Although anorexia nervosa (AN) and autism might appear to be quite different conditions, researchers have found a number of similarities in the way individuals with these conditions process social and emotional information. For example, people with autism and AN often have difficulty identifying and describing their own emotions, a phenomenon called alexithymia.12 Both conditions are also associated with difficulties in understanding non-verbal communication such as facial expression, body language, and tone of voice. This can it make it difficult to recognise what others are thinking and feeling, sometimes resulting in confusion and anxiety in social situations.3
Research from our group has aimed to gain a better understanding of which symptoms are shared between AN and autism, and what difficulties those with both conditions might experience. Firstly, we found that 28% of adults with AN and 24% of adults who had recovered from AN showed symptoms consistent with autism, compared to 4% of those without any history of mental health problems.4 We also found that autism symptoms were not related to weight or how long participants had been ill with AN.5 Together, these finding suggests that autistic symptoms in people with AN are not due to the effects of starvation or low weight, and instead might be stable traits present before and after the illness.
Next, we looked at different aspects of social and emotional cognition in those with AN, and how these abilities related to autism symptoms:
Empathy is made up of two major facets: cognitive and affective empathy. While cognitive empathy refers to our ability to recognise and understand the mental states of others, affective empathy is our ability to share the feelings of others, without any direct emotional stimulation to oneself.6 These abilities are important in social relationships, as they allow us to make sense of and respond to others’ behaviour.
We found that participants with a lifetime history of AN and low autistic symptoms did not show difficulties in either cognitive or affective empathy, compared to participants without any mental health problems. In contrast, participants with AN and high autistic symptoms showed difficulties in both aspects of empathy, as shown by lower scores on our empathy test.4 Our results suggest that those with AN and autism comorbidity have difficulties in empathising with others, which could lead to misunderstandings during social interactions.
Facial emotion recognition
Up to two-thirds of human communication occurs through non-verbal means, such as facial expression, gestures, and tone of voice.7 Difficulties in emotion recognition have been widely reported in those with autism, potentially contributing to difficulties in social interaction.8 It has also been suggested that individuals with AN may have difficulties in recognising emotional expressions, however past research investigating this ability has produced mixed findings.9 10
In our study, we found that individuals with AN and low autistic symptoms had no difficulty in identifying emotional facial expressions.11 However, participants with AN and high autistic symptoms were less accurate at identifying emotional expressions compared to those with low autistic symptoms and participants without any mental health problems. This was true for both basic (e.g., happy) and more complex emotions (e.g., amused). Findings from this study suggest that those with AN and autism comorbidity may find it difficult to understand certain aspects of nonverbal communication, such as facial expressions.
Attention to faces
Looking at others’ faces and eyes is important during social interactions, as this allows us to pick up on nonverbal cues such as facial expressions and eye gaze. Many studies have shown that individuals with autism pay less attention to faces than neurotypical people, a difference that is present from a very young age.12 Reduced attention to faces and eyes has been shown to be associated with more social difficulties in those with autism.13
In our experiment, participants watched a video clip showing people speaking to the camera, similar to what would be seen during a real social interaction. We tracked participants’ eye movements to see which part of the screen they were looking at. We found that participants with AN looked at faces for significantly less time than those recovered from AN and those without any mental health problems.14 Interestingly, this effect was found to be fully mediated by autistic traits. That is, reduced attention to faces in AN appears to be a result of the high levels of autistic traits present in this group.
In sum, these findings suggest there are important differences in social and emotional cognition in those with AN with and without autistic symptoms. Those with AN and ASD may benefit from different types of treatment, such as those that incorporate social skills and emotional awareness training. People with AN and ASD may also use also prefer different communicative styles, which could be accommodated for during treatment.
1) Westwood, H.; Kerr-Gaffney, J.; Stahl, D.; Tchanturia, K. Alexithymia in Eating Disorders: Systematic Review and Meta-Analyses of Studies Using the Toronto Alexithymia Scale. J. Psychosom. Res. 2017, 99, 66–81. https://doi.org/10.1016/j.jpsychores.2017.06.007.
