Anorexia Nervosa is one of the most challenging and enduring mental health disorders for an individual to overcome. Beyond the very serious medical symptoms of Anorexia Nervosa, it is characterized by specific mental health symptoms that maintain the disorder. This includes a tendency to become fixated on rules regarding eating and exercise.
Even when someone may recognize that their eating disorder behaviour has become problematic and may wish to stop, individuals with Anorexia Nervosa often report feeling extremely challenged to do so. But why? Why when you know what you’re doing may kill you, would you continue?
This is a question that many professionals, parents of children with eating disorders and individuals themselves ask all the time. Recent research on certain brain mechanisms may shed some light on this very perplexing issue. As a counsellor working with clients with Anorexia Nervosa, I find this research valuable, as it provides insight into a possible underlying factor in the development and maintenance of an eating disorder, while shifting the blame from both the clients and parents. While research has helped us to understand that diseases like cancer are largely out of the control of a client, it is my hope that science will help to de-stigmatize Anorexia Nervosa as well.
An Endophenotype for Anorexia Nervosa?
To better understand the possible neurological issues that may contribute to the development and maintenance of Anorexia Nervosa, it’s important to start with understanding endophenotypes. Phenotypes are parts of someone’s genetic makeup that are visible or “expressed”, such as a person’s eye colour or whether someone with a gene for cancer develops cancer. Specifically, research has found that a deficit in a very specific way of thinking, called “set-shifting” may be a possible endophenotype that is linked to the development and maintenance of Anorexia Nervosa.
What is Set-Shifting?
But what does it all mean? Set-shifting is our ability to switch back and forth between tasks and rules. When you’re playing a game of Crazy 8’s and the 8 card is played and turns the suit from diamonds to spades, your brain uses set-shifting to let the old rule of diamonds go, and quickly learn the new rule of “spades”. Similar card games are often used to test set-shifting in research settings.
Individuals with Anorexia Nervosa however, tend to have greater difficulty with this, making more errors and tending to stick to the old rule for a longer period of time. Researchers argue that this is may contribute to the difficulty in changing rules about which foods are allowed, and ways of thinking with regards to eating and beliefs about the self. One major connection that has been found is the link between set-shifting difficulties in adults with Anorexia Nervosa and reports of childhood Obsessive-Compulsive trait, which tend to be similar in their focus on rule maintenance and anxiety related to changes in rules.
Genetic Links to Set-Shifting and Anorexia Nervosa
To test the hypothesis that set-shifting challenges may be an endophenotype of Anorexia Nervosa, various research studies may be drawn upon. The rule of thumb for and endophenotype is (1) It’s inheritable, and (2) It is stable/exists before and after the illness occurs.
In terms of inheritance of the set-shifting deficit endophenotype, researchers compared pairs of sisters – either both healthy, or one healthy sister and one sister with Anorexia Nervosa. This research found that more rule change errors were made, and more time was spent making a decision about the rule change among the pairs of sisters in which one sister had Anorexia Nervosa. This was even true for the sister that was considered healthy, without an eating disorder. The take away from this is that while not all members of a family may experience an eating disorder, they may share a common endophenotype that may increase their risk or developing an eating disorder, leads to related challenges, or may be inherited throughout generations.
Long-term Set-Shifting Issues
Another consideration has been the possibility that set-shifting deficits may actually be the result of long-term malnutrition. To test this, researchers have compared adolescents with Anorexia Nervosa to adults with the disorder. The results have been inconclusive though – in some cases the adolescents seemed to do just as poorly on the task as adults, while in others they did better. Another hypothesis has been put forward, which is interesting from a treatment perspective – maybe the adolescents who experience set-shifting challenges when they’re teenagers represent the percentage of the affected population that tend to continue to struggle with an eating disorder into adulthood1. Knowing this could help professionals to target treatment for this individuals differently than those without set-shifting issues, who may be more likely to recover from their eating disorder in a relatively short timeframe.
Does Set-Shifting Improve with Anorexia Nervosa Recovery?
Lastly, the theory that set-shifting issues may be an endophenotype of Anorexia Nervosa is supported by the fact that these challenges seem to be stable throughout a person’s life, regardless of stage of recovery. While some characteristics, such as the length of time it takes someone to respond to the task improve, likely due to improved nutrition, people who have experienced Anorexia Nervosa tend to continue to make more errors on set-shifting tasks than people who have never had an eating disorder.
Why is This Important?
At this point, researchers seem to be concluding that set-shifting challenges proceed the development of Anorexia Nervosa, are a trait the individual caries throughout life, and may share with biologically-close relatives. What I found particularly interesting about this, is that it shines light on possible underlying issues that may contribute to Anorexia Nervosa. It provides insight into why clients tend to struggle with recovery, holding on tightly to old thought patterns and behaviours despite serious physical and mental health complications. I also think it encourages us to look more deeply into the causes of Anorexia Nervosa, beyond simply blaming the media, vanity or even the client for the back-and-forth pattern of recovery that is common.
Research is a bottomless endeavour, so this is an area of the field I’ll be keeping an eye on. I’m excited to see where these theories take eating disorder diagnosis and treatment.
~ Meredith of Parallel Wellness