Paper: "Alexithymia may explain the relationship between
autistic traits and eating disorder psychopathology"
This paper was published in 2020, in the journal Molecular Autism.
You can click HERE to download a PDF of the paper.
Keep reading to see a plain English summary, or you can watch my explanatory video!
Why is this an important issue?
Eating disorders (EDs) are deadly psychiatric illnesses which cause great suffering and physical damage to the body. EDs appear to occur at higher rates among autistic people and people with higher levels of autistic traits. Furthermore, when autistic people do develop EDs, they appear to have a longer course of illness and poorer response to standard psychological treatments. The longer someone is ill with an ED, the lower their likelihood is of recovery, which may explain why some studies find that autistic people with EDs have a poorer prognosis than non-autistic people with EDs.
At present, researchers and clinicians do not understand why autistic people might be more vulnerable to EDs, and in line with this, they do not know how best to help them recover. We need to know more about the factors that might contribute to the development and maintenance of an ED, as this may also give us a clue about what factors should be targeted in therapy to help people recover.
Here is a short video summary of this study. You can open it up to large screen, and turn captions on and off by clicking the 'CC' button.
What was the purpose of this study?
We investigated one possible mechanism that we thought might explain the higher risk of EDs in autistic people: alexithymia.
Wait a moment: what is
Alexithymia occurs at different levels of severity. The colour wheel here is a good example: some people may struggle to identify and differentiate between the six primary emotions in the centre circle, while others might struggle to differentiate between the more fine-grained emotions in the second and outer circles. We believe that 50-60% of autistic people might have alexithymia to a clinically severe level.
Research suggests that having alexithymia is a little bit like living with blinkers on, in the sense that you are unaware of what’s going on with your emotions. This means that it’s very, very difficult for you to manage them. For this reason, alexithymia is strongly associated with some coping strategies that can help the person regulate their emotions in the moment, but which can be dangerous or unhealthy over time - for instance, using drugs or alcohol to change how you feel, self-harming, or engaging in ED behaviours. It is possible that having alexithymia, as opposed to being autistic, is a greater cause for concern when it comes to mental illness.
So what did the researchers do?
We looked at relationships between autistic traits and ED symptoms in a large sample of non-autistic undergraduate students.
The reason we looked at autistic traits in non-autistic people, instead of studying autistic people, is that this allowed us to quickly and easily recruit a very large sample. Autistic traits are believed to exist on the same continuum as autism itself - as in, a person with high levels of autistic traits would be expected to cross the threshold at which they might receive a diagnosis. We therefore recruited non-autistic people with varying levels of autistic traits, ED symptoms, and alexithymia.
They completed an online survey involving questionnaires which measured each of these things. We then looked to see whether the relationship between autistic traits and ED symptoms was
a) dependent on alexithymia (which would be the case if people with high autistic traits only had higher levels of ED symptoms if they also had alexithymia).
b) independent of alexithymia (in which case, we would see a relationship between autistic traits and ED symptoms in people with any degree of alexithymia).
What were the results of the study?
Our results were very consistent across the large number of participants we tested. In both cases, we found that the relationship between autistic traits and ED symptoms was wholly or largely dependent on alexithymia.
What that means, in reality, is that people with autistic traits tended to have higher rates of alexithymia, and because they had higher rates of alexithymia, they also had higher rates of ED symptoms. That is, having higher levels of autistic traits was not, in of itself, associated with higher likelihood of ED symptoms. Having higher levels of alexithymia, which tended to go along with having higher autistic traits, was what actually created the relationship with ED symptoms. Alexithymia was the ‘active ingredient’, not autistic traits. As a diagram, this might look something like this:
In particular, difficulty identifying your emotions seemed to be the most important aspect of alexithymia. People with greatest difficulty identifying their emotions tended to have the most severe ED symptoms even when we controlled for variables that might muddy the waters (depression and anxiety).
We tried to look at cisgender male and female participants separately to see if there were any sex differences between participants. There was a hint that alexithymia might be more a feature of EDs in women, but we could not be sure that this finding was trustworthy due to the smallness of our male sample.
What are potential weaknesses in the study?
We cannot be fully sure that findings based on studies of non-autistic people with autistic traits can be extrapolated to autistic populations. Similarly, since our participants ranged in ED symptoms but few had an actual diagnosed ED, the findings might not hold true in people with actual EDs.
Because this study looked at a snapshot of participants’ current states, we cannot be sure of the direction between variables. We assumed that autistic traits and alexithymia are stable and a feature of your character, and therefore hypothesise that they would precede ED symptoms (and potentially put the person at risk of EDs). However, it is possible that ED symptoms made people look as if they had higher levels of autistic traits and alexithymia than they actually did. The malnutrition associated with EDs can give a person the appearance of having high levels of alexithymia and/or autistic traits, or even make them appear autistic.
It’s also important to recognise that alexithymia is unlikely to be the only factor that may make autistic people more vulnerable to EDs, as suggested in this very good paper.
How will these findings help autistic adults now or in the future?
These findings highlight alexithymia as a variable that could be important for mental illness (in this case EDs) - the findings suggest this is true for non-autistic people, and if it is true that autistic traits exist on the same continuum as autism itself, then it would seem possible that alexithymia is important for EDs in autistic people, too.
This finding supports other studies which suggest that alexithymia plays a large role in mental illness in autistic people - for instance, it has been shown to be associated with depression, anxiety, and self-injury (our study).
This highlights that alexithymia is a very important characteristic to identify in autistic people - especially as psychological therapies need to be adapted if a person has alexithymia, just as they need to be adapted for autism, too.
Thank you for reading!
Alexithymia is a difficulty identifying your emotions and being able to label how you feel. People who have alexithymia may simply not notice that they’re experiencing an emotion, or they may realise that they’re feeling something but not be able to identify what it is. They may struggle to decode the physical sensations that come along with emotions: for instance, if your heart is racing, you could be angry or frightened.
If you found this interesting, you may like to read:
You might also like to read our article in The Conversation. If you are interested in eating disorders in autistic people, you can listen to a webinar I participated in for Bodywhys, the Eating Disorder Association of Ireland. (Please be aware this discusses my lived experience, although without any numbers that might be triggering).
If you are struggling with an eating disorder or other mental health issues, please look at the resources page.