The school a girl attends can affect her chance of being diagnosed with an eating disorder. That’s the conclusion of research carried out by a joint UK-Swedish team. The results are published in the International Journal of Epidemiology.

Researchers from Oxford University, UCL, the University of Bristol, the London School of Hygiene and Tropical Medicine and the Karolinska Institute in Stockholm used routinely collected data from Sweden to take account of individual factors that would make someone more likely to develop an eating disorder.

Even after accounting for these factors, there were still differences in the rates of eating disorder according to the school attended.

Girls attending schools with higher proportions of female students, and high proportions of university- educated parents were more likely to be diagnosed with an eating disorder than girls at schools with lower proportions of female students and fewer university-educated parents.

Eating disorders, including anorexia nervosa, bulimia nervosa, binge eating disorder, and other eating disorders which don’t fit so neatly into the classification system, affect 5.7 per cent of adolescent girls. That’s almost two in a class of 30. They are serious illnesses: someone with bulimia nervosa is around twice as likely to die young as someone without it, while someone with anorexia nervosa is about 6 times more likely to die young.

Dr Helen Bould, Child and Adolescent Psychiatrist at the University of Oxford Department of Psychiatry, who led the research, said, ‘Eating disorders have an enormous effect on the lives of young people who suffer from them – it is important to understand the risk factors so that we can address them.

‘For a long time clinicians in the field have noted that they seem to see more young people with eating disorders from some schools than others, but this is the first empirical evidence that this is the case.’

The research team accounted for factors as diverse as parental income, whether parents had a history of mental ill health, parental education, the number of siblings and birth weight among others. Even allowing for all these characteristics, there were still variations between schools.

Dr Bould commented, ‘Unfortunately, this study can’t tell us what it is about schools that affects the rates of eating disorders: it might be an unintentional effect of the aspirational culture of some schools that makes eating disorders more likely; it might be that eating disorders are contagious and can spread within a school. On the other hand, it could be that some schools are better than others at identifying eating disorders in their students and ensuring they get diagnosed and treated.’

Sweden doesn’t have any single sex schools, due to its strict laws on gender equality. It is difficult to extrapolate these findings to the different educational system in the UK, where there are selective all-girls schools that are likely to have a high proportion of highly educated parents. However, given the results in Sweden it is possible that such schools would have higher rates of eating disorders.

During this study, Dr Bould was supported by the Elizabeth Blackwell Institute for Health Research at the University of Bristol, and subsequently by a Wellcome Doctoral Training Fellowship at the University of Oxford.