The Dutch Sensory Perception Quotient-Short in adults with and without autism

Central Sensitivity Symptoms and Autistic Traits in Autistic and Non-Autistic Adults

Central sensitivity syndromes (CSSs) are a group of health conditions thought to include an underlying sensitisation of the central nervous system. Evidence suggests autistic adults experience poorer physical health than the general population and are more likely to have a CSS. This study examined CSS diagnoses and symptoms in autistic and non-autistic adults, to determine whether CSS symptoms were related to autistic traits, mental health, sensory sensitivity, age or gender. Participants included 534 adults with clinical diagnoses of autism, CSS, both diagnoses or neither (i.e., comparison group), who were recruited through social media, support groups and institutional affiliations. Participants completed online self-report validated questionnaires, including the Autism Spectrum Quotient (AQ), Central Sensitization Inventory (CSI), Sensory Perception Quotient (SPQ), and the PHQ-9 and GAD-7. Autistic people without a diagnosed CSS reported significantly more CSS symptoms than the comparison group, with a mean score above the clinical cut-off. Non-autistic participants with a CSS had significantly more autistic traits than the comparison group. Autistic people with a CSS reported the most sensory sensitivity, with autism only and CSS only groups reporting similar levels of sensory sensitivity and all diagnostic groups reporting more sensory sensitivity than the comparison group. Sensory sensitivity, anxiety, autistic traits, age and gender were all significant predictors of CSS symptoms. The overlap in symptoms between autistic individuals and those with CSS suggests diagnostic overshadowing and possible under-diagnosis or misdiagnosis. Furthermore, these symptoms may exacerbate or mask one another. Notwithstanding potential limitations of representativeness and selection bias, increased awareness of the association between autistic traits and CSS symptoms is important for clinicians to improve diagnostic accuracy and treatment.

Why am I overwhelmed by bright lights? The behavioural mechanisms of post-stroke visual hypersensitivity

After stroke, patients can experience visual hypersensitivity, an increase in their sensitivity for visual stimuli as compared to their state prior to the stroke. Candidate behavioural mechanisms for these subjective symptoms are atypical bottom-up sensory processing and impaired selective attention, but empirical evidence is currently lacking. In the current study, we aimed to investigate the relationship between post-stroke visual hypersensitivity and sensory thresholds, sensory processing speed, and selective attention using computational modelling of behavioural data. During a whole/partial report task, participants (51 stroke patients, 76 orthopedic patients, and 77 neurotypical adults) had to correctly identify a single target letter that was presented alone (for 17-100 ms) or along a distractor (for 83ms). Performance on this task was used to estimate the sensory threshold, sensory processing speed, and selective attention abilities of each participant. In the stroke population, both on a group and individual level, there was evidence for impaired selective attention and -to a lesser extent- lower sensory thresholds in patients with post-stroke visual hypersensitivity as compared to neurotypical adults, orthopedic patients, or stroke patients without post-stroke sensory hypersensitivity. These results provide a significant advancement in our comprehension of post-stroke visual hypersensitivity and can serve as a catalyst for further investigations into the underlying mechanisms of sensory hypersensitivity after other types of acquired brain injury as well as post-injury hypersensitivity for other sensory modalities.

An evaluation of the German version of the Sensory Perception Quotient from an expert by experience perspective

Sensory processing is often altered in individuals with autism; thus, it is essential to develop reliable measurement tools to assess sensory perception. The Sensory Perception Quotient (SPQ) quantifies basic sensory sensitivities in adults via self-report. Adopting an expert by experience perspective, this study aimed to evaluate a German translation of the SPQ for its use in clinical and research applications, especially for autistic adults. 108 adults (n = 54 autistic) completed the German SPQ in an online assessment. A 92-item and a 35-item version of the German SPQ were analyzed for group differences and internal consistency. Our results show that adults with autism reported greater sensory sensitivity compared to non-autistic adults. Results further suggest good to excellent internal consistency for the 95-item and 35-item SPQ translations. This finding was supported by the correlative relationship between sensory sensitivity and autistic traits. These findings confirm the reliability of our SPQ translation, making it a suitable German assessment tool for basic sensory sensitivity in autistic adults.

