Temperament as an Early Risk Marker for Autism Spectrum Disorders? A Longitudinal Study of High-Risk and Low-Risk Infants

Infant sleep predicts trajectories of social attention and later autism traits

BACKGROUND

Children with neurodevelopmental disorders including autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) often experience sleep disturbances, but little is known about when these sleep differences emerge and how they relate to later development.

METHODS

We used a prospective longitudinal design in infants with a family history of ASD and/or ADHD to examine infant sleep and its relation to trajectories of attention and later neurodevelopmental disorders. We formed factors of Day and Night Sleep from parent-reported measures (including day/night sleep duration, number of naps in the day, frequency of night awakenings and sleep onset problems). We examined sleep in 164 infants at 5-, 10- and 14-months with/without a first-degree relative with ASD and/or ADHD who underwent a consensus clinical assessment for ASD at age 3.

RESULTS

By 14-months, infants with a first-degree relative with ASD (but not ADHD) showed lower Night Sleep scores than infants with no family history of ASD; lower Night Sleep scores in infancy were also associated with a later ASD diagnosis, decreased cognitive ability, increased ASD symptomatology at 3-years, and developing social attention (e.g., looking to faces). We found no such effects with Day Sleep.

CONCLUSIONS

Sleep disturbances may be apparent at night from 14-months in infants with a family history of ASD and also those with later ASD, but were not associated with a family history of ADHD. Infant sleep disturbances were also linked to later dimensional variation in cognitive and social skills across the cohort. Night Sleep and Social Attention were interrelated over the first 2 years of life, suggesting that this may be one mechanism through which sleep quality influences neurodevelopment. Interventions targeted towards supporting families with their infant's sleep problems may be useful in this population.

Continuity of temperament subgroup classifications from infancy to toddlerhood in the context of early autism traits

Our previous cross-sectional investigation (Chetcuti et al., 2020) showed that infants with autism traits could be divided into distinct subgroups based on temperament. This longitudinal study builds on this existing work by exploring the continuity of temperament subgroup classifications and their associations with behavioral/clinical phenotypic features from infancy to toddlerhood. 103 infants (68% male) showing early signs of autism were referred to the study by community healthcare professionals and seen for assessments when aged around 12-months (Time 1), 18-months (Time 2), and 24-months (Time 3). Latent profile analysis revealed inhibited/low positive, active/negative reactive, and sociable/well-regulated subgroups at each timepoint, and a unique reactive/regulated subgroup at Time 3. Cross-tabulations indicated a significant likelihood of children having a recurrent subgroup classification from one timepoint to the next, and no apparent patterns to the movement of children who did change from one subgroup to another over time. Temperament subgroups were associated with concurrent child social-emotional functioning and autism traits, but unrelated to child age, sex, or developmental level. These findings suggest that temperament subgroup classifications might represent a reliable and very early indicator of autism characteristics and social-emotional functioning among infants/toddlers with autism traits.

Prediction of autism in infants: progress and challenges

Autism spectrum disorder (henceforth autism) is a neurodevelopmental condition that can be reliably diagnosed in children by age 18-24 months. Prospective longitudinal studies of infants aged 1 year and younger who are later diagnosed with autism are elucidating the early developmental course of autism and identifying ways of predicting autism before diagnosis is possible. Studies that use MRI, EEG, and near-infrared spectroscopy have identified differences in brain development in infants later diagnosed with autism compared with infants without autism. Retrospective studies of infants younger than 1 year who received a later diagnosis of autism have also showed an increased prevalence of health conditions, such as sleep disorders, gastrointestinal disorders, and vision problems. Behavioural features of infants later diagnosed with autism include differences in attention, vocalisations, gestures, affect, temperament, social engagement, sensory processing, and motor abilities. Although research findings offer insight on promising screening approaches for predicting autism in infants, individual-level predictions remain a future goal. Multiple scientific challenges and ethical questions remain to be addressed to translate research on early brain-based and behavioural predictors of autism into feasible and reliable screening tools for clinical practice.

