What kind of illness is anorexia nervosa? Revisited: some preliminary thoughts to finding a cure

Treating the individual: moving towards personalised eating disorder care

Eating disorders (EDs) are complex and heterogeneous conditions, which are often not resolved with conventional, manualised treatments. Arguments for the development of holistic, person-centred treatments accounting for individual variability have been mounting amongst researchers, clinicians and people with lived experience alike. This review explores the transformative potential of personalised medicine in ED care, emphasising the integration of precision diagnostics and tailored interventions based on individual genetic, biological, psychological and environmental profiles. Building on advancements in genomics, neurobiology, and computational technologies, it advocates for a shift from categorical diagnostic frameworks to symptom-based and dimensional approaches. The paper summarises emerging evidence supporting precision psychiatry, including the development of biomarkers, patient-reported outcomes, predictive modelling, and staging models, and discusses their application in ED research and clinical care. It highlights the utility of machine learning and idiographic statistical methods in optimising therapeutic outcomes and identifies key challenges, such as ethical considerations, scalability and implementation.

How Do Patients and Their Supports Experience Temperament Based Therapy With Support (TBT-S)? A Qualitative Study

BACKGROUND

Temperament Based Therapy with Support (TBT-S) is an emerging intervention based on empirically supported neurobiological models. Due to its novelty, only a handful of studies to date have examined TBT-S, and none of these previous studies have provided a qualitative evaluation of how TBT-S is perceived by the target population. Therefore, the aim of the current study was to provide an increased understanding of how TBT-S is experienced by patients with an eating disorder and their supports.

METHOD

Forty-six patients with an eating disorder and 63 supports consented to be included in the study. The participants provided written responses to six open-ended questions during the post-treatment assessment, detailing their treatment experiences and offering additional feedback. Thematic analysis (TA) was used to analyze their written responses, aiming for a combination of latent and semantic themes.

RESULTS

The results reveal a substantial overlap between patients' and supports' experiences with TBT-S. In both groups, identified themes suggest increased knowledge and hopefulness as key benefits of the intervention. While both patients and support persons considered TBT-S to be worthwhile, patients also reported finding the intervention quite challenging. Additionally, both groups emphasized the neurobiological rationale as an essential component of TBT-S.

CONCLUSIONS

The qualitative evaluations from this study offer new insights into how TBT-S is experienced by the target population. The findings provide an opportunity to incorporate participant suggestions for improving the treatment, and serve as an important building block for future studies aimed at assessing the effectiveness of TBT-S as an augmentation to treatment-as-usual.

Embracing a different outlook: Strengths and goals of individuals currently in treatment for anorexia nervosa

PURPOSE

Developing personal goals beyond weight and shape, and promoting the agency to pursue those goals, could aid in treatment and recovery from anorexia nervosa (AN). This research explores the strengths, interests and goals of individuals currently receiving treatment for AN and evaluates how treatment services are supporting them to work towards personal goals across all areas of everyday life.

METHOD

A total of 58 community-dwelling adults currently receiving treatment for anorexia nervosa at any stage of recovery completed the Client Assessment of Strengths, Interests and Goals Self-Report (CASIG-SR). Participants reported their goals for accommodation, work and study, interpersonal relationships, recreational activities, spirituality, religion or life purpose, physical health and mental health, and the personal strengths and supports needed to achieve those goals. Concordance scores were calculated between importance of personal goals and level of support from current services regarding these goals.

RESULTS

Themes identified across goals, strengths and supports were Connection, Independence & Confidence, Meaning & Self: The Real Me, and Stability & Balance. Work and study goals and strengths were identified strongly. The key support needed was stability from the current treatment team to provide a stable base for change. Concordance scores indicate support provided for personal goals was less than the importance of the goal to the individual.

CONCLUSION

Results suggest goals for everyday living are critical to recovery in anorexia nervosa. Specific clinical considerations to increase motivation and hope are increased access to peer support, a focus on increasing positive affect, supporting safe exercise and promoting outdoor experiences and connection with nature.

LEVEL III

Evidence obtained from well-designed cohort or case-control analytic studies.

Myocardial mechanics in anorexia nervosa: a systematic review and meta-analysis of speckle tracking echocardiographic studies

BACKGROUND

Clinical complications of anorexia nervosa (AN) include cardiac structural and functional alterations. Available evidence on impaired myocardial deformation in AN patients without overt systolic dysfunction as assessed by left ventricular ejection fraction (LVEF) is scanty and based on a few studies. The aim of the present meta-analysis was to provide comprehensive and updated information on this issue.

