Relationship between repetitive behaviour and fear across normative development, autism spectrum disorder, and down syndrome

What Are You Worried About? Content and Extent of Worry in Autistic Adults

Autistic adults commonly experience anxiety and worry, although knowledge on how worry presents and the content, extent, and experiences among autistic adults is limited. A convergent parallel mixed-methods approach was used to explore the presentation and experiences of worry in autistic and non-autistic adults. Quantitative surveys were used to compare the content and extent of worry in autistic adults to non-autistic adults, with semi-structured interviews also conducted with autistic adults to gain a deeper understanding of the experiences, impacts and content of worry in autistic adults. Findings indicated that autistic adults demonstrated clinically significant levels of worry which were substantially higher than non-autistic adults. Autistic adults described worry as a cycle of negative thoughts impacting their daily life. Findings indicate that autistic adults may worry more than non-autistic adults, impacting on participation in activities of daily living, sleep, and mental health.

Anxiety, concerns and COVID-19: Cross-country perspectives from families and individuals with neurodevelopmental conditions

Background

The COVID-19 pandemic had a major impact on the mental health and well-being of children with neurodevelopmental conditions (NDCs) and of their families worldwide. However, there is insufficient evidence to understand how different factors (e.g., individual, family, country, children) have impacted on anxiety levels of families and their children with NDCs developed over time.

Methods

We used data from a global survey assessing the experience of 8043 families and their children with NDCs (mean of age (m) = 13.18 years, 37% female) and their typically developing siblings (m = 12.9 years, 45% female) in combination with data from the European Centre for Disease Prevention and Control, the University of Oxford, and the Central Intelligence Agency (CIA) World Factbook, to create a multilevel data set. Using stepwise multilevel modelling, we generated child-, family- and country-related factors that may have contributed to the anxiety levels of children with NDCs, their siblings if they had any, and their parents. All data were reported by parents.

Results

Our results suggest that parental anxiety was best explained by family-related factors such as concerns about COVID-19 and illness. Children's anxiety was best explained by child-related factors such as children's concerns about loss of routine, family conflict, and safety in general, as well as concerns about COVID-19. In addition, anxiety levels were linked to the presence of pre-existing anxiety conditions for both children with NDCs and their parents.

Conclusions

The present study shows that across the globe there was a raise in anxiety levels for both parents and their children with NDCs because of COVID-19 and that country-level factors had little or no impact on explaining differences in this increase, once family and child factors were considered. Our findings also highlight that certain groups of children with NDCs were at higher risk for anxiety than others and had specific concerns. Together, these results show that anxiety of families and their children with NDCs during the COVID-19 pandemic were predicted by very specific concerns and worries which inform the development of future toolkits and policy. Future studies should investigate how country factors can play a protective role during future crises.

Arriving at the empirically based conceptualization of restricted and repetitive behaviors: A systematic review and meta-analytic examination of factor analyses

An empirically based understanding of the factor structure of the restricted and repetitive behaviors (RRB) domain is a prerequisite for interpreting studies attempting to understand the correlates and mechanisms underpinning RRB and for measurement development. Therefore, this study aimed to conduct a systematic review and meta-analysis of RRB factor analytic studies. Sets of meta-analyses were performed to examine (a) the factor structure of individual RRB instruments, (b) associations between RRB subdomains across instruments, and (c) the association between RRB factors and other variables. Searches for peer-reviewed articles evaluating the factor structure of the RRB domain were performed in PsycINFO (Ovid), Medline (Ovid), and Embase (Ovid). No age, measurement, or informant-type limits were imposed. Quality and risk of bias for individual studies were assessed using relevant COSMIN sections. Among the 53 studies retained for review, 41 examined RRB factor structures among individuals with autism spectrum disorder (ASD) and 12 among non-ASD samples. Meta-analysis of factor correlations provided evidence that the RRB domain encompasses the following eight specific factors: repetitive motor behaviors, insistence on sameness, restricted interests, unusual interests, sensory sensitivity, and repetitive, stereotyped language. Although interrelated, RRB factors were distinct, showing a unique pattern of associations with demographic, cognitive, and clinical correlates. Meta-analyses of the associations between RRB factors and specific correlates, specifically adaptive functioning and communication impairments, should be considered preliminary due to the limited number of studies. Despite limitations, this review provides important insights into the factor structure of the RRB domain and highlights critical conceptual, measurement, and methodological limitations of the current research that will need to be addressed in order to improve our understanding of RRB.

