Biopsychological correlates of repetitive and restricted behaviors in autism spectrum disorders

Characterising repetitive behaviours in children and adolescents with Down syndrome

BACKGROUND

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.

METHOD

The study encompassed a cohort of 151 participants aged 4 to 18 years 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.

RESULTS

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.

CONCLUSIONS

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.

Iron Deficiency and Sleep/Wake Behaviors: A Scoping Review of Clinical Practice Guidelines-How to Overcome the Current Conundrum?

Current evidence suggests that iron deficiency (ID) plays a key role in the pathogenesis of conditions presenting with restlessness such as attention deficit hyperactivity disorder (ADHD) and restless legs syndrome (RLS). In clinical practice, ID and iron supplementation are not routinely considered in the diagnostic work-up and/or as a treatment option in such conditions. Therefore, we conducted a scoping literature review of ID guidelines. Of the 58 guidelines included, only 9 included RLS, and 3 included ADHD. Ferritin was the most frequently cited biomarker, though cutoff values varied between guidelines and depending on additional factors such as age, sex, and comorbidities. Recommendations surrounding measurable iron biomarkers and cutoff values varied between guidelines; moreover, despite capturing the role of inflammation as a concept, most guidelines often did not include recommendations for how to assess this. This lack of harmonization on the interpretation of iron and inflammation biomarkers raises questions about the applicability of current guidelines in clinical practice. Further, the majority of ID guidelines in this review did not include the ID-associated disorders, ADHD and RLS. As ID can be associated with altered movement patterns, a novel consensus is needed for investigating and interpreting iron status in the context of different clinical phenotypes.

Identifying Autistic-Like Symptoms in Children with ADHD: A Comparative Study Using ADOS-2

Purpose

Recent literature has focused attention on the presence of autistic-like symptoms in children with Attention Deficit/Hyperactivity Disorder (ADHD), who often exhibit social difficulties, posing challenges for a distinct clinical diagnosis. The current study aimed to identify the specific pattern of autistic symptoms in subjects with ADHD or Autistic Spectrum Disorder (ASD), examining similarities or differences at both the domain and individual item levels.

Patients and Methods

In this study, we enrolled 43 school-age children divided into the following: the ADHD group (n=25) consisted of children initially referred for ASD symptoms but subsequently clinically diagnosed with ADHD, and the ASD group consisted of 18 children with ASD. We used the Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2), to examine relative differences in the presence of symptoms such as deficits in communication and social interaction, and restricted and repetitive behaviors in these two groups. Comparison between groups was conducted to explore differences in IQ, age, ADOS-2 domains, and externalizing and internalizing problems among the groups.

Results

We found significant differences between the groups when comparing summary scores of ADOS-2 domains (Social Affect, Restricted and Repetitive Behavior, and Total Score). Interestingly, at the individual item level, the ADHD group exhibited a similar level of atypical behaviors compared to the ASD group in two items related to the social-communication area: "Pointing" and "Gestures". Additionally, the frequencies of "Stereotyped/idiosyncratic words or phrases", "Mannerisms", and "Repetitive interests and behaviors" also showed similarities between groups.

Conclusion

These findings indicate the importance of exploring and developing potential transdiagnostic domains that could be targeted for treatments specifically designed for children with ADHD.

Changes in Challenging Behaviors Accompanying Transition to a New Facility in Individuals with Intellectual Disabilities

Challenging behavior (CB), the most common example being extreme self-injurious or aggressive/destructive behavior, is often observed as a major behavior issue in individuals with severe intellectual disabilities. This study investigated how CB changed among residents of a facility for people with disabilities before and after it was restructured from a traditional format single room shared by two to three individuals with approximately 20 residents lived together to a format featuring private areas with two rooms per resident and a unitcare system. Twenty-one residents of Care Home A, which was rebuilt in the new care format, were selected. Care staff completed a questionnaire one month before, one month after, and six months after residents moved to the new facility. Scores were compared among each time point. The results revealed significant reductions in residents' aggressive, stereotyped, and targeted behaviors, such as hitting their own head and fecal smearing. The major features of the restructured facility were a living space consisting of two private rooms per resident and a shift to unit care for the entire ward. These new features enabled residents to reduce destructive stimuli and made it easier to understand what to do in each private room.

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.

Restricted and repetitive behaviors and association with cognition and adaptive functioning in children with autism spectrum disorder in Singapore

Background

One of the core features of autism spectrum disorder (ASD) is restricted, repetitive patterns of behavior, interests and activities (RRBs). RRBs are known to adversely affect cognition and adaptive functioning. We explored the relationship of RRBs with cognition and adaptive functioning in children with ASD in an Asian setting.

