Asperger's Syndrome and Anorexia

The Link Between Eating Disorders and Autistic Spectrum Disorders

Apr 18, 2009
Jennifer Copley

: Asperger's Can Cause Intolerance of Certain Foods - U.S. Department of Agriculture, Wikimedia Commons

Anorexia nervosa and Asperger's syndrome have a number of symptoms in common, and new research suggests that they may share some neurobiological common ground as well.

It has long been known that many of those on the autistic spectrum engage in unusual eating behaviours, and more recent research has found that those with anorexia nervosa have a higher prevalence of autistic spectrum disorders such as Asperger’s syndrome than is found in the general population.

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, Lohr, and Bulik (2007) also found that those with anorexia nervosa are more likely to have autistic spectrum disorders, as well as various 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 confirm or refute it.

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 or 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 do not suffer from serious eating disorders, and the majority of anorexics do not 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 cannot 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.