Anxiety in Wiedemann-Steiner syndrome

This study examined anxiety in Wiedemann-Steiner syndrome (WSS). Eighteen caregivers and participants with WSS completed the parent- and self-report versions of the Screen for Child Anxiety Related Disorder or the adapted version of the Screen for Adult Anxiety Related Disorder. Approximately 33.33% of parents and 65% of participants with WSS rated in the clinical range for overall anxiety. Across anxiety subtypes, parents primarily indicated concerns with Separation Anxiety (72%), which was also endorsed by the majority of participants with WSS (82%). The emergent trend showed Total Anxiety increased with age based on parent-informant ratings. The behavioral phenotype of WSS includes elevated anxiety. Clinical management should include incorporating early behavioral interventions to bolster emotion regulation given the observed risk of anxiety with age.

Restricted and repetitive behaviors and their developmental and demographic correlates in 4-8-year-old children: A transdiagnostic approach

Background: Restricted and repetitive behaviors (RRBs) are a broad class of behaviors characterized by frequent action repetition and intense preference for sameness. Research has predominantly focused on RRBs in diagnosed clinical groups, particularly in autism spectrum disorder and genetic disorders. Using a transdiagnostic approach, the current study examined RRBs in a diverse sample of children in relation to developmental and demographic correlates (age, language, non-verbal ability, child anxiety, sex, and socioeconomic status). Separate analyses examined two RRB subtypes; repetitive sensory and motor behaviors (RSMB) and insistence on sameness (IS). Method: Children (N = 260, age 4-8 years, 174 male, 86 female) in mainstream schools identified by teachers as having behavioral, emotional, and/or cognitive difficulties, were assessed using the Repetitive Behavior Questionnaire-2 (RBQ-2), the British Picture Vocabulary Scale (BPVS), Lucid Ability Scale, the Welsh Index of Multiple Deprivation (WIMD) and the Screen for Child Anxiety Related Emotional Disorders (SCARED). Recruitment excluded diagnosed clinical conditions. The Strengths and Difficulties Questionnaire (SDQ) was used to assess children's difficulties. Results: RRB scores were of high frequency and the scores for the IS were higher than for RSMB. The severity of anxiety symptoms and male sex were significantly associated with both RRB subtypes, and younger age and SES scores were associated with IS. Elevated RRB total and subtype scores were significantly related to SDQ scores for emotion, conduct, hyperactivity, and peer-relations. Discussion: The study provides the first evidence of RRBs in a diverse sample of young children with emerging difficulties in behavior, cognition, and/or emotion. The results contribute to proposals about psychological development in RRB and indicate that RRBs are best represented on a continuum of severity found across children in the early school years. The results support previous findings of a relation between RRB and anxiety reported in clinical samples and importantly, they indicate that it is time to move beyond the study of categorically defined groups and consider correlates of RRBs that include broad indices of mental health and well-being.

