The results, published in the British Journal of Psychiatry by the Royal College of Psychiatrists, showed that people diagnosed with a disorder had higher rates of other conditions and of prescriptions in the years before their diagnosis. The findings may give GPs a better chance of detecting eating disorders earlier.
Eating disorders - such as anorexia nervosa, bulimia nervosa and binge eating disorder - affect an estimated 1.6 million people in the UK, though the true figure may be higher as many people do not seek help.
They predominantly affect women but also men; most people are diagnosed during adolescence and early adulthood. Eating disorders have the highest mortality of all mental illnesses, both from physical causes and from suicide.
Yet despite the scale of the problem, resources to treat eating disorders are scarce. There are very few specialised treatment centres. People affected are often young and vulnerable, and may avoid detection. However, the earlier a disorder can be diagnosed, the better the likely outcome for the patient.
This is where the new research can make a big difference. It can help GPs to understand what could be early warning signs of a possible eating disorder.
The research team, from Swansea University Medical School, examined anonymised electronic health records from GPs and hospital admissions in Wales. 15,558 people in Wales were diagnosed as having eating disorders between 1990 and 2017.
In the 2 years before their diagnosis, data shows that these 15,558 people had:
- Higher levels of other mental disorders such as personality or alcohol disorders and depression
- Higher levels of accidents, injuries and self-harm
- Higher rate of prescription for central nervous system drugs such as antipsychotics and antidepressants
- Higher rate of prescriptions for gastrointestinal drugs (e.g. for constipation and upset stomach) and for dietetic supplements (e.g. multivitamins, iron)
Dr Jacinta Tan, who led the research, is associate professor of psychiatry at Swansea University and the Welsh representative of the Eating Disorder Faculty in the Royal College of Psychiatrists. Dr Tan, a consultant child and adolescent psychiatrist, said:
"I cannot emphasise enough the importance of detection and early intervention for eating disorders. Delays in receiving diagnosis and treatment are sadly common and also associated with poorer outcomes and great suffering.
This research contributes to the evidence about prevalence of eating disorders and begins to quantify the scale of the problem in the entire country of Wales. The majority of these patients we identified are not known to specialist eating disorder services.
The increased prescriptions by GPs both before and after diagnosis indicates that these patients, even if not known to specialist services, have significantly more difficulties or are struggling. This underlines the clinical need for earlier intervention for these patients and the need to support GPs in their important role in this."
Dr Joanne Demmler, senior data analyst in the National Centre for Population Health and Wellbeing Research, based at Swansea University, said:
"This has been an absolutely fascinating project to work on. We used anonymised clinical data on the whole population of Wales and unravelled it, with codes and statistics, to tell a story about eating disorders.
This 'story-telling' has really been an intricate part of our understanding of this extremely complex data and was only possible through a very close collaboration between data analysts and an extremely dedicated and enthusiastic clinician."
Professor Keith Lloyd, chair of the Royal College of Psychiatrists Wales, said:
"Eating disorders can have a devastating impact on individuals and their families so this study is very timely.
We're committed to making the case for adequate services and support for people with eating disorders in Wales delivered close to where they live."