Restricted And Repetitive Behaviors Research Articles

Concurrent predictors of behavioral inflexibility in minimally verbal and verbal autistic children.

Behavioral inflexibility (BI) refers to the rigid and inflexible patterns of behaviors that are a core aspect of autism. Few studies have investigated BI in autism separately from other restricted and repetitive behaviors (RRBs). The present study used a relatively new measure, the behavioral inflexibility scale (BIS; Lecavalier, L., Bodfish, J., Harrop, C., Whitten, A., Jones, D., Pritchett, J., Faldowski, R., & Boyd, B. (2020). Autism Research, 13(3), 489-499), to examine the relationship of BI and variables that are both core symptoms in autism as well as symptoms associated with cooccurring mental health conditions, atypical sensory experiences, and adaptive functioning in a sample of 87 children with autism. Additionally, we aimed to understand how these relationships may be related to autistic individuals' verbal status: minimally verbal (MV) or verbal. Results revealed that anxiety, attention deficit/hyperactive, depressive, oppositional defiance problems, and sensory differences were all significantly correlated with BI in the MV group. In contrast, only anxiety, depressive, and oppositional defiance problems were significantly correlated with BI in the verbal group. Linear regression analyses showed that oppositional defiance problems and atypical sensory experiences explained a significant proportion of the variance of BI in the MV group, whereas only depressive problems were significant in the verbal group after accounting for other mental health conditions. Overall, our findings demonstrate that multiple aspects of psychopathology are significantly related to BI and can have broader implications for interventions and mental health care in autistic children.

ASD or OCD? An evidence‐based differentiation of repetitive behaviors

While distinct diagnoses, the behavioral presentation of ritualistic/repetitive behaviors seen in obsessive compulsive disorder (OCD) and autism spectrum disorder (ASD) can present similarly. This results in difficulty with accurate diagnosis and implementation of evidence‐based treatments. OCD is characterized by prolonged and recurrent unwanted thoughts, known as obsessions, which cause a feeling of intense anxiety or distress. As a result, people with OCD perform repetitive behaviors known as compulsions to help alleviate distress. ASD is characterized as a developmental disorder causing persistent challenges associated with social communication, restricted and repetitive behaviors (RRB), and impairment in functioning. While the definitions are distinct, accurate conceptualization is not always clear. The picture can become even more complex with comorbidities. To parse these behaviors apart, we can consider the course of the behavior and assess the function. With better ability to differentiate, we can have a clearer picture of how to support the youth and family.

Longitudinal change in symptom severity in children with ASD: Results from the ELENA cohort.

Autism spectrum disorder (ASD) is a lifelong neurodevelopmental condition and understanding the changes in autism symptoms over time is crucial for tailoring support and interventions. This study therefore aimed to investigate the changes in symptom severity in a large cohort of children with ASD over a three-year follow-up period and identify factors that influence these changes. The study included 575 children diagnosed with ASD, ranging in age from 2 to 12 years, who were assessed at baseline and again 3 years later using the Autism Diagnostic Observational Schedule-2 (ADOS-2). ASD severity changes were investigated using the ADOS calibrated severity score (CSS) scores for total, social affect (SA) and restricted and repetitive behaviors (RRB). Results highlight four distinct patterns: stable high, stable low, increased, and decreased severity. The ADOS CSS total score changed for half of the sample, reflecting an increase in ASD severity for 21.9% and a decrease for 29.1% of children. For the other half, the ADOS CSS score remained stable, either high (34.4%) or low (14.6%). While the majority of previous studies reported stability in ASD severity, our findings revealed significant variability with frequent improvements in SA symptoms whereas RRBs remained stable or worsened. Our findings also showed that an improvement in SA was associated with the youngest group and early diagnosis. However, no clinical or sociodemographic factors were linked to changes in RRB, emphasizing the necessity for RRB-specific therapies. The third six-year follow-up point of the ongoing ELENA cohort study will map the long-term trajectories of the severity of ASD symptoms and their potential risk factors.

Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials: Antidepressants for Restricted and Repetitive Behaviors in Autism Spectrum Disorder.

In previously randomized controlled trials (RCTs) on the efficacy of antidepressants in restricted and repetitive behaviors (RRBs) in autism spectrum disorder (ASD), outcomes overwhelmingly showed no benefits of antidepressants studied in the larger multisite RCTs over placebo. However, the positive effect of antidepressants in the RRBs found in the small preliminary studies requires confirmation in larger trials. We aimed to systematically review the efficacy of antidepressants in the treatment of RRBs in ASD by including RCTs from the SCOPUS, PubMed, Embase, Cochrane Controlled Trials Register, Clinical Trials.gov, and other databases in January 2024. Analyzing data from 609 participants across nine RCTs showed no significant difference in the overall pooled mean-end score for RRBs between antidepressant- and placebo-treated groups [SMD (95% CI) of -0.25 (-0.53, 0.02), I2 = 54%, Tau2 = 0.10, prediction interval = -1.03, 0.53]. In small preliminary studies by one group, the clomipramine-treated group's pooled mean endpoint for obsessive-compulsive symptoms in ASD individuals showed a significantly better outcome than the desipramine-treated group, but in unconfirmed studies. Of the individual antidepressants investigated only clomipramine, and fluvoxamine illustrated some efficacy over placebo in small preliminary studies. These findings need confirmation in larger, multisite randomized controlled trials. There were no significant differences in the overall discontinuation rates or discontinuation due to adverse events between the antidepressant- and placebo-treated groups [RR (95% CI) of 1.30 (0.95, 1.78), I2 = 0%, and 1.33 (0.71, 2.47), I2=0%, respectively]. Common side effects included agitation, appetite disturbance, anorexia, gastrointestinal issues, and sleep disturbance, with no significant differences between the antidepressant and placebo groups. In conclusion, the results regarding the efficacy of antidepressants in the treatment of RRBs in ASD are inconsistent. Since previous evidence found a correlation between attention-deficit hyperactivity disorder (ADHD) symptoms including overactivity and impulsivity, and RRBs, further trials including the use of non-stimulants such as atomoxetine could be conducted.

Characterising repetitive behaviours in children and adolescents with Down syndrome.

Individuals with intellectual disability, including people with Down syndrome (DS), often exhibit restricted and repetitive behaviours (RRBs). However, RRBs have not been deeply characterised in children and adolescents with DS. The study encompassed a cohort of 151 participants aged 4 to 18years with DS. RRBs were assessed utilising the Repetitive Behaviour Scale-Revised. Additionally, data pertaining to cognitive and adaptive functioning, linguistic abilities, sleep patterns and emotional/behavioural issues were gathered. Self-injurious behaviours were reported less frequently whereas parents most commonly endorsed items related to behaviours associated with the need for sameness and ritualistic behaviours. We observed very few gender differences, whereas some age-related differences emerged, with adolescents exhibiting higher scores in items related with higher-level RRBs. The analysis of the association between RRBs and clinical features revealed that RRBs were associated with parent-reported sleep difficulties, as well as with internalising and externalising problems. We also observed a negative correlation with IQ whereas associations with adaptive skills emerged mainly for lower-level RRBs, such as motor stereotypies. Finally, RRBs were negatively associated with linguistic abilities, both expressive and receptive. RRBs in children and adolescents with DS are of significant clinical interest due to their associations with various clinical dimensions. Therefore, psychological and neuropsychiatric assessment should include an accurate evaluation of RRBs for young people with DS.

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 settings

BackgroundBrief 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.MethodIn 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.ResultsStudy 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.LimitationsDue 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.ConclusionsThe 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.

Assessing pragmatic language difficulties using the Revised Children's Communication Checklist-2. Exploratory structural equation modeling and associations with restricted and repetitive behaviors.