Understanding the heterogeneity of anxiety in autistic youth: A person-centered approach

The present study aimed to examine anxiety profiles among children and adolescents on the autism spectrum. It further aimed to characterize the association between the identified anxiety profiles and key clinical and developmental variables. The Spence Children's Anxiety Scale-Parent Version (SCAS-P) data from a large international pooled sample of 870 caregivers of autistic children and adolescents (M_age  = 11.6 years, SD_age  = 2.77; 107 females) was used. Latent profile analysis identified a three-anxiety profile solution exhibiting high entropy (0.80) and high latent profile probabilities, with good classification accuracy. Identified profiles fell along the severity spectrum and were named as the mild (n = 498), moderate (n = 272) and severe (n = 100) anxiety profiles. There were no statistically significant differences between the three anxiety profiles in terms of sex distribution. Participants in the mild profile were significantly younger than those in the severe profile, had significantly fewer social communication difficulties than youth in the moderate anxiety profile group and had significantly fewer restricted and repetitive behaviors and lower cognitive functioning scores compared to participants in moderate and severe anxiety profiles. This is the first study to move beyond identifying associations and group-level differences to exploring and identifying characteristics of anxiety-based subgroups at an individual level that differ on key clinical and developmental variables. The subgroups identified in this study are a preliminary, yet important, first step towards informing future assessment and individualized interventions aiming to support young people on the autism spectrum to reduce and manage anxiety. LAY SUMMARY: This study tried to understand if there are subgroups of autistic young people who may have similar anxiety profiles. We found that we could meaningfully group young people into three groups based on how severe the anxiety symptoms their caregivers reported were: a group with low levels of anxiety, those with moderate anxiety, and those with more severe anxiety. We also found that the young people in the mild group were younger, had fewer autism traits and lower levels of intellectual functioning than young people in the other two groups.

Behavioral Inflexibility Across Two Neurogenetic Conditions: Down Syndrome and Fragile X Syndrome

Behavioral inflexibility (BI) has been highlighted to occur across genetic and neurodevelopmental disorders. This study characterized BI in two common neurogenetic conditions: Fragile X syndrome (FXS) and Down syndrome (DS). Caregivers of children with FXS (N = 56; with ASD = 28; FXS only = 28) and DS (N = 146) completed the Behavioral Inflexibility Scale (BIS) via an online survey. Total BIS scores were higher in FXS+ASD than both FXS only and DS (p <.001). Most endorsed items were similar across the three groups, but scores were higher in the FXS+ASD group. In all groups, BI associated with other clinical variables (receptive behaviors, anxiety, social communication). The current data suggest that BI is variable across neurogenetic conditions and higher in individuals with comorbid ASD.

Toward better characterization of restricted and repetitive behaviors in individuals with germline heterozygous PTEN mutations

This study aimed to further our understanding of restricted and repetitive behaviors (RRB) among individuals with germline pathogenic mutations in PTEN by providing multimethod characterization and comparison of key RRB subdomains across individuals with PTEN mutations with autism spectrum disorder (ASD) (PTEN-ASD), with PTEN mutations without ASD (PTEN-No ASD) and with ASD and macrocephaly but without PTEN mutations (Macro-ASD). Of 86 total research participants, 38 had PTEN-ASD (M_age  = 8.93 years, SD_age  = 4.75), 25 Macro-ASD (M_age  = 11.99 years; SD_age  = 5.15), and 23 PTEN-No ASD (M_age  = 8.94 years; SD_age  = 4.85). The Repetitive Behavior Scale-Revised (RBS-R) and the Autism Diagnostic Interview-Revised (ADI-R) were used as measures of distinct RRB domains. There were significant group differences in the RBS-R repetitive motor behaviors (RMB; F = 4.52, p = 0.014, ω²  = 0.08), insistence on sameness (IS; F = 4.11, p = 0.02, ω²  = 0.05), and circumscribed interests (CI; F = 7.80, p = 0.001, ω²  = 0.14) scales. Post hoc comparisons showed that the PTEN-No ASD group had significantly lower RMB, IS, and CI scores compared to both PTEN-ASD and Macro-ASD groups. Importantly, PTEN-No ASD group still showed elevated RRB levels. Furthermore, there was a portion of individuals in PTEN-No ASD group whose Full-Scale Intelligence Quotient (FSIQ) was >70 that did not show floor level scores in the RMB domain. After adjusting for age and FSIQ scores, group differences were no longer statistically significant. RMB, IS, and CI domains showed distinct association patterns with sex, age, and FSIQ. This investigation provides the largest and most comprehensive characterization of distinct RRB domains in individuals with PTEN mutations to date. Despite the limitations, our findings have important assessment and treatment implications.

