Factor Analysis of Restricted and Repetitive Behaviors in Autism Using the Autism Diagnostic Interview-R

The current study examined the factor structure of restricted and repetitive behaviors (RRB) in children with autism. Factor extraction procedures of 12 items from the Autism Diagnostic Interview-Revised (ADI-R) were applied in N = 207 individuals with autism. Two interpretable factors were identified: Factor 1—repetitive sensory motor actions and Factor 2—resistance to change. There was a significant negative correlation between an index of level of adaptive functioning and Factor 1. Intraclass correlations were not significant for either factor in a subset of families with two or more siblings with autism (multiplex). No differences in scores were apparent for either factor when multiplex families and families containing only one affected individual with autism (singleton) were compared. RRB in autism are represented by two distinct factors which may reflect two separate groups within autism. Defining subgroups within autism will allow for reduction of clinical heterogeneity and enhance our ability to dissect the genetic etiology of this complex disorder.     

The pathophysiology of restricted repetitive behavior

Restricted, repetitive behaviors (RRBs) are heterogeneous ranging from stereotypic body movements to rituals to restricted interests. RRBs are most strongly associated with autism but occur in a number of other clinical disorders as well as in typical development. There does not seem to be a category of RRB that is unique or specific to autism and RRB does not seem to be robustly correlated with specific cognitive, sensory or motor abnormalities in autism. Despite its clinical significance, little is known about the pathophysiology of RRB. Both clinical and animal models studies link repetitive behaviors to genetic mutations and a number of specific genetic syndromes have RRBs as part of the clinical phenotype. Genetic risk factors may interact with experiential factors resulting in the extremes in repetitive behavior phenotypic expression that characterize autism. Few studies of individuals with autism have correlated MRI findings and RRBs and no attempt has been made to associate RRB and post-mortem tissue findings. Available clinical and animal models data indicate functional and structural alterations in cortical-basal ganglia circuitry in the expression of RRB, however. Our own studies point to reduced activity of the indirect basal ganglia pathway being associated with high levels of repetitive behavior in an animal model. These findings, if generalizable, suggest specific therapeutic targets. These, and perhaps other, perturbations to cortical basal ganglia circuitry are mediated by specific molecular mechanisms (e.g., altered gene expression) that result in long-term, experience-dependent neuroadaptations that initiate and maintain repetitive behavior. A great deal more research is needed to uncover such mechanisms. Work in areas such as substance abuse, OCD, Tourette syndrome, Parkinson's disease, and dementias promise to provide findings critical for identifying neurobiological mechanisms relevant to RRB in autism. Moreover, basic research in areas such as birdsong, habit formation, and procedural learning may provide additional, much needed clues. Understanding the pathophysioloy of repetitive behavior will be critical to identifying novel therapeutic targets and strategies for individuals with autism.     

Arranging and ordering in autism spectrum disorder: Characteristics,severity, and environmental correlates

Abstract

Background There is a need for a more accurate characterisation of higher level restricted and repetitive behaviour (RRB) in autism spectrum disorder (ASD), including why it might be considered problematic and events associated with its occurrence.

Method We selected one form of higher level RRB—arranging and ordering—that was rated as severe for a large percentage of the population sampled. We interviewed 20 students’ teachers and conducted naturalistic observations for 15 of those students.

Results The characteristics of arranging and ordering varied across, and sometimes within, individuals. Problems associated with compulsive-like^{11 The terms compulsions and compulsive-like behaviour will be used to refer to responses that share topographical similarities with the behaviour of individuals diagnosed with obsessive–compulsive disorder and for the purposes of maintaining consistency with the terminology used in the RBS-R. In particular, compulsive-like behaviour will be used when referring to any one or more of the responses included in the Compulsive Behaviour subscale of this scale.} behaviour also varied, with several unanticipated reported problems. With the exception of attention, social consequences were relatively infrequent.

Conclusions These data highlight the need for research on the assessment and treatment of arranging and ordering and clinical attention to compulsive-like behaviour in ASD. Interviews and naturalistic observations are useful for structuring additional observations and analyses.     

