Atypical Sensory Processing Is Associated With Lower Body Mass Index and Increased Eating Disturbance in Individuals With Anorexia Nervosa

Measuring habituation to stimuli: The Italian version of the Sensory Habituation Questionnaire

Sensory habituation allows us to decrease responsiveness to repetitive or prolonged stimuli over time, making them easy to filter out and not interfere with ongoing activities. As such, habituation could be an important aspect to be evaluated within a sensory and cognitive assessment. The main aim of the present study was to validate an Italian version of the Sensory Habituation Questionnaire (S-Hab-Q), a self-report tool assessing how long an adult individual takes to adapt to daily sensory stimuli. We examined the relationship between sensory habituation and sensory sensitivity by administering the Sensory Perception Quotient questionnaire (SPQ) and tested a factor model based on a sensory modality categorization of items. In addition, given the high probability of altered sensory processing in autism, we explored the relationship between sensory habituation and autistic traits by administering the Autism Quotient questionnaire (AQ). A total of 262 participants, aged 18 to 67 years, completed the S-Hab-Q, the SPQ, and the AQ questionnaires. The results showed that, as the original version of the S-Hab-Q, the Italian version had a high internal consistency and a significant correlation with the SPQ score. A confirmatory factor analysis, based on a two-factor model (i.e., vision and hearing vs. touch, smell, and taste), showed a good fit of the S-Hab-Q data. As expected, a significant correlation between the S-Hab-Q and the AQ score was found. Interestingly, mediation analysis revealed that the S-Hab-Q score mediated the relationship between SPQ and AQ scores. Overall, the results confirm that a questionnaire assessing habituation can be a feasible tool to profile individual habituation in daily life. Moreover, they suggest that sensory habituation contributes to explaining the link between sensory sensitivity and autistic traits.

The overlap of disordered eating, autism and ADHD: future research priorities as identified by adults with lived experience

The focus of mental health research in emerging fields should be driven by the priorities of people with relevant lived experience. Autism and ADHD are childhood-onset neurodevelopmental conditions that are associated with a range of health inequalities, including increased risk for eating disorders. The evidence base for how best to support neurodivergent individuals who experience disordered eating is still in its infancy, but research suggests that existing clinical approaches are not currently fit for purpose. In this Personal View, through community consultation with autistic people and people with ADHD who have experienced disordered eating, we present a comprehensive ranked list of research topics that people with lived experience prioritise. These priorities could be clustered into two areas: improving outcomes and identifying causal mechanisms. Within the theme of improving disordered eating outcomes, priorities are the improvement of treatment, the need for neurodiversity training in clinical services, and the identification and minimisation of unintended adverse effects of psychological intervention. Within the theme of identifying causal mechanisms, priorities are the identification of risk factors and a better understanding of the effect of autistic or ADHD neurocognitive profiles as potential contributors to eating disorder vulnerability. The final top ten research priorities are contextualised in terms of how they compare to the existing literature on the overlap between autism or ADHD and eating disorders, and concrete suggestions are made for how to implement these research priorities as testable hypotheses. Research informed by these priorities will build necessary understanding of the reasons behind the increased risk for eating disorders in neurodivergent people, and how to best support people who are affected by disordered eating to live positive and fulfilling lives.

Social communication and restricted, repetitive behavior as assessed with a diagnostic tool for autism (ADOS-2) in women with anorexia nervosa

OBJECTIVE

In anorexia nervosa (AN), the traits of autism spectrum disorder (ASD) are associated with poor outcomes. However, the subtle nature of these characteristics remains poorly understood. We investigated the in-depth patterns of ASD traits using Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) in women with AN.

METHODS

Of 28 women with ICD-10 AN, 16 (age 19-30 years) participated in the ADOS-2, a video-recorded, semistructured diagnostic assessment for social communication and interaction and restricted, repetitive behaviors and interests related to ASD. None of the participants had previously been diagnosed with ASD. Other measurements included the Eating Disorder Examination Questionnaire and the Wechsler Abbreviated Scale of Intelligence-IV.