Selective Mutism and Its Relations to Social Anxiety Disorder and Autism Spectrum Disorder

In current classification systems, selective mutism (SM) is included in the broad anxiety disorders category. Indeed, there is abundant evidence showing that anxiety, and social anxiety in particular, is a prominent feature of SM. In this article, we point out that autism spectrum problems in addition to anxiety problems are sometimes also implicated in SM. To build our case, we summarize evidence showing that SM, social anxiety disorder (SAD), and autism spectrum disorder (ASD) are allied clinical conditions and share communalities in the realm of social difficulties. Following this, we address the role of a prototypical class of ASD symptoms, restricted and repetitive behaviors and interests (RRBIs), which are hypothesized to play a special role in the preservation and exacerbation of social difficulties. We then substantiate our point that SM is sometimes more than an anxiety disorder by addressing its special link with ASD in more detail. Finally, we close by noting that the possible involvement of ASD in SM has a number of consequences for clinical practice with regard to its classification, assessment, and treatment of children with SM and highlight a number of directions for future research.

Using the big data approach to clarify the structure of restricted and repetitive behaviors across the most commonly used autism spectrum disorder measures

BACKGROUND

Restricted and repetitive behaviors (RRB) in autism spectrum disorder (ASD) encompass several distinct domains. However, commonly used general ASD measures provide broad RRB scores rather than assessing separate RRB domains. The main objective of the current investigation was to conduct a psychometric evaluation of the ability of the Social Responsiveness Scale (SRS-2), the Social Communication Questionnaire (SCQ), the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS) to capture different RRB constructs.

METHODS

Exploratory Structural Equation Modeling (ESEM) was conducted using individual item-level data from the SRS-2, SCQ, ADI-R and the ADOS. Data were obtained from five existing publicly available databases. For the SRS-2, the final sample consisted of N = 16,761 individuals (Mage = 9.43, SD = 3.73; 18.5% female); for the SCQ, of N = 15,840 (Mage = 7.99, SD = 4.06; 18.1% female); for the ADI-R, of N = 8985 (Mage = 8.86, SD = 4.68; 19.4% female); and for the ADOS, of N = 6314 (Mage = 12.29, SD = 6.79; 17.7% female).

RESULTS

The three-factor structure provided the most optimal and interpretable fit to data for all measures (comparative fit index ≥ .983, Tucker Lewis index ≥ .966, root mean square error of approximation ≤ .028). Repetitive-motor behaviors, insistence on sameness and unusual or circumscribed interests factors emerged across all instruments. No acceptable fit was identified for the ADOS.

LIMITATIONS

The five datasets used here afforded a large as well as wide distribution of the RRB item scores. However, measures used for establishing convergent and divergent validity were only available for a portion of the sample.

CONCLUSIONS

Reported findings offer promise for capturing important RRB domains using general ASD measures and highlight the need for measurement development.

Brief Report: Role of Parent-Reported Executive Functioning and Anxiety in Insistence on Sameness in Individuals with Germline PTEN Mutations

This study aimed to characterize the relationship between insistence on sameness (IS), executive functioning (EF) and anxiety among individuals with PTEN mutations and individuals with macrocephalic ASD. The sample included 38 individuals with PTEN mutation and ASD diagnosis (PTEN-ASD; M_age = 8.93 years, SD_age = 4.75), 23 with PTEN mutation without ASD (PTEN-no ASD; M_age = 8.94 years; SD_age = 4.85) and 25 with ASD and macrocephaly but with no PTEN mutation (Macro-ASD; M_age = 11.99 years; SD_age = 5.15). The final model accounted for 45.7% of variance in IS, with Set-Shifting EF subdomain as a unique independent predictor (t = 4.12, p < 0.001). This investigation provides the first preliminary evidence for the EF-anxiety-IS interrelationship in individuals with PTEN mutations and with macrocephalic ASD.