Examining the factor structure and discriminative utility of the Infant Behavior Questionnaire-Revised in infant siblings of autistic children

Using the Infant Behavior Questionnaire-Revised in a longitudinal sample of infant siblings of autistic children (HR; n = 427, 171 female, 83.4% White) and a comparison group of low-risk controls (LR, n = 200, 86 female, 81.5% White), collected between 2007 and 2017, this study identified an invariant factor structure of temperament traits across groups at 6 and 12 months. Second, after partitioning the groups by familial risk and diagnostic outcome at 24 months, results reveal an endophenotypic pattern of Positive Emotionality at both 6 and 12 months, (HR-autism spectrum disorder [ASD] < HR-no-ASD < LR). Third, increased 'Duration of Orienting' at 12 months was associated with lower scores on the 24-month developmental outcomes in HR infants. These findings may augment efforts for early identification of ASD.

Infant Effortful Control Mediates Relations Between Nondirective Parenting and Internalising-Related Child Behaviours in an Autism-Enriched Infant Cohort

Internalising problems are common within Autism Spectrum Disorder (ASD); early intervention to support those with emerging signs may be warranted. One promising signal lies in how individual differences in temperament are shaped by parenting. Our longitudinal study of infants with and without an older sibling with ASD investigated how parenting associates with infant behavioural inhibition (8-14 months) and later effortful control (24 months) in relation to 3-year internalising symptoms. Mediation analyses suggest nondirective parenting (8 months) was related to fewer internalising problems through an increase in effortful control. Parenting did not moderate the stable predictive relation of behavioural inhibition on later internalising. We discuss the potential for parenting to strengthen protective factors against internalising in infants from an ASD-enriched cohort.

Retained Primitive Reflexes and Potential for Intervention in Autistic Spectrum Disorders

We provide evidence to support the contention that many aspects of Autistic Spectrum Disorder (ASD) are related to interregional brain functional disconnectivity associated with maturational delays in the development of brain networks. We think a delay in brain maturation in some networks may result in an increase in cortical maturation and development in other networks, leading to a developmental asynchrony and an unevenness of functional skills and symptoms. The paper supports the close relationship between retained primitive reflexes and cognitive and motor function in general and in ASD in particular provided to indicate that the inhibition of RPRs can effect positive change in ASD.

Early signs of autism in infants whose mothers suffered from a threatened preterm labour: a 30-month prospective follow-up study

Infants born after a threatened preterm labour (TPL infants) are at high risk of autism spectrum disorder (ASD). Studying this population may provide insight on the pathophysiological underpinnings of this condition. This study aimed to (i) ascertain the presence and autistic symptom load in TPL infants aged age 30 months relative to non-TPL infants, regardless of preterm birth; (ii) explore the association between early (at 6 months) psychomotor development and temperament features with the autistic symptom load of TPL infants at age 30 months and (iii) examine the association among perinatal risk factors for ASD development with the autistic symptom load of TPL infants at age 30 months. A group of 111 mother-infant pairs recruited at TPL diagnosis and a group of 47 healthy mother-infant controls completed the follow-up. Irrespective of preterm birth, TPL infants showed higher autistic symptom load at age 30 months than non-TPL infants. TPL infants presented poorer communication and problem-solving skills, reduced smiling and laughter, and greater vocal reactivity at age 6 months, predicting higher autistic symptom load at age 30 months. Higher levels of anxiety symptoms in TPL mothers after a TPL diagnosis also predicted higher autistic symptom load for the infants at age 30 months. These results suggest that TPL infants may be an undescribed cluster, with features that differentiate them from other "at-risk" populations. These findings support the need for routine assessment of TPL infants and screening of anxiety symptoms in mothers.

