Sensory experiences of individuals with Autism Spectrum Disorder and autistic traits: a mixed methods approach

There has been a recent increase in research into sensory sensitivity in Autism Spectrum Disorders (ASDs), which has prompted the inclusion of sensory issues as an explicit criterion in the impending revision of diagnostic guidelines (DSM-5: American Psychiatric Association, 2010). However, one of the most interesting aspects of research in this field is that a clear disparity exists between the results of self- or parent-report studies and behavioural studies. The former class of studies shows that those with ASD report clear, consistent differences in their sensory experiences (Baranek et al., 2006; Crane et al., 2009; Leekam et al., 2007), whereas the findings in the behavioural field are complex to interpret, with all but a few areas of sensory processing (e.g. visual search: Joliffe & Baron-Cohen, 1997; Shah & Frith, 1983, 1993) demonstrating consistent consensus (e.g. Dudova et al., 2011; Tavassoli et al., 2012a). The thesis presented here aims to explore the nature of sensory sensitivities in those with ASD and the broader autism phenotype (BAP) further using a combination of qualitative and quantitative research designs. In addition, an approach was developed (the Sensory Audit: Chapter 8) which can be used to objectively assess an environment for sensory stressors. Chapters 2 and 3 report the development of a sensory questionnaire (GSQ: Robertson & Simmons, 2012), which was administered to those with varying AQ scores, as measured by the Autism Spectrum Quotient (AQ: Baron-Cohen et al., 2001). There were both quantitative (Chapter 2) and qualitative (Chapter 3) features of the questionnaire. In the quantitative component, seven modalities were assessed (vision, audition, gustation, olfaction, touch, vestibular processing and proprioception), taking into account both hyper- and hypo-sensitivity to stimuli. We found that there was a strong, positive relationship between sensory sensitivity and AQ score, with medium scorers (who would be unlikely to be diagnosed with ASD) reporting significantly more difficulties with sensory stimuli than low scorers. For Chapter 3, we found that those with high levels of autistic traits (i.e. may be likely to have a diagnosis of ASD) tended to report using different coping techniques from medium and low scorers (e.g. avoiding situations and using sensory soothing rather than non-sensory soothing). The results from these studies suggest that sensory issues may be prevalent throughout the population and that the differences observed in Chapter 2 are mirrored in the themes extracted for each group in Chapter 3. The second set of studies (Chapters 4-6) report data from three focus groups (caregivers of those with autism, adults with ASD and an elderly control group), as well as from interactive group interviews with children who have autism. Although similar themes (e.g. control, consequences of problematic stimuli and positive effects of sensory stimuli) arose in all four studies, there were different types of information gathered from the groups. For those with ASD (Chapter 4 and Chapter 5), the discussion mainly centred around how sensory stimuli made them feel, and the implications of this for them. For the caregivers (Chapter 4) and the elderly group (who mainly discussed their relatives’ experiences) (Chapter 6), the themes reflected their own experiences, concentrating on the implications of adverse reactions to sensory stimuli (for both themselves and their loved ones). The data from these studies provide insight into living with someone who has sensory issues, for both those with a diagnosis of ASD and their caregivers, as well as the relatives of elderly individuals suffering from vision and hearing loss. Chapter 7 reports a study into the relationship between olfactory processing and the broader autism phenotype (as measured by the AQ). Participants completed the AQ as well as the Sniffin’ Sticks Extended Test. A subset of the sample (n=62) also completed the Glasgow Sensory Questionnaire (GSQ) that was developed as part of Chapter 2. As expected, there were no significant differences in the Threshold, Discrimination or Identification performance of those with high and low AQ scores. However, there was significantly greater intra-participant variability in the Threshold scores for the top 15% of scorers on the AQ. Furthermore, a similar relationship to that reported in Chapter 2 between sensory score and autistic traits was observed. These results indicate that there may be other differences in various aspects of performance in those with ASD that are not being targeted by current behavioural paradigms (which may explain the disparity between reported sensory differences and those observed using direct measurement). Finally, the last study reported is that of the development of a pilot Sensory Audit. This was an effort to apply the information gained from our previous research in a practical, useful way for individuals with ASD. Details of the development of the Sensory Audit, as well as the results of the pilot study are reported in Chapter 8. By making this freely available, we hope to help companies ensure that their working environments do not contain any undue stressors that could increase stress for those with sensory issues in their workforce. The results are discussed in light of three overarching themes of the thesis as a whole. Firstly, the potential mechanisms underlying sensory responsiveness in ASD, with the suggestion that emotional states may be an important avenue to consider in future research. Secondly, the impact of atypical sensory processing on caregivers, with particular attention paid to the compensation of these issues by caregivers, and the social implications of challenging behaviour instigated by unpleasant sensory stimuli. Thirdly, the data are discussed in light of the relationship between sensory processing and the broader autism phenotype (as measured using the AQ). The greater levels of intra-participant variability in the olfactory task (Chapter 7) are highlighted, as is the elevated sensory responsiveness of those with moderate levels of autistic traits reported in Chapters 2 and 3. The final section of the discussion deals with the limitations of the thesis, potential practical applications of the research and future directions