In this paper, we investigated the psychometric properties of the Child Communication Checklist-Revised (CCC-R) for the first time with an English-speaking sample. We used a confirmatory application of exploratory structural equation modeling (ESEM) to re-evaluate the CCC-R's psychometric properties. We found strong support for its use as an assessment for pragmatic and structural language. Our second main aim was to explore associations between pragmatic and structural language and restricted and repetitive behaviors (RRBs), two hallmark characteristics of autism. We used the CCC-R and Repetitive Behavior Questionnaire (RBQ-2) to investigate these associations in a diverse non-clinical sample of children, taking a transdiagnostic approach. We intentionally excluded autism and other neurodevelopmental diagnoses to test, (1) the CCC-R in a broad sample and (2) the association between pragmatic language and RRB in children not already selected for that association. The sample comprised two groups of children, one was community sampled (n = 123) and the other (n = 143) included children with non-specific behavioral, emotional and/or cognitive difficulties referred to an assessment unit by schools. We found clear associations between pragmatic language difficulties and RRBs in both groups. Regression analysis showed that pragmatic language was the only significant contributor to RRBs even after Grammatical-Semantic score, age, sex, and socioeconomic status were controlled. The pattern was the same for both recruitment groups. However, the effects were stronger for the school-referred group which also had more pragmatic difficulties, grammatical-semantic difficulties and RRBs. A robust link between pragmatic language and RRBs, established in autism, has continuity across the broader non-clinical population.

Symptom dimensions of resting-state electroencephalographic functional connectivity in autism.

Autism spectrum disorder (ASD) is a common neurodevelopmental disorder characterized by social and communication deficits (SCDs), restricted and repetitive behaviors (RRBs) and fixated interests. Despite its prevalence, development of effective therapy for ASD is hindered by its symptomatic and neurophysiological heterogeneities. To comprehensively explore these heterogeneities, we developed a new analytical framework combining contrastive learning and sparse canonical correlation analysis that identifies symptom-linked resting-state electroencephalographic connectivity dimensions within 392 ASD samples. We present two dimensions with multivariate connectivity basis exhibiting significant correlations with SCD and RRB, confirm their robustness through cross-validation and demonstrate their conceptual generalizability using an independent dataset (n = 222). Specifically, the right inferior parietal lobe is the core region for RRB, while connectivity between the left angular gyrus and the right middle temporal gyrus show key contribution to SCD. These findings provide a promising avenue to parse ASD heterogeneity with high clinical translatability, paving the way for ASD treatment development and precision medicine.

