Autistic characteristics in eating disorders: Treatment adaptations and impact on clinical outcomes

Recent Advances in Cognitive-Behavioural Therapy for Eating Disorders (CBT-ED)

PURPOSE OF REVIEW

Eating disorders require more effective therapies than are currently available. While cognitive behavioural therapy for eating disorders (CBT-ED) has the most evidence to support its effectiveness, it requires substantial improvement in order to enhance its reach and outcomes, and to reduce relapse rates. Recent years have seen a number of noteworthy developments in CBT-ED, which are summarised in this paper.

RECENT FINDINGS

The key advances identified here include: improvements in the efficiency and availability of CBT-ED; expansion of applicability to younger cases across durations of eating disorder; and new methodologies. There have been important recent advances in the field of CBT-ED. However, it is important to stress that there remain gaps in our evidence base and clinical skills, and suggestions are made for future research and clinical directions.

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.

A qualitative evaluation of the pathway for eating disorders and autism developed from clinical experience (PEACE): clinicians' perspective

Introduction

The Pathway for Eating disorders and Autism developed from Clinical Experience (PEACE pathway) is a clinical pathway of adapted treatment for individuals with eating disorders and autism in the UK. This study aims to investigate multidisciplinary clinicians' views of the strengths and challenges of PEACE pathway adaptations, while identifying areas where further improvement is needed.

Method

Semi-structured interviews were conducted with 16 clinicians who worked on the PEACE pathway. Themes relevant to the benefits, challenges and areas of improvement were identified, and a thematic map was produced.

Results

PEACE Pathway brought clinical benefits such as improved understanding of patients' perspective, improved flexibility and individualisation in clinicians' approach, increased patient engagement, and provision of resources that are helpful to all patients with or without autism. Benefits to the service included increase in autism awareness, clinicians' confidence, and team collaboration. Challenges were also identified, including difficulties in incorporating autism adaptations into existing treatment protocol, implementing PEACE at different levels of care, staff schedule conflicts, and increased pressure to meet patients' needs. Overall, there is a need for systemic improvement in aftercare and community support for autism, more suitable autism screening tool, and more structured guidelines for making adaptations.

Conclusions and implications

PEACE Pathway has brought clinical and service benefits, while also bringing practical challenges rooted in the difficulty in distinguishing between autism and eating disorder in comorbid population. Future areas of improvement are highlighted for PEACE resources as well as in the national support system for autistic individuals.

New understandings meet old treatments: putting a contemporary face on established protocols

In the twenty years since the publication of the most widely used treatment manuals describing evidence-based therapies for eating disorders, there have been some substantial advances in the field. New methods of delivering treatments have been trialled and our perception of mental health has advanced; significant cultural changes have led to shifts in our societal landscape; and new technologies have allowed for more in-depth research to be conducted. As a result, our understanding of eating disorders and their treatment has broadened considerably. However, these new insights have not necessarily been translated into improved clinical practice. This paper highlights the changes we consider to have had the greatest impact on our work as experienced clinical psychologists in the field and suggests a list of new learnings that might be incorporated into clinical practice and research design.

Expanding considerations for treating avoidant/restrictive food intake disorder at a higher level of care

Existing descriptions of the treatment of avoidant/restrictive food intake disorder (ARFID) at higher levels of care (HLOC) for eating disorders are limited, despite HLOC settings frequently serving patients with ARFID. The purpose of this commentary is to expand on the preliminary literature that describes pediatric ARFID treatment at HLOC by describing two specific components of our approach to treating pediatric ARFID that may not yet have traction in the current literature. Specifically, we highlight the utility of (1) treatment accommodations that appropriately account for patients' neurodevelopmental needs (e.g., executive functioning, sensory processing) and (2) the adjunctive use of Dialectical Behavior Therapy (DBT) elements within family-based pediatric ARFID treatment. We also describe necessary future directions for research in these domains to clarify if incorporating these considerations and approaches into pediatric ARFID treatment at HLOC does indeed improve treatment outcomes.

