Sleep in youth with autism spectrum disorders: systematic review and meta-analysis of subjective and objective studies

Using Life Course Theory to Explore the Association Between Autistic Traits, Child, Family, and School Factors and the Successful Transition to Secondary School

Life Course Theory contends that school transitions can interrupt academic and wellbeing trajectories, depending on child, family, and school factors. Hierarchical regression analyses examined how autistic traits were associated with school transition outcomes. Autistic traits explained 12% of the variance in Quality of Life (QOL), 24% of the variance in mental health and 9% of the variance in school belonging. When autistic traits were accounted for, gender was a significant predictor of changes in QOL whereas changes in school belonging were predicted by cognitive functioning, parent education, school attendance and school refusal. Changes in mental health after transition were mostly predicted by family factors including family structure, family functioning and parent education but were also significantly predicted by sleep problems.

Stress in autism (STREAM): A study protocol on the role of circadian activity, sleep quality and sensory reactivity

Mental health issues are markedly increased in individuals with autism, making it the number one research priority by stakeholders. There is a crucial need to use personalized approaches to understand the underpinnings of mental illness in autism and consequently, to address individual needs. Based on the risk factors identified in typical mental research, we propose the following themes central to mental health issues in autism: sleep difficulties and stress. Indeed, the prevalence of manifold circadian disruptions and sleep difficulties in autism, alongside stress related to sensory overload, forms an integral part of autistic symptomatology. This proof-of-concept study protocol outlines an innovative, individualised approach towards investigating the interrelationships between stress indices, sleep and circadian activation patterns, and sensory sensitivity in autism. Embracing an individualized methodology, we aim to collect 14 days of data per participant from 20 individuals with autism diagnoses and 20 without. Participants' sleep will be monitored using wearable EEG headbands and a sleep diary. Diurnal tracking of heart rate and electrodermal activity through wearables will serve as proxies of stress. Those objective data will be synchronized with subjective experience traces collected throughout the day using the Temporal Experience Tracing (TET) method. TET facilitates the quantification of relevant aspects of individual experience states, such as stress or sensory sensitivities, by providing a continuous multidimensional description of subjective experiences. Capturing the dynamics of subjective experiences phase-locked to neural and physiological proxies both between and within individuals, this approach has the potential to contribute to our understanding of critical issues in autism, including sleep problems, sensory reactivity and stress. The planned strives to provide a pathway towards developing a more nuanced and individualized approach to addressing mental health in autism.

Predicting Adverse Behavior in Individuals with Autism Spectrum Disorder Through Off-body Sleep Analysis

Poor sleep quality in Autism Spectrum Disorder (ASD) individuals is linked to severe daytime behaviors. This study explores the relationship between a prior night's sleep structure and its predictive power for next-day behavior in ASD individuals. The motion was extracted using a low-cost near-infrared camera in a privacy-preserving way. Over two years, we recorded overnight data from 14 individuals, spanning over 2,000 nights, and tracked challenging daytime behaviors, including aggression, self-injury, and disruption. We developed an ensemble machine learning algorithm to predict next-day behavior in the morning and the afternoon. Our findings indicate that sleep quality is a more reliable predictor of morning behavior than afternoon behavior the next day. The proposed model attained an accuracy of 74% and a F1 score of 0.74 in target-sensitive tasks and 67% accuracy and 0.69 F1 score in target-insensitive tasks. For 7 of the 14, better-than-chance balanced accuracy was obtained (p-value<0.05), with 3 showing significant trends (p-value<0.1). These results suggest off-body, privacy-preserving sleep monitoring as a viable method for predicting next-day adverse behavior in ASD individuals, with the potential for behavioral intervention and enhanced care in social and learning settings.

Parental and Child Sleep: Children with Vision Impairment, Autistic Children, and Children with Comorbid Vision Impairment and Autism

BACKGROUND

Parents report associations between children's sleep disturbances and behaviors. Children with neurodevelopmental conditions (e.g., Williams Syndrome and autism) are consistently reported to experience increased sleeping problems. Sleep in children with vision impairment and children with a dual diagnosis of vision impairment and autism remains understudied.

METHODS

Our exploratory study compared sleep profiles in 52 children (aged 4-12 years) and their parents (n = 37), across four groups: children with vision impairment (VI; n = 9), autism (n = 10), comorbid vision impairment + autism (n = 6), and typically developing children (n = 27). Childhood sleep was measured using the parental report Childhood Sleep Habits Questionnaire and sleep diaries. Children's cognitive functioning was measured using digit span, semantic, and phonemic verbal fluency measures. Parental sleep was measured via the Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale.

RESULTS

Clinically disordered sleep was reported in all child groups (p ≤ 0.001), particularly children with VI + autism. Age, not sleep quality/quantity, predicted cognitive task performance in TD and autistic groups, but not in VI and VI + autism groups. The child's diagnosis affected parental sleep, particularly in children with a dual diagnosis of VI + autism.

CONCLUSIONS

All participants experienced problematic sleep to varying degrees. Those most affected were children and parents in the VI + autism group, suggesting that autism may be the main driver of sleep problems in our sample.

Sleep and Activity Patterns in Autism Spectrum Disorder

Background

Autism spectrum disorder (ASD) is a highly heritable and heterogeneous neurodevelopmental disorder characterized by impaired social interactions, repetitive behaviors, and a wide range of comorbidities. Between 44-83% of autistic individuals report sleep disturbances, which may share an underlying neurodevelopmental basis with ASD.

Methods

We recruited 382 ASD individuals and 223 of their family members to obtain quantitative ASD-related traits and wearable device-based accelerometer data spanning three consecutive weeks. An unbiased approach identifying traits associated with ASD was achieved by applying the elastic net machine learning algorithm with five-fold cross-validation on 6,878 days of data. The relationship between sleep and physical activity traits was examined through linear mixed-effects regressions using each night of data.

Results

This analysis yielded 59 out of 242 actimetry measures associated with ASD status in the training set, which were validated in a test set (AUC: 0.777). For several of these traits (e.g. total light physical activity), the day-to-day variability, in addition to the mean, was associated with ASD. Individuals with ASD were found to have a stronger correlation between physical activity and sleep, where less physical activity decreased their sleep more significantly than that of their non-ASD relatives.

Conclusions

The average duration of sleep/physical activity and the variation in the average duration of sleep/physical activity strongly predict ASD status. Physical activity measures were correlated with sleep quality, traits, and regularity, with ASD individuals having stronger correlations. Interventional studies are warranted to investigate whether improvements in both sleep and increased physical activity may improve the core symptoms of ASD.

Sleep quality relates to language impairment in children with autism spectrum disorder without intellectual disability

OBJECTIVES

This study aimed to identify sleep quality profiles of children with autism spectrum disorder (ASD), to compare these profiles with those of typically developing (TD) children, and to verify whether there are differences between them in terms of language skills.

METHODS

We evaluated the sleep quality and language skills of 47 children with ASD without intellectual disability (ID) and 32 children with TD. Using a hierarchical cluster analysis, we identified two sleep quality ASD profiles (poor and good). We then performed a series of MANCOVAs and ANOVAs to compare the sleep quality and language skills of the two ASD clusters and the TD group.

RESULTS

A main group effect (TD, "poor" cluster, and "good" cluster) was found in the total sleep quality and all its dimensions. Significant differences were revealed between the "good" and "poor" clusters in the total structural language score (F1,46 = 10.75, p < 0.001) and three of its subscales (speech: F1,46 = 9.19, p < 0.001; syntax, F1,46 = 8.61, p = 0.001; coherence: F1,46 = 11.36, p < 0.001); the total pragmatic language score (F1,46 = 7.00, p = 0.001) and three of its subscales (inappropriate initiation: F1,46 = 8.02, p = 0.001; use of context: F1,46 = 8.07, p = 0.001; nonverbal communication: F1,46 = 7.35, p = 0.001); and the social relations score (F1,46 = 9.97, p = 0.003).

CONCLUSIONS

Sleep quality in children with ASD (especially a subgroup) is worse than in children with TD. There is an association between sleep quality and language skills, both at the pragmatic and structural levels.

Correlations between sleep problems, core symptoms, and behavioral problems in children and adolescents with autism spectrum disorder: a systematic review and meta-analysis

Children and adolescents with autism spectrum disorder (ASD) experience various sleep problems. Sleep problems co-occur in a bidirectional relationship with ASD core symptoms and behavioral problems. However, studies on how these three factors are intricately linked to each other are limited. This meta-analysis examined the differential relationship between specific sleep problems, core symptoms, and behavioral problems in this population. This study was registered in PROSPERO (CRD42022339695). We systematically searched the PubMed/MEDLINE, Web of Science, and Scopus databases from inception to April 27, 2022. Observational studies that reported correlations between measures of sleep problems, ASD core symptoms, or ASD behavioral problems were included, and participants aged 18 years or below were enrolled. The correlation coefficient (r) was assessed as the primary effect metric. Total 22 cross-sectional studies were included, which comprised 2655 participants (mean age = 6.60 years old; mean percentage of boys = 80.64%). We found correlations between total sleep problems and total core symptoms (r 0.293 [95% confidence interval - 0.095 to 0.604]), total sleep problems and total behavioral problems (r 0.429 [0.299-0.544]), and total core symptoms and total behavioral problems (r - 0.050 [- 0.177 to 0.079]) and identified statistically significant correlations between specific components of sleep problems, ASD core symptoms, and ASD behavioral problems. Each specific sleep problem showed a unique association with core symptoms and behavioral problems. Sleep problems in ASD should be explored in detail, and the closely linked core symptoms and behavioral problems should be common therapeutic targets.