23 Latent Profiles of Children Referred for Possible Autism

Objective:Autism is a neurodevelopmental disorder characterized by impairments in social communication and the presence of restricted and repetitive behaviors (RRBs). Clinical diagnosis of autism is often complicated by heterogeneity in core autism traits and other individual characteristics (e.g., cognition). Previous literature suggests that degree of autism characteristics, cognitive ability, and age contribute to identifying homogenous subgroups of autism, which facilitates prognosis and treatment planning. The present study extends these findings by examining profiles of cognition, age, and autism characteristics (measured by the Autism Diagnostic Observation Schedule, Second Edition [ADOS-2]) in a clinical sample of school-aged children presenting with concern for possible autism. Profiles are also described according to whether children received an autism diagnosis and clinician ratings of emotional/behavioral problems, which have been shown to influence diagnostic clarity when assessing for autism.Participants and Methods:We conducted a retrospective chart review of 188 children (68% male) ages 4-17 years (M=8.9) who were referred for an autism evaluation. Latent profile analysis was conducted using age, ADOS-2 Social Affect (SA) and RRB scores, and verbal and non-verbal intelligence quotients (VIQ/NVIQ). Model fit comparing 2, 3, 4, and 5-class models was assessed using log-likelihood, AIC, BIC, SABIC, entropy, and Lo, Mendell, and Rubin (LMR) and bootstrap likelihood ratio (BLRT) tests. The frequency of clinical autism diagnosis and ADOS-2 emotional/behavioral problems were calculated across profiles in the best-fitting model.Results:The 5-class model demonstrated the best fit. The following characteristics were observed across five profiles: 1) mean age = 9.5 years, Low Average VIQ/NVIQ, and low SA (M=5.2) and RRB (M=0.7) scores; 2) mean age = 7.3 years, Average VIQ/NVIQ, and low SA (M=3.1) and RRB (M=0.8) scores; 3) mean age = 10.1 years, Low Average VIQ/NVIQ, and high SA (M=11.3) and RRB (M=4.2) scores; 4) mean age = 8.8 years, Average VIQ/NVIQ, and moderately high SA (M=9.6) and RRB (M=3.4) scores; and 5) Exceptionally High VIQ, Above Average NVIQ, and comparatively mid-level SA (M=6.6) and RRB (M=3.6) scores. Autism diagnosis and emotional/behavioral problems varied across profiles. Profiles 1 and 2 contained lower diagnosis rates (33% and 10%, respectively). Profiles 3 and 4 contained the highest diagnosis rates (97% in both), followed by profile 5 (75%). In terms of emotional/behavioral problems, Profile 2 exhibited the highest overactivity (56%). Profile 3 demonstrated the highest rate of tantrums/disruptive behaviors (20%).Conclusions:Findings revealed distinct profiles of IQ and autism characteristics within a clinical sample of school-aged children referred for possible autism. Children with the highest scoring ADOS profile were older compared to other profiles. Higher and lower scoring ADOS profiles exhibited both lower and higher IQ scores. Descriptive analyses suggested that the frequency of autism diagnosis was notably higher in moderate and high-scoring ADOS profiles; however, emotional/behavioral problems were salient in only one low and one high-scoring ADOS profile. The findings suggest that higher-scoring ADOS profiles consistently demonstrated high autism diagnosis rates but varied across IQ and behavioral problems. These results have implications for interpreting these characteristics during clinical autism diagnosis.

Barriers to an autistic identity: How RRBs may contribute to the underdiagnosis of females

BackgroundAutistic females are frequently underdiagnosed, misdiagnosed, and/or diagnosed later in life. Restricted and Repetitive Behaviors (RRBs) are increasingly critical for diagnosis and yet are commonly rated lower in females. Whether this reflects genuinely lower levels of these traits, or if female-typical RRBs have a different phenotypic presentation that may not register on current quantitative measurement tools is unclear. MethodsTwenty-one autistic females and 21 autistic males matched on chronological age and FSIQ completed the AQ, ADOS-2, and ADI-R. Items from the ADOS-2 and ADI-R were selected that were relevant to the four area s of restricted and repetitive behavior in the DSM-5 diagnostic criteria of autism. Using a mixed-methods analytical approach, scores and comments on these measures were compared between sexes to better characterize RRBs in autistic females. ResultsThere were no sex differences on the AQ, which broadly assesses autistic traits. When analyzed by the four DSM-5 RRB criteria, there were no sex differences on the ADI-R when using traditional algorithm scoring that narrows questions down to those that are more sensitive and specific in capturing autism in research samples with a high proportion of males. When incorporating additional items relevant to the DSM-5 to identify sex differences in a broader pool of items, females scored higher on stereotyped movements and speech. Females also engaged in more sensory behaviors during the ADOS-2. Qualitative analyses indicated that females were more likely to engage in stereotyped body rocking and spinning, stereotyped behaviors when anxious, to show major reactions to changes, repetitive language including listing and counting, and sensory behaviors, especially in the tactile domain. ConclusionExploratory findings highlight sex differences in RRBs that may help enhance diagnostic clarity for females. Higher tactile sensory behaviors in females suggests there may be increased diagnostic sensitivity for females with the updated DSM-5 that now includes sensory components as part of the diagnostic criteria.

