex-specific as well as generic risk factors in autistic and non-autistic men and women.

Association between prenatal maternal infection and disordered eating behaviours in adolescence: a UK population-based prospective birth cohort study

BACKGROUND

Prenatal infections have been proposed as a putative risk factor for a number of psychiatric outcomes across a continuum of severity. Evidence on eating disorders is scarce. We investigated whether exposure to prenatal maternal infections is associated with an increased risk of disordered eating and weight and shape concerns in adolescence in a large UK birth cohort.

METHODS

We used data from the Avon Longitudinal Study of Parents and Children. The primary exposure was maternal experience of infections at any time in pregnancy. Study outcomes were presence of any, monthly or weekly disordered eating at 14 and 16 years of age, and weight and shape concerns at 14 years. We defined the causal effect of the exposure on these outcomes using a counterfactual framework adjusting our analyses for a number of hypothesised confounders, and imputing missing confounder data using multiple imputation.

RESULTS

In total, 4884 children had complete exposure and outcome data at age 14 years, and 4124 at 16 years. Exposed children had a greater risk of reporting weekly disordered eating at both age 14 [risk difference (RD) 0.9%, 95% confidence interval (CI) -0.01 to 1.9, p = 0.08] and 16 (RD 2.3%, 95% CI 0.6-3.9, p < 0.01), though evidence of an association was weak at age 14 years. Exposed children also had greater weight and shape concerns at age 14 years (mean difference 0.15, 95% CI 0.05-0.26, p < 0.01).

CONCLUSIONS

Exposure to prenatal maternal infection is associated with greater risk of disordered eating in adolescence. This association could be explained by in utero processes leading to impaired neurodevelopment or altered immunological profiles. Residual confounding cannot be excluded.

Polygenic risk for schizophrenia, disordered eating behaviours and body mass index in adolescents

BACKGROUND

Recent studies suggest psychotic and eating disorders can be comorbid and could have shared genetic liability. However, this comorbidity has been overlooked in the epidemiological literature.AimsTo test whether polygenic risk scores (PRS) for schizophrenia are associated with disordered eating behaviours and body mass index (BMI) in the general population.

METHOD

Using data from the Avon Longitudinal Study of Parents and Children and random-effects logistic and linear regression models, we investigated the association between PRS for schizophrenia and self-reported disordered eating behaviours (binge eating, purging, fasting and excessive exercise) and BMI at 14, 16 and 18 years.

RESULTS

Of the 6920 children with available genetic data, 4473 (64.6%) and 5069 (73.3%) had at least one disordered eating and one BMI outcome measurement, respectively. An s.d. increase in PRS was associated with greater odds of having binge eating behaviours (odds ratio, 1.36; 95% CI 1.16-1.60) and lower BMI (coefficient, -0.03; 95% CI, -0.06 to -0.01).

CONCLUSIONS

Our findings suggest the presence of shared genetic risk between schizophrenia and binge eating behaviours. Intermediate phenotypes such as impaired social cognition and irritability, previously shown to be positively correlated in this sample with schizophrenia PRS, could represent risk factors for both phenotypes. Shared genetic liability between binge eating and schizophrenia could also explain higher rates of metabolic syndrome in individuals with schizophrenia, as binge eating could be a mediator of this association in drug-naïve individuals. The finding of an association between greater PRS and lower BMI, although consistent with existing epidemiological and genetic literature, requires further investigation.Declaration of interestNone.