The initial description of autism and anorexia was described in the early 1980's by Chris Gilbert. The research was ignored largely in the ED international community. He found about a 20% of patients with AN fit with autism spectrum disorders (ASD). The group makes criteria prior to the development of AN. In an inpatient unit this comorbidity of ASD and AN has been found to be around 50% in one study (which seems high from my experience). Patients with ASD tend to do less well in our traditional treatment models.
Patients with ASD show three typical cognitive patterns. First, the demonstrate what is described as poor "theory of mind", which means they have difficulty in reading other peoples emotional cues, and how to behave socially. The best article I have read on this that helped me understand this was this one.
Second, people with ASD demonstrate cognitive rigidity with a high focused on detail, which is often referred to as weak central coherence. Third, ASD patients have great difficult with what we call set shifting, which means flexibility.
We know from the work of Janet's group that patients with AN also show difficulties with cognitive rigidity and a focus on detail. They cant see the trees for the wood. The brain seems to be wired that way. They learn very detailed rules about eating and dieting. With starvation, this rigidity and rule adherence accentuates. The focus on detail (weight and shape) make it difficult to see the bigger picture (the global values that we hold). The difficulty with set shifting means that once these rules are in place patients with AN find it very difficult to take a step back and see the bigger picture (such as the consequences of their behaviour). What is great about this neurological research is that it helps us understand that the behaviour that we see in AN is a product of biologcally based thinking patterns. This does not mean that these are unchangable (think neuroplasticity), but it does mean that the behaviours in a pateint with AN is not simply willful refusal to eat, they are the product of biologically mediated patterns of thinking. The short point here is that the behaviour is not the patients fault. As Professor Treasure points out, these patterns are all made worse by starvation, which is why this needs to be a central part of treatment.
What helps me understand the possible links between ASD and AN more is the work on emotion regulation and social engagement in AN. Treasure talks of an increased sensitivity to "punishment" or negative affect. This includes avoidance of negative emotions and an increased sensitivity to negative facial expressions. This is worse in states of acute illness and less so when weight is recovered, but the traits may be there in childhood. Interestingly, as the focus is on threat and negativity, these negative cues are processed preferentially to positive cues. This may be an explanation for the exaggerated social negativity bias and sense of poor self worth in patients with anorexia. To me this highlights the importance of a therapy which helps patients attune to and preferentially "take in the good" to combat the negativity bias. I would suspect an increasing focus on Compassion Focused Therapy may be present in future years. In discussing therapy implication Janet Treasure discusses acceptance and mindfulness approaches.
As with most things in eating disorders, Treasure argues that some of the social and emotional deficit are present before onset, and that starvation makes them worse. Patients in the acute phase of the illness will present with features similar to ASD. Probably about 20% will presnet with these features prior to onset of anorexia. It is also possible that these deficits are more prevalant in the patients who go on to develop more serious froms of the illness and require an inpateint admission.
The similarity between the cognitive profiles of AN and ASD patients is striking. The field of Autism is one in which the field of eating disorders should monitor for advances in understanding and treatment.
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