Executive Function Skills Are Linked to Restricted and Repetitive Behaviors: Three Correlational Meta Analyses

There is a consensus on the centrality of restricted and repetitive behaviors (RRBs) in the diagnosis of Autism Spectrum Disorder (ASD), yet the origins of these behaviors are still debated. We reconsider whether executive function (EF) accounts of RRBs should be revisited. EF deficits and high levels of RRBs are often pronounced in individuals with ASD and are also prevalent in young typically developing children. Despite this, the evidence is mixed, and there has been no systematic attempt to evaluate the relationship across studies and between task batteries. We examine recent evidence, and in three highly powered random-effects analyses (N = 2964), examine the strength of the association between RRB levels and performance on set shifting, inhibitory control, and parental-report based EF batteries. The analyses confirm significant associations between high levels of the behaviors and poor EF skills. Moreover, the associations remained stable across typical development and in individuals with ASD and across different types of EF measures. These meta-analyses consolidate recent evidence identifying that cognitive mechanisms correlate with high RRBs that are seen in individuals with ASD, as well as in typical development. We propose that the EF account may be critical for guiding future interventions in ASD research. LAY SUMMARY: Restricted and repetitive behaviors (RRBs) are diagnostic criteria for Autism yet also common in typical development, and if they persist over time some can have a negative impact on learning and social acceptance. The present meta-analyses found that high levels of RRBs related to poor performance on set-shifting and inhibitory control tasks, as well as high ratings on parental report scales. Future studies should create interventions that aim to improve these skills as they may help manage challenging RRBs.

The autism advantage at work: A critical and systematic review of current evidence

BACKGROUND

Despite difficulties entering the workforce, people on the autism spectrum are often successful. Furthermore, they are suggested to bring unique abilities (e.g., attention to detail, tolerance for repetitive tasks) related to the repetitive and restrictive behaviours and interests (RRBI) diagnostic domain, that may be advantageous in employment.

AIMS

This critical and systematic review examined evidence supporting the superior workplace performance of employees on the autism spectrum, particularly regarding the RRBI domain.

METHOD AND PROCEDURES

A systematic review (PRISMA guidelines) evaluated empirical peer-reviewed studies that assess employees on the autism spectrum's performance in the workplace or on work-specific tasks. Nine databases were searched, with additional papers identified from reference lists and consultation.

OUTCOMES AND RESULTS

Two quantitative and four qualitative papers met criteria. Results reflect themes; attention to detail, tolerance of repetitive tasks, special/circumscribed interests, other RRBI related advantages/concerns.

CONCLUSIONS AND IMPLICATIONS

Due to the nature and quality of the identified studies there is currently no strong evidence supporting or negating a workplace autism advantage. This review highlights the need for more research and urges constraint in utilising stereotypes that may not apply to all on the autism spectrum, arguing an individual differences approach to supporting autism strengths at work.

Deconstructing the repetitive behaviour phenotype in autism spectrum disorder through a large population-based analysis

OBJECTIVE

Restricted and repetitive pattern of behaviours and interests (RRB) are a cardinal feature of autism spectrum disorder (ASD), but there remains uncertainty about how these diverse behaviours vary according to individual characteristics. This study provided the largest exploration to date of the relationship between Repetitive Motor Behaviours, Rigidity/Insistence on Sameness and Circumscribed Interests with other individual characteristics in newly diagnosed individuals with ASD.

METHOD

Participants (N = 3,647; 17.7% females; Mage = 6.6 years [SD = 4.7]) were part of the Western Australian (WA) Register for ASD, an independent, prospective collection of demographic and diagnostic data of newly diagnosed cases of ASD in WA. Diagnosticians rated each of the DSM-IV-TR criteria on a 4-point Likert severity scale, and here we focused on the Repetitive Motor Behaviours, Insistence on Sameness and Circumscribed Interests symptoms.

