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.

Measuring self and informant perspectives of Restricted and Repetitive Behaviours (RRBs): psychometric evaluation of the Repetitive Behaviours Questionnaire-3 (RBQ-3) in adult clinical practice and research settgs.

BACKGROUND: Brief questionnaires that comprehensively capture key restricted and repetitive behaviours (RRBs) across different informants have potential to support autism diagnostic services. We tested the psychometric properties of the 20-item Repetitive Behaviours Questionnaire-3 (RBQ-3), a questionnaire that includes self-report and informant-report versions enabling use across the lifespan. METHOD: In Study 1, adults referred to a specialised adult autism diagnostic service (N = 110) completed the RBQ-3 self-report version, and a relative or long-term friend completed the RBQ-3 informant-report version. Clinicians completed the abbreviated version of the Diagnostic Interview for Social and Communication Disorders (DISCO-Abbreviated) with the same adults as part of the diagnostic process. For half of the assessments, clinicians were blind to the RBQ-3 ratings. We tested internal consistency, cross-informant reliability and convergent validity of the RBQ-3. In Study 2, a follow-up online study with autistic (N = 151) and non-autistic (N = 151) adults, we further tested internal consistency of the RBQ-3 self-report version. We also tested group differences and response patterns in this sample. RESULTS: Study 1 showed good to excellent internal consistency for both self- and informant-report versions of the RBQ-3 (total score, α = 0.90, ω = 0.90, subscales, α = 0.76-0.89, ω = 0.77-0.88). Study 1 also showed cross-informant reliability as the RBQ-3 self-report scores significantly correlated with RBQ-3 informant-report scores for the total score (rs = 0.71) and subscales (rs= 0.69-0.72). Convergent validity was found for both self and informant versions of the RBQ-3, which significantly correlated with DISCO-Abbreviated RRB domain scores (rs = 0.45-0.54). Moreover, the RBQ-3 scores showed significantly weaker association with DISCO -Abbreviated scores for the Social Communication domain, demonstrating divergent validity. Importantly, these patterns of validity were found even when clinicians were blind to RBQ-3 items. In Study 2, for both autistic and non-autistic groups, internal consistency was found for the total score (α = 0.82-0.89, ω = 0.81-0.81) and for subscales (α = 0.68-0.85, ω = 0.69-0.85). A group difference was found between groups. LIMITATIONS: Due to the characteristics and scope of the specialist autism diagnostic service, further testing is needed to include representative samples of age (including children) and intellectual ability, and those with a non-autistic diagnostic outcome. CONCLUSIONS: The RBQ-3 is a questionnaire of RRBs that can be used across the lifespan. The current study tested its psychometric properties with autistic adults without intellectual disability and supported its utility for both clinical diagnostic and research settings.

Social communication disorder outside autism? A diagnostic classification approach to delineating pragmatic language impairment, high functioning autism and specific language impairment.

BACKGROUND: Developmental disorders of language and communication present considerable diagnostic challenges due to overlapping of symptomatology and uncertain aetiology. We aimed to further elucidate the behavioural and linguistic profile associated with impairments of social communication occurring outside of an autism diagnosis. METHODS: Six to eleven year olds diagnosed with pragmatic language impairment (PLI), high functioning autism (HFA) or specific language impairment (SLI) were compared on measures of social interaction with peers (PI), restricted and repetitive behaviours/interests (RRBIs) and language ability. Odds ratios (OR) from a multinomial logistic regression were used to determine the importance of each measure to diagnostic grouping. MANOVA was used to investigate differences in subscale scores for the PI measure. RESULTS: Greater degrees of PI difficulties (OR = 1.22, 95% CI = 1.05-1.41), RRBI (OR = 1.23, 95% CI = 1.06-1.42) and expressive language ability (OR = 1.16, 95% CI = 1.03-1.30) discriminated HFA from PLI. PLI was differentiated from SLI by elevated PI difficulties (OR = 0.82, 95% CI = 0.70-0.96) and higher expressive language ability (OR = 0.88, 95% CI = 0.77-0.98), but indistinguishable from SLI using RRBI (OR = 1.01, 95% CI=0.94-1.09). A significant effect of group on PI subscales was observed (θ = 1.38, F(4, 56) = 19.26, p < .01) and PLI and HFA groups shared a similar PI subscale profile. CONCLUSIONS: Results provide empirical support for a conceptualisation of PLI as a developmental impairment distinguishable from HFA by absence of RRBIs and by the presence of expressive language difficulties. PI difficulties appear elevated in PLI compared with SLI, but may be less pervasive than in HFA. Findings are discussed with reference to the proposed new category of 'social communication disorder' in DSM-5.

'If I don't Do It, I'm Out of Rhythm and I Can't Focus As Well': Positive and Negative Adult Interpretations of Therapies Aimed at 'Fixing' Their Restricted and Repetitive Behaviours in Childhood.

