Mixed-methods investigation into the role of sensory, social and emotional factors in the overlap between autism and anorexia nervosa

Abstract

BACKGROUND: It is estimated that around a third of individuals with anorexia nervosa (AN) are Autistic. Despite this elevated prevalence, underlying mechanisms of this overlap remain poorly understood, with early work implicating a range of factors including sensory, social and emotional factors. Autistic individuals with AN have been reported to have poorer eating disorder (ED) treatment outcomes and experiences compared to their non-Autistic peers, such as longer and more frequent inpatient stays, more severe ED symptomology and a greater detriment to psychosocial functioning. Therefore, to provide more effective support, it is imperative to identify underlying factors. The current thesis aims are to explore the possible role of sensory, social and emotional factors in autism and AN, seeking to identify both shared and autism-specific differences that may help untangle the overlap between the two.

METHODS: Adopting a mixed-methods approach, the current thesis draws on several methodologies to address overarching thesis aims. Firstly, a systematic review was conducted to explore the relationship between sensory processing and eating behaviours in autism across the lifespan. Secondly, a qualitative study was conducted to explore experiences of sensory and social factors with Autistic and non-Autistic adults and their parents. Finally, an observational study was conducted to explore group differences in nonverbal social communication behaviours, as well as to explore the relationship between non-verbal behaviours and sensory and emotional factors.

RESULTS: Thesis findings suggest that investigated factors play an important yet inter-twined role in the overlap between autism and AN. Sensory processing was found to be play an important role in Autistic experiences of AN, with tentative evidence to suggest that sensory differences may be integral in discriminating between Autistic and non-Autistic individuals. Key differences in social interactions and communication were also identified in the qualitative study, however this was not supported by quantitative findings. Finally, emotional difficulties, particularly alexithymia (being able to identify and describe your own emotions) were found to play an important role in experiences of AN and were tentatively linked with sensory and social factors.

DISCUSSION: Results from the current thesis tentatively highlight targets for future ED interventions, as well the need to acknowledge and adapt for the heterogenous Autistic experience. Not only could this involve modifying current ED interventions, but it also could involve the development of novel, neurodiverse-affirming approaches. Future research should continue to adopt a mixed-method approach and extend research focus to a broader range of ED diagnoses. Such research studies should include participatory approaches, from the designing of studies to the active role of those with lived/living experience in conducting the research, thereby ensuring that future research reflects the priorities and realities of Autistic individuals with EDs.