My daughter has just been diagnosed with anorexia nervosa. I read everything I could about it online. Some forums talk about the higher rate of autism in girls with eating disorders. I worry that the doctors missed something - should I get her assessed for autism, too? She’s very smart and has friends, but she seems to have some autism traits, too.
Do I Have a Dual Diagnosis?
Dear Dual Diagnosis,
Thank you for writing in about a topic that needs more attention in the autism and the eating disorder communities. There is indeed research that indicates a higher rate of autistic
traits in people with anorexia nervosa (AN) diagnoses. Anecdotally, many of the autism specialist practitioners notice a much higher rate of eating disorders in general within the autism community, but especially with females on the spectrum.
For instance, in an article published in the
International Journal of Eating Disorders in 2012, the authors reported “[d]espite not having high rates of diagnosable ASD, our EOED [early onset eating disorder] participants did have elevated ASD traits. In particular, high levels of repetitive stereotyped behavior were identified, as was a trend toward elevated difficulties with reciprocal social interactions.” This article goes on to suggest that both people on the autism spectrum and those with anorexia nervosa have weak central coherence and other executive function challenges, specifically difficulty shifting attention.
Central coherence is the ability to see the big picture – to be able to see contexts. It could be that if someone has weak central coherence he or she may not be able to immediately link his or her behavior to a consequence that is further down the road. But there are many other aspects of ASD that can lead to eating disorders as well: limited food choices due to sensory limitations; inability to track time (to know when to eat); or poor interoception, which leads to someone not knowing when he or she is hungry or full.
Another article, published in the
Journal of Autism and Developmental Disorders, looked at using a common autism screening tool – the Autism Quotient – to look for autism traits in people with anorexia. Their results found that there were higher scores on the AQ from the AN group but not high enough to be within the range of a positive diagnosis for an autism spectrum disorder. The authors note that their “results do not allow for conclusions to be drawn regarding whether a proportion of those with an AN also have an underlying ASD.”
In addition, many individuals with autism also are diagnosed with Avoidant/Restrictive Food Intake (ARFI) which, on the surface, appears to be very similar to anorexia. The major difference between the two diagnoses lies in the motivation: those with anorexia have a strong drive to be thin, while those with ARFI typically are more driven by sensory concerns.
While we don't have conclusive evidence of the exact relationship of autism and anorexia, all of this information does indicate that both professionals who work in the autism community as well as those in the eating disorder community should be aware of the characteristics of the other diagnosis in order to provide appropriate support.
In regards specifically to your daughter, I’ll emphasize that having friends does not mean she does not have autism –
a lot of people on the autism spectrum have friends! If you're noticing that your daughter is showing some signs of autism, it is important to bring her in for an ASD evaluation. This will ensure that she has the most support for managing symptoms and meeting her life goals. Because undiagnosed autism can cause a great deal of anxiety, it may be difficult to treat the eating disorder if undiagnosed autism is playing a role.