Restricted and repetitive behaviours (RRBs) are observed in many children presenting with characteristics of autism and are frequently the targets of psychological interventions. This study used Interpretative Phenomenological Analysis (IPA) to identify positive and negative interpretations from four young adults who received behavioural interventions in their childhood designed to 'fix' RRBs. Two superordinate themes were identified: (1) Doubt, stigma and being fixed according to others, and (2) Embracing Authenticity. They highlighted juxtaposed positions from exclusion, rejection, criticism, and self-doubt in childhood, to rejecting societal censure and embracing authentic growth in adult life. As adults, though the participants recognised themselves as neurologically different from others, they redefined themselves through a lens of neurodiversity, and therefore as not needing to be fixed.

Assessing Restricted and Repetitive Behaviours in Online-Sampled Autistic and Non-autistic Individuals: Factor Structure of the Repetitive Behaviours Questionnaire for Adults (RBQ-2A).

The Repetitive Behaviours Questionnaire for Adults (RBQ-2A) measures two factors of restricted and repetitive behaviours (RRBs) associated with autism. However, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) provides four criteria for RRBs: repetitive motor behaviours, insistence on sameness, restricted interests, and interest in sensory aspects of the environment (or atypical sensitivity). The current paper aimed to examine whether the RBQ-2A is a psychometrically sound measure of these four factors. Study 1 had university students (N = 368) complete the RBQ-2A and other related measures online and revealed that the RBQ-2A can assess the factors highlighted in the DSM-5 and that these four factors comprise a general RRB construct. Study 2 had individuals disclosing a diagnosis of autism (N = 283) complete the RBQ-2A and other related measures online and supported that this four-factor structure provided good psychometric properties. While the current paper provides findings for an online autistic population, further research is needed to generalize these findings to autistic individuals less likely to partake in online studies (e.g., those with intellectual or language disabilities). Overall, the results suggest that the RBQ-2A reliably and validly assesses RRBs.

A prospective study of associations between early fearfulness and perceptual sensitivity and later restricted and repetitive behaviours in infants with typical and elevated likelihood of autism.

LAY ABSTRACT: Restricted interests and repetitive behaviours are central to the diagnosis of autism and can have profound effects on daily activities and quality of life. These challenges are also linked to other co-occurring conditions such as anxiety and sensory sensitivities. Here, we looked at whether early emerging signs of anxiety and sensory problems appear before symptoms of autism by studying infants with a family history of autism, as these infants are more likely to develop autism themselves. Studying infant siblings provides an opportunity for researchers to focus on early developmental markers of autism as these infants can be followed from birth. This study found that early infant signs of anxiety (e.g. fear/shyness) predicted later perceptual sensitivity, and those infants who scored higher on fear/shyness and sensitivity were more likely to experience more persistent repetitive behaviours, but also social and communication difficulties in toddlerhood. Early signs of anxiety and perceptual sensitivity may thus relate to both later social difficulties and repetitive behaviours. These findings support the importance of further research exploring the causal links between these domains in relation to autism, resulting in increased understanding of children who go onto develop autism in the future and guiding early interventions and supports.

The Mediating Effects of Alexithymia, Intolerance of Uncertainty, and Anxiety on the Relationship Between Sensory Processing Differences and Restricted and Repetitive Behaviours in Autistic Adults.

Distress caused by sensory processing differences for autistic individuals may be reduced by repetitive behaviours (RRB), including repetitive motor (RMB) and insistence on sameness (ISB) behaviours. Intolerance of uncertainty (IU) and anxiety mediate the relationship between sensory processing and RRB in autistic children. We replicated this model in autistic adults, extending it to include alexithymia. Serial mediation, using data from 426 autistic adults, identified significant direct effects from sensory processing to RMB and ISB, and indirect effects through alexithymia-IU-anxiety for RMB, and IU alone, and alexithymia-IU for ISB. Different mechanisms may underpin RMB and ISB. Alexithymia alongside, IU and anxiety, should be considered when understanding the relationship between sensory processing and RRB, and when offering interventions to support autistic people.

The impact of COVID-19 measures on parent-reported restricted and repetitive behaviours in pre-school children with autism.

Background: COVID-19 restrictive measures have had a considerable impact on daily life routines, which may be especially challenging for families of children with autism. In pre-schoolers with autism, it is likely that the disruption of routines mainly impacts the presence of restrictive and repetitive behaviours (RRBs). Furthermore, influence of comorbid conditions, secondary behavioural difficulties and home environment characteristics on RRBs was explored. Method: A cross-sectional online survey design was used to collect parent-report data on 254 children with autism (2.5-6 years) during lockdown in the early months of the pandemic. RRBs were assessed using the Repetitive Behaviour Scale-Revised (RBS-R). Results: Parents reported a significant increase in stereotypic, self-injurious, compulsive and ritualistic behaviour, and restricted interests after implementation of COVID-19 restrictions. The presence of a co-occurring condition, such as language impairments or intellectual disability, was associated with more self-injurious and stereotypic behaviour. However, there was no effect of home environment on RRBs. Further, most children showed increases in internalising and/or externalising behaviour. Increased inattentive behaviour was associated with more ritualistic and stereotypic behaviour, and restricted interests. Decreases in hyperactivity were related to more restricted interests. Importantly, in a subset of children, parents reported less behavioural difficulties during the lockdown. Conclusions: Findings highlight the importance of flexible implementation and continuity of care for pre-schoolers with autism and support for parents. Further follow-up of children with autism and RRBs, and co-occurring behavioural difficulties is needed and could enhance our understanding of the long-term effects associated with sudden restrictive measures to daily routines.