Early measurement of autism risk constructs in the general population: A new factor structure of the First Years Inventory (FYIv3.1) for ages 6-16 months

Early detection of autism risk in the community is critical to increasing families' access to early intervention, yet few measures have been developed and tested for the general population of infants <16 months to tap a broader range of autism risk constructs. This study aimed to (a) examine the factor structure of the First Years Inventory, version 3.1 (FYIv3.1), with a sample of 6454 infants 6-16 months, and (b) determine the ability of the resulting factors to discriminate clinical outcome groups at 3 years of age. The FYIv3.1 is a parent-report tool designed to detect early behavioral risk signs that may be associated with a later diagnosis of ASD and related neurodevelopmental conditions. Factor analytic models were used to determine the number of constructs and inter-factor correlations. Findings supported a seven-factor structure: communication, imitation and play (CIP); social attention and affective engagement (SAE); sensory hyperresponsiveness (HYPER); sensory hyporesponsiveness (HYPO); self-regulation in daily routines (SREG); sensory interests, repetitions, and seeking behaviors (SIRS); motor coordination and milestones (MCM). Mean comparisons on these factors demonstrated significant discrimination of the three outcome groups at age 3 years including those classified as having an ASD diagnosis and/or high autism symptoms, those classified as having other developmental disorders/conditions/concerns, and those classified with no known conditions/concerns. These findings support the validity and multidimensionality of early ASD risk constructs, as well as the potential use of the FYIv3.1 for phenotypic subtyping in the general population, and early detection in a broader age range of 6-16 months in future clinical studies. LAY SUMMARY: The FYIv3.1 is a 69-item parent-report questionnaire about infant behaviors that may indicate an elevated likelihood for later neurodevelopmental conditions such as autism. Analyses of responses from 6454 parents of infants 6-16 months indicated that items could be grouped reliably into seven categories. Compared to children with or without other developmental conditions, children in the outcome group with autism spectrum disorder and/or high autism symptoms at age three showed more behavioral risk signs in social-communication, sensory, and motor domains during infancy.

The Vocabulary of Infants with an Elevated Likelihood and Diagnosis of Autism Spectrum Disorder: A Systematic Review and Meta-Analysis of Infant Language Studies Using the CDI and MSEL

Diagnoses of autism spectrum disorder (ASD) are typically accompanied by atypical language development, which can be noticeable even before diagnosis. The siblings of children diagnosed with ASD are at elevated likelihood for ASD diagnosis and have been shown to have higher prevalence rates than the general population. In this paper, we systematically reviewed studies looking at the vocabulary size and development of infants with autism. One inclusion criterion was that infants were grouped either pre-diagnostically as elevated or typical likelihood or post-diagnostically as ASD or without ASD. This review focused on studies that tested infants up to 24 months of age and that assessed vocabulary either via the parent-completed MacArthur–Bates Communicative Developmental Inventory (CDI) or the clinician-administered Mullen Scales of Early Learning (MSEL). Our systematic search yielded 76 studies. A meta-analysis was performed on these studies that compared the vocabulary scores of EL and TL infants pre-diagnostically and the scores of ASD and non-ASD infants post-diagnostically. Both pre- and post-diagnostically, it was found that the EL and ASD infants had smaller vocabularies than their TL and non-ASD peers, respectively. The effect sizes across studies were heterogenous, prompting additional moderator analyses of age and sub-group analyses of the language measure used (CDI or MSEL) as potential moderators of the effect size. Age was found to be a moderator both in the pre- and post-diagnostical groups, however, language measure was not a moderator in either diagnostic group. Interpretations and future research directions are discussed based on these findings.

Food for Thought: Machine Learning in Autism Spectrum Disorder Screening of Infants

Diagnoses of autism spectrum disorders (ASD) are typically made after toddlerhood by examining behavioural patterns. Earlier identification of ASD enables earlier intervention and better outcomes. Machine learning provides a data-driven approach of diagnosing autism at an earlier age. This review aims to summarize recent studies and technologies utilizing machine learning based strategies to screen infants and children under the age of 18 months for ASD, and identify gaps that can be addressed in the future. We reviewed nine studies based on our search criteria, which includes primary studies and technologies conducted within the last 10 years that examine children with ASD or at high risk of ASD with a mean age of less than 18 months old. The studies must use machine learning analysis of behavioural features of ASD as major methodology. A total of nine studies were reviewed, of which the sensitivity ranges from 60.7% to 95.6%, the specificity ranges from 50% to 100%, and the accuracy ranges from 60.9% to 97.7%. Factors that contribute to the inconsistent findings include the varied presentation of ASD among patients and study design differences. Previous studies have shown moderate accuracy, sensitivity and specificity in the differentiation of ASD and non-ASD individuals under the age of 18 months. The application of machine learning and artificial intelligence in the screening of ASD in infants is still in its infancy, as observed by the granularity of data available for review. As such, much work needs to be done before the aforementioned technologies can be applied into clinical practice to facilitate early screening of ASD.