Volumetric magnetic resonance and diffusion tensor imaging of C58/J mice: neural correlates of repetitive behavior

Brain Imaging and Behavior - Restricted, repetitive behavior (RRB) involves sequences of responding with little variability and no obvious function. RRB is diagnostic for autism spectrum disorder...     

Stereotyped behaviours in children with autism spectrum disorders and atypical development as measured by the BPI-01

Objective: As repetitive behaviours in children with autism spectrum disorders (ASDs) can significantly interfere with one's daily functioning, continued research on these behaviours is needed.

Methods: This study examined the occurrence of repetitive motor movements in toddlers (17–37 months) with ASD and atypical development and the relationship between stereotypies and sensory impairment.

Results: Children with ASD (n?=?13) exhibited significantly more repetitive behaviours than the non-ASD group (n?=?12). Greater percentages of endorsement were evident for the ASD group on nearly all items of the Behaviour Problems Inventory-01 (BPI-01) Stereotypy subscale. More repetitive behaviours tended to co-occur with other stereotypies for the ASD group. A moderate correlation was found between stereotypy severity and sensory deficits.

Conclusion: These findings suggest that stereotyped behaviours can be identified at very young ages, negatively affect the behavioural presentation of those with ASDs and should be considered when developing treatment plans.     

Validation of the Repetitive Behavior Scale-Revised in Spanish-Speakers Participants with Autism Spectrum Disorder

Restricted and repetitive behavior (RRB) is one of the two key diagnostic features of autism spectrum disorder (ASD). DSM-5 highlights the importance of severity-based diagnostic modifiers assigned on the basis of intensity of needed supports. Therefore, there is a need for available measures that assess the severity of RRB. The repetitive behavior scale-revised (RBS-R) is probably the most used informant-based rating scale for the assessment of RRB and interests observed in ASD. The present study examined the psychometric properties of the Spanish version of the RBS-R in a sample of 233 participants with ASD, aged 3 to 63 years. Results revealed a six-factor model, good internal consistency, and concurrent-divergent validity. These findings suggest the utility of the Spanish version of RBS-R.     

Autistic adults’ experience of restricted repetitive behaviours

BackgroundRestricted and Repetitive Behaviours (RRB) are a core characteristic of autism, though little is known about autistic people’s lived experience of these phenomena. Research has defined RRB in terms of: 1) a distinction between higher-order and lower-order RRB; as well as 2) a perceived lack of function and 3) a perceived lack of voluntary control.MethodTwelve autistic adults without intellectual disability were interviewed to elucidate an understanding of these three issues from their lived experience.ResultsThematic analysis identified four key themes regarding RRB: Self-regulation; positive impacts; negative impacts and suppression. The distinction between higher-order and lower-order RRB was not reflected in the adults’ lived experience. In addition to having both positive and negative impacts, the expression of RRB for some behaviours in certain contexts was largely, though not wholly, under voluntary control. Perceived negative evaluations from others can result in strategies to minimise the expression of RRB to observers, although suppressing RRB can be stressful with a cost to the individual.ConclusionsThese findings provide insight into the important functions of RRB and both its positive and negative impacts. It indicates that future research should look to help maximise the positive impacts and minimize the negative, and consider the impact suppression of RRB has on mental health and functioning.     

The Repetitive Behavior Scale-Revised: Independent Validation in Individuals with Autism Spectrum Disorders

A key feature of autism is restricted repetitive behavior (RRB). Despite the significance of RRBs, little is known about their phenomenology, assessment, and treatment. The Repetitive Behavior Scale-Revised (RBS-R) is a recently-developed questionnaire that captures the breadth of RRB in autism. To validate the RBS-R in an independent sample, we conducted a survey within the South Carolina Autism Society. A total of 320 caregivers (32%) responded. Factor analysis produced a five-factor solution that was clinically meaningful and statistically sound. The factors were labeled “Ritualistic/Sameness Behavior,” “Stereotypic Behavior,” “Self-injurious Behavior,” “Compulsive Behavior,” and “Restricted Interests.” Measures of internal consistency were high for this solution, and interrater reliability data suggested that the RBS-R performs well in outpatient settings.     