Challenges and opportunities for conceptualizing intuitive eating in autistic people

Although intuitive eating (IE) has become an increasingly adopted intervention target, current conceptualisations of IE have yet to pivot away from (neuro)normative physiology and phenomenology. Autistic individuals commonly report disordered eating behaviours and/or poorer well-being but appear to benefit from adaptive interventions using an affirmative approach. This article uses autism as a case example to summarise challenges related to IE's prevailing conceptualisation, before proposing how future research and current practice can be extended to the autistic population. Scholars are encouraged to evaluate the full 10-principal IE framework while utilising a participatory-led approach. We argue that research using a mixed methods design is urgently needed to comprehensively explore the (re)conceptualisation of IE in autistic people. While IE shows promise for producing positive outcomes in the autistic population, we discuss the potential challenges for research and practice due to its current emphasis on accurate interoception, emotional awareness and processing, and executive functioning. This suggests the need for research and practice to integrate autistic needs and experiences into future developments with an affirmative approach. Public Significance: IE is an effective intervention for reducing disordered eating behaviours. Autistic individuals commonly present disordered eating behaviours and have unique nutritional needs which often require intervention. However, there is limited understanding of IE among the autistic population. Research-informed definitions involving autistic perspectives will support translating the IE framework to this underrepresented population.

Longitudinal exploration of biopsychosocial profiles in individuals with anorexia nervosa

BACKGROUND

Previous work in individuals with Anorexia Nervosa (AN) has demonstrated a range of psycho-social difficulties such as increased anxiety, depression, obsessive-compulsive symptoms, as well as difficulties in work and with interpersonal interactions. However, making inferences regarding the stability of these psycho-social difficulties from previous studies is challenging, due to lack of a control group and known frequentist statistical issues.

METHODS

134 participants, 40 healthy controls (HC) and 94 participants with AN, completed self-reported measures designed to explore eating disorder concerns, body mass index, mood symptoms, work and social functioning as well as traits associated with autism at two time points, two years apart. A principal component analysis and Bayesian mixed effects models were used to build and explore group differences in bio-psychosocial profiles at time points.

RESULTS

The Bayesian models demonstrated evidence for individuals with AN having higher scores for a component representing psycho-social difficulties and lower scores for a component representing biological difficulties compared to HC, at both time points. There was no evidence of a group difference for a component representing autism.

CONCLUSIONS

Our results demonstrate that persistent psycho-social difficulties are a feature in individuals with AN.

"It's not about wanting to be thin or look small, it's about the way it feels": an IPA analysis of social and sensory differences in autistic and non-autistic individuals with anorexia and their parents

BACKGROUND

Despite increasing evidence to support an overlap between autism and anorexia nervosa (AN), underlying mechanisms remain poorly understood. Social and sensory factors have emerged as promising targets in both autism and AN, however there remains scope to compare these differences across autistic and non-autistic experiences of AN. Drawing on dyadic multi-perspectives, this study explored experiences of social and sensory differences in autistic and non-autistic adults and their parents and/or carers.

METHODS

Using interpretative phenomenological analysis (IPA), dyadic interviews were conducted with 14 dyads, with seven autistic dyads and seven non-autistic dyads. Data analysis was subjected to a triangulation of interpretations: (1) the participants themselves; (2) a neurotypical researcher; (3) and an Autistic researcher with lived/living experience of AN.

RESULTS

IPA identified three themes in each group, with similarities and differences between autistic and non-autistic dyads. Similar themes were identified regarding the importance of social connectedness and socio-emotional difficulties, as well a common lack of trust in the social and sensory self and body. Autism-specific themes centred on feelings of social 'defectiveness', disparities between sensing and expressing certain cues, and lifelong, multi-sensory processing differences. Non-autistic themes reflected social comparisons and inadequacy, and sensitivities to the learning of ideals and behaviour through early experiences.

