By Jennifer Copley (Last Updated 21 May 2011)
Nearly two-thirds of those with Asperger’s syndrome have unusual eating habits (Wendt et al., 2005), and up to many anorexic teen girls show signs of having Asperger’s syndrome (Atwood, 2007).
There are more girls than boys who meet the diagnostic criteria for anorexia, but in some cases boys with Asperger’s syndrome have become so thin that they have been referred to doctors due to suspicion of anorexia. The higher incidence of girls with anorexia overall is likely attributable to cultural pressures to remain extremely thin.
Studies Find a Possible Link Between Asperger’s Syndrome and Anorexia Nervosa
One study, reported by psychiatry professor Janet Treasure (2007), head of the South London and Maudsley NHS Trust Eating Disorders Unit, found that more than 1 in 5 anorexics met the criteria for an autistic spectrum disorder. Asperger’s syndrome expert Tony Attwood (2007) reports a similar rate, with between 18% and 23% of teenage girls who suffer from anorexia also meeting some or all of the diagnostic criteria for Asperger’s syndrome. By contrast, the prevalence rate for all autistic spectrum disorders in the general population is less than 1%.
A systematic review of 32 individual studies in various countries conducted by Berkman et al. (2007) also found that those with anorexia nervosa are more likely to have autistic spectrum disorders and anxiety disorders (such as obsessive-compulsive disorder) than those in the general population.
Common Symptoms of Anorexia Nervosa and Asperger’s Syndrome
Janet Treasure, noting a number of apparent trait similarities among anorexia sufferers and those with Asperger’s syndrome, has proposed that like Asperger’s, anorexia has a genetic, neurobiological basis. This claim is thus far controversial and more research is required to comprehensively confirm or refute it, though a recent study has identified gene variants associated with anorexia (Children’s Hospital of Philadelphia, 2010).
Treasure asserts that anorexia results in part from aspects of neural processing, or the ways in which the brain interprets information. Neural processing can affect both psychological reactions and behaviour, and atypical neural processing is also implicated in autistic spectrum disorders.
Symptoms that are relatively common among both those with autistic spectrum disorders and anorexia sufferers include:
- A tendency to focus on minute details rather than perceiving things holistically, thus becoming easily distracted and often missing the big picture
- Obsessive-compulsive behaviour
- A need to do things perfectly and completely
- Difficulties with multitasking, or shifting back and forth between two different tasks or ideas
- A lack of flexibility in both cognition and responses, which makes it very difficult to cope with changes in plans or routines
- Higher-than-average incidence of anxiety disorders and mood disorders such as depression
- Atypical eating behaviours, unusual food preparation routines, and/or refusal to eat one or more types of food
- In some cases, ritualized and/or extreme exercise routines
It should be noted that not all those with either anorexia nervosa or Asperger’s syndrome will have all of these traits. Also, research indicates that despite the higher-than-average prevalence rates linking the two conditions, the majority of people with Asperger’s syndrome don’t suffer from serious eating disorders, and the majority of anorexics don’t meet the diagnostic criteria for autistic spectrum disorders.
Atypical Eating Behaviours in Those with Asperger’s Syndrome
There has been little research conducted into the intersection of eating disorders and autistic spectrum disorders, despite the fact that both are associated with abnormal eating patterns. Due to sensory hypersensitivity, those with autistic spectrum disorders often restrict themselves to a small number of dietary choices because they can’t tolerate the textures, smells, or tastes of many foods and may even experience nausea if they attempt to eat them. Avoidance of many different foods may lead to extreme thinness, though it can also potentially cause weight gain if only high-calorie items are tolerated.
People with Asperger’s syndrome and other autistic spectrum disorders may also require unusual food presentation styles or meal routines, a trait often found in anorexics as well. Many children diagnosed with Asperger’s syndrome were originally brought to see paediatricians due to their parents’ concerns about their eating behaviours.
Overall, while there are many intriguing similarities between anorexia nervosa and autistic spectrum disorders, there has not been sufficient research conducted to draw any definitive conclusions. However, prevalence rates and common symptoms suggest the possibility that the conditions may share some neurobiological features.
For more articles on Asperger’s syndrome, visit the main Autism and Asperger’s Syndrome page.
- Attwood, T. (2007). The Complete Guide to Asperger’s Syndrome. London, UK: Jessica Kingsley Publishers.
- Berkman, N.; Lohr, K.; & Bulik, C. (2007). “Outcomes of Eating Disorders: A Systematic Review of the Literature.” International Journal of Eating Disorders, 40(4), 293-309. Retrieved April 18, 2009, from the EBSCO MasterFILE Premier database.
- Children’s Hospital of Philadelphia. (20 November 2010). “Gene Links to Anorexia Identified: Largest Genetic Study of the Eating Disorder Detects Common and Rare Variants.” ScienceDaily.com.
- Gillig, C. (2002). A Guide to Asperger Syndrome. New York, NY: Cambridge University Press.
- The National Autistic Society. (2008). “Statistics: How Many People Have Autistic Apectrum Disorders?” NAS.org.uk.
- Treasure, P. (17 August 2007). “Is anorexia the female Asperger’s?” The Sunday Times. Retrieved April 18, 2009, from Canadian Reference Centre database.
- Wendt, T.; Paavonen, J.E.; Ylisaukko-Oja, T.; Sarenius, S.; Källman, T.; Järvelä, I.; & von Wendt, L. (2005). “Subjective Face Recognition Difficulties, Aberrant Sensibility, Sleeping Disturbances and Aberrant Eating Habits In Families With Asperger Syndrome.” BMC Psychiatry, 5:20.