The Multi-Modal Evaluation of Sensory Sensitivity (MESSY): Assessing a commonly missed symptom of acquired brain injury

Objective: Sensory hypersensitivity is common after acquired brain injury. Since appropriate diagnostic tools are lacking, these complaints are overlooked by clinicians and available literature is limited to light and noise hypersensitivity after concussion. This study aimed to investigate the prevalence of sensory hypersensitivity in other modalities and after other types of brain injury. Method: We developed the Multi-Modal Evaluation of Sensory Sensitivity (MESSY), a patient-friendly questionnaire that assesses sensory sensitivity across multiple sensory modalities. 818 neurotypical adults (mean age = 49; 244 male) and 341 chronic acquired brain injury patients (including stroke, traumatic brain injury, and brain tumour patients) (mean age = 56; 126 male) completed the MESSY online. Results: The MESSY had a high validity and reliability in neurotypical adults. Post-injury sensory hypersensitivity (examined using open-ended questions) was reported by 76% of the stroke patients, 89% of the traumatic brain injury patients, and 82% of the brain tumour patients. These complaints occurred across all modalities with multisensory, visual, and auditory hypersensitivity being the most prevalent. Patients with post-injury sensory hypersensitivity reported a higher sensory sensitivity severity on the multiple-choice items of the MESSY as compared to neurotypical adults and acquired brain injury patients without post-injury sensory hypersensitivity (across all sensory modalities) (effect sizes (partial eta squared) ranged from .06 to .22). Conclusions: These results show that sensory hypersensitivity is prevalent after different types of acquired brain injury as well as across several sensory modalities. The MESSY can improve recognition of these symptoms and facilitate further research.

Research Review: A systematic review and meta-analysis of sex differences in narrow constructs of restricted and repetitive behaviours and interests in autistic children, adolescents, and adults

BACKGROUND

Evidence that autism often manifests differently between males and females is growing, particularly in terms of social interaction and communication, but it is unclear if there are sex differences in restricted and repetitive behaviours and interests (RRBIs) when rigorously focusing on the narrow construct level (i.e., stereotyped behaviour, restricted interests, insistence on sameness, and/or sensory experiences).

METHODS

We conducted a systematic review and four random effects meta-analyses investigating sex differences in narrow construct measures of RRBIs in autistic children, adolescents, and adults (Prospero registration ID: CRD42021254221). Study quality was appraised using the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Forty-six studies were narratively synthesised and 25 of these were included in four random effects meta-analyses. Results found that autistic males had significantly higher levels of stereotyped behaviours (SMD = 0.21, 95% confidence interval (CI) [0.09, 0.33], p < .001) and restricted interests (SMD = 0.18, 95% CI [0.07, 0.29], p < .001) compared to autistic females. In contrast, there were no significant sex differences for sensory experiences (SMD = -0.09, 95% CI [-0.27, 0.09], p = .32) and insistence on sameness (SMD = 0.01, 95% CI [-0.03, 0.05], p = .68). The findings from the narrative synthesis were generally consistent with those from the meta-analyses and also found qualitative sex differences in the way RRBIs manifest.

CONCLUSIONS

Our findings show significant differences in narrowly defined RRBIs in males and females. Practitioners need to be aware of such differences, which could be contributing to the under-recognition of autism in females and may not be captured by current diagnostic instruments.

Examining the latent structure and correlates of sensory reactivity in autism: a multi-site integrative data analysis by the autism sensory research consortium

BACKGROUND

Differences in responding to sensory stimuli, including sensory hyperreactivity (HYPER), hyporeactivity (HYPO), and sensory seeking (SEEK) have been observed in autistic individuals across sensory modalities, but few studies have examined the structure of these "supra-modal" traits in the autistic population.

METHODS

Leveraging a combined sample of 3868 autistic youth drawn from 12 distinct data sources (ages 3-18 years and representing the full range of cognitive ability), the current study used modern psychometric and meta-analytic techniques to interrogate the latent structure and correlates of caregiver-reported HYPER, HYPO, and SEEK within and across sensory modalities. Bifactor statistical indices were used to both evaluate the strength of a "general response pattern" factor for each supra-modal construct and determine the added value of "modality-specific response pattern" scores (e.g., Visual HYPER). Bayesian random-effects integrative data analysis models were used to examine the clinical and demographic correlates of all interpretable HYPER, HYPO, and SEEK (sub)constructs.

RESULTS

All modality-specific HYPER subconstructs could be reliably and validly measured, whereas certain modality-specific HYPO and SEEK subconstructs were psychometrically inadequate when measured using existing items. Bifactor analyses supported the validity of a supra-modal HYPER construct (ωH = .800) but not a supra-modal HYPO construct (ωH = .653), and supra-modal SEEK models suggested a more limited version of the construct that excluded some sensory modalities (ωH = .800; 4/7 modalities). Modality-specific subscales demonstrated significant added value for all response patterns. Meta-analytic correlations varied by construct, although sensory features tended to correlate most with other domains of core autism features and co-occurring psychiatric symptoms (with general HYPER and speech HYPO demonstrating the largest numbers of practically significant correlations).

