Babies born in Spring "more likely to be anorexic"

Babies born in the Spring are more likely to suffer from the eating disorder anorexia nervosa.

Although there had been suggestions in the past that such a link exists, until now the data had not been considered to be statistically significant.

The new study, by a team at the Wellcome Trust Centre for Human Genetics at the University of Oxford, looked at the birth dates of 1,293 patients with anorexia and compared them with the population as a whole. This showed that more of the people with anorexia were born between March and June that would have been expected by chance, and fewer than expected being born between September and October.

Study leader Dr Lahiru Handunnetthi explained that "this is the largest ever study to assess the presence of a season of birth effect in anorexia. Susceptibility to anorexia nervosa is significantly influenced by a person’s season of birth, being higher in those people born in the spring and lower in those born in the autumn."

This result echoes other studies that have shown that some mental disorders such as schizophrenia, bipolar disorder and major depression are more common among those born in the spring.

Dr Handunnetthi cautioned that people should not read too much into the result of the study - "our study only provides evidence of an association. Now we need more research to identify which factors are putting people at particular risk."

Possible explanations for the link could be due to environmental factors around the time of conception or when the baby is developing in the womb. As Dr Handunnetthi noted, "seasonal changes in temperature, sunlight exposure and vitamin D levels, maternal nutrition and exposure to infections are all possible risk factors."

By identifying these possible factors it is hoped that new forms of treatments could be developed - and even help prevent the disease occurring in the first place.

The study is published in the British Journal of Psychiatry.

This article was published on Thu 28 April 2011