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.

     

A Distinct Three-Factor Structure of Restricted and Repetitive Behaviors in an Epidemiologically Sound Sample of Preschool-Age Children with Autism Spectrum Disorder

Journal of Autism and Developmental Disorders - Prior studies investigating restricted and repetitive behavior (RRB) subtypes within autism spectrum disorder (ASD) have found varied factor...     

Don’t Forget About the Teachers! Parent and Teacher BASC-2 Reports of Children on the DSM-5 Autism Spectrum

ABSTRACT

The new DSM-5 dimensional framework of Autism Spectrum Disorders (ASD) features severity ratings of social communication (SC) and restrictive/repetitive behaviors (RRB) and little research has been conducted since its inception. There has been a recent increase in the administration and adoption of broadband behavior-rating scales by clinicians, to ascertain a summary of the client’s behavior, including use with children on the autism spectrum. One such widely utilized accepted instrument is the Behavior Assessment System for Children, 2nd ed. (BASC-2), a multidimensional measure to assess internalizing and externalizing behaviors as well as adaptive functioning for individuals 2–25 years of age. The current study examined and compared the Parent Rating Scale (PRS) and Teacher Rating Scale (TRS) of the BASC-2 for children on the DSM-5 autism spectrum in order contribute novel information to the BASC-2 literature. Utilizing a sample of 67 children and adolescents with ASD, the PRS and TRS of the BASC-2 were compared using paired sample t-tests to assess for differences in parent- versus teacher-reported behavior patterns. Mean parent ratings for atypicality, functional communication, and withdrawal, and mean teacher ratings for atypicality and withdrawal, were clinically elevated. Mean parent and teacher ratings for adaptability and social skills, and mean teacher ratings for functional communication were in the at-risk range. Parent ratings of adaptability, functional communication, and social skill were significantly more severe than teacher ratings of these same subscales. Implications of these results for the assessment of children and adolescents with ASD are suggested.     

The effect of DSM-5 criteria on externalizing,internalizing, behavioral and adaptive symptoms in children diagnosed with autism

Objective: Diagnostic criteria for autism spectrum disorders (ASDs) are changing with the fifth edition of the Diagnostic and Statistical Manual (DSM-5), which simplifies the diagnostic categories into social/emotional deficits and repetitive and restricted behavior. ASDs have been closely linked to a variety of other disorders, in particular externalizing disorders such as ADHD, and internalizing disorders including anxiety disorders and obsessive compulsive disorder. The present study examines the externalizing, internalizing, behavioral and adaptive symptoms of children with ASD.

Method: Children diagnosed with the DSM-IV who do not meet diagnostic criteria for DSM-5 and were compared to a non-ASD sample and a sample of those who meet the new criteria. Differences were examined between the three experimental groups with respect to internalizing, externalizing, behavioral severity and adaptive behavior.

Results: No significant differences were observed between the DSM-5 and DSM-IV groups with respect to composite and subscale scores on the externalizing, behavior severity index and adaptive behavior domains of the Behavior Assessment System for Children, Second Edition.

Conclusions: Significantly more impairment was evident for both ASD groups compared to the no-ASD group.     

Relationships among Repetitive Behaviors, Sensory Features, and Executive Functions in High Functioning Autism

This study examined the relationship between repetitive behaviors and sensory processing issues in school-aged children with high functioning autism (HFA). Children with HFA (N = 61) were compared to healthy, typical controls (N = 64) to determine the relationship between these behavioral classes and to examine whether executive dysfunction explained any relationship between the variables. Particular types of repetitive behavior (i.e., stereotypy and compulsions) were related to sensory features in autism; however, executive deficits were only correlated with repetitive behavior. This finding suggests that executive dysfunction is not the shared neurocognitive mechanism that accounts for the relationship between restricted, repetitive behaviors and aberrant sensory features in HFA. Group status, younger chronological age, presence of sensory processing issues, and difficulties with behavior regulation predicted the presence of repetitive behaviors in the HFA group.     