CONCLUSIONS

While similarities were observed across both groups, there appeared to be notable differences in the perceived role and influence of social and sensory differences. These findings may have important implications on the delivery and modification of eating disorder interventions. Specifically, they suggest that while treatment targets may look similar, subtle differences in underlying mechanisms and approaches may be required for Autistic individuals with AN across sensory, emotion and communication-based interventions.

Eating disorder outcomes: findings from a rapid review of over a decade of research

BACKGROUND

Eating disorders (ED), especially Anorexia Nervosa (AN), are internationally reported to have amongst the highest mortality and suicide rates in mental health. With limited evidence for current pharmacological and/or psychological treatments, there is a grave responsibility within health research to better understand outcomes for people with a lived experience of ED, factors and interventions that may reduce the detrimental impact of illness and to optimise recovery. This paper aims to synthesise the literature on outcomes for people with ED, including rates of remission, recovery and relapse, diagnostic crossover, and mortality.

METHODS

This paper forms part of a Rapid Review series scoping the evidence for the field of ED, conducted to inform the Australian National Eating Disorders Research and Translation Strategy 2021-2031, funded and released by the Australian Government. ScienceDirect, PubMed and Ovid/MEDLINE were searched for studies published between 2009 and 2022 in English. High-level evidence such as meta-analyses, large population studies and Randomised Controlled Trials were prioritised through purposive sampling. Data from selected studies relating to outcomes for people with ED were synthesised and are disseminated in the current review.

RESULTS

Of the over 1320 studies included in the Rapid Review, the proportion of articles focused on outcomes in ED was relatively small, under 9%. Most evidence was focused on the diagnostic categories of AN, Bulimia Nervosa and Binge Eating Disorder, with limited outcome studies in other ED diagnostic groups. Factors such as age at presentation, gender, quality of life, the presence of co-occurring psychiatric and/or medical conditions, engagement in treatment and access to relapse prevention programs were associated with outcomes across diagnoses, including mortality rates.

CONCLUSION

Results are difficult to interpret due to inconsistent study definitions of remission, recovery and relapse, lack of longer-term follow-up and the potential for diagnostic crossover. Overall, there is evidence of low rates of remission and high risk of mortality, despite evidence-based treatments, especially for AN. It is strongly recommended that research in long-term outcomes, and the factors that influence better outcomes, using more consistent variables and methodologies, is prioritised for people with ED.

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.

"Work WITH us": a Delphi study about improving eating disorder treatment for autistic women with anorexia nervosa

BACKGROUND

There is an increased prevalence of anorexia nervosa (AN) in autistic women and this group has poorer treatment outcomes compared to non-autistic women with AN. However, there is little research into improving eating disorder treatment for autistic women. This study investigated how best to support autistic women with AN within eating disorder services.

METHOD

A three-stage Delphi study was conducted with 49 participants with relevant expertise as a researcher, clinician, or expert by experience.

RESULTS

A total of 70 statements were generated, with 56 reaching consensus after the final round. Statements reaching consensus made recommendations for adaptations to treatment, staff training, and service organisation.

CONCLUSIONS

The results highlight the need to distinguish between autism- and AN-related difficulties, accommodate autistic traits such as sensory sensitivities and communication differences, and ensure the autistic voice is present in both the development and delivery of care. Future research should investigate the impact of these adaptations on outcomes. The applicability of these recommendations to autistic people with other eating disorders and of other genders needs to be investigated further.

A lived experience response to the proposed diagnosis of terminal anorexia nervosa: learning from iatrogenic harm, ambivalence and enduring hope

The ethical approach to treatment non-response and treatment refusal in severe-enduring anorexia nervosa (SE-AN) is the source of significant ethical debate, particularly given the risk of death by suicide or medical complications. A recent article proposed criteria to define when anorexia nervosa (AN) can be diagnosed as 'terminal' in order to facilitate euthanasia or physician-assisted suicide (EAS), otherwise known as medical assistance in dying, for individuals who wish to be relieved of suffering and accept treatment as 'futile'. This author utilises their personal lived experience to reflect on the issues raised, including: treatment refusal, iatrogenic harm, suicidality and desire to end suffering, impact of diagnosis/prognosis, schemas, alexithymia, countertransference, ambivalence, and holding on to hope. Within debates as critical as the bioethics of involuntary treatment, end-of-life and EAS in eating disorders, it is crucial that the literature includes multiple cases and perspectives of individuals with SE-AN that represent a wide range of experiences and explores the complexity of enduring AN illness, complex beliefs, communication patterns and relational dynamics that occur in SE-AN.

