Studies Investigate the Mysterious Link Between Anorexia and Autism

In the 1980s and even earlier, some researchers were beginning to notice that there was a mysterious link between autism and eating disorders like anorexia nervosa. Psychologist Christopher Gillberg initially suggested that anorexia might be the “female form of autism.” His guess wasn’t quite correct, but it led him to a new question that would prove much more useful: Do autism and anorexia have shared underlying causes?

Gillberg, a professor of child and adolescent psychiatry at the University of Gothenburg in Sweden, was curious in part because of his observation of three young boys with autism. The boys’ female cousins had all been diagnosed with anorexia, an eating disorder characterized by low body weight, voluntary food restriction, distorted body image, and an intense fear of gaining weight. Gillberg believed that autism ran in the children’s family but that it manifested itself as autism in boys and as anorexia in girls.

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Gillberg’s theories do appear to have at least a kernel of truth to them. There is definitely some form of link between the two disorders. More recent studies have shown that people with anorexia are more likely to be autistic than those who don’t have anorexia. Anorexia is still fairly rare, affecting only about 0.3 percent of the population. But about 20 to 30 percent of people with anorexia are autistic, compared to about one percent of the overall population.

There isn’t as much data showing the reverse, however—that autistic people are at high risk for eating disorders—but experts believe it’s likely that that’s the case. Children between the ages of 7 and 11 who have been diagnosed with social difficulties have been shown to have a greater risk of disordered eating than their peers. And according to a study done on data from Denmark’s National Health Registry, people diagnosed with autism are more than five times more likely to suffer from anorexia.

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So do autism and anorexia share underlying causes? Maybe. Anorexia involves an unhealthy focus on weight and body image due to emotional issues and a desire to be accepted, but people with autism may restrict their eating for other reasons, such as food aversions, emotional issues, or an intense interest in topics like calorie-counting, exercise, or a limited diet.

Researchers posit that many people with autism, anorexia, or both, tend to struggle with alexithymia (difficulty identifying emotions) and avoidant/restrictive food intake disorder (ARFID), pointing to the possibility that the two disorders could be caused or influenced by the same factors.

People with autism who have anorexia also tend to have worse outcomes than their peers who have eating disorders but no autism. This may be partially due to the fact that eating disorder interventions don’t tend to cater to people with autism and their sensory sensitivities.

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But if the link between autism and anorexia is as strong as we think it may be, then that will all soon have to change. Some eating disorder facilities are already making changes to ensure that people with autism and other disorders can receive the type of care that will work for them.

“It really does help to know that they’re autistic if you want to be trying to help them with their eating disorder, and with their life more generally,” says William Mandy, professor of clinical psychology at University College London in the U.K.

The bottom line is this: we still don’t know the full nature of the connection between autism and eating disorders, but we do know that autism and anorexia share similar traits and both tend to show up more frequently within the other group than in the rest of the population. Given what we do know about the overlap, it should be made a top priority not only to study this connection further but also to do more work in addressing the needs of people who are dealing with both conditions simultaneously.

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