Evidence of a Distinct Behavioral Phenotype in Young Boys With Fragile X Syndrome and Autism

ObjectiveHow does the behavioral expression of autism in fragile X syndrome (FXS + Aut) compare with idiopathic autism (iAut)? Although social impairments and restricted, repetitive behaviors are common to these variants of autism, closer examination of these symptom domains may reveal meaningful similarities and differences. To this end, the specific behaviors comprising the social and repetitive behavioral domains in young children with FXS + Aut and iAut were profiled.MethodTwenty-three male subjects 3 to 5 years old with FXS + Aut were matched by age to a group of 38 boys with iAut. Repetitive behavior was assessed using the Repetitive Behavior Scales-Revised. Social behavior was evaluated using Autism Diagnostic Observation Schedule social item severity scores.ResultsRates of stereotypy, self-injury, and sameness behaviors did not differ between groups, whereas compulsive and ritual behavior scores were significantly lower for subjects with FXS + Aut compared with those with iAut. Those with FXS + Aut scored significantly lower (less severe) than the iAut group on five Autism Diagnostic Observation Schedule measurements of social behavior: gaze integration, quality of social overtures, social smile, facial expressions, and response to joint attention.ConclusionsThe behavioral phenotype of FXS + Aut and iAut are most similar with respect to lower-order (motoric) restricted, repetitive behaviors and social approach, but differ in more complex forms of restricted, repetitive behaviors and some social response behaviors. These findings highlight the phenotypic heterogeneity of autism overall and its unique presentation in an etiologically distinct condition.     

TOBY play-pad application to teach children with ASD – A pilot trial

Abstract

Purpose: To investigate use patterns and learning outcomes associated with the use of Therapy Outcomes By You (TOBY. Playpad, an early intervention iPad application.

Methods: Participants were 33 families with a child with an autism spectrum disorder (ASD) aged 16 years or less, and with a diagnosis of autism or pervasive developmental disorder – not otherwise specified, and no secondary diagnoses. Families were provided with TOBY and asked to use it for 4–6 weeks, without further prompting or coaching. Dependent variables included participant use patterns and initial indicators of child progress.

Results: Twenty-three participants engaged extensively with TOBY, being exposed to at least 100 complete learn units and completing between 17% and 100% of the curriculum.

Conclusions: TOBY may make a useful contribution to early intervention programming for children with ASD delivering high rates of appropriate learning opportunities. Further research evaluating the efficacy of TOBY in relation to independent indicators of functioning is warranted.     

Application of the Repetitive Behavior Scale-Revised – Italian version – in preschoolers with autism spectrum disorder

Restricted repetitive and stereotyped patterns of behavior, interests, and activities (RRB) are mandatory features for a diagnosis of Autism Spectrum Disorder (ASD) according to the Diagnostic and Statistical Manual of mental disorders-fifth edition (DSM-5). Despite the strong diagnostic role of RRB, their expressiveness and their relationship with other clinical/demographic features in ASD is not fully elucidated.The Italian version of the Repetitive Behavior Scale-Revised (RBS-R) was applied to a relatively large sample of preschool-aged children with ASD who underwent a comprehensive clinical assessment. The relationship between RRB and sex, age, non-verbal IQ, autism severity, as well as the diagnostic accuracy of the RBS-R were explored.Stereotyped and Ritualistic/Sameness behaviors were the most common RRB in preschoolers with ASD, without widespread differences between males and females. No significant correlations between RRB and chronological age, or non-verbal IQ were detected. The expressiveness of ritualistic/sameness behaviors positively correlated with autism severity, assessed through the Calibrated Severity Score (CSS) derived from the Autism Diagnostic Observation Schedule (ADOS). Receiver Operator Characteristic (ROC) analysis showed high diagnostic accuracy using the Global Rating Score, which represents the judgment of the parents of as the RRB affect the child's life. However, while the Global Rating Score performed well, the remaining subscales did not.This investigation extends the limited research on early pattern and associated features of RRB in young children with ASD. The use of the RBS-R may increase the knowledge of the RRB complexity and variability and in turn improve the diagnostic and therapeutic procedures within the autistic spectrum.     