The relationship between self-reported sensory experiences and autistic traits in the general population:a mixed methods analysis

There have been few examples of inductive research in sensory reactivity, particularly in relation to autistic traits among the general population. This study used a mixed methods approach to explore the nature of sensory experiences among people with different levels of autistic traits. Participants completed the Glasgow Sensory Questionnaire and the Autism Spectrum Quotient. Both quantitative and qualitative analyses were performed on the data. Responses to the open questions were analyzed as part of this study, and the closed questionnaire data have been reported elsewhere. Data were coded and responses quantitatively compared by group. In addition, data were qualitatively analyzed using a general inductive approach, which resulted in two themes: “problematic sensory experiences” and “calming sensory experiences.” Results show that coping mechanisms and certain aspects of the sensory experience vary according to autistic trait level, and provide insight into the nature of sensory reactivity across the general population

A Measurement Invariance Analysis of the Interpersonal Needs Questionnaire and Acquired Capability for Suicide Scale in Autistic and Non-Autistic Adults.

Background: Autistic adults are more likely to engage in suicidal thoughts and behaviors, but there is little research to explore the underlying reasons. It is unclear whether self-report suicide scales that have been designed for non-autistic people accurately measure suicide risk constructs in autistic people. Therefore, this study explored, for the first time, whether the measurement properties of the self-report scales of the Interpersonal Theory of Suicide are equivalent in autistic and non-autistic adults. Methods: In this study, responses from 342 autistic and 353 non-autistic people on the Interpersonal Needs Questionnaire-10 (INQ-10) and Acquired Capability for Suicide Scale-Fearlessness about Death (ACSS-FAD) were compared by using measurement invariance analysis. Data were gathered through an online cross-sectional survey of the self-report measures. Results: Results suggest that measurement properties of the INQ-10 were different in autistic people. Autistic characteristics, such as different theory of mind and preference for concrete language, may have led the scale items to load differently on the factors in the autistic group than in the non-autistic group. The measurement properties of the ACSS-FAD were invariant between autistic and non-autistic people. Conclusions: Scores on the INQ-10 cannot be meaningfully compared between autistic and non-autistic people due to different measurement properties. Future research could explore how autistic people experience the concepts of burdensomeness and belonging, to consider how measures could accurately capture this. This would allow researchers to explore the role of these constructs in the development of suicidal thoughts and behaviors in autistic people. Clinicians should be aware that suicide risk factors may present differently in autistic people. Scores on the ACSS-FAD can be meaningfully compared, but the negatively worded scale items may pose similar response difficulties to autistic and non-autistic people

Influence of Crohn’s disease related polymorphisms in innate immune function on ileal microbiome