Methods

This cross-sectional study was conducted at a tertiary developmental pediatrics center in Singapore from September 2019 to October 2021. Parent-child dyads (parents and their children ≤7 years old diagnosed with ASD) were recruited. Parents completed the Repetitive Behavior Questionnaire-2 (RBQ-2), which reports total score and two subscales - Motor/Sensory Behaviors (RBQ-2 MS) and Rigidity/Routines/Preoccupation with Restricted Interests (RBQ-2 RRPRI). Standardized assessments included Mullen Scales of Early Learning (MSEL) and Vineland Adaptive Behavior Scales (VABS-II). Data analysis utilized descriptive statistics and Pearson's correlation.

Results

Parents of 113 children [75.2% male, mean (SD) age 5.0 (1.2) years] participated. Median (IQR) RBQ-2 score was 29.0 (11.0). Significant negative correlations (adjusted for age, gender and family history of ASD) were observed for total RBQ-2 scores with MSEL ELC scores (r = -0.248, n = 101, p = 0.014) and VABS-II ABC scores (r = -0.281, n = 88, p = 0.009). Specifically, these correlations of fair strength were seen only with the RBQ-2 MS subscale for both ELC (r = -0.321, n = 101, p = 0.001) and ABC (r = -0.3478, n = 88, p = 0.001).

Conclusion

In children with ASD, severity of RRBs correlated with adverse cognition and adaptive functioning measures in our study, consistent with Western literature. While our study does not show causality, it adds to literature serving as a foundation for further research for both clinicians and researchers to target RRBs in improving outcomes with children in ASD.

Associations of emotional/behavioral problems with accelerometer-measured sedentary behavior, physical activity and step counts in children with autism spectrum disorder

Background

The evidence for associations of emotional/behavioral status with sedentary behavior (SB), physical activity (PA) and step counts is scarce in children with autism spectrum disorder (ASD). Also, ASD-related deficiencies may affect actual levels of PA. We aimed to describe accelerometer-measured SB, PA and step counts in children with ASD, and to examine the associations of emotional/behavioral problems with SB, PA and step counts after assessing associations between accelerometer-measured SB, PA and step counts and ASD-related deficiencies.

Methods

A total of 93 ASD children, aged 6-9 years, were recruited from the Center for Child and Adolescent Psychology and Behavioral Development of Sun Yat-sen University in Guangzhou, China. Participants wore an accelerometer for seven consecutive days. Of the original 93, 78 participants' accelerometer-measured valid PA were obtained, and the data were shown as time spent in SB, light, moderate, moderate-to-vigorous and vigorous PA, and step counts. Participants' emotional/behavioral problems were assessed via the Strengths and Difficulties Questionnaire (SDQ), and anxiety symptoms were evaluated by the Screen for Child Anxiety Related Emotional Disorders (SCARED). ASD-associated deficiencies include restricted repetitive behaviors (Repetitive Behavior Scale-Revised), poor social competence (Social Responsiveness Scale Second Edition) and motor development restrictions (Developmental Coordination Disorder Questionnaire).

Results

Of the 78 participants, daily vigorous PA (VPA) and moderate-to-vigorous PA (MVPA) averaged 15.62 and 51.95 min, respectively. After adjustment for covariates, SDQ emotional symptoms (β = -0.060, p = 0.028) were inversely associated with the average daily minutes in VPA. Meanwhile, SDQ emotional symptoms (β = -0.033, p = 0.016) were inversely associated with the average daily MVPA minutes in the crude model. After adjustment for covariates, SCARED somatic/panic (β = -0.007, p = 0.040) and generalized anxiety (β = -0.025, p = 0.014) were negatively associated with the average daily VPA minutes; SCARED total anxiety (β = -0.006, p = 0.029) was conversely associated with daily MVPA duration. After adjustment for covariates, no significant associations between accelerometer-measured SB, PA and step counts and ASD-related deficiencies were found (p > 0.05).

Conclusions

Accelerometer-measured SB, PA and step counts showed no associations with ASD-related deficiencies. On this basis, we further found that the emotional symptoms were inversely associated with VPA and MVPA. These results emphasize the importance of VPA and MVPA in children with ASD. The longitudinally investigations on the directionality of these associations between emotional symptoms with VPA and MVPA are needed in the future.

A machine learning-based diagnostic model for children with autism spectrum disorders complicated with intellectual disability

Background

Early detection of children with autism spectrum disorder (ASD) and comorbid intellectual disability (ID) can help in individualized intervention. Appropriate assessment and diagnostic tools are lacking in primary care. This study aims to explore the applicability of machine learning (ML) methods in diagnosing ASD comorbid ID compared with traditional regression models.

