Repetitive behaviours, anxiety and sensory problems in children with autism and correlates of anxiety in their parents

Repetitive and restricted behaviours have been considered as a core symptom of autism since the first descriptions provided by Leo Kanner (Kanner, 1943) and Hans Asperger (Asperger, 1944), and this view has been supported through all the incarnations of international diagnostic systems. However, when compared with other core features: problems in communication and problems in reciprocal social interaction, repetitive behaviours have been relatively neglected in terms of research. In particular, little is known about the triggers for repetitive behaviours and what functions they might serve for individuals with autism. Early theoretical accounts of autism proposed that sensory problems and anxiety are the key triggers for repetitive behaviours. Research in the field of developmental psychology has also demonstrated that in very young children, repetitive behaviours serve the function of constraining sensory unpredictability and warding of anxiety and this relationship has also been found in individuals with Obsessive Compulsive Disorder, a condition defined by anxiety and ritualism. However, the three way relationship between repetitive behaviours, sensory problems and anxiety has not been explored in the autism literature before. The main aim of the thesis (Part 1) was to explore this relationship in children with autism. In addition to this main focus, the work of the thesis also included a study of the mothers of the same children (Part 2), investigating mothers‘ own anxiety, sensory correlates of this anxiety and other factors. The main effects of autism are on the individual who is on the autism spectrum, however, impact is also felt by families. Parents of children with autism have been found to have higher prevalence of affective disorders when compared to both parents of typically developing children and parents of children with other disabilities. The second main aim of the thesis was to explore correlates of anxiety in mothers of children with autism. In Part 1, a series of studies are reported using questionnaire data to investigate repetitive behaviours (RRBs), anxiety and sensory problems in children with autism. Part 2, focused on anxiety in the mothers of these children and correlates of their anxiety. The first empirical chapter (Chapter 3) examined RRBs in children with and without autism and validated the Repetitive Behaviour Questionnaire-2 (RBQ-2; Leekam et al., 2007) for the first time with children with autism. Results indicated that the RBQ-2 provides a highly reliable measure of repetitive behaviours for children with autism aged from 2 to 17 years. Factor analysis revealed that a two-factor structure with the repetitive motor and sensory behaviour (RSM) factor and the insistence on sameness (IS) factor best represented the data. Internal consistency was high for both the total RBQ-2 scale and for each RSM and IS subscale separately. This chapter also explored moderators of repetitive behaviours in children and adolescents with autism and found that while RSM behaviours were negatively associated with lower chronological age, and lower expressive language levels, IS behaviours were not. Further analysis was conducted using a secondary dataset from a longitudinal study of RRBs in typically developing children at age 15, 24 and 72 months old. Results showed that IS and RSM behaviours represent relatively independent classes of behaviours in developmental terms. The second empirical chapter (Chapter 4) examined anxiety in children with autism and provided validation for the school age and preschool version of the Spence Anxiety Scales. Using this scale it was found that as many as 49% of children with autism met the criteria for elevated overall anxiety and that separation anxiety and physical injury fears were the most prevalent anxiety subtypes. Good agreement on total anxiety scores between children‘s and parents‘ reports was found. Analysis on the mediators of anxiety suggested that anxiety was not associated with chronological age, impairments in communication and social interaction, and expressive language levels. The third empirical chapter (Chapter 5) provided evidence that sensory problems in children and adolescents with autism are both multisensory and multimodal in nature. More precisely, only 2 children had problems in a single sensory modality while on the other hand, 40% of children had problems simultaneously across all five primary sensory modalities. Almost 91% of children and adolescents showed mixed types of sensory modulation problems, with 65.3% of children having problems in all four sensory quadrants (sensory hyper- and hypo-sensitivity, seeking, and avoidance). This chapter also explored the mutual relationship between the four sensory subscale (quadrants) of the Sensory Profile. Results indicated that children and adolescents with autism fluctuate between the states of hypo- and hyper-responsiveness; that avoidance behaviours are compensatory strategies related to being over-stimulated, and that seeking behaviours are more related to being over-stimulated rather than hypo-stimulated. The final chapter in Part 1, Chapter 6, examined the interrelations between RRB, sensory problems and anxiety. Results showed that both insistence on sameness (IS) and repetitive motor (RM) behaviours were associated with sensory problems. However, only IS behaviours were associated with anxiety while RM behaviours were not. Meditation analyses models showed that sensory sensitivity and anxiety were reinforcing each other in the relationship with IS behaviours. The two chapters in Part 2 examined the frequency and correlates of anxiety in mothers of children with autism. Findings from these two chapters (Chapters 8 and 9) suggested that anxiety is very prevalent among mothers of children with autism with 46% of mothers meeting the cut-off criteria for clinically significant anxiety. For the first time, sensory problems in mothers were examined, and were also found to be very prevalent in mothers, appearing in 60% per cent of mothers. The frequency of sensory features in mothers was correlated with the frequency of sensory features in their children. Further analysis suggested that higher levels of sensory over-sensitivity, higher levels of intolerance of uncertainty, and the dominant use of escape-avoidance coping style contributed to anxiety levels in mothers. Furthermore, it was found that sensory sensitivity in mothers was related to their higher use of escape-avoidant coping strategy and the mediation analysis suggested that sensory sensitivity, escape-avoidance coping and anxiety reinforced each other. The importance of these findings for future theoretical and clinical work is considered in detail in the general discussion chapter (Chapter 10)