RESULTS

The associations between RRB domains, indexed by Kendall's Tau, were weak, ranging from non-significant for both Circumscribed Interests and Repetitive Motor Behaviours to significant (.20) for Insistence on Sameness and Repetitive Motor Behaviours. Older age at diagnosis was significantly associated with lower Circumscribed Interests and significantly associated with higher Insistence on Sameness and Repetitive Motor Behaviours. Male sex was significantly associated with higher Repetitive Motor Behaviours but not Insistence on Sameness or Circumscribed Interests.

CONCLUSIONS

The pattern of associations identified in this study provides suggestive evidence for the distinctiveness of Repetitive Motor Behaviours, Insistence on Sameness and Circumscribed Interests, highlighting the potential utility of RRB domains for stratifying the larger ASD population into smaller, more phenotypically homogeneous subgroups that can help to facilitate efforts to understand diverse ASD aetiology and inform design of future interventions.

The role of emotion regulation and core autism symptoms in the experience of anxiety in autism

LAY ABSTRACT

Many children with autism spectrum disorder have problems with managing their emotions (emotion regulation) and anxiety. In this study, over 1000 parents completed an online survey which showed that emotion regulation and anxiety are closely linked. Although emotion regulation and anxiety are inter-connected, the results also show that autism symptoms play an important role in anxiety in autism spectrum disorder. Emotion regulation problems may be an important target for the treatment of anxiety in autism.

Interrelationship Between Cognitive Control, Anxiety, and Restricted and Repetitive Behaviors in Children with 22q11.2 Deletion Syndrome

Restricted and repetitive behaviors (RRB) are common in individuals with 22q11.2 microdeletion syndrome (22q11.2DS), yet the underlying mechanisms of these behaviors remain poorly characterized. In the present pilot investigation, we aimed to further our understanding of RRB in 22q11.2DS by exploring their relationship with cognitive control and anxiety as well as with sex, chronological age, and full-scale IQ. Parents of 38 children with 22q11.2DS (17 females; Mage = 11.15 years, SD = 2.46) completed the Social Communication Questionnaire as a measure of RRB and social and communication (SC) problems and the Behavioral Assessment System for Children-2 as a measure of anxiety and cognitive control. Higher RRB scores were significantly associated with higher anxiety levels (r = 0.44, P = 0.006), more impairments in cognitive control (r = 0.56, P < 0.001), and higher SC scores (r = 0.43, P = 0.011). In the first step of the hierarchical regression model, anxiety accounted for 24.5% of variance (F = 10.05, P = 0.003); cognitive control accounted for an additional 18.1% of variance (Fchange = 11.15, P < 0.001) in the second step; SC score accounted for only 0.8% of additional variance in the third step (Fchange = 0.40, P = 0.53). The final model explained 43.4% of variance (F = 7.42, P = 0.001), with cognitive control as a unique independent predictor of RRB score (t = 2.52, P = 0.01). The current study provides the first exploration of the cognitive control-anxiety-RRB link in individuals with 22q11.2DS and points to cognitive control as a potentially viable target for treatments aimed at reducing RRB. Autism Res 2019, 12: 1737-1744. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: People with 22q11.2 deletion syndrome show high levels of repetitive behaviors, however, the previous research has not explored why people with this syndrome exhibit high rates of repetitive behaviors. Understanding the reasons for the high levels of repetitive behaviors is important given that these behaviors can be highly impairing. Our study found that repetitive behaviors were associated with impaired ability to self-regulate and high levels of anxiety. These findings need to be further replicated; however, they are important as they suggest potentially promising ways of reducing these behaviors.