What we can do about Autism and Eating Disorder comorbidity

OBJECTIVE

We are pleased to introduce this special issue about Autism and Feeding and Eating Disorders, representing reflections on this complex comorbidity.

METHOD

Contributions focussed on several main themes: (1) the definition and assessment of autism and eating disorder (ED) comorbidity; (2) the brain imaging findings of similarities and differences between autism and EDs; (3) sensory systems and interoception; (4) comorbidity across the age spectrum and (5) improving treatment outcomes in ED and autism comorbidity.

RESULTS

The papers in this issue highlight the importance of research, screening and practical adaptations in the field of ED and autism comorbidity. Autism is a neurodevelopmental condition with several strengths and weaknesses. When patients present with this comorbidity, it is important that their ED is treated which requires careful adaptation and tailoring for people with autism.

DISCUSSION

This special issue is an attempt to facilitate further research and stimulate collaborations between all of the stakeholders, particularly clinicians who have expertise in autism and clinicians working in the field of ED. We have included diverse themes from international researchers conducting qualitative and quantitative studies, providing research evidence to inform treatment modifications for this complex comorbidity.

Examining the relationship between autistic spectrum disorder characteristics and structural brain differences seen in anorexia nervosa

Cortical differences have been reported in Anorexia Nervosa (AN) compared with healthy controls (HC); however, it is unclear if Autism Spectrum Disorder (ASD) characteristics are related to these cortical differences. The aim of this study was to examine if structural measures were correlated to ASD traits in AN. In total 184 female participants participated in the study; 57 acutely underweight AN participants (AAN), 59 weight-restored participants (WR) and 68 HC. Participants underwent structural magnetic resonance imaging as well as completing the Autism Diagnostic Observation schedule, second edition to examine ASD characteristics. Group differences in curvature, gyrification, surface area, thickness, global grey matter and white matter were measured. Correlation and regression analysis were conducted to examine the relationship between cortical measures and ASD characteristics. Two decreased gyrification clusters in the right post central and supramarginal gyrus and decreased global grey matter were observed in the AAN group compared to HC and WR. No correlations between ASD traits and structural measures existed. Our results suggest structural differences seen in individuals with AN do not appear to be related to ASD characteristics.

Association of autism diagnosis and polygenic scores with eating disorder severity

Among individuals with eating disorders (ED), those with co‐occurring autism are often considered to have more severe presentations and poorer prognosis. However, previous findings have been contradictory and limited by small sample size and/or cross‐sectional assessment of autistic traits. We examine the hypothesis that autism diagnosis and autism polygenic score (PGS) are associated with increased ED severity in a large ED cohort using a broad range of ED severity indicators. Our cohort included 3189 individuals (64 males) born 1977–2000 with current or previous anorexia nervosa who participated in the Anorexia Nervosa Genetics Initiative‐Sweden (ANGI‐SE) and for whom genotypes and linkage to national registers were available. We identified 134 (4.2%) individuals with registered autism diagnoses. Individuals with confirmed autism diagnosis had significantly more severe ED across three sets of severity indicators. Some of the largest effects were found for the proportion of individuals who attempted suicide and who received tube feeding (higher in autism), and for the time spent in inpatient care (longer in autism). Results for autism PGS were not statistically significant. Adapting ED treatment to the needs of individuals with co‐occurring autism is an important research direction to improve treatment outcome in this group.

Among 3189 Swedish individuals with current or previous anorexia nervosa, those with confirmed autism diagnosis (4.2%) experienced higher eating disorder severity across 27 out of 29 indicators.

Some of the highest risk increases were found for having attempted suicide, having received tube feeding, and time spent in inpatient care for eating disorders.

