As a patient with a longstanding and severe eating disorder, my 20 years of illness bring an acute understanding of the poor outcomes that can result from existing treatments for eating disorders. Anorexia nervosa in particular is notable for poor recovery rates and insufficient prevention of its adverse impacts, which include preventable death. ^{Reference Solmi, Monaco, Højlund, Monteleone, Trott and Firth1} Anorexia nervosa is typically characterised by severe underweight status and a fear of/difficulty in gaining weight, often alongside psychopathological features such as marked body image disturbance and cognitive rigidity. The main treatment approaches used today include enhanced cognitive–behavioural therapy (CBT-E), the Maudsley model for the treatment of anorexia nervosa (MANTRA) and family-based therapy (FBT) for children and young people. ^{Reference Muratore and Attia2}

While nutritional rehabilitation is centrally important in such treatments, the physiological components of anorexia nervosa have largely been conceptualised as a secondary consequence of an underlying illness whose essence exists in the realm of the mind. In recent years, scientific findings and lived experience accounts have challenged this conceptualisation, emphasising the risk of reinforcing an unhelpfully dualistic binary between mental and physical health, leaving potential treatment targets in the realm of biology relatively overlooked. ^{Reference Downs3}

There is a growing body of research supporting the conceptualisation of anorexia nervosa as a metabo-psychiatric disorder with primary biological components including genetic, anthropometric and metabolic factors. ^{Reference Bulik, Carroll and Mehler4} These play a role in predisposing risk and in the aetiology of anorexia nervosa, as well as influencing the course and maintenance of illness. For example, a range of psychiatric symptoms and physiological risks can resolve during recovery with adequate nutritional rehabilitation. ^{Reference Downs3} As such, it is logical to think that treatments may exist that better target this complex interplay of biological processes and psychological experience, much of which remains poorly understood. ^{Reference Skowron, Kurnik-Łucka, Dadański, Bętkowska-Korpała and Gil5}

The development of novel treatments for anorexia nervosa that address these knowledge and treatment gaps is to be applauded. Such treatments range from psychopharmacological and biological interventions to new psychotherapeutic and technologically enhanced approaches. However, there are also valid challenges to prioritising new interventions, especially when existing treatments may offer more potential than is widely accepted.

Within this article, I draw upon published research, critically interpreted from my perspective as a person with lived experience, to explore some of these challenges in greater depth. These include: (a) the limitations of research into novel treatment candidates; (b) the untapped potential of existing treatments; (c) the ethical and methodological challenges of research in this area; and (d) the potential unintended consequences of efforts to improve treatment for anorexia nervosa. The systemic factors that constrain treatments old and new are also explored. Lastly, I take a constructive and inclusive orientation by offering recommendations for how these complex challenges may best be addressed. My hope is to support more inclusive and integrative methods of creating knowledge about anorexia nervosa and its treatment, where no potential is left untapped and nobody is left behind.

Research into novel treatments has a range of limitations

Despite having little clinical application to date, ^{Reference Magrini, Curzio, Tampucci, Donzelli, Cori and Imiotti6} research into novel treatment candidates for anorexia nervosa has considered a wide range of approaches. These include, but are not limited to, modification of gut microbiota with faecal transplants; transcranial and deep brain stimulation; metabolic interventions such as the ketogenic diet; and psychopharmacological agents such as ketamine and psilocybin. In psychotherapies, technologies including virtual reality are also being adopted to target interoceptive and embodied components of anorexia nervosa, albeit largely within established exposure and response prevention paradigms. ^{Reference Downey and Gorrell7}

The pursuit of novel treatments is hampered by a range of theoretical and methodological limitations. Sample sizes remain small and demographically unrepresentative, ^{Reference Magrini, Curzio, Tampucci, Donzelli, Cori and Imiotti6} with many research trials still using exclusively female participants and persisting in under-representing ethnic and other minorities. ^{Reference Halbeisen, Brandt and Paslakis8} Considering the widely heterogeneous nature of anorexia nervosa, and established differences in symptomatology that exist across minority groups and identities (such as males and sexual/gender minorities), ^{Reference Halbeisen, Brandt and Paslakis8} research that is insufficiently representative risks further marginalising those whose diverse experiences are incongruent with existing, limited research – exacerbating health inequalities.

