Scientists studying girls with the eating disorder anorexia have found they show a mild echo of the characteristics of autism - a finding which could point to new ways of helping anorexics overcome their illness.
A study by the leading autism expert Professor Simon Baron-Cohen at Cambridge University's Autism Research Centre found that compared to typical girls, anorexics had an above-average number of autistic traits.
They were also found to have an above-average interest in systems and order, and below-average scores in empathy - a profile similar to, but less pronounced than, that seen in people with autism, suggesting the two disorders may have common underlying features, Baron-Cohen said.
"Traditionally, anorexia has been viewed purely as an eating disorder. This is quite reasonable, since the girls' dangerously low weight and their risk of malnutrition or even death has to be the highest priority," he said.
"But this new research is suggesting that underlying the surface behaviour, the mind of a person with anorexia may share a lot with the mind of a person with autism. In both conditions, there is a strong interest in systems. In girls with anorexia, they have latched onto a system that concerns body weight, shape, and food intake."
People with autism have varying levels of impairment across three main areas - social interaction and empathy or understanding, repetitive behaviour and interests, and language and communication.
Cohen said autism and anorexia shared features, such as rigid attitudes and behaviours, a tendency to be very self-focused, and a fascination with detail. Both disorders also share similar differences in the structure and function of brain regions involved in social perception.
As many as one in 50 school age children in the United States is diagnosed with autism. In Europe, experts say the rate is around one in 100 children. Most cases are diagnosed in boys.
But Dr Bonnie Auyeung, who worked on the research, said the findings suggested a proportion of females with autism may be being overlooked because doctors see them first with anorexia.
The study, published in the BioMed Central journal Molecular Autism, tested how 66 girls aged 12 to 18 with anorexia but without autism scored on tests to measure autistic traits.