Assessing subtypes of restricted and repetitive behaviour using the Adult Repetitive Behaviour Questionnaire-2 in autistic adults

Background The majority of previous research into restricted and repetitive behaviours (RRBs) has focussed on children, partly due to a lack of suitable measures for RRBs in adults. This study aimed to explore the psychometric properties of the Adult Repetitive Behaviour Questionnaire-2 (RBQ-2A) in a large sample of autistic adults using a self-report questionnaire method. Methods The RBQ-2A and Autism-Spectrum Quotient (AQ) were administered online. Data from 275 autistic adults aged 18–66 (M = 36.56, SD = 12.24; 100 men and 171 women) were analysed using polychoric principal components analysis (PCA). Reliability and validity were assessed using Cronbach’s alpha and correlation analyses. Results Background The majority of previous research into restricted and repetitive behaviours (RRBs) has focussed on children, partly due to a lack of suitable measures for RRBs in adults. This study aimed to explore the psychometric properties of the Adult Repetitive Behaviour Questionnaire-2 (RBQ-2A) in a large sample of autistic adults using a self-report questionnaire method. Methods The RBQ-2A and Autism-Spectrum Quotient (AQ) were administered online. Data from 275 autistic adults aged 18–66 (M = 36.56, SD = 12.24; 100 men and 171 women) were analysed using polychoric principal components analysis (PCA). Reliability and validity were assessed using Cronbach’s alpha and correlation analyses. Result

Restricted and repetitive behaviors in autism spectrum disorders: A review of research in the last decade

Restricted and repetitive behaviors (RRBs) are a core feature of autism spectrum disorders. They constitute a major barrier to learning and social adaptation, but research on their definition, cause, and capacity for change has been relatively neglected. The last decade of research has brought new measurement techniques that have improved the description of RRBs. Research has also identified distinctive subtypes of RRBs in autism spectrum disorders. Research on potential causal origins and immediate triggers for RRBs is still at an early stage. However, promising new ideas and evidence are emerging from neurobiology and developmental psychology that identify neural adaptation, lack of environmental stimulation, arousal, and adaptive functions as key factors for the onset and maintenance of RRBs. Further research is needed to understand how these factors interact with each other to create and sustain atypical levels of RRB. The literature indicates that RRBs have the potential to spontaneously reduce across time, and this is enhanced for those with increased age and cognitive and language ability. Research on interventions is sparse. Pharmacological treatments can be helpful in some children but have adverse side effects. Behavioral intervention methods provide the better intervention option with positive effects, but a more systematic and targeted approach is urgently needed. Evidence suggests that we will learn best from the last decade of research by taking a developmental perspective, by directing future research toward subtypes of RRBs, and by implementing early intervention targeted to improve RRBs before these behaviors become entrenched

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; M age = 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

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

Relations among restricted and repetitive behaviors, anxiety and sensory features in children with autism spectrum disorders

The purpose of this study was to explore how atypical reactions to sensory stimuli contribute to the relation between restricted and repetitive behaviors and anxiety in children with autism spectrum disorders (ASD). In Study 1, factor analysis of restricted and repetitive behaviors was carried out using the Repetitive Behavior Questionnaire-2 (RBQ-2), completed by 120 parents of 2- to 17-year-olds with ASD. Two subtypes resulted: repetitive sensory and motor behaviors, and insistence on sameness, accounting for 40% of the variance. This two-factor solution was retained even when the sensory items of the RBQ-2 were removed. In Study 2, 49 of the same parents also completed the Spence Anxiety Scales and the Sensory Profile. The insistence on sameness factor was significantly associated with anxiety while the repetitive motor behaviors factor was not. The relation between anxiety and insistence on sameness was mediated by sensory avoiding and to a lesser extent by sensory sensitivity. Implications for arousal explanations of ASD and for clinical practice are discussed

Deconstructing the repetitive behaviour phenotype in Autism Spectrum Disorder 1 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

Understanding Restricted and Repetitive Behaviors in Autism: Linking Taxonomy to Genetics

The current project aims to conduct the largest ever investigation investigate the genetic architecture of the fine-grained domains of restricted and repetitive behaviors through genome-wide association studies (GWAS) and analysis of de novo protein coding mutations