Many emerging treatments for anorexia nervosa have not yet been proven effective in creating therapeutic change. Ketamine, for example, has been shown to have some potential benefits, largely in terms of reducing anxiety and improving mood via rapid-acting antidepressant effects. However, the impact of ketamine on weight restoration and the core psychopathological features of anorexia nervosa – such as distorted body image and fear of weight gain – are not well demonstrated and need further exploration. ^{Reference Keeler, Treasure, Juruena, Kan and Himmerich9,Reference Ragnhildstveit, Slayton, Jackson, Brendle, Ahuja and Holle10}

Research also exists within a context, which must also be considered if such novel treatment candidates are to translate into meaningful benefits for patients in clinical practice. The often-siloed ecosystem of research in psychiatry is a challenge for understanding a condition such as anorexia nervosa, with its interconnected array of biological, psychological, and social factors, as situated within a broader ecological context. ^{Reference Downs11} Eating disorder research itself has been described as operating within its own segregated niche as an overly specialised area. ^{Reference Haynos, Egbert, Fitzsimmons-Craft, Levinson and Schleider12} Research into novel treatments risks having limited utility if undertaken within contexts that are not conducive to knowledge exchange and transdisciplinary innovation. A shift is therefore required towards research processes that increase integration and evidence synthesis across disciplines, including people with lived experience, in order to be truly congruent with the multifactorial and complex nature of anorexia nervosa and its treatment.

The potential of existing treatments is not fully realised

A range of systemic factors limits the potential of existing treatments, many of which may be addressed by a greater quantity of high-quality research. For instance, more representative findings can be achieved by recruiting more diverse and plentiful samples, and a more systematic and coordinated approach can help synthesise multiple areas and types of knowledge. However, any new treatments that are developed – irrespective of how effective they may be within the context of clinical trials – will eventually be deployed within the constraints of existing care structures. Many specialist services for eating disorders are overstretched and underfunded in, for instance, the UK and USA. ^{Reference Kaye and Bulik13,Reference Ayton, Viljoen, Ryan, Ibrahim and Ford14}

In the UK context, national frameworks such as those provided by the National Institute for Health and Care Excellence (NICE) and the Royal College of Psychiatrists’ Medical Emergencies in Eating Disorders (MEED) set out best practice for eating disorders treatment. ^{Reference National Guideline Alliance15,16} While these provide clear recommendations for assessment, intervention and risk management, services often lack the resources, staffing and training to implement them effectively. ^{Reference Ayton and Ibrahim17} Healthcare professionals frequently report insufficient training in eating disorders ^{Reference Ayton, Ibrahim, Downs, Baker, Kumar, Virgo and Breen18} and, despite the Parliamentary and Health Service Ombudsman (PHSO) calling for urgent improvements, ¹⁹ progress towards meeting minimum standards of care remains critically lacking. Without addressing these systemic shortcomings, even the most evidence-based treatments risk failing in real-world practice, reinforcing the need to prioritise not only the development of new interventions but also the resourcing and accountability required to ensure that existing standards are met.

There is evidence to suggest that existing treatments can achieve significantly improved patient outcomes where factors relating to treatment provision are addressed. For example, the efficacy of CBT-E is often limited by factors such as short-term treatment durations, a lack of focus on co-occurring conditions, and premature discharge without full nutritional rehabilitation. A recent study by Ibrahim et al ^{Reference Ibrahim, Ryan, Viljoen, Tutisani, Gardner, Collins and Ayton20} used integrated and enhanced cognitive–behavioural therapy (I-CBTE) in a cohort of 212 severely malnourished patients with an average duration of illness of ∼17 years. Patients who received this evidence-based treatment delivered in a more integrated format, and who were discharged at higher body mass index than is typical in usual practice, experienced better and more sustained outcomes. Furthermore, the duration and severity of illness were not reliable predictors of treatment success, emphasising the value of a more individualised, multidisciplinary approach to care, even among the most longstanding and severe cases.