METHODS

Following the PRISMA guidelines, systematic searches were conducted across bibliographic databases (Pub-Med, OVID, EMBASE and Cochrane library) to identify eligible studies from inception up to 31 January 2024. Searches were limited to clinical investigations published in English reporting data on left ventricular (LV) mechanics (i.e. global longitudinal strain) in patients with anorexia and controls. The statistical difference of the echocardiographic variables of interest between groups such as LVEF and global longitudinal strain (GLS) was calculated by standardized mean difference (SMD) with 95% confidence interval (CI) by using random-effects models.

RESULTS

Five studies including 171 AN and 147 healthy normal-weight individuals were considered for the analysis. Pooled average LVEF values were 63.2 ± 0.4% in the healthy control group and 64.6 ± 1.0% in the AN group (SMD -0.08 ± 0.11, CI: -0.15/0.30, P  = 0.51); the corresponding values of GLS were -20.1 ± 0.9% and -20.2 ± 0.9% (SMD 0.07 ± 0.3, CI: -0.46/0.60, P  = 0.80). Unlike GLS, apical strain (data from three studies) was higher in AN than in controls (-23.1 ± 1.8 vs. -21.3 ± 1.8; SMD: -0.42 ± 0.17, CI: -0.08/-0.76, P  = 0.01).

CONCLUSIONS

The results of the present meta-analysis do not support the view that myocardial deformation as assessed by GLS is impaired in patients with AN and preserved LVEF. The role of STE in detecting subclinical cardiac damage in this clinical condition deserves to be evaluated in future studies including regional LV strain.

Two identical twin pairs discordant for longstanding anorexia nervosa and OSFED: lived experience accounts of eating disorder and recovery processes

Research into the risk of anorexia nervosa (AN) has examined twin pairs to further the understanding of the contributions of genetics, trait inheritance, and environmental factors to eating disorder (ED) development. Investigations of twin experiences of EDs have been biologically-based and have not considered the qualitative, phenomenological aspects of twin experiences. A gap in the literature exists regarding understanding of discordant twins with EDs. This research was developed in response, with the aim to deepen understanding of AN in discordant twins and to create novel ideas for further research and testing. The case studies presented in this article provide lived experience insights of two identical discordant twin pairs: one twin pair discordant for longstanding AN and one twin pair discordant for 'atypical' AN (the twin with AN has recovered). The perspectives and experiences of each co-twin (one with AN and one without) explore a number of factors that may have contributed to twin discordance in these cases, and how each twin has responded to the impact of AN in their lives. Through use of first-person accounts in case study presentation, this article centres social justice values of lived experience leadership and involvement in research. This article aims to extend current knowledge and understanding of EDs in discordant twins, particularly regarding risk for ED development, ED duration, diagnosis and treatment, and recovery processes.

Severe and enduring anorexia nervosa and the proposed "Terminal anorexia" category: an expanded meta synthesis

This updated meta-synthesis explores further dimensions of the lived experience of severe and enduring anorexia nervosa (SE-AN) since recent contention regarding proposed "terminal anorexia nervosa (T-AN)". The paper aims to update the original synthesis and to situate participant responses to the category of "T-AN". Thus, extending the proposed conceptualization of the SE-AN experience. A systematic search identified published scholarship (between August 2022 and July 2023), derived from five bibliographic databases. A comprehensive methodology combining Interpretative Phenomenological Analysis and a meta-ethnographic framework enabled the synthesis of meta-themes across 9 new studies. These meta-themes were mapped onto the primary synthesis to further develop upon the earlier LE conceptualization of SE-AN. Nine extracted papers expanded the voices to 447 people within 45 studies. All papers affirmed and enriched the previous themes, and a novel theme was generated from the recent papers. The new theme, "walking on a knife's edge, caught between worlds", informed an expanded conceptualization of SE-AN, termed the Web of Hope. Thus, demonstrating how participants held onto hope in the face of the SE-AN experience. Death, dying and "terminality", were notably absent in the 36 papers in the previous meta-synthesis. Since the proposal of the category of "terminal anorexia" in 2022, studies on the lived experience of SE-AN increasingly focused on how people hold onto hope alongside SE-AN. The findings further drive the field to reflect on therapeutic interventions, labelling and diagnosis, in the face of unknowns, on the premise of "first, do no harm".