Classification and Epidemiology of Sleep Disorders in Children and Adolescents

Sleep disturbances are common in children and adolescents but still remain unrecognized and undertreated. Several classification systems of sleep disorders are available, which include recent attempts to develop more specific nosologic categories that reflect developmental aspects of sleep. The prevalence of sleep disorders has been studied across various samples of healthy, typically developing children and those with special medical, psychiatric, and neurodevelopmental needs. Sleep disorders are highly prevalent in children and adolescents with psychiatric disorders, making it important for mental health professionals to be aware of sleep problems and to address them in the context of psychiatric comorbidities.

Restless sleep disorder in a sample of children and adolescents with autism spectrum disorder: preliminary results from a case series

STUDY OBJECTIVES

Sleep disorders are a frequent comorbidity among children with autism spectrum disorder (ASD). Among sleep-related issues of ASD, restless sleep is a common complaint. In recent years, restless sleep disorder (RSD) has been proposed as a new clinical entity, characterized by agitated sleep as its predominant manifestation. Despite the high prevalence of sleep disorders and data reporting restless sleep among ASD patients, to date no study has yet characterized RSD within patients with ASD. Therefore, the aim of our study was to assess the occurrence of RSD in a sample of children and adolescents with ASD through clinical and polysomnographic assessment.

METHODS

Children and adolescents with ASD ages 6-18 years were recruited for the study. Through parental interviews, patients with a suspected RSD were selected and offered diagnostic investigation by video-polysomnography and blood tests to assess martial balance.

RESULTS

Among the 129 participants included, 16 patients (12.4%) were found to have a suspected RSD. Only 6 (4.7%) underwent video-polysomnography due to lack of compliance or family refusal. In 6/6 participants examined, the disorder was confirmed by video-polysomnography movement analysis (total movement index ≥ 5 events/h) and ferritin values were found in the normal range.

CONCLUSIONS

RSD does not appear to be particularly frequent among patients with ASD and that of iron metabolism may not be the main factor implicated in the pathogenesis of RSD within this population. Additional evaluation is needed to confirm the result and further investigate the etiological mechanisms underlying the disorder.

CITATION

Voci A, Mazzone L, De Stefano D, Valeriani M, Bruni O, Moavero R. Restless sleep disorder in a sample of children and adolescents with autism spectrum disorder: preliminary results from a case series. J Clin Sleep Med. 2024;20(3):427-432.

Mental Health Problems Among Adolescents With Mild Intellectual Disability and Relation to Sleep Quality and Perceived Social Support: A Comparative Study

The current cross-sectional study sought to determine the mental health problems of adolescents with mild intellectual disability (ID) and influencing factors. This study, which used a comparison group, was performed with 188 adolescents (91 with mild ID and 97 without ID) between January 2019 and June 2019 in Turkey. Data were collected using a Personal Information Form, the Strengths and Difficulties Questionnaire, Pittsburgh Sleep Quality Index, and Perceived Social Support Scale. Adolescents with mild ID were at higher risk for mental health problems compared to those without ID. According to linear regression analysis, sex, age, birth order, maternal age, parents' educational level, sleep quality, and perceived social support were statistically significant predictive factors of mental health problems in adolescents with mild ID. Results of this study indicate that adolescents with mild ID are at greater risk for mental health problems and that effective prevention/intervention strategies are needed. [Journal of Psychosocial Nursing and Mental Health Services, 62(3), 39-50.].

Sleep problems in children with autism spectrum disorder and attention-deficit/hyperactivity disorder: A comparative study and effects on communication skills

Sleep disturbances are highly prevalent among children with neurodevelopmental disorders, like Autism Spectrum Disorder (ASD) and Attention-Deficit/Hiperactivity Disorder (ADHD). The first objective of this study is to examine the differences in sleep problems between a group of children with ASD without intellectual disabilities, a group with ADHD and a typically developing (TD) group. A second objective is aimed at analyzing the effects of sleep problems and symptom severity on their communication skills. Participants were 122 children between 7 and 12 years old distributed in three groups: 32 TD children, 47 children with ASD and 43 children with ADHD, matched on age and intelligence. Parents completed different questionnaires that measured sleep disturbances and communication skills. Findings show significant differences between the clinical groups and the TD group in most types of sleep disorders. Moreover, the group with ADHD showed significantly more sleep breathing disorders and hyperhidrosis in comparison with ASD and TD, as well as more total sleep problems. In contrast to ASD, the predictive power of sleep problems on communication difficulties was greater in the group with ADHD. The results of the mediation analysis indicate that in both groups, sleep problems partially mediate the relationship between symptoms and communication. This investigation highlights the need of considering sleep disorders when assessing communication skills in ASD and ADHD, given its indirect influence in this domain. Understanding the sleep dysfunctions of both conditions and their repercussions is crucial to develop adjusted interventions.

Risk factors and clinical profile of autism spectrum disorder in southern Brazil

In Brazil, as in other countries, it is expected a significant variation of epidemiological and clinical characteristics among individuals with autism spectrum disorder (ASD). This study was performed to explore maternal risk factors and clinical characteristics of children with ASD in a population located in southern Brazil. Data were collected from medical records and analyzed to explore biomarkers associated with ASD. Out of 321 children with ASD, 86.5% were males with a male-to-female ratio of 5.7:1, 50.7% were mild/moderate while 49.3% presented severe ASD. Between the risk factors investigated, gestational infection was significantly associated with severe ASD patients. There was also an association between epilepsy and severe autism. Several gastrointestinal (GI) symptoms were significantly associated with severe ASD. Obesity, followed by lower levels of cholesterol, were also significant factors associated with an ASD diagnosis when compared to age-matched controls. Finally, severe ASD was associated with significantly higher serum serotonin levels when compared to age-matched controls and mild/moderate ASD cases. Our findings demonstrate that our population shares many features associated with ASD around the world, such as GI symptoms, epilepsy, and high serotonin levels. It is worth highlighting the low cholesterol levels associated with obesity as an unusual feature that deserves more attention.

Melatonin as a Mediator of the Gut Microbiota-Host Interaction: Implications for Health and Disease

In recent years, the role played by melatonin on the gut microbiota has gained increasingly greater attention. Additionally, the gut microbiota has been proposed as an alternative source of melatonin, suggesting that this antioxidant indoleamine could act as a sort of messenger between the gut microbiota and the host. This review analyses the available scientific literature about possible mechanisms involved in this mediating role, highlighting its antioxidant effects and influence on this interaction. In addition, we also review the available knowledge on the effects of melatonin on gut microbiota composition, as well as its ability to alleviate dysbiosis related to sleep deprivation or chronodisruptive conditions. The melatonin-gut microbiota relationship has also been discussed in terms of its role in the development of different disorders, from inflammatory or metabolic disorders to psychiatric and neurological conditions, also considering oxidative stress and the reactive oxygen species-scavenging properties of melatonin as the main factors mediating this relationship.

Abnormal Porphyrin Metabolism in Autism Spectrum Disorder and Therapeutic Implications

Autism spectrum disorder (ASD) is a mosaic of neurodevelopmental conditions composed of early-onset social interaction and communication deficits, along with repetitive and/or restricted patterns of activities, behavior, and interests. ASD affects around 1% of children worldwide, with a male predominance. Energy, porphyrin, and neurotransmitter homeostasis are the key metabolic pathways affected by heavy metal exposure, potentially implicated in the pathogenesis of ASD. Exposure to heavy metals can lead to an altered porphyrin metabolism due to enzyme inhibition by heavy metals. Heavy metal exposure, inborn genetic susceptibility, and abnormal thiol and selenol metabolism may play a significant role in the urinary porphyrin profile anomalies observed in ASD. Altered porphyrin metabolism in ASD may also be associated with, vitamin B6 deficiency, hyperoxalemia, hyperhomocysteinemia, and hypomagnesemia. The present review considers the abnormal porphyrin metabolism in ASD in relation to the potential pathogenic mechanism and discusses the possible metabolic therapies such as vitamins, minerals, cofactors, and antioxidants that need to be explored in future research. Such targeted therapeutic therapies would bring about favorable outcomes such as improvements in core and co-occurring symptoms.