Caregiver Psychological Distress Predicts Temperament and Social-Emotional Outcomes in Infants with Autism Traits

Child temperament and caregiver psychological distress have been independently associated with social-emotional difficulties among individuals with autism. However, the interrelationship among these risk factors has rarely been investigated. We explored the reciprocal interplay between child temperament (surgency, negative affectivity, and self-regulation) and caregiver psychological distress in the development of child internalizing and externalizing symptoms, in a cohort of 103 infants showing early autism traits. Caregivers completed questionnaires when children were aged around 12-months (Time 1 [T1]), 18-months (Time 2 [T2]), and 24-months (Time 3 [T3]). Cross-lagged path models revealed a significant pathway from T1 caregiver psychological distress through lower T2 child self-regulation to subsequently greater T3 child internalizing symptoms. No such caregiver-driven pathway was evident through T2 child negative affectivity or in the prediction of T3 child externalizing symptoms. Further, no support was found for temperament-driven pathways through caregiver psychological distress to child social-emotional difficulties. Child surgency was mostly unrelated to caregiver psychological distress and social-emotional difficulties. These findings implicate the need to support the mental health of caregivers with an infant with autism traits in order to enhance the emotion regulation and social-emotional development of their infants.

Early non-social behavioural indicators of autism spectrum disorder (ASD) in siblings at elevated likelihood for ASD: a systematic review

We aimed at identifying early non-social behavioural indicators that predict later ASD. Likewise, we were interested in the moment in which non-social signs discriminate between children at elevated likelihood for ASD with a later diagnosis of ASD, and children at elevated likelihood for ASD with a typical developmental outcome. In addition, we intended to explore the developmental evolution of children's symptomatology over time. A systematic literature search was conducted for longitudinal studies on early non-social behavioural indicators among siblings at elevated likelihood for ASD. The following databases were searched: PUBMED, Web of Science, PsycINFO, CINAHL and EMBASE. The study identification process was conducted by two reviewers independently. Compared to siblings at elevated likelihood for ASD with a typical developmental outcome, siblings at elevated likelihood for ASD with later ASD show impairments in attention disengagement, in gross and fine motor development and characteristic restricted and repetitive interests and behaviours, starting at 12 months of age. Moreover, early attention disengagement exerts a predictive role towards a later ASD diagnosis, given that from 12 months siblings at elevated likelihood for ASD who will receive an independent ASD diagnosis towards 24-36 months present marked difficulties in disengaging in comparison with siblings at elevated likelihood for ASD that will not satisfy the criteria for an ASD diagnosis. The findings call for a more comprehensive vision on early indicators of ASD. Further research is needed to extend results to other behavioural domains.

Temperament in individuals with Autism Spectrum Disorder: A systematic review

The study of temperament in Autism Spectrum Disorder (ASD) has the potential to provide insight regarding variability in the onset, nature, and course of both core and co-morbid symptoms. The aim of this systematic review was to integrate existing findings concerning temperament in the context of ASD. Searches of Medline, PsychInfo and Scopus databases identified 64 relevant studies. As a group, children and adolescents with ASD appear to be temperamentally different from both typically developing and other clinical non-ASD groups, characterized by higher negative affectivity, lower surgency, and lower effortful control at a higher-order level. Consistent with research on typically developing children, correlational findings and emerging longitudinal evidence suggests that lower effortful control and higher negative affect are associated with increased internalizing and externalizing problems in ASD samples. Longitudinal studies suggest there may be temperamental differences between high familial risk infants who do and do not develop ASD from as early as 6-months of age. Limitations of existing research are highlighted, and possible directions for future research to capitalize on the potential afforded through the study of temperament in relation to ASD are discussed.

