On the limited visibility of eating disorders research

Eating disorders affect up to 5% of the population at any point in time, and place an enormous physical, psychological, and financial burden on both individuals who are affected and their families. On average, only 50% of people with an eating disorder make a full recovery¹, and anorexia nervosa has one of the highest mortality rates of all psychiatric disorders.² It is estimated that eating disorders cost between £3.9 and £4.6 billion per year to the National Health Service (NHS) and result in losses of between £6.8 and £8 billion to the economy.³ If we are to address this major public health problem, we need to understand the aetiology of eating disorders and gather evidence for effective treatments. However, eating disorders research is remarkably scant. The most recent National Institute for Care Excellence (NICE) guidelines on the recognition and treatment of eating disorders⁴ find that the evidence-base for both psychological and pharmacological therapies currently used to treat eating disorders relies on a few small studies, and that many areas remain under-researched.

To quantify the magnitude of the disparity between research on eating disorders and other mental illnesses, we searched Web of Science for papers mentioning eating disorders in their title (“anorexia nervosa” OR “bulimia nervosa” OR “binge eating disorder” OR “binge eating” OR “eating disorders” OR “disordered eating”) and found that, in 2018, only 1,390 studies were published. This figure stands in stark contrast to 9,064 studies on mood disorders (“depression” OR “depressive symptoms”); 6,121 on psychosis (“schizophrenia” OR “psychosis” OR “psychotic symptoms” OR “psychotic experiences” OR “negative symptoms”); 4,596 on neurodevelopmental disorders (“ADHD” OR “attention deficit hyperactive disorder” OR”ASD” OR “autism spectrum disorders” OR “autism” OR “autistic traits”), and 1,610 on bipolar disorder (“bipolar disorder” OR “mania” OR “hypomania”).

An additional factor hindering progress in understanding and treating eating disorders is that the available research base lacks visibility. To quantify this, we explored how often eating disorder research is featured in the highest impact factor psychiatry journals. We found that compared to other psychiatric conditions, the latter publish fewer papers researching eating disorders, both in absolute and relative terms, despite having featured several letters and articles calling for the need of more research in this field.^5,6 We (FS, ECL) hand-searched all 2018 issues of the top five psychiatry journals (by impact factor)^a yielding a total of 443 new research articles. Of these, only 3 (0.7%) featured research focused solely on eating disorders, as opposed to 89 (20.1%) on schizophrenia, 79 (17.8%) on depression, 26 (5.9%) on bipolar disorder, and 36 (8.1%) on neurodevelopmental disorders. Of all the papers on eating disorders published in 2018, only 0.2% were published in the top psychiatry journals, compared to 0.9% of those on depression, 1.5% of those on schizophrenia, 1.6% of those on bipolar disorder, and 0.8% of those on neurodevelopmental disorders.

The lower number of eating disorder research papers published annually compared to other conditions might reflect the low levels of funding they receive, documented in the recent MQ reports on research funding in mental health.⁷ However, it is unlikely that this alone would explain the lower relative number of eating disorder studies published in major journals. We believe that this disparity is indicative of the marginalization of eating disorders amongst mental health researchers and professionals. Eating disorders are more common in women and are characterised by the presence of intense body image concerns and disordered eating behaviours often, but not always, aimed at weight loss. A number of studies have shown that, because of these characteristics, they are stigmatised, by the general population,⁸ but also by professionals.⁹ In the UK, medical students receive minimal training on eating disorders¹⁰ and questions on eating disorders are often omitted from large population studies. The failure to include questions on eating disorders in the 2014 UK Adult Psychiatry Morbidity Survey not only represents a missed opportunity to obtain up to date prevalence figures on these conditions, but also sent an erroneous message to the research community that eating disorders are not as important as other psychiatric disorders.

Over the past few years, funding bodies such as the Medical Research Council/Medical Research Foundation have introduced funding calls targeted at eating disorder research. Increased investment in research into eating disorders is welcome and much needed, and will eventually lead to improvements in services and treatment effectiveness. However, these initiatives alone are unlikely to close the current large gap in eating disorder research outputs and visibility, until we stop viewing eating disorders as a ‘niche specialty’ within psychiatry and grant them ‘parity of esteem’ with other psychiatric disorders.