Exploring Traits of Autism and Their Impact on Functional Disability in Children with Somatic Symptom Disorder

Subclinical traits of autism were measured in children with somatic symptom disorder (SSD, n = 28) and compared with age-matched controls (n = 26) using the Autism Spectrum Quotient (AQ) children's version. The KINDL^R quality of life questionnaire was used to assess functional disability. Although there was no significant group difference in total traits of autism, SSD group had significantly greater difficulty in attention switching domain. Logistic regression analysis confirmed attention switching and age were associated with increased likelihood of SSD. In SSD group, difficulty in attention switching significantly negatively correlated with total, family, and friends quality of life scores. In conclusion, assessment and treatment targeting difficulties in attention switching could be useful when dealing with children with SSD.

Largely Typical Electrophysiological Affective Responses to Special Interest Stimuli in Adolescents with Autism Spectrum Disorder

Circumscribed interests are a symptom of autism spectrum disorder (ASD) that may be related to exaggerated affective neural responses. However, the use of generic ASD-interest image stimuli has left an open question as to whether affective responses towards individual interests are greater in ASD compared to typically developing (TD) controls. We compared amplitudes of the late positive potential (LPP), an affective electroencephalographic response, between adolescents with ASD (N = 19) and TD adolescents (N = 20), using images tailored to individual likes and dislikes. We found an LPP response for liked and disliked images, relative to neutral, with no difference in amplitude between groups. This suggests that the LPP is not atypical in adolescents with ASD towards images of individual interests.

Interrelationship between insistence on sameness, effortful control and anxiety in adolescents and young adults with autism spectrum disorder (ASD)

BACKGROUND

Both self-regulation and insistence on sameness (IS) are related to anxiety, which is a common feature of individuals with autism spectrum disorder (ASD). Here, we aimed to characterise the IS-self-regulation-anxiety interrelationship by investigating the potential contribution made by self-regulation, assessed via effortful control (EC), to the IS-anxiety relationship in a sample of adolescents and young adults with ASD.

METHOD

Seventy-one older adolescents and younger adults with ASD (49 males, 22 females; Mage = 18.71 years, SD = 2.51, range 14.42-24.81) completed the Adult Repetitive Behaviour Questionnaire-2, Effortful Control Scale of the Adult Temperament Questionnaire and the DSM-5 Dimensional Anxiety Scales.

RESULTS

IS was associated with both EC (r = -.39, p = .001) and anxiety (r = .45, p < .001), and anxiety was in turn associated with EC (r = -.44, p < .001). To characterise the nature of this interrelationship, two mediation analyses were performed using the serial mediation model in PROCESS with 5000 resamples in bootstrapping. There was a significant indirect effect of EC on anxiety, through IS (b = -.06; BCa 95% CI [-.13, -.02]), and indirect effect on anxiety through EC (b = 1.62; BCa 95% CI [.59, 3.24]) with the mediators accounting for 29.07 and 26.04% of the total effect, respectively.

CONCLUSIONS

Our study provides the first exploration of the IS-anxiety-self-regulation link in ASD. The finding that lower levels of self-regulation are related both to anxiety and IS behaviours points to self-regulation as a viable intervention target for both anxiety and IS behaviours.

Repetitive Behaviours and Restricted Interests in Individuals with Down Syndrome-One Way of Managing Their World?

This paper argues that the repetitive behaviour and restrictive interests (RBRI) displayed by individuals with Down syndrome have mostly positive functions. However, as research has developed from interests in Obsessional Compulsive Disorder or Autistic Spectrum Disorder, unfortunately a view has arisen that RBRI in individuals with Down syndrome are also likely to be pathological. This is particularly the case in adults. The paper reviews: (a) measures employed and the perspectives that have been used; (b) the development in typically developing individuals, those with Down syndrome, and those with other conditions associated with intellectual disability; (c) positive and possible negative effects of RBRI; and (d) the need for more research. The conclusion is that, for their level of development, RBRI are helpful for most individuals with Down syndrome.