We have previously identified NOD2 genotype and inflammatory bowel diseases (IBD) phenotype, as associated with shifts in the ileal microbiome (“dysbiosis”) in a patient cohort. Here we report an integrative analysis of an expanded number of Crohn's disease (CD) related genetic defects in innate immune function (NOD2, ATG16L1, IRGM, CARD9, XBP1, ORMDL3) and composition of the ileal microbiome by combining the initial patient cohort (Batch 1, 2005–2010, n = 165) with a second consecutive patient cohort (Batch 2, 2010–2012, n = 118). These combined patient cohorts were composed of three non-overlapping phenotypes: 1.) 106 ileal CD subjects undergoing initial ileocolic resection for diseased ileum, 2.) 88 IBD colitis subjects without ileal disease (predominantly ulcerative colitis but also Crohn’s colitis and indeterminate colitis, and 3.) 89 non-IBD subjects. Significant differences (FDR C. difficile infection, and NOD2 genotype on ileal dysbiosis in the expanded analysis. The relative abundance of the Proteobacteria phylum was positively associated with ileal CD and colitis phenotypes, but negatively associated with NOD2R genotype. Additional associations with ORMDL3 and XBP1 were detected at the phylum/subphylum level. IBD medications, such as immunomodulators and anti-TNFα agents, may have a beneficial effect on reversing dysbiosis associated with the IBD phenotype. Exploratory analysis comparing microbial composition of the disease unaffected region of the resected ileum between 27 ileal CD patients who subsequently developed endoscopic recurrence within 6–12 months versus 34 patients who did not, suggested that microbial biomarkers in the resected specimen helped stratify patients with respect to risk of post-surgical recurrence.</div

Reducing in-stent restenosis therapeutic manipulation of miRNA in vascular remodeling and inflammation

Background: Drug-eluting stents reduce the incidence of in-stent restenosis, but they result in delayed arterial healing and are associated with a chronic inflammatory response and hypersensitivity reactions. Identifying novel interventions to enhance wound healing and reduce the inflammatory response may improve long-term clinical outcomes. Micro–ribonucleic acids (miRNAs) are noncoding small ribonucleic acids that play a prominent role in the initiation and resolution of inflammation after vascular injury.&lt;p&gt;&lt;/p&gt; Objectives: This study sought to identify miRNA regulation and function after implantation of bare-metal and drug-eluting stents.&lt;p&gt;&lt;/p&gt; Methods: Pig, mouse, and in vitro models were used to investigate the role of miRNA in in-stent restenosis.&lt;p&gt;&lt;/p&gt; Results: We documented a subset of inflammatory miRNAs activated after stenting in pigs, including the miR-21 stem loop miRNAs. Genetic ablation of the miR-21 stem loop attenuated neointimal formation in mice post-stenting. This occurred via enhanced levels of anti-inflammatory M2 macrophages coupled with an impaired sensitivity of smooth muscle cells to respond to vascular activation.&lt;p&gt;&lt;/p&gt; Conclusions: MiR-21 plays a prominent role in promoting vascular inflammation and remodeling after stent injury. MiRNA-mediated modulation of the inflammatory response post-stenting may have therapeutic potential to accelerate wound healing and enhance the clinical efficacy of stenting

Understanding suicide risk in autistic adults : comparing the interpersonal theory of suicide in autistic and non-autistic samples

This study explored whether the Interpersonal Theory of suicide informs our understanding of high rates of suicidality in autistic adults. Autistic and non-autistic adults (n = 695, mean age 41.7 years, 58% female) completed an online survey of self-reported thwarted belonging, perceived burden, autistic traits, suicidal capability, trauma, and lifetime suicidality. Autistic people reported stronger feelings of perceived burden, thwarted belonging and more lifetime trauma than non-autistic people. The hypothesised interaction between burdensomeness and thwarted belonging were observed in the non-autistic group but not in the autistic group. In both groups autistic traits influenced suicidality through burdensomeness/thwarted belonging. Promoting self-worth and social inclusion are important for suicide prevention and future research should explore how these are experienced and expressed by autistic people

The relationship between sensory sensitivity and autistic traits in the general population.

Individuals with Autism Spectrum Disorders (ASDs) tend to have sensory processing difficulties (Baranek et al. in J Child Psychol Psychiatry 47:591–601, 2006). These difficulties include over- and under-responsiveness to sensory stimuli, and problems modulating sensory input (Ben-Sasson et al. in J Autism Dev Disorders 39:1–11, 2009). As those with ASD exist at the extreme end of a continuum of autistic traits that is also evident in the general population, we investigated the link between ASD and sensory sensitivity in the general population by administering two questionnaires online to 212 adult participants. Results showed a highly significant positive correlation (r = .775, p &#60; .001) between number of autistic traits and the frequency of sensory processing problems. These data suggest a strong link between sensory processing and autistic traits in the general population, which in turn potentially implicates sensory processing problems in social interaction difficulties