RESULTS

Five individuals (18% of all, 31% of those assessed) scored above the cutoff for autism in ADOS-2. They had challenges in social communication and interaction, manifesting as sustained difficulties in social relationships and deficits in conversation skills. Few described being frequently misunderstood by others, including in the eating disorder treatment settings. Three individuals showed prominent restricted and repetitive behaviors such as ritual seeking, eating-related routines, sensory sensitivity related to food texture and selective eating, and intense interest in specific topics. The mean duration of AN in women above the cutoff was twice as long compared with those below (12.3 vs. 6.2 years).

DISCUSSION

The ASD-related characteristics and behavior appear to contribute to the manifestation and duration of AN in a subgroup of women. Among these women, the traits of ASD appear to be mixed with eating disorder symptoms, which should be taken into account in the treatment.

Sensory processing across eating disorders: A systematic review and meta-analysis of self-report inventories

OBJECTIVE

This review investigated the extant literature regarding the relationship between eating disorder diagnoses and sensory processing as measured by validated and reliable self-report inventories. Increasing evidence highlights the role of sensory processing in cognitive functions. Sensory processing is implicated in mental-ill health, including eating disorders (ED) and body image disturbances. However, the pathophysiological underpinnings of sensory processing, encompassing exteroception and interoception, in relation to ED remain underexplored.

METHOD

We included studies involving participants aged 15 years or older with an eating disorder diagnosis confirmed by semi-structured or structured interviews. We further limited inclusion to articles using validated and reliable self-report instruments to measure sensory processing. Our meta-analysis focused on studies using the interoceptive awareness subscale from the second version of the Eating Disorder Inventory. We used the Critical Appraisal checklist for quasi-experimental studies to assess the quality of included articles.

RESULTS

There were 19 studies that met our inclusion criteria. Most studies showed moderate-to-high quality. Anorexia nervosa (AN) and bulimia nervosa (BN) were associated with heightened exteroception. Moreover, people with AN reported a heightened sense of taste compared to those with BN. Our meta-analysis comprising 10 studies, 19 samples, and 6382 participants revealed that AN (binge-purge subtype) and BN were associated with increased interoceptive difficulties compared to AN (restrictive subtype) or binge-eating disorder.

DISCUSSION

Overall, this review emphasizes the need for a deeper investigation into sensory processing, spanning both exteroception and interoception, in relation to ED. This may prove important for individualizing person-centered care.

PUBLIC SIGNIFICANCE

How people process internal, for example, hunger, and external, for example, taste and sensations is known to influence cognition and mental-ill health, including ED and body image disturbances. However, the ways in which sensory processing may contribute to ED are incompletely understood. We found that individuals with AN or BN experienced heightened exteroception, while people with an eating disorder characterized by purging reported increased interoceptive difficulties. These patterns could inform the development of more personalized treatments.

Anorexia nervosa through the lens of a severe and enduring experience: 'lost in a big world'

BACKGROUND

Severe and enduring anorexia nervosa (SE-AN), is a serious and persistent illness, despite 'state of the art' treatment. Criteria have been theoretically proposed, but not tested, and may not adequately capture illness complexity, which potentially inhibits treatment refinements. The clinical reality of death as an outcome for some people who experience SE-AN (1 in 20) and broadening access to voluntary assisted dying, further complicates the field, which is undeveloped regarding more fundamental concepts such as nosology, treatment, recovery definitions and alternative conceptualisations of SE-AN. The present paper is in response to this and aims to build upon qualitative literature to enhance phenomenological understandings of fatal SE-AN.

METHOD

A published book, being the legacy of a 32-year-old professional artist offers a rich account of a life lived with AN, for 18 years with continuous treatment. A polysemous narrative via the interrelationship between the languages of the artist's words and visual art is translated via interpretative phenomenological analysis (IPA), offering rich insight into the SE-AN experience.

FINDINGS

The process of analysis induced three superordinate themes (1) Disappearing Self (2) Dialectical Dilemma (3) Death and Dying: Finding Meaning. Two cross cutting themes traversed these themes: (a) Colour and (b) Shifting Hope, where the former produced a visual representation via the 'SE-AN Kaleidoscope'. Collectively the themes produce a concept of SE-AN, grounded in the data and depicted visually through the artist's paintings.