Age-Related Differences in Accelerometer-Assessed Physical Activity and Sleep Parameters Among Children and Adolescents With and Without Autism Spectrum Disorder: A Meta-Analysis

Importance

Physical inactivity and sleep disorders are health-related concerns of youth with autism spectrum disorder (ASD) that can persist from childhood and exacerbate core symptoms. However, evidence on group differences in accelerometer-assessed physical activity and sleep parameters among youth with and without ASD is inconclusive and age-specific effects remain unclear.

Objective

To synthesize evidence on group differences in accelerometer-assessed physical activity and sleep parameters and examine the moderating effects of age between children and adolescents with and without ASD.

Data Sources

American Psychological Association PsychInfo, CINAHL Ultimate, ERIC, MEDLINE, SPORTDiscus with Full Text, and Web of Science from inception to February 2023.

Study Selection

Two independent reviewers screened articles for observational research comparing accelerometer-assessed physical activity levels and sleep parameters in children and adolescents with and without ASD.

Data Extraction and Synthesis

After developing a standardized form, relevant data were extracted. Quality was assessed using the McMaster Critical Review Form and rated based on sample, measurement, and analyses. The Preferring Reporting Items for Systematic Reviews and Meta-Analyses guideline was followed.

Main Outcomes and Measures

The primary outcomes were actigraphy-measured MVPA, sleep latency, sleep efficiency, total sleep time, and wake after sleep onset. Data were pooled using a random-effects model. Hedges g was used to express the effect size index. Meta-regression on age was also performed to investigate the potential moderating effects.

Results

Collectively, 1757 studies were initially identified. Among 104 articles that were assessed, 28 were included, comprising moderate-to-vigorous physical activity (MVPA), 4 sleep parameters, and 73 independent effect sizes. A total of 28 studies were included in analysis, comprising 805 children and adolescents with ASD and 1573 without ASD (age range, 5.1-16.9 years). Compared with peers without ASD, children and adolescents with ASD had a small-to-moderate difference in MVPA (g = -0.450; 95% CI, -0.622 to -0.277), total sleep time (g = -0.332; 95% CI, -0.574 to -0.090), sleep efficiency (g = -0.424; 95% CI, -0.645 to -0.203), and a moderate difference in sleep latency (g = 0.514; 95% CI, 0.351 to 0.677) measured by actigraphy. Children and adolescents with ASD experienced an age-related decline in moderate-to-vigorous physical activity (β = -0.049 [95% CI, -0.097 to -0.001]; P = .045), indicating that younger children with ASD showed a smaller difference in MVPA compared with their peers without ASD. Moderating effects of age on sleep parameters were not significant.

Conclusions and Relevance

The findings of this meta-analysis suggested that children and adolescents with ASD had lower MVPA and worse sleep than peers without ASD, and the difference in MVPA varied with age. These findings reinforce the need for public health initiatives aimed at reducing these group disparities.

How do Autistic and Neurotypical Children's Interests Influence their Accuracy During Novel Word Learning?

Word learning depends on attention - children must focus on the right things at the right times. However, autistic children often display restricted interests, limiting their intake of stimuli during word learning. This study investigates how category interests influence word learning in autism and neurotypical development. Autistic and neurotypical children matched on receptive vocabulary used a touch-screen computer to learn novel words associated with animals (high-interest stimuli) and objects (neutral-interest stimuli) via fast mapping. Response accuracy and speed were examined at referent selection, 5-minute retention, and 24-hour retention. Both groups identified meanings of novel words associated with unfamiliar animals and objects via mutual exclusivity with comparable accuracy. After 5 minutes, autistic children retained animal names with greater accuracy than neurotypical children. Autistic children showed a greater increase in their accuracy between 5-minute and 24-hour retention and outperformed neurotypical children across conditions after a night's sleep. Across groups, 24-hour retention was predicted by number of target word repetitions heard at referent selection, indicating a relationship between fast mapping input and retention. However, autistic children were slower to respond correctly, particularly in the animal condition. For autistic children, superior word learning associated with high-interest stimuli was relatively short-term, as sleep appeared to consolidate their memory representations for neutral-interest stimuli. Although these results demonstrate that fundamental word learning mechanisms are not atypical in autism, slower response times may signal a speed-accuracy trade-off that could have implications for naturalistic language acquisition. Our findings also indicate favourable environmental conditions to scaffold word learning.

Subjective and objective sleep alterations in medication-naïve children and adolescents with autism spectrum disorder: a systematic review and meta-analysis

AIMS

This study aimed to summarize the evidence on sleep alterations in medication-naïve children and adolescents with autism spectrum disorder (ASD).

METHODS

We systematically searched PubMed/Medline, Embase and Web of Science databases from inception through March 22, 2021. This study was registered with PROSPERO (CRD42021243881). Any observational study was included that enrolled medication-naïve children and adolescents with ASD and compared objective (actigraphy and polysomnography) or subjective sleep parameters with typically developing (TD) counterparts. We extracted relevant data such as the study design and outcome measures. The methodological quality was assessed through the Newcastle-Ottawa Scale (NOS). A meta-analysis was carried out using the random-effects model by pooling effect sizes as Hedges' g. To assess publication bias, Egger's test and p-curve analysis were done. A priori planned meta-regression and subgroup analysis were also performed to identify potential moderators.

RESULTS

Out of 4277 retrieved references, 16 studies were eligible with 981 ASD patients and 1220 TD individuals. The analysis of objective measures showed that medication-naïve ASD patients had significantly longer sleep latency (Hedges' g 0.59; 95% confidence interval [95% CI] 0.26 to 0.92), reduced sleep efficiency (Hedges' g -0.58; 95% CI -0.87 to -0.28), time in bed (Hedges' g -0.64; 95% CI -1.02 to -0.26) and total sleep time (Hedges' g -0.64; 95% CI -1.01 to -0.27). The analysis of subjective measures showed that they had more problems in daytime sleepiness (Hedges' g 0.48; 95% CI 0.26 to 0.71), sleep latency (Hedges' g 1.15; 95% CI 0.72 to 1.58), initiating and maintaining sleep (Hedges' g 0.86; 95% CI 0.39 to 1.33) and sleep hyperhidrosis (Hedges' g 0.48; 95% CI 0.29 to 0.66). Potential publication bias was detected for sleep latency, sleep period time and total sleep time measured by polysomnography. Some sleep alterations were moderated by age, sex and concurrent intellectual disability. The median NOS score was 8 (interquartile range 7.25-8.75).

CONCLUSION

We found that medication-naïve children and adolescents with ASD presented significantly more subjective and objective sleep alterations compared to TD and identified possible moderators of these differences. Future research requires an analysis of how these sleep alterations are linked to core symptom severity and comorbid behavioural problems, which would provide an integrated therapeutic intervention for ASD. However, our results should be interpreted in light of the potential publication bias.

Are sleep disturbances a cause or consequence of autism spectrum disorder?

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by core symptoms such as atypical social communication, stereotyped behaviors, and restricted interests. One of the comorbid symptoms of individuals with ASD is sleep disturbance. There are two major hypotheses regarding the neural mechanism underlying ASD, i.e., the excitation/inhibition (E/I) imbalance and the altered neuroplasticity hypotheses. However, the pathology of ASD remains unclear due to inconsistent research results. This paper argues that sleep is a confounding factor, thus, must be considered when examining the pathology of ASD because sleep plays an important role in modulating the E/I balance and neuroplasticity in the human brain. Investigation of the E/I balance and neuroplasticity during sleep might enhance our understanding of the neural mechanisms of ASD. It may also lead to the development of neurobiologically informed interventions to supplement existing psychosocial therapies.

A systematic review of non-coding RNA genes with differential expression profiles associated with autism spectrum disorders

AIMS

To identify differential expression of shorter non-coding RNA (ncRNA) genes associated with autism spectrum disorders (ASD).

BACKGROUND

ncRNA are functional molecules that derive from non-translated DNA sequence. The HUGO Gene Nomenclature Committee (HGNC) have approved ncRNA gene classes with alignment to the reference human genome. One subset is microRNA (miRNA), which are highly conserved, short RNA molecules that regulate gene expression by direct post-transcriptional repression of messenger RNA. Several miRNA genes are implicated in the development and regulation of the nervous system. Expression of miRNA genes in ASD cohorts have been examined by multiple research groups. Other shorter classes of ncRNA have been examined less. A comprehensive systematic review examining expression of shorter ncRNA gene classes in ASD is timely to inform the direction of research.

METHODS

We extracted data from studies examining ncRNA gene expression in ASD compared with non-ASD controls. We included studies on miRNA, piwi-interacting RNA (piRNA), small NF90 (ILF3) associated RNA (snaR), small nuclear RNA (snRNA), small nucleolar RNA (snoRNA), transfer RNA (tRNA), vault RNA (vtRNA) and Y RNA. The following electronic databases were searched: Cochrane Library, EMBASE, PubMed, Web of Science, PsycINFO, ERIC, AMED and CINAHL for papers published from January 2000 to May 2022. Studies were screened by two independent investigators with a third resolving discrepancies. Data was extracted from eligible papers.

