Girls with anorexia have elevated autistic traits
In particular, compared to typical girls, girls with anorexia have an above average number of autistic traits, an above average interest in systems, whilst they score below average in empathy. This profile resembles – to a lesser degree – that seen in people with autism.
At first glance, anorexia and autism seem very different, but they both share certain features, such as rigid attitudes and behaviours, a tendency to be very self-focussed, and a fascination with detail. Both conditions also share similar alterations in structure and function of brain regions involved in social perception.
The team, led by Professor Simon Baron-Cohen at the Autism Research Centre at Cambridge University, tested how 66 adolescent girls (aged 12-18) with anorexia but without autism scored on tests to measure traits related to autism. They compared them to over 1,600 typical teenagers in the same age range, and measured their autistic traits using the Autism Spectrum Quotient (AQ), their 'systemizing' using the Systemising Quotient (SQ), and their empathy using the Empathy Quotient (EQ).
They found that on the AQ, five times more girls with anorexia scored in the range that people with autism score in, compared to the typical girls. In addition, on the AQ, over half of the girls with anorexia showed the 'broader autism phenotype', compared to just 15% of typical girls. On the tests of empathy and systemising (how strong an interest the person has in repeating patterns and predictable rule-based systems), girls with anorexia had a higher SQ, and a reduced EQ, a profile that parallels that seen in autism.
Professor Baron-Cohen said: "Traditionally, anorexia has been viewed purely as an eating disorder. This is quite reasonable, since the girl's dangerously low weight, and their risk of malnutrition or even death has to be the highest priority. 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."
Dr Bonnie Auyeung, a member of the research team, added: "Autism is diagnosed more often in males. This new research suggests that a proportion of females with autism may be being overlooked or misdiagnosed, because they present to clinics with anorexia".
Dr Tony Jaffa, who co-led the study, said: "Acknowledging that some patients with anorexia may also have a raised number of autistic traits and a love of systems gives us new possibilities for intervention and management. For example, shifting their interest away from body weight and dieting on to a different but equally systematic topic may be helpful. Recognizing that some patients with anorexia may also need help with social skills and communication, and with adapting to change, also gives us a new treatment angle."