LIMITATIONS

Conclusions may not be generalizable beyond the specific pool of items used in the current study, which was limited to caregiver report of observable behaviors and excluded multisensory items that reflect many "real-world" sensory experiences.

CONCLUSION

Of the three sensory response patterns, only HYPER demonstrated sufficient evidence for valid interpretation at the supra-modal level, whereas supra-modal HYPO/SEEK constructs demonstrated substantial psychometric limitations. For clinicians and researchers seeking to characterize sensory reactivity in autism, modality-specific response pattern scores may represent viable alternatives that overcome many of these limitations.

A multilevel investigation of sensory sensitivity and responsivity in autistic adults

Atypical sensory processing is a core symptom of autism spectrum disorders (ASD). We aimed at better characterizing visual sensitivity and responsivity in ASD at the self-reported, behavioral and neural levels, and at describing the relationships between these levels. We refer to sensory sensitivity as the ability to detect sensory stimuli and to sensory responsivity as an affective response to sensory stimuli. Participants were 25 neurotypical and 24 autistic adults. At the self-reported level, autistic participants had higher scores of sensory sensitivity and responsivity than neurotypicals. The behavioral and neural tasks involved contrast-reversing gratings which became progressively (in)visible as their contrast or spatial frequency evolved. At the behavioral level, autistic participants had higher detection and responsivity thresholds when gratings varied in spatial frequency, but their thresholds did not differ from neurotypicals when gratings varied in contrast. At the neural level, we used fast periodic visual stimulations and electroencephalography to implicitly assess detection thresholds for contrast and spatial frequency, and did not reveal any group difference. Higher self-reported responsivity was associated with higher behavioral responsivity, more intolerance of uncertainty and anxiety, in particular in ASD. At the self-reported level, higher sensitivity was associated with more responsivity in both groups, contrary to the behavioral level where these relationships were not found. These heterogeneous results suggest that sensitivity and responsivity per se are not simply increased in ASD, but may be modulated by other factors such as environmental predictability. Multi-level approaches can shed light on the mechanisms underlying sensory issues in ASD.

Self and caregiver report measurement of sensory features in autism spectrum disorder: a systematic review of psychometric properties

BACKGROUND

Unusual responses to sensory stimuli are considered a diagnostic symptom of autism spectrum disorder with mounting research efforts put towards understanding, characterizing, and treating such symptoms.

METHODS

This paper examines self and caregiver report tools used to measure sensory features in ASD through a systematic review of the psychometric evidence for their use. A total of 31 empirical papers were reviewed across 20 assessment tools. Substantial differences were identified in the specific sensory features defined across assessment tools. Sensory assessment questionnaires were evaluated against quality psychometric evidence criteria to provide a use recommendation.

RESULTS

Five assessments were identified to be "appropriate with conditions," while no sensory assessment tools were identified to have sufficient quality psychometric evidence to provide a recommendation of "Appropriate" for measuring sensory features in ASD.

CONCLUSION

Evidence from this review highlights potentially significant shortcomings among the current methods used to measure sensory features in ASD and suggests the need for more efforts in developing psychometrically sound sensory assessment tools for use in ASD populations.

The Emerging Role of Virtual Reality as an Adjunct to Procedural Sedation and Anesthesia: A Narrative Review

Over the past 20 years, there has been a significant reduction in the incidence of adverse events associated with sedation outside of the operating room. Non-pharmacologic techniques are increasingly being used as peri-operative adjuncts to facilitate and promote anxiolysis, analgesia and sedation, and to reduce adverse events. This narrative review will briefly explore the emerging role of immersive reality in the peri-procedural care of surgical patients. Immersive virtual reality (VR) is intended to distract patients with the illusion of "being present" inside the computer-generated world, drawing attention away from their anxiety, pain, and discomfort. VR has been described for a variety of procedures that include colonoscopies, venipuncture, dental procedures, and burn wound care. As VR technology develops and the production costs decrease, the role and application of VR in clinical practice will expand. It is important for medical professionals to understand that VR is now available for prime-time use and to be aware of the growing body in the literature that supports VR.