RESULTS

Forty-eight eligible studies were included in our systematic review with the majority examining miRNA gene expression alone. Sixty-four miRNA genes had differential expression in ASD compared to controls as reported in two or more studies, but often in opposing directions. Four miRNA genes had differential expression in the same direction in the same tissue type in at least 3 separate studies. Increased expression was reported in miR-106b-5p, miR-155-5p and miR-146a-5p in blood, post-mortem brain, and across several tissue types, respectively. Decreased expression was reported in miR-328-3p in bloods samples. Seven studies examined differential expression from other classes of ncRNA, including piRNA, snRNA, snoRNA and Y RNA. No individual ncRNA genes were reported in more than one study. Six studies reported differentially expressed snoRNA genes in ASD. A meta-analysis was not possible because of inconsistent methodologies, disparate tissue types examined, and varying forms of data presented.

CONCLUSION

There is limited but promising evidence associating the expression of certain miRNA genes and ASD, although the studies are of variable methodological quality and the results are largely inconsistent. There is emerging evidence associating differential expression of snoRNA genes in ASD. It is not currently possible to say whether the reports of differential expression in ncRNA may relate to ASD aetiology, a response to shared environmental factors linked to ASD such as sleep and nutrition, other molecular functions, human diversity, or chance findings. To improve our understanding of any potential association, we recommend improved and standardised methodologies and reporting of raw data. Further high-quality research is required to shine a light on possible associations, which may yet yield important information.

Early life sleep disruption has long lasting, sex specific effects on later development of sleep in prairie voles

In mammals, sleep duration is highest in the early postnatal period of life and is critical for shaping neural circuits that control the development of complex behaviors. The prairie vole is a wild, highly social rodent that serves as a unique model for the study of complex, species-typical social behaviors. Previous work in our laboratory has found that early life sleep disruption (ELSD) in prairie voles during a sensitive window of postnatal development leads to long lasting changes in social and cognitive behaviors as well as structural changes in excitatory and inhibitory neural circuits in the brain. However, it is currently unknown how later sleep is impacted by ELSD, both shortly after ELSD and over the long term. Therefore, the aim of this study was to describe the effects of ELSD on later life sleep, compared to sleep in normally developing prairie voles. First, we conducted tethered electroencephalogram/electromyogram (EEG/EMG) recordings in juvenile prairie voles undergoing ELSD, compared to Control conditions. Second, we conducted 24 h of home cage tethered EEG/EMG recordings in either adolescent or adult male and female prairie voles that had previously undergone ELSD or Control conditions as juveniles. We found that, as adults, male ELSD prairie voles showed persistently lower REM sleep duration and female ELSD prairie voles showed persistently higher NREM sleep duration compared to Controls, but no other sleep parameters differed. We concluded that 1) persistent effects of ELSD on sleep into adulthood may contribute to the social and cognitive deficits observed in adult voles, and 2) sleep disruption early in life can influence later sleep patterns in adulthood.

Loss of sleep when it is needed most - Consequences of persistent developmental sleep disruption: A scoping review of rodent models

Sleep is an essential component of development. Developmental sleep disruption (DSD) impacts brain maturation and has been associated with significant consequences on socio-emotional development. In humans, poor sleep during infancy and adolescence affects neurodevelopmental outcomes and may be a risk factor for the development of autism spectrum disorder (ASD) or other neuropsychiatric illness. Given the wide-reaching and enduring consequences of DSD, identifying underlying mechanisms is critical to best inform interventions with translational capacity. In rodents, studies have identified some mechanisms and neural circuits by which DSD causes later social, emotional, sensorimotor, and cognitive changes. However, these studies spanned methodological differences, including different developmental timepoints for both sleep disruption and testing, different DSD paradigms, and even different rodent species. In this scoping review on DSD in rodents, we synthesize these various studies into a cohesive framework to identify common neural mechanisms underlying DSD-induced dysfunction in brain and behavior. Ultimately, this review serves the goal to inform the generation of novel translational interventions for human developmental disorders featuring sleep disruption.

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

Background

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.

Methods

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).

Results

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.

Conclusion

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.

The impact of COVID-19 on sleep for autistic children: A systematic review

BACKGROUND

Up to 80% of children with autism experience behavioural sleep problems, predominantly relating to bedtime resistance, sleep anxiety, sleep dysregulation, and shorter duration, which are associated with increased autistic symptom expression and emotional and behavioural difficulties. Researchers predicted the COVID-19 pandemic would worsen sleep and behavioural difficulties for autistic children, due to their need for routine and certainty. This systematic review is the first to focus on delineating the role of sleep disturbance in exacerbating autistic symptoms and internalising and externalising behaviours during the pandemic.

METHOD

In this PROSPERO registered systematic review, we aggregated and synthesised findings from empirical studies from 2020 onwards that included children with autism and examined sleep outcomes, using narrative and framework synthesis due to the variety of methods and designs employed. We identified additional relevant themes through inductive thematic analysis.

RESULTS

Seventy-one studies met the search criteria, and we selected seventeen for review following screening and quality assessment. These studies reported mixed findings; with strongest support for worsening of sleep problems typically experienced by autistic children, including difficulties with sleep regulation and shorter sleep duration. Further, sleep problems were associated with increased expression of autistic characteristics.

CONCLUSIONS

Preliminary findings of worsening sleep and increased autistic characteristics for autistic children throughout the COVID-19 pandemic highlight the need for ongoing, accessible and flexible service provision during exposure to environmental stressors. We propose that behavioural sleep interventions are well suited to telehealth adaptation and play an important role in supporting families when in-person treatment for sleep problems is not possible.

Stronger Associations Between Sleep and Mental Health in Adults with Autism: A UK Biobank Study

This study examined sleep and its cognitive and affective correlates in adults with and without autism spectrum disorder (ASD), utilizing UK Biobank data. There were no group differences in subjective sleep duration [n = 220 ASD; n = 2200 general population (GP)]. Accelerometer measures of sleep duration or nighttime activity did not differ by group, but sleep efficiency was marginally lower in ASD (n = 83 ASD; n = 824 GP). Sleep efficiency was associated with wellbeing and mental health, and pathways between accelerometer sleep measures and wellbeing and mental health were significantly stronger for adults with ASD (who also reported substantially poorer wellbeing and > 5 × likelihood of experiencing mental distress). These findings highlight the need to monitor sleep to maintain good mental health in adult ASD.

Sleep disturbances and emotional dysregulation in young children with autism spectrum, intellectual disability, or global developmental delay

OBJECTIVE

Sleep disturbance and emotional dysregulation (ED) are common and often functionally impairing in young children with neurodevelopmental disorders (NDD). This study investigated the relationship between sleep disturbance and ED in a sample of preschoolers with ASD, intellectual disability, or global developmental delay, and examined possible predictors of their persistence over time.

METHODS

All children under 6 years of age clinically referred between July 2018 and May 2022 to two neuropsychiatric specialized centers for NDD received a comprehensive diagnostic evaluation, including the Child Behavior Checklist 1.5-5 (CBCL), the Autism Diagnostic Observation Schedule-2 (ADOS-2), and standardized tests of cognitive and global development. Sleep disturbances were assessed with the CBCL-sleep score, and ED with the CBCL Attention, Aggression, and Anxious/Depressed scales (CBCL-AAA). A reassessment of sleep and ED was conducted after 6 months or longer, including the Child Sleep Habits Questionnaire (CSHQ). Multivariate analyses and mixed linear regression models were conducted.

RESULTS

A total of 136 children, 75.7% male, median age 38.27 months, IQR 15.39, 41.2% with global developmental disorder (GDD) or intellectual disability (ID) participated in the study. Of them, 64.7% were diagnosed with autism spectrum disorder (ASD) and 35.3% with other NDD (w/o ASD). Sleep disturbances (CBCL-Sleep) and ED (CBCL-AAA) were positively correlated (p < 0.001), after accounting for age, ID/GDD and autism symptom severity, in both the entire sample and separately in each diagnostic group (ASD and NDD w/o ASD). Seventy-five children (55%) were reassessed a mean 17.2 months afterwards. There was persistence of the positive correlation between sleep problems and ED (p < 0.001) in both the entire sample and each diagnostic group. The longitudinal mixed linear model showed that ED at follow-up was predicted by baseline sleep problems (p = 0.008), ED (p < 0.001), and ASD severity (p = 0.015).

CONCLUSIONS

Sleep disturbances are significantly associated with ED in young children with NDD, either with or without ASD, both cross-sectionally and prospectively over time. Sleep problems represent an important comorbidity and a potential treatment target for improving emotional stability in NDD.

Changes in sleep duration and disturbances during Covid-19 lockdown and internalizing-externalizing behaviors in children with attention deficit hyperactivity disorders

OBJECTIVE

To examine how changes in sleep patterns and sleep problems occurring between the pre-pandemic and the Covid-19 lockdown period influenced mood-behavioral functioning of children with Attention Deficit Hyperactivity Disorder (ADHD).