Metabolomics and transcriptomics analysis of prefrontal cortex in the Pax2 neuron-specific deletion mice

Restricted and repetitive behaviors (RRBs) are one of the characteristics of various neuropsychiatric disorders with complex and diverse molecular mechanisms. Repetitive self-grooming behavior is one of the manifestations of RRBs in humans and rodents. Research on the neural mechanism of repetitive self-grooming behavior is expected to reveal the underlying logic of the occurrence of RRBs. Pax2 is an important member of the paired-box transcription factor family. It is expressed in different regions of the developing central nervous system. Our previous study showed that Pax2 heterozygous gene knockout mice (Pax2+/− KO mice) exhibit significantly increased self-grooming, which suggests that the Pax2 gene is involved in the control of self-grooming behavior, but the molecular mechanism is still unclear. In this study, we further constructed the Pax2 neuron-specific deletion mice (Nestin-Pax2 mice). Targeted metabolomics and transcriptomics techniques was used to analyze. The results showed that there is an excitatory/inhibitory imbalance of the neurotransmitter system and the Arc gene was significantly up-regulated in the prefrontal cortex (PFC) of Nestin-Pax2 mice. This study suggests that the potential regulatory mechanism of the increased repetitive self-grooming behavior in Pax2 gene deletion mice is that the deletion of the Pax2 gene affects the expression of Arc in the PFC, leading to impaired synaptic plasticity and excitatory/inhibitory imbalance, and participating in the occurrence of repetitive self-grooming behavior.

Sociocultural factors associated with detection of autism among culturally and linguistically diverse communities in Australia

BackgroundThe age at which parents or caregivers first develop concerns about their child’s development has significant implications on formal diagnosis and intervention. This study aims to determine the sociocultural factors that are associated with the age and type of first concern reported by parents of autistic children among culturally and linguistically diverse (CALD) communities in Australia. We also assessed whether sociocultural factors predict autism traits measured in terms of social affect (SA), restricted and repetitive behaviours (RRB), and calibrated severity scores (CSS).MethodsThis study is a secondary data analysis of the data collected from six Autism Specific Early Learning and Care Centres (ASELCCs) as part of the Autism Co-operative Research Centre (CRC) program between 2015 and 2019. Data analysed in this study included a family history questionnaire with sociodemographic and sociocultural information, parent-reported age and type of first concern, and clinician/researcher administered Autism Diagnostic Observation Schedule - Second Edition (ADOS-2) which includes standardised domain-wise scores of social affect (SA) and restricted and repetitive behaviours (RRB) as well as calibrated severity scores (CSS), a measure of severity of autism. Primary analysis included multivariable linear regression models to examine the predictive influence of sociodemographic and sociocultural factors on the dependant variables of age of concern (AOC) and the autism traits (SA, RRB, and CSS).ResultsThe mean AOC in the sample was 18.18 months and the most common concerns were speech/language delay, limited social interaction, and hyperactivity/behavioural changes. The multivariable linear regression models showed factors such as increase in age of child, those from a CALD background, annual family income, sibling’s autism diagnosis, and developmental concerns to be significantly associated with parental AOC. Additionally, we also found that increase in child’s age and CALD status to be significant predictors of autism trait (RRB) and severity measured in terms of the CSS score. Further, females (compared to males) were associated with higher difficulties with social communication and interaction skills.ConclusionUnderstanding key factors that contribute to early identification of autism can help tailor awareness programs for parents and caregivers, whilst also informing the development of services focused on serving all CALD communities.

