Despite being a relatively uncommon disorder, anorexia nervosa is the deadliest psychiatric disorder and young women are particularly at risk. Current estimates of rates of anorexia nervosa among young people are at least 10 years old and mostly derived from community GP records, rather than hospitals and specialist services which are likely to be a more reliable source of information.
The researchers drew on monthly records submitted by specialist psychiatrists to the Child and Adolescent Psychiatry Surveillance System in the UK and Ireland over eight months in 2015. The records covered 8 to 17-year olds diagnosed for the first time with anorexia nervosa.
Based on these figures, the rate of new cases was 26/100,000 for girls and 2/100,000 for boys, with an overall rate of 14 new cases for every 100,000 young people. Most new cases were in young women (91%), from England (70%), and of white ethnicity (92%).
The rate of new cases rose steadily with age, peaking at 16, with a substantial drop by the age of 17. For girls, this peak occurred at 15 compared with 16 for boys.
Focusing on the lower half of the age bracket, the researchers estimated that the rate of new cases for 8 to 12-year olds was 3.2/100,000 compared to 2.1/100,000 in 2006. This finding is supported by international studies that also suggest that cases of anorexia nervosa are increasing in younger children.
Whilst the increase in anorexia nervosa in younger children may be due to earlier exposure to pressures to lose weight, it may also indicate that health services, families and schools are getting better at catching the disorder in its early stages. Early identification means young people get the support they need as quickly as possible and before the eating disorder becomes a chronic and long-term problem, and future research should look at developing earlier interventions suitable for younger children.– Lead researcher Professor Sarah Byford, from the Institute of Psychiatry, Psychology & Neuroscience
While the figures are estimates and missing data may have affected the accuracy of the calculations - such as those young people who chose not to seek help or those managed by their GP – the results are the best estimates to date of the rate of anorexia nervosa among young people in the UK and Ireland.
The researchers say that more work needs to be done to understand what might be causing the rise in new cases in younger children, but that healthcare service providers should be aware of the trend towards earlier identification and earlier onset of anorexia nervosa.
The study is published in the journal BMJ Open.