METHODS

Parents of 992 children with ADHD (85.4% boys, mean age: 11.52 years, SD = 3.17), recruited from the Italian ADHD family association, completed a modified version of the Sleep Disturbance Scale for Children and filled out 11 emotional behavioral items selected from the Child Behavior Checklist (CBCL) 6-18 questionnaire. Subgroups identified based on sleep duration changes ("maintained", "increased", "reduced") and of sleep problems during lockdown ("onset", "remission", "maintained", "no sleep problem") were analyzed to evaluate the association with internalizing and externalizing scores.

RESULTS

Sleep duration showed no or low influence on internalizing and externalizing behaviors after control for age, sex, and socioeconomic status. Patients with ADHD with "no sleep problem" showed significant lower scores in internalizing and externalizing behaviors than those who "maintained" or had "onset" of different sleep problems. The effect sizes were higher for internalizing than externalizing behaviors. Lower internalizing scores were found in those who remitted difficulty in falling asleep, daytime sleepiness, nightmares, vs. the "maintained" or "onset" groups and those who remitted hypnic jerks vs. the "onset" group. Children with ADHD who "maintained" sleep terrors reported higher internalizing and mainly externalizing scores than the other groups.

CONCLUSION

Sleep problems negatively influence daytime functioning of patients with ADHD. but mood and behavioral domains show different susceptibility to the changes of sleep problems, and different vulnerability to specific sleep problems.

Parasympathetic functioning and sleep problems in children with autism spectrum disorder

Respiratory sinus arrhythmia (RSA), an index of parasympathetic nervous system activity, has been linked with sleep quality among children with neurotypical development. The current study extended examination of these processes to children with autism spectrum disorder (ASD), a group at considerable risk for sleep problems. Participants included 54 children with ASD (aged 6-10 years, 43% Hispanic). RSA data were collected via a wired MindWare system during a 3-min baseline and a 3-min challenge task. Parents reported on their children's sleep problems and sleep duration using the Children's Sleep Habits Questionnaire, Abbreviated. Although no significant correlations emerged between RSA indices and parent-reported child sleep, baseline RSA and RSA reactivity interacted in the prediction of sleep problems. For children with higher RSA reactivity, higher baseline RSA was associated with fewer sleep problems, but for children with lower RSA reactivity, baseline RSA was not predictive. No main effects or interactions of RSA predicted sleep duration. Findings suggest resilience against sleep problems for children with ASD presenting with higher baseline RSA and higher RSA reactivity. Implications of these results center upon directly targeting psychophysiology (i.e., parasympathetic nervous system regulation) as a possible mechanism to improve sleep in children with ASD, and developing personalized interventions based on physiological markers of risk and resilience.

Melatonin Treatment for Pediatric Patients with Insomnia: Is There a Place for It?

Sleep is a vital physiological function that is impaired in ranges from 10% in the typically developing pediatric population to over 80% in populations of children with neurodevelopmental disorders and/or psychiatric comorbidities. Pediatric insomnia disorder is an increasing public health concern given its negative impact on synaptic plasticity involved in learning and memory consolidation but also on mood regulation, hormonal development and growth, and its significant impact on quality of life of the child, the adolescent and the family. While first-line treatment of pediatric insomnia should include parental education on sleep as well as sleep hygiene measures and behavioural treatment approaches, pharmacological interventions may be necessary if these strategies fail. Melatonin treatment has been increasingly used off-label in pediatric insomnia, given its benign safety profile. This article aims to identify the possible role of melatonin treatment for pediatric insomnia, considering its physiological role in sleep regulation and the differential effects of immediate release (IR) versus prolonged release (PR) melatonin. For the physician dealing with pediatric insomnia, it is particularly important to be able to distinguish treatment rationales implying different dosages and times of treatment intake. Finally, we discuss the benefit-risk ratio for melatonin treatment in different pediatric populations, ranging from the general pediatric population to children with different types of neurodevelopmental disorders, such as autism spectrum disorder or ADHD.

Melatonin usage in children and young adults, a registry-based cohort study

Sleep disorder is common in children and adolescents, particularly in those with attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD). While non-pharmacological treatment is first line, occasionally an add-on of an oral drug is needed. The endogenous hormone melatonin is increasingly used for sleep disorders in children and adolescents. In this registry-based cohort study we follow dispensation of melatonin in young individuals, 0-25 years of age, in Stockholm, Sweden during 2016-2019. In all 9980 individuals, were dispensed melatonin in 2016 and followed for 3 years. Child psychiatrist was the most common prescribing specialty, 55% of all prescriptions. Only 20% had a recorded diagnosis of sleep disorder. The majority, 65% had a neuro psychiatric diagnose. Half of the individuals had at least 4 prescribed drugs dispensed during the follow-up. Almost half of our cohort were dispensed melatonin during the entire study period and doses and volumes of drug dispensed increased by 50 and 100%, respectively. Continuous medication was most common among children 6-12 years, where 7 out of 10 individuals were still adherent after three years. As long-term safety data is lacking, we find this concerning, and this illustrates the need of long-term follow-up of melatonin use in children and young individuals.

Electrodermal Activity Moderates Sleep-Behavior Associations in Children with Autism Spectrum Disorder

Relative to children without autism spectrum disorder (ASD), children with ASD experience elevated sleep problems that can contribute to behavioral comorbidities. This study explored the interaction between psychophysiology and sleep to determine which children with ASD may be at risk for, or resilient to, effects of poor sleep on daytime behavior. Participants included 48 children (aged 6-10 years) with ASD. Measures of sympathetic nervous system activity (electrodermal activity; EDA) were collected during a baseline and in response to a laboratory challenge task. Parents reported on their children's sleep problems and behavioral functioning, including broad externalizing symptoms and situational noncompliance, using standardized questionnaires and a clinical interview. EDA moderated the significant positive associations between sleep problems and both behavioral outcomes. The link between sleep problems and broad externalizing symptoms and situational noncompliance was positive and significant in the context of lower baseline EDA and nonsignificant in the context of higher baseline EDA. Sleep problems also interacted with EDA reactivity in predicting situational noncompliance, but not broad externalizing symptoms. Findings highlight the complex interplay among sleep, daytime behavior, and psychophysiology in children with ASD. Results are interpreted in the context of differential susceptibility and dual-risk frameworks. This study underscores the importance of high-quality sleep for children with ASD, especially those with the biological sensitivity or vulnerability factors (i.e., EDA) identified in this study. Clinical implications are discussed, and directions for future research are provided.

Associations between sleep problems and domains relevant to daytime functioning and clinical symptomatology in autism: A meta-analysis

Autistic individuals experience significantly higher rates of sleep problems compared to the general population, which negatively impacts various aspects of daytime functioning. The strength of associations across domains of functioning has not yet been summarized across studies. The present meta-analysis examined the strength of associations between sleep problems and various domains of daytime functioning in autistic individuals. Searches were conducted in EMBASE, PubMed, Web of Science, and Google Scholar through May 2020. Inclusion criteria were: an index of sleep disturbance in individuals diagnosed with autism spectrum disorder (ASD); data collected prior to any sleep-related intervention; statistical data indicating relations between sleep problems and outcomes relevant to behavior, cognition, and physical or mental health. Exclusion criteria were: statistics characterizing the relationship between sleep disturbance and outcome variables that partialled out covariates; studies examining correlations between different measures of sleep disturbance. Participants totaled 15,074 from 49 published articles and 51 samples, yielding 209 effect sizes. Sleep problems were significantly associated with more clinical symptomatology and worse daytime functioning. Subgroup analyses demonstrated that sleep problems were most strongly associated with internalizing and externalizing symptoms and executive functioning, followed by core autism symptoms, family factors, and adaptive functioning. Findings highlight the far-reaching consequences of sleep problems on daytime functioning for autistic individuals and support the continued prioritization of sleep as a target for intervention through integrated care models to improve wellbeing. LAY SUMMARY: Autistic individuals experience higher rates of sleep problems, such as difficulty falling asleep and staying asleep, compared to the general population. We quantitatively summarized the literature about how sleep problems are related to different aspects of daytime functioning to identify areas that may be most affected by sleep. Sleep problems were related to all areas assessed, with the strongest associations for mood and anxiety symptoms. We recommend prioritizing sleep health in autistic individuals to improve wellbeing and quality of life.