Cell-type-specific disruption of cortico-striatal circuitry drives repetitive patterns of behavior in fragile X syndrome model mice

Individuals with fragile X syndrome (FXS) are frequently diagnosed with autism spectrum disorder (ASD), including increased risk for restricted and repetitive behaviors (RRBs). Consistent with observations in humans, FXS model mice display distinct RRBs and hyperactivity that are consistent with dysfunctional cortico-striatal circuits, an area relatively unexplored in FXS. Using a multidisciplinary approach, we dissect the contribution of two populations of striatal medium spiny neurons (SPNs) in the expression of RRBs in FXS model mice. Here, we report that dysregulated protein synthesis at cortico-striatal synapses is a molecular culprit of the synaptic and ASD-associated motor phenotypes displayed by FXS model mice. Cell-type-specific translational profiling of the FXS mouse striatum reveals differentially translated mRNAs, providing critical information concerning potential therapeutic targets. Our findings uncover a cell-type-specific impact of the loss of fragile X messenger ribonucleoprotein (FMRP) on translation and the sequence of neuronal events in the striatum that drive RRBs in FXS.

Impact of sleep disorders on behavioral issues in preschoolers with autism spectrum disorder.

Sleep disorders are one of the most common problems in children with Autism Spectrum Disorder (ASD). However, they often tend to be underdiagnosed and incorrectly treated in clinical practice. This study aims to identify sleep disorders in preschool children with ASD and to explore their relationship with the core symptoms of autism, the child's developmental and cognitive level as well as the psychiatric comorbidities. We recruited 163 preschool children with a diagnosis of ASD. The Children's Sleep Habits Questionnaire (CSHQ) assessed sleep conditions. Multiple standardized tests were used to evaluate intellectual abilities, the presence of repetitive behaviors (through the Repetitive Behavior Scale-Revised), as well as the emotional-behavioral problems and the psychiatric comorbidities (through the Child Behavior Checklist -CBCL 11/2-5). The results showed that poor disorders had consistently higher scores in all areas assessed by the CSHQ and on the CBCL across all domains. The correlational analysis showed that severe sleep disorders were associated with higher scores in internalizing, externalizing, and total problems at the CBCL syndromic scales, and in all DSM-oriented CBCL subscales. Moreover, we found that the association between sleep disorders and restricted and repetitive behaviors (RRBs) is explained by the anxiety-related symptoms. Based on these findings, the study recommends that screening for sleep problems followed by early intervention should constitute a routine part of clinical practice for children with ASD.

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.

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.

Associations between the pupil light reflex and the broader autism phenotype in children and adults.

The pupil light reflex (PLR), a marker of neuronal response to light, is a well-studied index of autonomic functioning. Studies have found that autistic children and adults have slower and weaker PLR responses compared to non-autistic peers, suggesting lower autonomic control. Altered autonomic control has also been associated with increased sensory difficulties in autistic children. With autistic traits varying in the general population, recent studies have begun to examine similar questions in non-autistic individuals. The current study looked at the PLR in relation to individual differences in autistic traits in non-autistic children and adults, asking how differences in the PLR could lead to variation in autistic traits, and how this might change across development. Children and adults completed a PLR task as a measure of sensitivity to light and autonomic response. Results showed that, in adults, increased levels of restricted and repetitive behaviors (RRB) were associated with a weaker and slower PLR. However, in children, PLR responses were not associated with autistic traits. Differences in PLR were also found across age groups, with adults showing smaller baseline pupil diameter and stronger PLR constriction as compared with children. The current study expanded on past work to examine the PLR and autistic traits in non-autistic children and adults, and the relevance of these findings to sensory processing difficulties is discussed. Future studies should continue to examine the neural pathways that might underlie the links between sensory processing and challenging behaviors.