Intellectually able adults with autism spectrum disorder show typical resting-state EEG activity

There is broad interest in discovering quantifiable physiological biomarkers for psychiatric disorders to aid diagnostic assessment. However, finding biomarkers for autism spectrum disorder (ASD) has proven particularly difficult, partly due to high heterogeneity. Here, we recorded five minutes eyes-closed rest electroencephalography (EEG) from 186 adults (51% with ASD and 49% without ASD) and investigated the potential of EEG biomarkers to classify ASD using three conventional machine learning models with two-layer cross-validation. Comprehensive characterization of spectral, temporal and spatial dimensions of source-modelled EEG resulted in 3443 biomarkers per recording. We found no significant group-mean or group-variance differences for any of the EEG features. Interestingly, we obtained validation accuracies above 80%; however, the best machine learning model merely distinguished ASD from the non-autistic comparison group with a mean balanced test accuracy of 56% on the entirely unseen test set. The large drop in model performance between validation and testing, stress the importance of rigorous model evaluation, and further highlights the high heterogeneity in ASD. Overall, the lack of significant differences and weak classification indicates that, at the group level, intellectually able adults with ASD show remarkably typical resting-state EEG.

No differences between adults with and without autism in audiovisual synchrony perception

LAY ABSTRACT

It has been known for a long time that individuals diagnosed with autism spectrum disorder perceive the world differently. In this study, we investigated how people with or without autism perceive visual and auditory information. We know that an auditory and a visual stimulus do not have to be perfectly synchronous for us to perceive them as synchronous: first, when the two are within a certain time window (temporal binding window), the brain will tell us that they are synchronous. Second, the brain can also adapt quickly to audiovisual asynchronies (rapid recalibration). Although previous studies have shown that people with autism spectrum disorder have different temporal binding windows, and less rapid recalibration, we did not find these differences in our study. However, we did find that both processes develop over age, and since previous studies tested only young people (children, adolescents, and young adults), and we tested adults from 18 to 55 years, this might explain the different findings. In the end, there might be quite a complex story, where people with and without autism spectrum disorder perceive the world differently, even dependent on how old they are.

A Multidimensional Investigation of Sensory Processing in Autism: Parent- and Self-Report Questionnaires, Psychophysical Thresholds, and Event-Related Potentials in the Auditory and Somatosensory Modalities

Background

Reconciling results obtained using different types of sensory measures is a challenge for autism sensory research. The present study used questionnaire, psychophysical, and neurophysiological measures to characterize autistic sensory processing in different measurement modalities.

Methods

Participants were 46 autistic and 21 typically developing 11- to 14-year-olds. Participants and their caregivers completed questionnaires regarding sensory experiences and behaviors. Auditory and somatosensory event-related potentials (ERPs) were recorded as part of a multisensory ERP task. Auditory detection, tactile static detection, and tactile spatial resolution psychophysical thresholds were measured.

Results

Sensory questionnaires strongly differentiated between autistic and typically developing individuals, while little evidence of group differences was observed in psychophysical thresholds. Crucially, the different types of measures (neurophysiological, psychophysical, questionnaire) appeared to be largely independent of one another. However, we unexpectedly found autistic participants with larger auditory Tb ERP amplitudes had reduced hearing acuity, even though all participants had hearing acuity in the non-clinical range.

Limitations

The autistic and typically developing groups were not matched on cognitive ability, although this limitation does not affect our main analyses regarding convergence of measures within autism.

Conclusion

Overall, based on these results, measures in different sensory modalities appear to capture distinct aspects of sensory processing in autism, with relatively limited convergence between questionnaires and laboratory-based tasks. Generally, this might reflect the reality that laboratory tasks are often carried out in controlled environments without background stimuli to compete for attention, a context which may not closely resemble the busier and more complex environments in which autistic people's atypical sensory experiences commonly occur. Sensory questionnaires and more naturalistic laboratory tasks may be better suited to explore autistic people's real-world sensory challenges. Further research is needed to replicate and investigate the drivers of the unexpected association we observed between auditory Tb ERP amplitudes and hearing acuity, which could represent an important confound for ERP researchers to consider in their studies.

A systematic review of person-centred adjustments to facilitate magnetic resonance imaging for autistic patients without the use of sedation or anaesthesia

LAY ABSTRACT

Autistic patients often undergo magnetic resonance imaging examinations. Within this environment, it is usual to feel anxious and overwhelmed by noises, lights or other people. The narrow scanners, the loud noises and the long examination time can easily cause panic attacks. This review aims to identify any adaptations for autistic individuals to have a magnetic resonance imaging scan without sedation or anaesthesia. Out of 4442 articles screened, 53 more relevant were evaluated and 21 were finally included in this study. Customising communication, different techniques to improve the environment, using technology for familiarisation and distraction have been used in previous studies. The results of this study can be used to make suggestions on how to improve magnetic resonance imaging practice and the autistic patient experience. They can also be used to create training for the healthcare professionals using the magnetic resonance imaging scanners.