CONCLUSIONS

The picture of SE-AN revealed in the analysis extends upon conceptualisations of SE-AN, highlighting key processes which are thus far under explored. These factors are implicated in illness persistence eliciting opportunities for further research testing including diagnostic considerations and treatment directions. In SE-AN, distorted body image extends to a global distortion in the perception of self. Additional criteria for the severe and enduring stages of illness related to (1) self and identity processes (2) measures of 'global impoverishment' across life domains are proposed for consideration in the future testing of putative defining features of SE-AN.

In-person and online sensory wellbeing workshop for eating disorders: updated case series

BACKGROUND

A one-off sensory wellbeing workshop has been developed to help patients with eating disorders (ED) manage sensory sensitivities. The aim of this study was to evaluate and compare the outcomes of the workshop in online versus face-to-face (F2F) formats among a sample of patients with ED.

METHODS

Cumulative link models were applied to the outcome measures (awareness of sensory wellbeing, awareness of strategies to enhance sensory wellbeing, and confidence in managing sensory wellbeing) to test the differences between online and F2F workshops. Participants' ratings of usefulness of the workshop were also compared between online and F2F workshops.

RESULTS

A total of 14 workshops (4 online and 10 F2F) were run from 2020 to 2023. All participants reported significant and substantial improvements in all outcome measures. There was no significant difference in outcomes between online and F2F workshops. The majority of patients rated the workshops as useful.

CONCLUSIONS

Both online and face-to-face formats of the sensory workshop led to improvement in sensory wellbeing management for patients with ED. Future studies are warranted to test the impact of the workshop on ED treatment outcomes.

Novel ketamine and zinc treatment for anorexia nervosa and the potential beneficial interactions with the gut microbiome

Anorexia nervosa (AN) is a severe illness with diverse aetiological and maintaining contributors including neurobiological, metabolic, psychological, and social determining factors. In addition to nutritional recovery, multiple psychological and pharmacological therapies and brain-based stimulations have been explored; however, existing treatments have limited efficacy. This paper outlines a neurobiological model of glutamatergic and γ-aminobutyric acid (GABA)-ergic dysfunction, exacerbated by chronic gut microbiome dysbiosis and zinc depletion at a brain and gut level. The gut microbiome is established early in development, and early exposure to stress and adversity contribute to gut microbial disturbance in AN, early dysregulation to glutamatergic and GABAergic networks, interoceptive impairment, and inhibited caloric harvest from food (e.g., zinc malabsorption, competition for zinc ions between gut bacteria and host). Zinc is a key part of glutamatergic and GABAergic networks, and also affects leptin and gut microbial function; systems dysregulated in AN. Low doses of ketamine in conjunction with zinc, could provide an efficacious combination to act on NMDA receptors and normalise glutamatergic, GABAergic and gut function in AN.

Is Alexithymia the Link Between Anorexia and Autism Spectrum Disorders?

Objective

Alexithymia main features include deficits in empathy, emotion recognition and regulation. Alexithymia has been recently proposed as a potential key to explain the presence of the so-called 'autistic spectrum disorder' signs (ASD), in patients with Anorexia Nervosa (AN). Objective of this review is to summarize current knowledge on the potential role of alexithymia in linking ASD and AN.

Method

A systematic search has been conducted on PUBMED database of the last 10 years, in accordance with PRISMA Guidelines, applying queries in the 'PubMed Advanced Search Builder'.

Results

We initially retrieved 18 papers; the final selection has led to seven papers. According to the available studies, alexithymia is widely represented in samples of AN patients and comorbid ASD traits. However, the specific load of alexithymia in AN with ASD features is still in debate, as well as the potential role of interoceptive deficits. We have found several limitations in the reviewed studies, which shared a cross-sectional design, with no comparison between a pre and a post-treatment condition (except for one study), small samples sizes and some heterogeneity of administered instruments.

Conclusions

the specific load of alexithymia in explaining the link between AN and ASD is still in debate. Interoception deficit has been proposed as having a crucial role. Further research should be devoted to longitudinal studies and not only to cross-sectional observations.