Parent-rated anxiety in autistic adolescents and young adults: Concurrent links to autism traits and chronic sleep problems

BackgroundAnxiety is prevalent among autistic individuals, but less is known about the different anxiety problems autistic adolescents and young adults experience and the main behavioral manifestations of their anxiety. This study investigated these issues and the relation between the overall level of anxiety and a range of factors in autistic adolescents and young adults, including autism traits, challenging behaviors, adaptive behavior, sleep problems, and gastrointestinal issues. Method66 parents of autistic adolescents and young adults completed an interview and responded to questionnaires on their children’s anxiety, autism traits, sensory processing, challenging behaviors, adaptive behavior, and medical issues. ResultsThe most frequently parent-endorsed moderate and severe anxiety problems were related to social situations, new situations, upcoming events, loud noises, and changes in routine. In contrast, parents were least likely to endorse anxiety problems related to being separated from others, being noticed, or being late. Regarding anxiety-related behaviors, parents frequently endorsed avoidance, requiring constant reassurance, performing repetitive behaviors, shutting down, and overreacting to changes. Individuals with more severe social cognition difficulties, restricted and repetitive behaviors (RRBs), and chronic sleep problems demonstrated elevated levels of anxiety. Chronic sleep problems emerged as the primary concurrent predictor of anxiety in autistic adolescents and young adults and mediated the association between RRBs and anxiety. ConclusionsFuture anxiety treatment should consider targeting sleep problems simultaneously for autistic adolescents and young adults.

Dimensional Assessment of Restricted and Repetitive Behaviors: Development and Preliminary Validation of a New Measure

This study aimed to provide initial validation of the Dimensional Assessment of Restricted and Repetitive Behaviors (DARB), a new parent-report measure designed to capture the full range of key restricted and repetitive behaviors (RRB) subdomains. Parents of 1,892 children and adolescents with autism spectrum disorder (mean [SD] age= 10.81 [4.14] years) recruited from the SPARK (Simons Foundation Powering Autism Research for Knowledge) research match completed the DARB, several existing RRB instruments, and measures of social and communication impairments and anxiety. A subsample of 450 parents completed the DARB after 2 weeks to evaluate the test-retest stability. Exploratory graph analysis conducted in the exploratory subsample identified 8 dimensions that were aligned with hypothesized RRB subdomains: repetitive sensory motor behaviors, insistence on sameness, restricted interests, unusual interests, sensory sensitivity, self-injurious behaviors, obsessions and compulsive behaviors, and repetitive language. The confirmatory application of the exploratory structural equation modeling conducted in the confirmatory subsample showed that the derived factor structure had a good fit to the data. Derived factors had excellent reliability, convergent and divergent validity, and very strong test-retest stability and showed a distinct pattern of associations with key demographic, cognitive and clinical correlates. The DARB will be useful in a variety of research and clinical contexts considering the prominence and clinical impact of RRB in autism spectrum disorder. Strong preliminary evidence indicates that the new scale is comprehensive and captures a wide range of distinct RRB subdomains not simultaneously captured by any of the existing instruments.

Additive or Interactive Associations of Food Allergies with Glutathione S-Transferase Genes in Relation to ASD and ASD Severity in Jamaican Children.

To investigate additive and interactive associations of food allergies with three glutathione S-transferase (GST) genes in relation to ASD and ASD severity in Jamaican children. Using data from 344 1:1 age- and sex-matched ASD cases and typically developing controls, we assessed additive and interactive associations of food allergies with polymorphisms in GST genes (GSTM1, GSTP1 and GSTT1) in relation to ASD by applying conditional logistic regression models, and in relation to ASD severity in ASD cases as measured by the Autism Diagnostic Observation Schedule-2nd Edition (ADOS-2) total and domains specific comparison scores (CSs) by fitting general linear models. Although food allergies and GST genes were not associated with ASD, ASD cases allergic to non-dairy food had higher mean ADOS-2 Restricted and Repetitive Behaviors (RRB) CS (8.8 vs. 8.0, P = 0.04). In addition, allergy to dairy was associated with higher mean RRB CS only among ASD cases with GSTT1 DD genotype (9.9 vs. 7.8, P < 0.01, interaction P = 0.01), and GSTP1 Val/Val genotype under a recessive genetic model (9.8 vs. 7.8, P = 0.02, interaction P = 0.06). Our findings are consistent with the role for GST genes in ASD and food allergies, though require replication in other populations.