Autism and chronic ill health: an observational study of symptoms and diagnoses of central sensitivity syndromes in autistic adults

BACKGROUND

Autistic adults, particularly women, are more likely to experience chronic ill health than the general population. Central sensitivity syndromes (CSS) are a group of related conditions that are thought to include an underlying sensitisation of the central nervous system; heightened sensory sensitivity is a common feature. Anecdotal evidence suggests autistic adults may be more prone to developing a CSS. This study aimed to investigate the occurrence of CSS diagnoses and symptoms in autistic adults, and to explore whether CSS symptoms were related to autistic traits, mental health, sensory sensitivity, or gender.

METHODS

The full sample of participants included 973 autistic adults (410 men, 563 women, mean age = 44.6) registered at the Netherlands Autism Register, who completed questionnaires assessing autistic traits, sensory sensitivity, CSS, physical and mental health symptoms. The reliability and validity of the Central Sensitization Inventory (CSI) in an autistic sample was established using exploratory and confirmatory factor analyses. Chi2 analyses, independent t-tests, hierarchical regression and path analysis were used to analyse relationships between CSS symptoms, autistic traits, measures of mental health and wellbeing, sensory sensitivity, age and gender.

RESULTS

21% of participants reported one or more CSS diagnosis, and 60% scored at or above the clinical cut-off for a CSS. Autistic women were more likely to report a CSS diagnosis and experienced more CSS symptoms than men. Sensory sensitivity, anxiety, age and gender were significant predictors of CSS symptoms, with sensory sensitivity and anxiety fully mediating the relationship between autistic traits and CSS symptoms.

LIMITATIONS

Although this study included a large sample of autistic adults, we did not have a control group or a CSS only group. We also could not include a non-binary group due to lack of statistical power.

CONCLUSIONS

CSS diagnoses and symptoms appear to be very common in the autistic population. Increased awareness of an association between autism and central sensitisation should inform clinicians and guide diagnostic practice, particularly for women where CSS are common and autism under recognised.

An German Short-Version of the "Sensory Perception Quotient" for Adults With Autism Spectrum Disorder

Sensory features in autism spectrum disorder (ASD) have received increasing interest in clinical work and research during the recent years. With the Sensory Perception Quotient (SPQ), Tavasolli and colleagues have produced a self-rating scale for adults with ASD that measures sensory hyper-sensitivity in different sensory modalities, without also tapping cognitive or motivational aspects that precede or follow autistic sensory experiences. Here, we present the results of a translation of the SPQ to German and its short version as well as their validation in samples of autistic or neuro-typical participants. We, furthermore, present the psychometric properties and validities of Tavasolli's original SPQ-short version as well as an alternative short version based on different psychometric item-selection criteria. We can show here that our alternative SPQ-short version, overlapping with the original short-version in 61% of its items, exhibits superior reliabilities, reasonable concurrent validities with other related measures. It, furthermore, exhibits excellent differentiation between autistic and non-autistic samples, underscoring its utility as a screening instrument in research and a clinical instrument to supplement the ASD diagnostic process.

The importance of home: Satisfaction with accommodation, neighborhood, and life in adults with autism

Although good quality housing and a socially cohesive neighborhood are associated with a higher well‐being in the general population, housing is a rarely studied topic in autism research. In the present study, we describe the housing situation of a large sample of adults with autism and mostly (above) average intellectual abilities (n = 1429; 17 to 84 years), and examine predictors of independent living, accommodation satisfaction, neighborhood satisfaction, and satisfaction with life based on an online survey. The outcomes of independently living adults were compared with those from a Dutch community sample (n = 929). Nearly 80% of the autistic adults lived independently. Older participants, women, and those with higher self‐reported IQ's were more likely to live independently. Autistic adults living independently were equally satisfied with their accommodation and neighborhood as the comparison group, but were less satisfied with their life in general. In both groups, higher satisfaction with accommodation and neighborhood was associated with higher life satisfaction. We advocate further research to better understand and anticipate the housing needs of the growing group of adults with autism.