Influence of a Gluten-free,Casein-free Diet on Behavioral Disturbances in Children and Adolescents Diagnosed with Autism Spectrum Disorder: A 3-month Follow-up Pilot Study

ABSTRACT

Introduction: Diet and dietary interventions have drawn considerable attention in the literature as etiopathogenic factors and therapeutic approaches to Autism Spectrum Disorders (ASD), respectively. The objective of this study was to determine the influence of a gluten-free, casein-free (GFCF) diet on the alterations of behavior in children and adolescents diagnosed with ASD. We also aim to explore the possible association between ASD symptoms and urinary concentrations of beta-casomorphin.

Methods: A total of 28 patients were recruited for this crossover clinical trial. Patients followed a normal diet (including gluten and casein) for three months and a GFCF diet for another three months. The order of the intervention —i.e., beginning with normal diet or with GFCF diet— was determined at random. The subjects were evaluated at three time points: at the onset of the study, after the first diet, and after the second diet. Each evaluation entailed three questionnaires on behavior and autism, a food frequency questionnaire (to determine adherence to the diet) and a determination of concentrations of beta-casomorphin in urine using chromatographic techniques.

Results: No significant behavioral changes were found after a GFCF diet. No association was found between ASD symptoms and urinary concentrations of beta-casomorphin.

Conclusion: A GFCF diet followed for three months do neither show significant changes in behavioral symptoms of autism nor in urine concentrations of beta-casomorphin using chromatographic detection. However, we need further studies including elements of placebo and double-blindness and more sophisticated beta-casomorphin detection techniques to better define subjects who might benefit from these diets.     

Functional Characteristics of Disruptive Behavior in Developmentally Disabled Children with and without Autism

Expanding on Reese et al. [2003], functional behavioral assessment interviews [O’Neill et al., 1997] concerning disruptive behavior were conducted with parents of 23 children with autism (6 females, 17 males, chronological ages [CA] 24–60 months) and 23 controls without autism pair-matched for CA, developmental age and sex. All children exhibited frequent disruptive behavior. The interviews suggested that matched control children’s disruptive behavior typically functioned to gain attention or items, or to escape demands in general. This was also true for girls with autism. For boys with autism, disruptive behavior more often functioned to (a) escape demands that interfere with repetitive behavior, (b) retain access to an item used in repetitive routines, or (c) avoid idiosyncratically aversive sensory stimuli (e.g., ordinary household noises). These results emphasize the importance of considering behavioral characteristics that are associated with sex and specific disorders or syndromes when conducting functional behavioral assessments.David M. Richman is now at the University of Maryland-Baltimore County.     

Association of oligodendrocytes differentiation regulator gene DUSP15 with autism

Objectives: Autism is a pervasive neurodevelopmental disorder with high heritability. Genetic factors play crucial roles in the aetiology of autism. Dual specificity phosphatase 15 (DUSP15) has been recognised as a key regulator gene for oligodendrocytes differentiation. A previous study detected one de novo missense variant (p.Thr107Met) with probable deleterious function in exon 6 of DUSP15 among patients with autism. Therefore, we sequenced this mutation in autistic children and performed an association analysis between DUSP15 polymorphisms and autism.

Methods: We performed a case–control study between 255 children affected with autism and 427 healthy controls. Four tag-single nucleotide polymorphisms (SNPs) were selected. These SNPs and the previously reported mutation in exon 6 of DUSP15 were genotyped via Sanger sequencing.

Results: Our results showed that rs3746599 was significantly associated with autism under allelic, additive and dominant models, respectively (χ^2?=^?9.699, P?=?0.0018; χ^2?=^?16.224, P?=?0.001; χ^2?=^?7.198, P?=?0.007). The association remained significant after Bonferroni correction and permutation tests (n?=?10,000). We did not detect the missense variant p.Thr107Met reported in previous studies. However, a de novo missense variant of DUSP15 (p.Ala56Thr) with a probable disease-causing effect was detected in one autistic child while absent in healthy controls.

Conclusions: Our findings initially suggest that DUSP15 might be a susceptibility gene for autism in Chinese Han population.