A clinical and cost-effectiveness trial of a parent group intervention to manage challenging restricted and repetitive behaviours in young children with autism spectrum disorder: study protocol for a randomised controlled trial.

BACKGROUND: Restricted and repetitive behaviours vary greatly across the autism spectrum, and although not all are problematic some can cause distress and interfere with learning and social opportunities. We have, alongside parents, developed a parent group based intervention for families of young children with autism, which aims to offer support to parents and carers; helping them to recognise, understand and learn how to respond to their child's challenging restricted repetitive behaviours. METHODS: The study is a clinical and cost-effectiveness, multi-site randomised controlled trial of the Managing Repetitive Behaviours (MRB) parent group intervention versus a psychoeducation parent group Learning About Autism (LAA) (n = 250; 125 intervention/125 psychoeducation; ~ 83/site) for parents of young children aged 3-9 years 11 months with a diagnosis of autism. All analyses will be done under intention-to-treat principle. The primary outcome at 24 weeks will use generalised estimating equation (GEE) to compare proportion of children with improved RRB between the MRB group and the LAA group. The GEE model will account for the clustering of children by parent groups using exchangeable working correlation. All secondary outcomes will be analysed in a similar way using appropriate distribution and link function. The economic evaluation will be conducted from the perspective of both NHS costs and family access to local community services. A 'within trial' cost-effectiveness analysis with results reported as the incremental cost per additional child achieving at least the target improvement in CGI-I scale at 24 weeks. DISCUSSION: This is an efficacy trial to investigate the clinical and cost-effectiveness of a parent group based intervention designed to help parents understand and manage their child's challenging RRB. If found to be effective, this intervention has the potential to improve the well-being of children and their families, reduce parental stress, greatly enhance community participation and potential for learning, and improve longer-term outcomes. TRIAL REGISTRATION: Trial ID: ISRCTN15550611 Date registered: 07/08/2018. Sponsor and Monitor: Cumbria, Northumberland, Tyne and Wear NHS Foundation Trust R&D Manager Lyndsey Dixon, Address: St Nicholas Hospital, Jubliee Road, Gosforth, Newcastle upon Tyne NE3 3XT, lyndsey.dixon@cntw.nhs.uk , Tel: 0191 246 7222.

Teachers' perceptions of Restricted and Repetitive Behaviours (RRBs) in children with ASD: Attributions, confidence and emotional response.

BACKGROUND: Restricted and Repetitive Behaviours (RRBs) are some of the most difficult behaviours to manage in children with Autism Spectrum Disorders (ASD). Although RRBs frequently occur in educational settings, we know little about the way in which teachers understand these behaviours. AIMS: The study aimed to explore the attributions, emotional response and feelings of confidence held by teachers working in different educational settings when faced with RRBs. METHODS AND PROCEDURES: A single group survey design using behavioural vignettes was adopted in order to elicit teacher beliefs and ratings. OUTCOMES AND RESULTS: Analysis indicated that there were differences in the attributions and confidence ratings held for different types of RRBs. Significant differences were also observed between teachers working in mainstream and specialist educational settings. Emotional response and confidence scores were often predictive of one another alongside factors related to teaching experience. CONCLUSION AND IMPLICATIONS: The findings indicate that teachers from mainstream schools potentially hold less helpful beliefs in response to RRBs and therefore are a professional group who may benefit the most from additional support and training. Further research could consider conducting a qualitative exploration of why teachers hold certain beliefs about RRBs and/or sampling those who are less experienced in working with children with ASD.

Anxiety, Intolerance of Uncertainty and Restricted and Repetitive Behaviour: Insights Directly from Young People with ASD.

In order to investigate the experience of anxiety and restricted and repetitive behaviours (RRB) in young people with ASD, 19 families with young people with ASD aged between 13 and 20 years completed questionnaire measures of RRB, anxiety, and intolerance of uncertainty. Ten young people also completed a novel semi-structured interview exploring an individualised example of an RRB. Findings demonstrated that young people with ASD can self-report and show insight in to their RRB, and replicated previous findings based on parent report showing a significant positive relationship between RRB and anxiety. This is the first evidence of young person self-report using both quantitative and qualitative data and indicates a range of reasons why young people may engage in RRB.