Current and lifetime somatic symptom burden among transition-aged autistic young adults

Somatic symptoms are the most common cause of outpatient medical visits in the general population, yet their presence and severity in individuals on the autism spectrum has rarely been studied. We sought to assess the prevalence, impact, and clinical correlates of 14 commonly reported somatic symptoms in a sample of 290 transition-aged autistic young adults (mean [SD] age: 23.10 [2.38] years, range 18-26; 76.7% diagnosed with autism before age 18) recruited from the Simons Foundation SPARK participant pool. A modified version of the Patient Health Questionnaire-15 was used to assess somatic symptom prevalence/impact, along with measures of depression, anxiety, autistic traits, and quality of life. Somatic symptom burden was much higher in autistic young adults than previously reported in the general population. The most commonly reported current symptoms were fatigue (72.8%), sleep problems (69.0%), and menstrual problems (61.4% of females). Moderate or severe symptom levels were reported by 53.9% of females and 18.75% of males in our cohort, with the odds of females endorsing any given symptom being 2-4 times greater than males. Both individual symptoms and total symptom burden were related to higher levels of depression, anxiety, and autistic traits, along with lower quality of life. Despite little research on this topic previously, somatic symptoms are highly prevalent in autistic young adults, particularly women. Future research is needed to investigate links between somatic symptoms, medical and psychiatric morbidity, and health care utilization in the autistic population.

Examining the Relationship Between Sleep Quality, Social Functioning, and Behavior Problems in Children with Autism Spectrum Disorder: A Systematic Review

Over forty percent of autistic children experience poor sleep quality, and social interaction difficulties are a core characteristic of autism. However, the relationship between sleep quality and social functioning and behavior remains poorly understood. This systematic review examined the evidence concerning the impact of sleep quality on the social functioning and behavior problems in autistic children and adolescents. It also identified key related factors and evaluated how this issue has been researched to date. Seven key journals were hand-searched and five databases were systematically searched, using keywords. Titles and abstracts of 4123 items were screened against eligibility criteria by two researchers. Relevant studies were retained if they were peer-reviewed empirical papers, published in English between 2000 and 2021. Then, the full text of 97 papers was screened and if they met the eligibility criteria, their reference lists were hand-searched. Forty-six studies were included in the final review. Data were systematically extracted and two authors critically appraised the strengths and weaknesses of studies using Critical Appraisal Skills Programme tools. Key themes were identified, because a meta-analysis was not possible due to the studies' heterogeneity. The review identified that sleep quality and social functioning are associated with one another and there is a small amount of evidence that a bi-directional causal relationship may exist. Evidence suggests that several nights of suboptimal sleep duration and a lack of deep continuous sleep negatively impact externalizing and internalizing behavior. Sleep quality is also reduced by anxiety and sensory sensitivity. However, longitudinal studies with larger samples are needed to establish causality. Future research needs to examine confounding factors and to develop consensus regarding best-practice processes for the objective measurement of sleep with autistic children. Additional research also needs to further examine the consequences of poor sleep quality on internalizing behavior, and the impact of socio-cultural practices.

Population-Based Psychiatric Comorbidity in Children and Adolescents With Autism Spectrum Disorder: A Meta-Analysis

Psychiatric comorbidity in autism spectrum disorder (ASD) is a subject of critical scientific importance, affecting the quality of life, prognosis, and functional outcomes. The prevalence of psychiatric disorders vary considerably according to variables such as index subject characteristics, study setting, sampling frame, diagnostic methods used, as well as country of geographic origin. To date, most studies comprise clinical or treatment referral samples in tertiary care or subjects enrolled in clinical trials and genetic cohort collections. Such samples carry the potential for overestimation of both the frequency and severity of psychiatric comorbidity. A systematic literature search was performed using PubMed and Web of Science databases restricted to population-based study publications in the English between May 1, 2015, and May 31, 2020. A comprehensive keyword list was generated to investigate co-occurrence of psychiatric disorders in children and adolescents with ASD. A wide range of DSM-5 based disorders such as anxiety, mood, ADHD, intellectual disability/intellectual developmental disorder, eating/feeding, gender dysphoria and sleep-wake disorders were assessed. Initial search revealed a total of 1674 articles after removal of duplicates. Two independent researchers conducted a parallel-blinded screening process to identify the eligible studies based on titles and abstracts; 39 studies were analyzed in the current review. The main findings show prevalence estimates of 22.9% (95% CI: 17.7- 29.2) for intellectual disability; 26.2% (22-31) for attention-deficit hyperactivity disorder; 11.1% (8.6-14.1) for anxiety disorders; 19.7% (11.9-30.7) for sleep disorders; 7% (5.2- 9.3) for disruptive disorders; 2% (1.3- 3.1) for bipolar disorders; 2.7% (1.8- 4.2) for depression; 1.8% (0.4-8.7) for obsessive-compulsive disorder; and 0.6% (0.3-1.1) for psychosis. Psychiatric comorbidity in population-based studies is lower than in clinical and referred samples. However, our results also indicate that the frequency of psychiatric comorbidity in children and adolescents with ASD in the population context is considerable, without the influence of referral bias implicit in clinical and treatment samples. There is a need for better targeted diagnostic tools to detect psychiatric comorbidity in children and youth in future population-based studies, as an essential component in providing care as well as new insights into the nature and mechanisms of its underlying associations.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021234464].

Autism Spectrum Disorder and Intellectual Disability: A Pilot Study Exploring Associations between Child Sleep Problems, Child Factors and Parent Factors

Sleep problems are common in children with autism spectrum disorder (ASD). However, few studies have undertaken group comparisons of sleep profiles and factors associated with poorer sleep between children with ASD without intellectual disability (ID; hereafter referred to as ASD) and ASD with co-occurring ID (hereafter referred to as ASD + ID). This study aimed to (1) compare child (sleep problems and emotional and behavioural problems (EBPs)) and parent factors (parenting stress and mental health) for children with ASD compared to children with ASD + ID, and (2) examine the associations between sleep problems and child and parent factors in both groups. Parents of 56 children with ASD (22 ASD, 34 ASD + ID) aged 6–13 years took part in the study. No statistically significant differences in sleep problems were found between children with ASD compared to children with ASD + ID. However, total EBPs were independently associated with child sleep problems in both groups. Further, ‘Self-Absorbed’ and ‘Communication Disturbance’ EBPs were significantly greater in the ASD + ID compared to the ASD group. Overall treatment outcomes for children with ASD may be further improved if consideration is given to the specific types of EBPs being experienced by the child and their association with sleep problems.

Nightmares in Children with Foetal Alcohol Spectrum Disorders, Autism Spectrum Disorders, and Their Typically Developing Peers

Children with Foetal Alcohol Spectrum Disorders (FASD) and Autism Spectrum Disorders (ASD) experience significantly higher rates of sleep disturbances than their typically developing (TD) peers. Pre-sleep anxiety and waking emotional content is known to affect the content and frequency of nightmares, which can be distressing to children and caregivers. This is the first study to analyse nightmare frequency and content in FASD, and to assess its association with psychometric outcomes. Using online caregiver questionnaires, we assessed reports from 277 caregivers of children with ASD (n = 61), FASD (n = 112), and TD children (n = 104) using the Children's Sleep Habits Questionnaire (CSHQ), the Child Behaviour Checklist (CBCL), the Spence Children's Anxiety Scale (SCAS), and the Behaviour Rating Inventory for Executive Functioning (BRIEF). Within the ASD group, 40.3% of caregivers reported their children had nightmares. Within the FASD group, 73.62% of caregivers reported their children had nightmares, and within the TD group, 21.36% of caregivers reported their children had nightmares. Correlation analysis revealed significant associations between anxiety and nightmares, maladaptive behaviour and nightmares, and executive functioning and nightmares in the TD and FASD groups, but not ASD group. This paper adds to the emerging body of work supporting the need for sleep interventions as part of clinical practice with regard to children with ASD and FASD. As a relatively niche but important area of study, this warrants much needed further research.

Factor Structure of the Children's Sleep Habits Questionnaire in Young Children with and Without Autism

The Children's Sleep Habits Questionnaire (CSHQ) is often used to assess sleep in children with autism spectrum disorder (ASD), but little is known about its factor structure in younger children with ASD. We evaluated alternative factor structures and measurement invariance for CSHQ items in 2- to 4-year-olds with ASD or typical development (TD). Bifactor models indicated subscales' variance was subsumed by a general factor predominantly reflecting sleep initiation and nighttime awakening items. A factor consisting of 7 of these items was measurement invariant across ASD and TD. Thus, comparisons between young children with ASD and TD is appropriate for a measure composed of 7 CSHQ items relating to sleep initiation and awakenings but not for other CSHQ item composites.

Subjective and Electroencephalographic Sleep Parameters in Children and Adolescents with Autism Spectrum Disorder: A Systematic Review

Background: Sleep problems have commonly manifested in children and adolescents with autism spectrum disorder (ASD) with a complex and multifactorial interaction between clinical and etiological components. These disorders are associated with functional impairment, and provoke significant physical and mental affliction. The purpose of this study is to update the existing literature about objective and subjective sleep parameters in children and adolescents with ASD, extrapolating information from polysomnography or sleep electroencephalography, and sleep related questionnaires. Methods: We have conducted a systematic review of case-control studies on this topic, performing a web-based search on PubMed, Scopus and the Web of Science databases according to the Preferred Reporting items for Systematic Review and Meta-analyses (PRISMA) guidelines. Results: Data collected from 20 survey result reports showed that children and adolescents with ASD experienced a higher rate of sleep abnormalities than in typically developing children. The macrostructural sleep parameters that were consistent with subjective parent reported measures unveil a greater percentage of nighttime signs of insomnia. Sleep microstructure patterns, in addition, pointed towards the bidirectional relationship between brain dysfunctions and sleep problems in children with ASD. Conclusions: Today’s literature acknowledges that objective and subjective sleep difficulties are more often recognized in individuals with ASD, so clinicians should assess sleep quality in the ASD clinical population, taking into consideration the potential implications on treatment strategies. It would be worthwhile in future studies to examine how factors, such as age, cognitive level or ASD severity could be related to ASD sleep abnormalities. Future research should directly assess whether sleep alterations could represent a specific marker for atypical brain development in ASD.