Repeating the analyses with autism polygenic score instead of autism diagnosis yielded non‐statistically significant results for all 29 eating disorder severity indicators.

Sensory processing and eating behaviours in autism: A systematic review

OBJECTIVES

The aim of this study was to assess the relationship between sensory processing and a broad range of eating behaviours across the lifespan.

METHODS

Five electronic databases of published and unpublished quantitative studies were systematically searched, evaluated for risk of bias and synthesised according to identified eating outcomes.

RESULTS

Across 25 studies, there was consistent evidence of a relationship between sensory processing and a range of eating behaviours. There was early evidence for the particular role of taste/smell sensitivities, as well as hypersensitivities, although future research is needed looking at different sensory patterns and modalities. There was also tentative evidence to suggest this relationship extends across development.

DISCUSSION

Study findings are discussed in relation to implications for sensory-based eating and feeding interventions and the development of eating disorders. Methodological and conceptual limitations are discussed and suggestions for future research are made to address these limitations. A broader investigation of multi-sensory issues and clearly defined eating behaviours, including disordered eating in clinically diagnosed samples, will allow for a more comprehensive and robust understanding of the relationship between sensory processing and eating behaviours in autism.

How to support adults with anorexia nervosa and autism: Qualitative study of clinical pathway case series

INTRODUCTION

Previous research has explored the overlapping presentation between autism and eating disorders (ED). This study aims to summarize the clinical challenges associated with co-occurring autism and anorexia nervosa (AN) based on clinicians' case notes and minutes from case discussions, to understand how to better support people with the comorbidity.

METHOD

Thematic analysis was conducted on de-identified notes on 20 cases with AN and autistic characteristics and minutes from case discussions. Themes relevant to clinical challenges in supporting those with the comorbidity were identified, and a thematic map was produced to visually represent the results.

RESULTS

The key challenges faced by clinicians when treating patients with AN and autism included: communication difficulties, maintaining boundaries, autism screening, presence of other comorbidities, sensory difficulties, atypical presentation of eating difficulties, cognitive rigidity, and emotional difficulties. Adaptations to resolve some of these difficulties included exposure-based food experiments, keeping a record of patients' self-reported communication preferences, individual-level modification of communication style, and providing tools for patients to identify emotions.

CONCLUSIONS AND IMPLICATIONS

Further exploration to establish the effectiveness of the adaptations is warranted. Furthermore, tools for differentiating between ED, autism and other comorbidities are needed to help clinicians clarify the cause of a presenting symptom, and help them to best support and maintain boundaries with patients.

Autism and anorexia nervosa: Longitudinal prediction of eating disorder outcomes

BACKGROUND

Recently, elevated levels of autistic features and autism diagnoses have been reported among people with anorexia nervosa (AN). In clinical settings high levels of autistic features have been linked to more complex, highly comorbid illness presentation and poorer treatment outcome. This study aimed to examine whether autistic features predict AN symptom profile in long term.

METHODS

Altogether 118 women with lived experience of AN completed two autism assessments at time 1, the Autism Diagnostic Observation Schedule (ADOS) and the short version of the Autism Quotient (AQ10). Measures assessing AN symptom profile, including eating disorders symptoms, anxiety, depression, OCD symptoms, and Body Mass Index (BMI), were also recorded. The symptom profile measures were administered again 6 months and 2 years later. We conducted two analyses to examine the extent to which the ADOS and AQ10 scores predicted broad AN symptom profile at each three time points.

RESULTS

Overall, high levels of autistic features were consistently associated with worse psychological symptoms, but not BMI, across all time points. Both the analysis using baseline ADOS scores and self-reported AQ10 scores showed similar pattern.

CONCLUSION

The present findings consolidate previously reported associations between autistic features and worse psychological outcome among people with AN. The findings also suggest that self-report measures may be sufficient for assessing the impact of autistic features on illness outcome among people with AN. Importantly, the study highlights the need for development and further investigation of neurodiversity accommodations in the treatment of AN.