Similarly, the Pathway for Eating Disorders and Autism Clinical Excellence (PEACE) demonstrates how adapting existing treatments for anorexia nervosa, rather than reinventing them, can improve outcomes for groups who have been underserved by treatments to date. ^{Reference Hartmann, Weber, Herpertz and Zeeck21} By tailoring interventions to autistic individuals’ needs – for example by adjusting sensory aspects of treatment and providing neurodivergent-friendly psychoeducation – PEACE has increased treatment acceptability and effectiveness. ^{Reference Hay, Claudino, Touyz and Abd Elbaky22} This highlights the potential for innovation within service delivery itself, ensuring that current treatments are made more accessible and effective for diverse groups, regardless of whether or not new interventions are introduced.

Despite evidence supporting treatment individualisation and quality improvement as important routes towards better outcomes for anorexia nervosa, these examples must be balanced alongside findings from systematic reviews and meta-analyses which indicate that no psychological treatment has demonstrated clear superiority over others to date. ^{Reference Li, Halls, Byford and Tchanturia23,Reference Tchanturia, Dandil, Li, Smith, Leslie and Byford24} Even in the context of well-conducted clinical trials, where treatment is delivered by highly trained professionals with high fidelity, remission rates remain low, suggesting a significant gap in efficacy beyond issues of service delivery alone. This reinforces the need for a dual focus: ensuring that existing treatments are delivered to their maximum potential, while acknowledging that further innovation may also be required.

Methodological and ethical challenges persist

Studies focussed on optimising and developing new treatments for anorexia nervosa also pose several ethical and methodological challenges. For example, randomised controlled trials (RCTs) are regarded as the gold standard for evaluating treatment efficacy, yet they often require withholding or delaying treatment for participants in control groups. In the context of anorexia nervosa, this could result in life-threatening consequences and/or the perpetuation of the harms inherent to malnutrition. ^{Reference Birch, Downs and Ayton25} As a result, participants in such trials may still access ‘treatment as usual’ in the community, rather that no treatment at all. While this may mitigate risks, it may introduce a confounding factor, because the care provided in community settings may be widely heterogeneous and/or remain unaccounted for in analyses, complicating comparisons between groups.

Furthermore, assessing informed consent within RCTs of individuals with anorexia nervosa is made challenging by the impact of malnutrition on cognitive function. ^{Reference Birch, Downs and Ayton25} Despite many people with anorexia nervosa appearing highly functional in many areas of their lives, participants may struggle with fluctuating capacity to consent, making it difficult to ensure ethical standards are upheld. ^{Reference Turner and McCradden26} Tools are available to assess decision-making capacity, but inconsistent implementation and lack of training hinder their effective use. ^{Reference Takimoto27} Weighing these concerns with the ethical imperative to improve treatment and alleviate suffering is essential. Future research therefore requires methods that address both the complexity and nuance of anorexia nervosa, while ensuring that rigorous ethical and scientific standards are upheld.

Current research practices risk unintended consequences

In addressing this subject, it is also important to be aware of the tendency for limited resources to create competition between the needs and priorities of different groups. In the context of research, this can manifest as academic rivalry, with researchers discrediting work perceived as competing with their own rather than recognising it as complementary. Structural factors also play a role: major funders often prioritise novel treatments over refining existing ones, with grant applications scored on their ‘innovation’ rather than their potential to improve real-world outcomes. This emphasis on novelty can lead to the rebranding of similar treatment approaches under different names rather than fostering genuine progress.

Additionally, funding bodies are increasingly steering mental health research towards biological mechanisms, while grant reviewers frequently favour tightly controlled trial designs that limit participant diversity and access to concurrent care. At its worst, these dynamics risk diverting resources away from service delivery and refinement research – areas that could yield more immediate improvements for patients. Expanding research funding is crucial, but so is ensuring a more balanced allocation of resources that supports both innovation and the optimisation of existing, evidence-based care.