Autism BrainNet: A Collaboration Between Medical Examiners, Pathologists, Researchers, and Families to Advance the Understanding and Treatment of Autism Spectrum Disorder

CONTEXT.—

Autism spectrum disorder is a neurodevelopmental condition that affects over 1% of the population worldwide. Developing effective preventions and treatments for autism will depend on understanding the neuropathology of the disorder. While evidence from magnetic resonance imaging indicates altered development of the autistic brain, it lacks the resolution needed to identify the cellular and molecular underpinnings of the disorder. Postmortem studies of human brain tissue currently represent the only viable option to pursuing these critical studies. Historically, the availability of autism brain tissue has been extremely limited.

OBJECTIVE.—

To overcome this limitation, Autism BrainNet, funded by the Simons Foundation, was formed as a network of brain collection sites that work in a coordinated fashion to develop a library of human postmortem brain tissues for distribution to researchers worldwide. Autism BrainNet has collection sites (or Nodes) in California, Texas, and Massachusetts; affiliated, international Nodes are located in Oxford, England and Montreal, Quebec, Canada.

DATA SOURCES.—

Pubmed, Autism BrainNet.

CONCLUSIONS.—

Because the death of autistic individuals is often because of an accident, drowning, suicide, or sudden unexpected death in epilepsy, they often are seen in a medical examiner's or coroner's office. Yet, autism is rarely considered when evaluating the cause of death. Advances in our understanding of chronic traumatic encephalopathy have occurred because medical examiners and neuropathologists questioned whether a pathologic change might exist in individuals who played contact sports and later developed severe behavioral problems. This article highlights the potential for equally significant breakthroughs in autism arising from the proactive efforts of medical examiners, pathologists, and coroners in partnership with Autism BrainNet.

'Investigating longitudinal associations between parent reported sleep in early childhood and teacher reported executive functioning in school-aged children with autism'

Up to 80% of children with autism spectrum disorder (ASD) experience sleep disturbance. Poor sleep impairs executive functioning (EF), a lifelong difficulty in ASD. Evidence suggests EF difficulties in ASD are exacerbated by poor sleep. We examine whether early childhood sleep disturbances are associated with worsening EF trajectories in school-aged children with ASD. A subsample (n=217) from the Pathways in ASD longitudinal study was analyzed. The Children's Sleep Habits Questionnaire captured sleep duration, onset, and night awakenings before age 5 (Mean=3.5years). Metacognition (MI) and Behavioral Regulation (BRI) indices, on the Teacher Behavior Rating Inventory of Executive Functioning, were used to measure cognitive and affective components of EF respectively at four time-points (7.8-11.8years). We applied latent growth curve models to examine associations between sleep and EF, accounting for relevant covariates, including school-age sleep (Mean=6.7years). Sleep traits had different age-related impacts on behavioral regulation, but not metacognition. Longer sleep onset at 3.5 years was associated with a worsening BRI difficulties slope (b=2.07, p<0.04), but conversely associated with lower BRI difficulties at 7.7 years (b=-4.14, p=0.04). A longer sleep onset at 6.7 years was related to higher BRI difficulties at 7.7 years (b=7.78, p<0.01). Longer sleep duration at 6.7 years was associated with higher BRI difficulties at age 7.7 (b=3.15, p=0.01), but subscale analyses revealed shorter sleep duration at age 6.7 was linked to a worsening inhibition slope (b=-0.60, p=0.01). Sleep onset is a robust early correlate of behavior regulation in children with ASD, whereas sleep duration is a later childhood correlate.

Attention-deficit/hyperactivity disorder symptoms and sleep problems in preschool children: the role of autistic traits

BACKGROUND

Sleep problems are elevated in children with attention-deficit/hyperactivity disorder (ADHD). However, until now there has been comparatively little research on the role of autistic traits in this association. The current study examined the association between ADHD symptoms and sleep problems in Japanese preschool children and whether autistic traits might also be important for this relationship.

METHODS

Data were analyzed from 1053 children (average age 64.14 months, range 58-71; 50.3% male) that were drawn from the Tama Children's Survey (TCS). Parent-reported information was obtained on ADHD symptoms using the Strengths and Difficulties Questionnaire (SDQ) and autistic traits with the Social Responsiveness Scale Second Edition (SRS-2). Parents also provided information on three different categories of sleep problems experienced by their children - parasomnias, sleep disordered breathing and awakening/daytime problems. Ordinal logistic regression analysis was used to examine the associations.

RESULTS

In analyses adjusted for sociodemographic factors, the mother's mental health and child's emotional problems, compared to children with no ADHD symptoms or autistic traits, children with only ADHD symptoms had significantly increased odds for only one of 11 individual sleep problems - waking in a negative mood. In contrast, children with comorbid ADHD symptoms and autistic traits had elevated odds for five sleep problems with odds ratios ranging from 2.10 (takes time to become alert in the morning) to 3.46 (excessive body movement while sleeping).

CONCLUSIONS

Sleep problems may be especially elevated in children with comorbid ADHD symptoms and autistic traits.

Sleep disturbances in autism spectrum disorder without intellectual impairment: relationship with executive function and psychiatric symptoms

The autism spectrum disorder (ASD) is a neurodevelopmental condition, frequently accompanied by medical and psychiatric pathology. One of the most commonly found problems associated with ASD is sleep disturbances, which are estimated to affect approximately 80% of the people with ASD, not only during childhood but also in the adolescence and adult stages. Nevertheless, the relationship of these sleep difficulties with autism severity, as well as other associated impairments such as executive functioning and psychiatric disorders (eg, depression), has not yet been widely studied. The main objective of the present study was to explore the relationship between sleep disturbances, subjective measures of executive function, and psychiatric pathology in the ASD population. To reach that goal, a group of 89 participants with ASD (44 children/adolescents and 45 adults) was recruited and evaluated with self-reported measures of executive function performance and psychiatric pathology tests. Multivariate analysis showed a significant association between sleep disturbances and psychiatric symptoms in both ASD groups, with greater sleep disturbances predicting more severe psychiatric pathology. No significant association was found with executive function in any group. Limitations included a small sample size and lack of objective measures. Sleep problems seem to be associated with the severity of psychiatric pathology throughout the lifespan, increasing the chance of developing psychiatric symptoms when they were present. Improving sleep quality in ASD at all ages may result in preventing and/or decreasing psychiatric pathology in this population.

Disrupted nocturnal melatonin in autism: Association with tumor necrosis factor and sleep disturbances

Sleep disturbances, abnormal melatonin secretion, and increased inflammation are aspects of autism spectrum disorder (ASD) pathophysiology. The present study evaluated the daily urinary 6-sulfatoxymelatonin (aMT6s) excretion profile and the salivary levels of tumor necrosis factor (TNF) and interleukin-6 (IL-6) in 20 controls and 20 ASD participants, as well as correlating these measures with sleep disturbances. Although 60% of ASD participants showed a significant night-time rise in aMT6s excretion, this rise was significantly attenuated, compared to controls (P < .05). The remaining 40% of ASD individuals showed no significant increase in nocturnal aMT6s. ASD individuals showed higher nocturnal levels of saliva TNF, but not IL-6. Dysfunction in the initiation and maintenance of sleep, as indicated by the Sleep Disturbance Scale for Children, correlated with night-time aMT6s excretion (r = -.28, P < .05). Dysfunction in sleep breathing was inversely correlated with aMT6s (r = -.31, P < .05) and positively associated with TNF level (r = .42, P < .01). Overall such data indicate immune-pineal axis activation, with elevated TNF but not IL-6 levels associated with disrupted pineal melatonin release and sleep dysfunction in ASD. It is proposed that circadian dysregulation in ASD is intimately linked to heightened immune-inflammatory activity. Such two-way interactions of the immune-pineal axis may underpin many aspects of ASD pathophysiology, including sleep disturbances, as well as cognitive and behavioral alterations.