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

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

Sensory processing across eating disorders: A systematic review and meta-analysis of self-report inventories

OBJECTIVE

This review investigated the extant literature regarding the relationship between eating disorder diagnoses and sensory processing as measured by validated and reliable self-report inventories. Increasing evidence highlights the role of sensory processing in cognitive functions. Sensory processing is implicated in mental-ill health, including eating disorders (ED) and body image disturbances. However, the pathophysiological underpinnings of sensory processing, encompassing exteroception and interoception, in relation to ED remain underexplored.

METHOD

We included studies involving participants aged 15 years or older with an eating disorder diagnosis confirmed by semi-structured or structured interviews. We further limited inclusion to articles using validated and reliable self-report instruments to measure sensory processing. Our meta-analysis focused on studies using the interoceptive awareness subscale from the second version of the Eating Disorder Inventory. We used the Critical Appraisal checklist for quasi-experimental studies to assess the quality of included articles.

RESULTS

There were 19 studies that met our inclusion criteria. Most studies showed moderate-to-high quality. Anorexia nervosa (AN) and bulimia nervosa (BN) were associated with heightened exteroception. Moreover, people with AN reported a heightened sense of taste compared to those with BN. Our meta-analysis comprising 10 studies, 19 samples, and 6382 participants revealed that AN (binge-purge subtype) and BN were associated with increased interoceptive difficulties compared to AN (restrictive subtype) or binge-eating disorder.

DISCUSSION

Overall, this review emphasizes the need for a deeper investigation into sensory processing, spanning both exteroception and interoception, in relation to ED. This may prove important for individualizing person-centered care.

PUBLIC SIGNIFICANCE

How people process internal, for example, hunger, and external, for example, taste and sensations is known to influence cognition and mental-ill health, including ED and body image disturbances. However, the ways in which sensory processing may contribute to ED are incompletely understood. We found that individuals with AN or BN experienced heightened exteroception, while people with an eating disorder characterized by purging reported increased interoceptive difficulties. These patterns could inform the development of more personalized treatments.

MiRNA research-The potential for understanding the multiple facets of anorexia nervosa

Anorexia nervosa (AN) has a multifaceted and complex pathology, yet major gaps remain in our understanding of factors involved in AN pathology. MicroRNAs (miRNAs) play a regulatory role in translating genes into proteins and help understand and treat diseases. An extensive literature review on miRNAs with AN and comorbidities has uncovered a significant lack in miRNA research. To demonstrate the importance of understanding miRNA deregulation, we surveyed the literature on depression and obesity providing examples of relevant miRNAs. For AN, no miRNA sequencing or array studies have been found, unlike other psychiatric disorders. For depression and obesity, screenings and mechanistic studies were conducted, leading to clinical studies to improve understanding of their regulatory influences. MiRNAs are promising targets for studying AN due to their role as signaling molecules, involvement in psychiatric-metabolic axes, and potential as biomarkers. These characteristics offer valuable insights into the disease's etiology and potential new treatment options. The first miRNA-based treatment for rare metabolic disorders has been approved by the FDA and it is expected that these advancements will increase in the next decade. MiRNA research in AN is essential to examine its role in the development, manifestation, and progression of the disease. PUBLIC SIGNIFICANCE: The current understanding of the development and treatment of AN is insufficient. miRNAs are short regulatory sequences that influence the translation of genes into proteins. They are the subject of research in various diseases, including both metabolic and psychiatric disorders. Studying miRNAs in AN may elucidate their causal and regulatory role, uncover potential biomarkers, and allow for future targeted treatments.

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

OBJECTIVE

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

METHOD

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

RESULTS

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

DISCUSSION

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

PUBLIC SIGNIFICANCE

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

Pragmatic clinical trials to advance research in children and adolescents with eating disorders

OBJECTIVE

To discuss the utility of pragmatic clinical trials (PCTs) to help advance research in eating disorders (EDs).

METHODS

We describe challenges associated with traditional explanatory research trials and examine PCTs as an alternative, including a review of the PRECIS-2 tool.

RESULTS

There are many challenges associated with the design and completion of traditional RCTs within the field of EDs. Pragmatic clinical trials are studies that closely align with conditions available in everyday practice and focus on outcomes that are relevant to patients and clinicians. Results of PCTS maximize applicability and generalizability to clinical settings.

DISCUSSION

Available therapies established for the treatment of EDs provide remission rates that rarely exceed 50%, implying a need for additional research on new or adjunctive treatments. In addition to a general overview of PCTs, we draw upon published literature and our own experiences involving adjunctive olanzapine for the treatment of children and youth with anorexia nervosa to help highlight challenges associated with randomized controlled trial (RCT) design and implementation, and offer pragmatic suggestions that would allow patients greater choice in treatment trials, while at the same time capturing outcomes that are most likely to advance treatment efforts.