2) Kinnaird, E.; Stewart, C.; Tchanturia, K. Investigating Alexithymia in Autism: A Systematic Review and Meta-Analysis. Eur. Psychiatry 2019, 55, 80–89. https://doi.org/10.1016/j.eurpsy.2018.09.004.
3) Leppanen, J.; Sedgewick, F.; Treasure, J.; Tchanturia, K. Differences in the Theory of Mind Profiles of Patients with Anorexia Nervosa and Individuals on the Autism Spectrum: A Meta-Analytic Review. Neurosci. Biobehav. Rev. 2018, 90, 146–163. https://doi.org/10.1016/j.neubiorev.2018.04.009.
4) Kerr-Gaffney, J.; Harrison, A.; Tchanturia, K. Autism Spectrum Disorder Traits Are Associated with Empathic Abilities in Adults with Anorexia Nervosa. J. Affect. Disord. 2020, 266, 273–281. https://doi.org/10.1016/j.jad.2020.01.169.
5) Kerr-Gaffney, J.; Harrison, A.; Tchanturia, K. The Social Responsiveness Scale Is an Efficient Screening Tool for Autism Spectrum Disorder Traits in Adults with Anorexia Nervosa. Eur. Eat. Disord. Rev. 2020. https://doi.org/10.1002/erv.2736.
6) Blair, R. J. R. Responding to the Emotions of Others: Dissociating Forms of Empathy through the Study of Typical and Psychiatric Populations. Conscious. Cogn. 2005, 14 (4), 698–718. https://doi.org/10.1016/j.concog.2005.06.004.
7) Ko, B. C. A Brief Review of Facial Emotion Recognition Based on Visual Information. Sensors 2018, 18 (2), 401. https://doi.org/10.3390/s18020401.
8) Loth, E.; Garrido, L.; Ahmad, J.; Watson, E.; Duff, A.; Duchaine, B. Facial Expression Recognition as a Candidate Marker for Autism Spectrum Disorder: How Frequent and Severe Are Deficits? Mol. Autism 2018, 9, 7. https://doi.org/10.1186/s13229-018-0187-7.
9) Kucharska, K.; Jeschke, J.; Mafi, R. Intact Social Cognitive Processes in Outpatients with Anorexia Nervosa: A Pilot Study. Ann. Gen. Psychiatry 2016, 15 (1), 1–6. https://doi.org/10.1186/s12991-016-0108-0.
10) Harrison, A.; Tchanturia, K.; Treasure, J. Attentional Bias, Emotion Recognition, and Emotion Regulation in Anorexia: State or Trait? Biol. Psychiatry 2010, 68 (8), 755–761. https://doi.org/10.1016/j.biopsych.2010.04.037.
11) Kerr-Gaffney, J.; Mason, L.; Jones, E.; Hayward, H.; Ahmad, J.; Harrison, A.; Loth, E.; Murphy, D.; Tchanturia, K. Emotion Recognition Abilities in Adults with Anorexia Nervosa Are Associated with Autistic Traits. J. Clin. Med. 2020, 9 (4), 1057. https://doi.org/10.3390/jcm9041057.
12) Jones, E. J. H.; Gliga, T.; Bedford, R.; Charman, T.; Johnson, M. H. Developmental Pathways to Autism: A Review of Prospective Studies of Infants at Risk. Neurosci. Biobehav. Rev. 2014, 39, 1–33. https://doi.org/10.1016/j.neubiorev.2013.12.001.
13) Corden, B.; Chilvers, R.; Skuse, D. Avoidance of Emotionally Arousing Stimuli Predicts Social–Perceptual Impairment in Asperger’s Syndrome. Neuropsychologia 2008, 46 (1), 137–147. https://doi.org/10.1016/j.neuropsychologia.2007.08.005.
14) Kerr-Gaffney, J., Mason, L., Jones, E., Hayward, H., Harrison, A., Murphy, D., Tchanturia, K. Autistic Traits Mediate Reductions in Social Attention in Adults with Anorexia Nervosa. Munscript submitted for publication.
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