Lights Out: Examining Sleep in Children with Vision Impairment

Sleep is crucial for development across cognitive, physical, and social-emotional domains. Sleep quality and quantity impact domains of daytime functioning, attainment, and global development. Previous work has explored sleep profiles in typically developing children and children with developmental disorders such as Down syndrome and Williams Syndrome, yet there is a complete absence of published work regarding the sleep profiles of children with vision impairment aged 4–11 years. This is the first known study that examines the sleep profiles in children with vision impairment (n = 58) in comparison to 58 typically developing children (aged 4–11 years) in the UK. Sleep was measured using the Childhood Sleep Habits Questionnaire (CSHQ; parental report), actigraphy and sleep diaries. Results showed group differences in subjective CSHQ scores but not objective actigraphy measures. Surprisingly, the findings revealed disordered sleep (namely, poor sleep quantity) in both groups. Discordance between CSHQ and actigraphy measures could represent heightened awareness of sleeping problems in parents/caregivers of children with vision impairment. The implications of this study extend beyond group comparison, examining disordered sleep in ‘typically developing’ children, exploring the potential role of light perception and the importance of sleep quality and quantity in both groups.

Sulfur amino acid metabolism and related metabotypes of autism spectrum disorder: A review of biochemical evidence for a hypothesis

There are multiple lines of evidence for an impaired sulfur amino acid (SAA) metabolism in autism spectrum disorder (ASD). For instance, the concentrations of methionine, cysteine and S-adenosylmethionine (SAM) in body fluids of individuals with ASD is significantly lower while the concentration of S-adenosylhomocysteine (SAH) is significantly higher as compared to healthy individuals. Reduced methionine and SAM may reflect impaired remethylation pathway whereas increased SAH may reflect reduced S-adenosylhomocysteine hydrolase activity in the catabolic direction. Reduced SAM/SAH ratio reflects an impaired methylation capacity. We hypothesize multiple mechanisms to explain how the interplay of oxidative stress, neuroinflammation, mercury exposure, maternal use of valproate, altered gut microbiome and certain genetic variants may lead to these SAA metabotypes. Furthermore, we also propose a number of mechanisms to explain the metabolic consequences of abnormal SAA metabotypes. For instance in the brain, reduced SAM/SAH ratio will result in melatonin deficiency and hypomethylation of a number of biomolecules such as DNA, RNA and histones. In addition to previously proposed mechanisms, we propose that impaired activity of "radical SAM" enzymes will result in reduced endogenous lipoic acid synthesis, reduced molybdenum cofactor synthesis and impaired porphyrin metabolism leading to mitochondrial dysfunction, porphyrinuria and impaired sulfation capacity. Furthermore depletion of SAM may also lead to the disturbed mTOR signaling pathway in a subgroup of ASD. The proposed "SAM-depletion hypothesis" is an inclusive model to explain the relationship between heterogeneous risk factors and metabotypes observed in a subset of children with ASD.

Differential Item Functioning Based on Autism Features, IQ, and Age on the Screen for Child Anxiety Related Disorders (SCARED) Among Youth on the Autism Spectrum

Anxiety commonly occurs among youth on the autism spectrum, yet measurement of anxiety in this population is complicated by a number of factors, including potentially overlapping symptomatology, the child's intellectual functioning, and changes in anxiety across development. Moreover, few studies have examined the psychometric properties of anxiety measures in this population, and no study to date has tested whether there are systematic differences in the measurement of anxiety, or differential item functioning (DIF), across the high degree of heterogeneity and the developmental course of autism. To test this possibility, data were combined across multiple studies using the National Database for Autism Research, an NIH-funded data repository. Parent-report on the Screen for Child Anxiety Related Disorders (SCARED) and Social Communication Questionnaire (SCQ) were used as measures of anxiety and autism features, respectively. A confirmatory factor analysis indicated good fit of the literature standard five-factor structure. Moderated nonlinear factor analysis (MNLFA) revealed multiple items with intercept and loading DIF based on level of autism features, IQ, and age, especially for items related to social behavior. Therefore, although the measure's factor structure is consistent with that found in the general population, the SCARED may not capture differences in anxiety equivalently for all children on the spectrum and across their development. Clinicians and researchers need to be especially vigilant in measuring anxiety symptoms in children with autism by removing items flagged for DIF from the SCARED and/or by using multiple measures and informants. LAY ABSTRACT: Autistic youth often experience clinical levels of anxiety. Many tools used to measure anxiety were developed for the general population, but not for use with autistic youth. This study found that the Screen for Child Anxiety Related Disorders (SCARED) measures the same five dimensions of anxiety as in the general population. Parents, however, may respond differently to questions on the SCARED based on their child's autism features, intellectual functioning, and age, which impacts our ability to accurately measure anxiety among autistic youth.

Sleep Disorders in Autism Spectrum Disorder Pre-School Children: An Evaluation Using the Sleep Disturbance Scale for Children

Background and Objectives: Sleep disorders are common in children with Autism Spectrum Disorder (ASD). The aims of this study were to describe the incidence and characteristics of sleep disorders using a questionnaire completed by the caregiver in a sample of preschool-aged children with ASD and to identify possible differences in a control group of peers. Materials and Methods: Sleep disorders were investigated with the Sleep Disturbance Scale for Children (SDSC) in a population of pre-school-aged (3–5 years) ASD children and in a control group. The Autism Diagnostic Observation Schedule—second ed. (ADOS-2) was further used to assess autism symptom severity. A total of 84 children (69 males; mean age 3.9 ± 0.8 years) with a diagnosis of ASD and 84 healthy controls (65 males; mean age of 3.7 ± 0.8 years) that were matched for age and sex were enrolled. Results: ASD children reported significantly higher (pathological) scores than the control group on the SDSC total scores and in some of the factor scores, such as Difficulty in Initiating and Maintaining Sleep (DIMS), disorders of excessive somnolence (DOES), and sleep hyperhidrosis. A total of 18% of ASD children had a pathological SDSC total T-score, and 46% had an abnormal score on at least one sleep factor; DIMS, parasomnias, and DOES showed the highest rates among the sleep factors. Younger children (3 years) reported higher scores in DIMS and sleep hyperhidrosis than older ones (4 and 5 years). No specific correlation was found between ADOS-2 and SDSC scores. Conclusions: Pre-school children with ASD showed a high incidence of sleep disorders with different distributions of specific sleep factors according to their age. We suggest a screening assessment of sleep disorders using the SDSC in these children with a more in-depth evaluation for those reporting pathological scores on the questionnaire.

Umbrella systematic review of systematic reviews and meta-analyses on comorbid physical conditions in people with autism spectrum disorder

BACKGROUND

Comorbid physical conditions may be more common in people with autism spectrum disorder (ASD) than other people.

AIMS

To identify what is and what is not known about comorbid physical conditions in people with ASD.

METHOD

We undertook an umbrella systematic review of systematic reviews and meta-analyses on comorbid physical conditions in people with ASD. Five databases were searched. There were strict inclusion/exclusion criteria. We undertook double reviewing for eligibility, systematic data extraction and quality assessment. Prospective PROSPERO registration: CRD42015020896.

RESULTS

In total, 24 of 5552 retrieved articles were included, 15 on children, 1 on adults, and 8 both on children and adults. Although the quality of included reviews was good, most reported several limitations in the studies they included and considerable heterogeneity. Comorbid physical conditions are common, and some are more prevalent than in the general population: sleep problems, epilepsy, sensory impairments, atopy, autoimmune disorders and obesity. Asthma is not. However, there are substantial gaps in the evidence base. Fewer studies have been undertaken on other conditions and some findings are inconsistent.

CONCLUSIONS

Comorbid physical conditions occur more commonly in people with ASD, but the evidence base is slim and more research is needed. Some comorbidities compound care if clinicians are unaware, for example sensory impairments, given the communication needs of people with ASD. Others, such as obesity, can lead to an array of other conditions, disadvantages and early mortality. It is essential that potentially modifiable physical conditions are identified to ensure people with ASD achieve their best outcomes. Heightening clinicians' awareness is important to aid in assessments and differential diagnoses, and to improve healthcare.

Sleep Disturbances and Patterns in Children With Neurodevelopmental Conditions

Background: Children with neurodevelopmental conditions (NDC) often experience sleep problems which are long-lasting and more complex than typically developing children. These sleep problems impact their families and there is little guidance for management specifically for sleep for families of children with neurodevelopmental conditions. The present study aims to use parental report to evaluate sleep disturbances and sleep patterns in a large sample of children with NDC. We aim to identify associations with age, diagnosis, and medication groups. Methods: Data on 601 children aged between 2 and 17 years was analyzed from a UK non-profit service for sleep for families of children with NDC. Parents/carers completed the children's sleep habit questionnaire, a 7 day sleep diary, and information on child age, diagnosis, and medication. Parents also reported previous sleep management techniques they had tried. Results: Overall, we found differences between age, diagnosis, and medication use groups for sleep disturbances and sleep diary parameters in these populations. Sensory conditions were associated with high night time waking duration. Parents reported their child's short sleep duration was the most common problem for them. Conclusions: Key areas for further research are outlined including the long term considerations for parental presence at bedtime for sleep anxiety, melatonin use and efficacy, and consideration for interventions to reduce daytime fatigue in children aged 7-11 years old.