Anorexia's underpinnings differ in those with autism, suggests study

In the wake of increasing awareness of neurodiversity, the way in which we understand how autism (ASD) interacts with mental health is evolving. Research into eating disorders, in particular, is beginning to grapple with the ways in which autistic people with eating disorders may diverge from patterns identified in non-autistic participants. These investigations not only have the potential to improve our understanding of eating disorders across the board, but also to identify more effective therapeutic approaches for neurodiverse patients. 

A new study by researchers at the University of Edinburgh and University of the West of Scotland suggests that those with ASD experience eating disorders in a distinctly different way, and show evidence of different underlying mechanisms to those found in non-autistic patients. In their recent work, published in the Journal of Eating Disorders, the Scottish team explores these experiences in greater depth, looking closely at the social and sensory factors that autistic people and their parents and carers see as playing a role in their anorexia. 

To do this, the team used a method called Interpretative Phenomenological Analysis, or IPA. Rather than being concerned with objective 'truths', IPA is interested in how participants subjectively interpret their experiences. This, as the team writes, acknowledges the complexity of experiences and also allows for a deeper analysis of the experiences of a small, largely homogenous group of people. 

Participants were autistic or non-autistic adults who had at some point received a clinical diagnosis of anorexia, as well as their parents or a person who had played a role in their care across their development. Fourteen pairs were recruited: seven autistic, and seven non-autistic. 

The team spoke with the pairs in semi-structured interviews, during which they were asked to give a brief overview of how they received a diagnosis of anorexia, as well as any factors or behaviours they thought affected their condition. More specific questions then focused on social and sensory factors, and prompts were included for parents and caregivers on how those they cared for developed over time.

In this study, both a neurotypical researcher and an autistic researcher with lived experience of anorexia analysed and interpreted responses with the participant. This approach not only provides deeper, more accurate insights, it also offers a great example of research about a marginalised group of people that meaningfully involves them.

A number of key themes emerged from the IPA analysis. Both those with and without ASD identified with the idea of a "social self": a sense of self that was driven by social factors, and that was seen to play a significant role in the development of anorexia. The two groups, however, differed in how they experienced their social selves. 

Autistic participants reported that their issues with their social self were driven more by a sense of "defectiveness", for which they felt they were to blame. For those without ASD, the social self was driven more by comparison; themes emerged around feelings of inadequacy compared to others, as well as over-empathy towards others while showing little for themselves. 

While both groups expressed difficulties expressing emotions, both autistic and non-autistic participants differed in their reasoning as to why this happened. Though they reported heightened sensitivity to emotions, autistic pairs felt that difficulties expressing emotions were related to an inability to actually identify those emotions, while non-autistic pairs felt that their "heightened consideration for others" led them to not express how they felt.

Confusion about signals of hunger and fullness, which led to a distrust of their body, was present in both groups. However, autistic participants reported that being unable to identify bodily cues was a "lifelong and multi-dimensional" issue, whereas non-autistic participants felt that this was a consequence of their anorexia. 

These could be useful insights for developing interventions tailored to both autistic and non-autistic people; the team note that current research suggests that autistic individuals with eating disorders may respond well both to interventions addressing feelings of defectiveness, and accommodation — rather than 'fixing' — of sensory-based eating preferences. They also advocate for consideration of differing communication styles between ASD and non-ASD patients when providing support. 

Despite the insights provided by the study, it was not without limitations. Though themes emerged from the data, experiences of interviewees varied widely. Further research may better illuminate the prevalence of each of the experiences. The dyadic nature of recruitment also meant that those who were unwilling to take part with caregivers were not included in the research. In addition, there was a female bias, which does reflect the demographics of patients with anorexia, but excludes men and those who fall outside the gender or sex binaries. Other factors, such as age of ASD diagnosis or anorexia onset were not included – these factors may provide further insights.

Developing successful interventions requires an intimate understanding of the condition itself. This research clearly demonstrates that though we may have one label for a condition, not everyone with that label will experience it in the same way, or indeed have the same underpinnings. 

Similarities across different patients — such as difficulty understanding bodily signals, and feelings of a lack of belonging — are crucial for developing successful, widely applicable interventions. But identifying and engaging with differences between those who come under the same diagnosis banner is also hugely important, as it allows clinicians to devise better treatment approaches for populations who are likely under-served. 

Read the paper in full: https://doi.org/10.1186/s40337-023-00813-z