Method

From January 2017 to December 2021, 241 children with ASD, with an average age of 6.41 ± 1.96, diagnosed in the Developmental Behavior Department of the Children's Hospital Affiliated with the Medical College of Zhejiang University were included in the analysis. This study trained the traditional diagnostic models of Logistic regression (LR), Support Vector Machine (SVM), and two ensemble learning algorithms [Random Forest (RF) and XGBoost]. Socio-demographic and behavioral observation data were used to distinguish whether autistic children had combined ID. The hyperparameters adjustment uses grid search and 10-fold validation. The Boruta method is used to select variables. The model's performance was evaluated using discrimination, calibration, and decision curve analysis (DCA).

Result

Among 241 autistic children, 98 (40.66%) were ASD comorbid ID. The four diagnostic models can better distinguish whether autistic children are complicated with ID, and the accuracy of SVM is the highest (0.836); SVM and XGBoost have better accuracy (0.800, 0.838); LR has the best sensitivity (0.939), followed by SVM (0.952). Regarding specificity, SVM, RF, and XGBoost performed significantly higher than LR (0.355). The AUC of ML (SVM, 0.835 [95% CI: 0.747-0.944]; RF, 0.829 [95% CI: 0.738-0.920]; XGBoost, 0.845 [95% CI: 0.734-0.937]) is not different from traditional LR (0.858 [95% CI: 0.770-0.944]). Only SVM observed a good calibration degree. Regarding DCA, LR, and SVM have higher benefits in a wider threshold range.

Conclusion

Compared to the traditional regression model, ML model based on socio-demographic and behavioral observation data, especially SVM, has a better ability to distinguish whether autistic children are combined with ID.

A Personalized Multidisciplinary Approach to Evaluating and Treating Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder without a known cure. Current standard-of-care treatments focus on addressing core symptoms directly but have provided limited benefits. In many cases, individuals with ASD have abnormalities in multiple organs, including the brain, immune and gastrointestinal system, and multiple physiological systems including redox and metabolic systems. Additionally, multiple aspects of the environment can adversely affect children with ASD including the sensory environment, psychosocial stress, dietary limitations and exposures to allergens and toxicants. Although it is not clear whether these medical abnormalities and environmental factors are related to the etiology of ASD, there is evidence that many of these factors can modulate ASD symptoms, making them a potential treatment target for improving core and associated ASD-related symptoms and improving functional limitation. Additionally, addressing underlying biological disturbances that drive pathophysiology has the potential to be disease modifying. This article describes a systematic approach using clinical history and biomarkers to personalize medical treatment for children with ASD. This approach is medically comprehensive, making it attractive for a multidisciplinary approach. By concentrating on treatable conditions in ASD, it is possible to improve functional ability and quality of life, thus providing optimal outcomes.

Biopsychological correlates of repetitive and restricted behaviors in autism spectrum disorders

BACKGROUND

Autism Spectrum Disorder (ASD) is considered a neurodevelopmental condition that is characterized by alterations in social interaction and communication, as well as patterns of restrictive and repetitive behaviors (RRBs). RRBs are defined as broad behaviors that comprise stereotypies, insistence on sameness, and attachment to objects or routines. RRBs can be divided into lower-level behaviors (motor, sensory, and object-manipulation behaviors) and higher-level behaviors (restrictive interests, insistence on sameness, and repetitive language). According to the DSM-5, the grade of severity in ASD partially depends on the frequency of RRBs and their consequences for disrupting the life of patients, affecting their adaptive skills, and increasing the need for parental support.

METHODS

We conducted a systematic review to examine the biopsychological correlates of the symptomatic domains of RRBs according to the type of RRBs (lower- or higher-level). We searched for articles from the National Library of Medicine (PubMed) using the terms: autism spectrum disorders, ASD, and autism-related to executive functions, inhibitory control, inflexibility, cognitive flexibility, hyper or hypo connectivity, and behavioral approaches. For describing the pathophysiological mechanism of ASD, we also included animal models and followed PRISMA guidelines.

RESULTS

One hundred and thirty-one articles were analyzed to explain the etiology, continuance, and clinical evolution of these behaviors observed in ASD patients throughout life.

CONCLUSIONS

Biopsychological correlates involved in the origin of RRBs include alterations in a) neurotransmission system, b) brain volume, c) inadequate levels of growth factors, d) hypo- or hyper-neural connectivity, e) impairments in behavioral inhibition, cognitive flexibility, and monitoring and f) non-stimulating environments. Understanding these lower- and higher-level of RRBs can help professionals to improve or design novel therapeutic strategies.