We must also prioritise a shift away from exclusionary research practices in anorexia nervosa research, particularly when certain groups – such as men, ethnic minorities and neurodivergent individuals – are systematically excluded from studies. ^{Reference Halbeisen, Brandt and Paslakis8} This exclusion creates a feedback loop that reinforces stigma for marginalised groups: a lack of evidence for how diverse groups can most effectively be included and responded to in treatment leads to poorer outcomes, in turn adding to assumptions about certain groups being less likely to experience or recover from anorexia nervosa. Stigma may also manifest in patients feeling blamed when treatments fail for reasons unrelated to their individual characteristics, but rather due to systemic problems in service delivery such as a lack of resources and training.

The problem of exclusion is especially pronounced for those with atypically presenting eating disorders or diagnoses such as avoidant/restrictive food intake disorder (ARFID) and atypical anorexia nervosa, where even greater gaps in knowledge and treatment persist. The dominance of anorexia nervosa in both research and public discourse has contributed to a form of hierarchical stigma whereby certain eating disorders are perceived as more serious, complex or even more ‘deserving’ of treatment and scientific attention than others. ^{Reference Downs, Adams, Federici, Sharpe and Ayton28} Yet, for eating disorder diagnoses besides anorexia nervosa, and for those with diverse identities and presentations of illness, the development of novel interventions is arguably even more pressing, precisely because they have been relatively overlooked in research to date.

Furthermore, concern has been expressed about the role of narratives portraying more severe cases of anorexia nervosa as ‘untreatable’, and how this has been used to justify the premature withdrawal of treatment for some patients. ^{Reference Downs, Ayton, Collins, Baker, Missen and Ibrahim29} While future efforts to expand the range of treatments for anorexia nervosa appear to move the field away from such notions of futility, they could arguably be supported by the same rationale – i.e. the need for novel treatments is justified by a belief that current interventions may be futile for a sufficiently significant number of patients, however much these interventions are improved. There is a risk of this narrative being overgeneralised or applied imprecisely, especially when tools to predict how, when and why different patients will (or will not) respond to treatment are severely lacking. Notions of futility regarding the potential of current treatments may also invoke what McGorry et al describe as the ‘soft bigotry of low expectations’ – a pessimistic stance that constrains aspects of progress by dismissing or undervaluing the positive evidence base that already exists. ^{Reference McGorry, Nelson, Wood, Shah, Malla and Yung30} In the context of anorexia nervosa research, this could be reflected by a false dichotomy of proven treatments being neglected in favour of uncovering novel approaches, even when there is evidence to show that investing in both is warranted. Pessimism may be reflected within clinical contexts, too, where treatment failure may be incorrectly or prematurely attributed to specific interventions, a lack of patient engagement or the nature of illness itself. This may further divert attention away from better understanding and addressing the broader range of factors that undermine treatment quality.

Taken together, these factors highlight the risk within the field of falling into binary divisions – be that between the methodological rigour of generating research findings or the immediate needs of patients in the here-and-now; investing in new treatments or refining existing approaches; focusing on either biological or psychological explanations in isolation, and so on. To create more expansive knowledge and treatment for anorexia nervosa, the task is to resist choosing between these seemingly opposing factors. Instead, mutual benefit can be obtained from integrating refinements to existing treatments with novel research findings to create more personalised and effective care.

Recommendations: investing in novel treatments and systemic change

The recommendations in Box 1 attempt to outline a way forward for anorexia nervosa treatment and research – one that does not pit novel treatments against established ones, or any one group of patients, clinicians or researchers against another. Rather than false dichotomies that stifle progress, we can create virtuous cycles that integrate and expand knowledge, driving innovation and improving treatment opportunities for all.

By investing in both new treatment development and systemic change, we can foster hope – not just for patients and their supporters, who need confidence that recovery is possible, but also for clinicians striving to offer more effective care, for researchers developing treatments that truly add value and for policymakers working to reduce the treatment gap for anorexia nervosa. In this way, no potential is left untapped, and no patient is left behind:

The following recommendations (Box 1) will help address the difficulties outlined in this paper, across theory, research and clinical practice.