Exploring sensory phenotypes in autism spectrum disorder

BACKGROUND

Atypical reactions to the sensory environment are often reported in autistic individuals, with a high degree of variability across the sensory modalities. These sensory differences have been shown to promote challenging behaviours and distress in autistic individuals and are predictive of other functions including motor, social, and cognitive abilities. Preliminary research suggests that specific sensory differences may cluster together within individuals creating discrete sensory phenotypes. However, the manner in which these sensory differences cluster, and whether the resulting phenotypes are associated with specific cognitive and social challenges is unclear.

METHODS

Short sensory profile data from 599 autistic children and adults between the ages of 1 and 21 years were subjected to a K-means cluster analysis. Analysis of variances compared age, adaptive behaviour, and traits associated with autism, attention-deficit and hyperactivity disorder, and obsessive and compulsive disorder across the resultant clusters.

RESULTS

A five-cluster model was found to minimize error variance and produce five sensory phenotypes: (1) sensory adaptive, (2) generalized sensory differences, (3) taste and smell sensitivity, (4) under-responsive and sensation seeking, and (5) movement difficulties with low energy. Age, adaptive behaviour, and traits associated with autism, attention-deficit and hyperactivity disorder, and obsessive and compulsive disorder were found to differ significantly across the five phenotypes.

LIMITATIONS

The results were based on parent-report measures of sensory processing, adaptive behaviour, traits associated with autism, attention-deficit and hyperactivity disorder, and obsessive and compulsive disorder, which may limit the generalizability of the findings. Further, not all measures are standardized, or psychometrically validated with an autism population. Autistic individuals with an intellectual disability were underrepresented in this sample. Further, as these data were obtained from established records from a large provincial database, not all measures were completed for all individuals.

CONCLUSIONS

These findings suggest that sensory difficulties in autistic individuals can be clustered into sensory phenotypes, and that these phenotypes are associated with behavioural differences. Given the large degree of heterogeneity in sensory difficulties seen in the autistic population, these sensory phenotypes represent an effective way to parse that heterogeneity and create phenotypes that may aid in the development of effective treatments and interventions for sensory difficulties.

Brief Report: The Benefits of an Employer-Based Work-Experience Program for Participants with ASD

An employer-based work-experience program run by a multinational organization temporarily employs people with an autism spectrum disorder (ASD) to prepare them for external employment. This study observes the impact of participation for people with ASD in establishing employment (with or without a competitive salary). A quasi-experimental design constructed a control group that can be considered similar to the group of participants in the employer-based program, except for supported-employment entitlement. Results indicate a 29% increase in post-five-year employment for participants than the control group, but no effect was found on employment with a competitive salary, only for the post-second year. Inclusivity enhances the careers of people with ASD, but their potential to establish employment with a competitive salary remains limited.

Evaluating the latent structure of the non-social domain of autism in autistic adults

Background

The social domain of autism has been studied in depth, but the relationship between the non-social traits of autism has received less attention. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) outlines four criteria that make up the non-social domain including repetitive motor movements, insistence on sameness, restricted interests and sensory sensitivity. There is a lack of research into the relationship between these four criteria. This study aimed to evaluate the relationship between the non-social traits of autism in a large sample of autistic adults. It explored whether these traits are best conceptualised as four distinct factors, or exist along a single dimension.

Methods

Participants included autistic adults from the Netherlands Autism Register. The four components identified within the DSM-5 non-social domain were measured by items from the Adult Routines Inventory, the Autism Spectrum Quotient short and the Sensory Perception Quotient short. Confirmatory factor analysis, as well as exploratory factor analysis and exploratory structural equation modelling, was implemented to examine the relationship between these four criteria.

Results

Results indicated that a four-factor model provided the best fit, mapping onto the DSM-5 criteria. These four factors were moderately correlated, suggesting that four distinct, yet related factors best describe the non-social domain of autism. The one-factor model did not provide a good fit, highlighting that the non-social domain of autism is not a unitary construct.

Limitations

The study included autistic adults who were cognitively able to complete the self-report measures. This may limit the generalisability of the findings to those who are less able to do so.

Conclusions

This study provided evidence for the multidimensional nature of the non-social domain of autism. Given only two of the four criteria within the non-social domain need to be endorsed for a diagnosis of autism, there is room for substantial variation across individuals, who will have a unique profile within the non-social domain. The results have implications for our understanding of the heterogeneous nature of autistic traits, as well as for how we conceptualise autism as a diagnostic category. This is important for the provision of diagnosis and support within research and clinical practice.