Girls with anorexia nervosa have some of the traits observed in people with autism, researchers at the Autism Research Centre at Cambridge University reported in the journal Molecular Autism.
As background information, the authors explained that anorexia nervosa ('anorexia') is an eating disorder in which the patient refuses to maintain a minimum body weight (>15% below expected body weight). There is also an abnormal preoccupation with food and weight.
Anorexia appears to be the result of a mix of social pressures, genetic disposition, body dysmorphia (chronic mental illness in which the person cannot stop thinking about a flaw in their appearance) and familial dynamics (how members of a family interact with one another).
Professor Simon Baron-Cohen and colleagues commented that girls with anorexia have a higher number of autistic traits compared to girls without anorexia.
The researchers added that girls with anorexia are more interested in systems and score below average in empathy compared to other girls of the same age. "This profile resembles - to a lesser degree - that seen in people with autism", they commented.
Autism and anorexia, at first glance, appear to be completely different. However, both show some common features, including:
- A fascination for detail
- A tendency to focus on oneself
- Inflexible behaviors
- Rigid attitudes
As far as social perception is concerned, anorexia and autism both share similar changes in structure and function of brain regions.
Professor Baron-Cohen and team tested 66 girls, aged 12 to 18 years, to measure autism-related traits. All the girls had anorexia but not autism.
The team compared their scores with 1,609 "typical" girls of the same age, The AQ (Autism Spectrum Quotient) was used to measure their autistic traits, the EQ (Empathy Quotient) to measure their empathy, and the SQ (Systemizing Quotient) for their "systemizing".
The team found:
- On the AQ test, the girls with anorexia were five times as likely to score within a range a person with autism would score.
- On the AQ, more than half of the girls with anorexia compared to 15% of the typical girls showed the "broader autism phenotype".
- The girls with anorexia had considerably lower Empathy Quotients than the other girls.
- The Systemizing Quotient among the girls with anorexia was much higher than the typical girls.
"Systemizing" refers to how much a person likes repeating patterns and predictable rule-based systems.
People with autism have a lower EQ and higher SQ than other people, as did the girls with anorexia.
Are girls with autism being overlooked because they present with anorexia?
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."
Co-author, Dr Bonnie Auyeung, said "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".
Co-leader of the study, Tony Jaffa, commented "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."
In January, 2011, researchers from King's College London concluded in the journal European Eating Disorders Review that "The cognitive profile in current AN (anorexia nervosa) resembles that of ASD (autism spectrum disorder) with important clinical implications."
Researchers from the Universitat Jaume, Spain, reported that 48.5% of women with bulimia or anorexia also have a personality disorder.