I have always been struck by similarities between the autism and eating disorder communities. Both conditions are rather misunderstood, and research into causes and cures is in its infancy at best. Both communities are home to parent-activists advocating for better research and care, for insurance coverage and a chance for their children to lead healthy, fulfilling lives. Causes into both disorders are filled with controversy, although scientists are getting closer to understanding the neurochemistry unique to each disorder.
But an interesting theory has been floating around, led largely by the efforts of Janet Treasure in the UK, that suggests some intriguing similarities between autism and anorexia. An article in New Scientist titled "Anorexia linked to 'autistic' thinking*," looks at the striking similarities in cognition patterns between people with autism and those with anorexia.
Now, evidence suggests that people with anorexia have cognitive traits associated with ASD [autism spectrum disorders]. "Eating disorders and autism spectrum disorders are obviously not the same thing, but they do have some things in common," says Janet Treasure of the Institute of Psychiatry in London. Treasure had already discovered that anorexia was associated with extreme attention to detail and a rigid, inflexible style of thinking - traits also associated with ASD...
...Simon Baron-Cohen of the Autism Research Centre in Cambridge, UK, is also measuring whether adolescents with anorexia score higher on autistic traits than healthy people, as he suspects that some of them may actually have undiagnosed Asperger's syndrome. "We have always known that Asperger's syndrome was diagnosed more often in males," he says. "The new question is whether it takes a different form in females, and can account for at least a subgroup of those who are diagnosed with anorexia."
If it does, this could have important implications for the way that anorexia is treated. "As well as treating the 'eating disorder' the clinician and the patient might [also] focus on social skills," says Baron-Cohen, although he adds that weight gain would remain a key target.No one, of course, is suggesting that everyone who has anorexia is autistic--far from it. But there are other similarities between ASD and anorexia. A recent study found that adolescent males with Asperger's Syndrome had abnormal levels of cortisol [the paper's abstract is here]. The authors of the study "believe these findings may help to explain why individuals with this condition have difficulties with minor changes to their routine or changes in their environment." Similarly, people with AN have similar abnormalities in cortisol and these some cognitive traits.
Males outnumber females in ASD, while the reverse is true for anorexia. Perhaps, assert Treasure et al., some females with AN have simply not been diagnosed with ASD because they are female.
Studies of women with AN showed that they have higher levels of autistic traits than healthy controls. Autistic-type thinking (which is usually roughly defined as poorer social skills, attention to detail, and resistance to change) is also associated with poorer outcomes in anorexia. A different study found a subgroup of AN patients that showed persistent stereotypical "autistic" thinking, a decade after diagnosis:
Ten years after AN onset, the former AN cases showed no major neuropsychological deficits. A subgroup with autistic features had test profiles similar to those observed in autism spectrum disorders. The AN group as a whole showed poor results on the object assembly subtest indicating weak central coherence with a tendency to focus on details at the expense of configural information. This cognitive style may account for their obsession with details, with implications for psychoeducational approaches in treatment programmes/interventions.
In my opinion, both autism and anorexia are caused by subtle differences in neurochemistry from a variety of systems. In anorexia alone, changes have been found in serotonin, dopamine/endorphins, leptin, ghrelin, cortisol, and neuropeptide Y, to name a few. Exactly which systems are altered, and by how much, probably explains to some degree why some people become addicted to exercise and others don't; why some begin bingeing and purging and others don't. Perhaps there is some overlap in this altered neurochemistry that could explain the overlap between the two sets of symptoms. No one has any answers for sure--the evidence is still out. But it's an interesting theory that deserves some attention.
*Picture could be triggering. I'm always baffled at some of these magazines' choices of images.