CONCLUSIONS

Pragmatic clinical trials provide alternatives to RCT design that can help bolster research in EDs that aims to explore real-world effects of interventions.

PUBLIC SIGNIFICANCE

Available therapies established for the treatment of eating disorders (EDs) in children and adolescents provide remission rates that rarely exceed 50%, implying a need for additional research on new or adjunctive treatments. In this article, we discuss the utility of pragmatic trials to help promote research that can help advance knowledge that is relevant to clinical care settings.

Energy expenditure during nutritional rehabilitation: a scoping review to investigate hypermetabolism in individuals with anorexia nervosa

BACKGROUND

Weight gain and nutritional rehabilitation are essential first steps to achieve medical stabilization in anorexia nervosa, and frequent resistance to weight gain requires patients to consume high kilocalorie loads. Adaptive hypometabolism is common when patients begin treatment, and rebound hypermetabolism is suspected to be a significant barrier to weight gain. The aim of this review was to summarize existing data describing metabolic changes in anorexia nervosa during weight restoration. The reported findings challenge current hypotheses of weight gain resistance and highlight key areas for future research.

METHODS

Using scoping review guidelines, three databases were searched for studies investigating metabolic changes in anorexia nervosa before and after renourishment. Two reviewers systematically screened the titles and abstracts of 447 articles, and full-text versions of 106 studies were assessed for eligibility. A total of 36 studies were included for review. Data regarding the study description, sample population (including age, weight, BMI, duration of treatment, and caloric intake), and metabolic variable descriptions were extracted.

RESULTS

Female patients with anorexia nervosa from studies across 13 countries were included. Across the studies, average BMI increased from 13.7 kg/m2 at admission to 17.57 kg/m2. Patients presented to treatment with clinically reduced energy expenditure levels. After varying levels of nutritional rehabilitation and weight restoration, measured energy expenditure increased significantly in 76% of the studies. Energy expenditure values at the second timepoint increased to the standard range for normal weight female teenagers and adults. Despite these increases, the studies do not indicate the presence of a hypermetabolic state during renourishment. Additionally, all studies including both measured and predicted energy expenditure reported that predicted energy expenditure overestimated measured values.

CONCLUSION

This study provides a detailed evaluation of the literature investigating energy expenditure and metabolic rate in patients with anorexia nervosa before and following a period of renourishment. The findings from this review identify important gaps in the current beliefs of energy expenditure in anorexia nervosa and highlight a need for further exploration of metabolic alterations during weight restoration.

Temperament impact on eating disorder symptoms and habit formation: a novel model to inform treatment

BACKGROUND

Temperament has long been described as the biological dimension of personality. Due to advancing brain-imaging technology, our understanding of temperament has deepened and transformed over the last 25 years. Temperament combines genetic, neurobiological and trait research. Temperament has been included peripherally in some eating disorder (ED) treatment approaches but has been ignored by most. Temperament fills a fundamental treatment gap by clarifying who is more vulnerable to develop ED and why some individuals are susceptible to specific ED symptoms while others are not. In addition, temperament targets possible treatment solutions.

MAIN TEXT

There is a need for a novel model that incorporates and explores the role of temperament in ED treatment intervention. This paper is a metaphoric temperament model to inform treatment intervention. It describes how temperament traits influences new decisions which impact new behavioural responses. In turn, it neurobiologically tracks how and why the brain efficiently transforms new decisions into new habits. This model integrates both temperament and habit research to explore (a) what temperament is; (b) how new decisions develop into habits neurobiologically; (c) that the brain wires destructive symptoms into habits in the same way that it wires healthy/productive behaviours into habits; (d) traits that trigger ED symptoms are the same traits that influence productive behaviours; and in regard to treatment implications (e) when treatment structure and intervention target client temperaments, the potential for new healthy "trait-syntonic" habits could develop.

CONCLUSIONS

This paper introduces a metaphoric model that synthesizes and integrates temperament neurobiological and trait findings with ED symptoms, habits, and client trait-based solutions. The model synthesizes and integrates different research domains to establish a brain-based foundation to inform treatment intervention. The model targets clients' temperament traits as central collections of innate self-expressions that could be utilized as tools to redirect client trait-syntonic ED responses into trait-syntonic productive outcomes. The brain bases of temperament and habit formation serve as a biological foundation for ED treatment intervention.