Atypical Development of Attentional Control Associates with Later Adaptive Functioning, Autism and ADHD Traits

Autism is frequently associated with difficulties with top-down attentional control, which impact on individuals’ mental health and quality of life. The developmental processes involved in these attentional difficulties are not well understood. Using a data-driven approach, 2 samples (N = 294 and 412) of infants at elevated and typical likelihood of autism were grouped according to profiles of parent report of attention at 10, 15 and 25 months. In contrast to the normative profile of increases in attentional control scores between infancy and toddlerhood, a minority (7–9%) showed plateauing attentional control scores between 10 and 25 months. Consistent with pre-registered hypotheses, plateaued growth of attentional control was associated with elevated autism and ADHD traits, and lower adaptive functioning at age 3 years.

Early Electronic Screen Exposure and Autistic-Like Behaviors among Preschoolers: The Mediating Role of Caregiver-Child Interaction, Sleep Duration and Outdoor Activities

Research into early screen exposure has raised growing concerns about its impact upon children’s neuropsychological well-being. However, possible pathways remain unclear. This study therefore aimed not only to evaluate the association between screen exposure during the ages of 0–3 years and preschoolers’ autistic-like behaviors, but also the mediating roles of the frequency of caregiver-child interaction, sleep duration and level of participation in outdoor activities. Based on the 2017 survey of the Longhua Child Cohort Study, data of 29,595 child-caregiver dyads were obtained via a caregiver-reported questionnaire, with the data from 29,461 dyads included in the data analysis. Multiple linear and logistic regression models were employed to estimate the associations between screen exposure, caregiver-child interaction, sleep duration, outdoor activities, and children’s autistic-like behaviors. The results indicated that screen exposure during 0–3 years of age was associated with the presence of autistic-like behaviors at preschool age, and the strength of the association was enhanced with the increase of average daily screen time (Odds Ratios (ORs) ranging from 1.358 to 4.026). The frequency of caregiver-child interaction and sleep duration mediated 5.32% and 1.19% of the variance of the association respectively, but outdoor activities did not mediate the association. Our findings indicate that preschoolers who are exposed to screens at aged 0–3 years might have an increased risk of autistic-like behaviors, and that, the frequency of caregiver-child interaction and sleep duration might function as potential mediators of this association.

The temperament features associated with autism spectrum disorder in childhood: A systematic review

BACKGROUND

Temperament is an important construct that shapes child development. Temperament is suggested to present differently in different groups, such as children with neurodevelopmental disorders. However, it is not known whether there are specific temperament features associated with Autism Spectrum Disorder (ASD).

AIM

This systematic review aimed to synthesise extant literature to determine whether there are temperament features associated with ASD in infancy, toddlerhood and childhood.

METHODS AND PROCEDURES

Following the PRISMA guidelines for systematic reviews, we searched PsycINFO, CINAHL, Academic Search Ultimate and ProQuest for all available articles from database conception until January 2020. The Joanna Briggs Institute Critical Appraisal checklists were used to assess the methodological quality of included articles.

OUTCOMES AND RESULTS

Twenty-six articles met the selection criteria: (1) reported on the temperament of children (0-12 years of age) diagnosed with ASD, (2) peer-reviewed; and (3) published in English. Articles varied in overall methodological quality. Infants later diagnosed with ASD were found to more frequently be described as having 'easy' temperament features in early infancy, compared to typically developing infants and infants with developmental concerns but not ASD. Once diagnosed, children with ASD were reported to, as a group, display more negative affect, less extraversion and less effortful control than typically developing children.

CONCLUSIONS AND IMPLICATIONS

The literature suggests that more challenging temperament features are associated with ASD in childhood, but less is known about within group variability. Overall, this review highlights the need for further investigation into the variability of temperament in children with ASD.

Linking risk factors and outcomes in autism spectrum disorder: is there evidence for resilience?

Autism spectrum disorder (referred to here as autism) is one of several overlapping neurodevelopmental conditions that have variable impacts on different individuals. This variability results from dynamic interactions between biological and non-biological risk factors, which result in increasing differentiation between individuals over time. Although this differentiation continues well into adulthood, the infancy period is when the brain and behavior develop rapidly, and when the first signs and symptoms of autism emerge. This review discusses advances in our understanding of the causal pathways leading to autism and overlapping neurodevelopmental conditions. Research is also mapping trajectories of brain and behavioral development for some risk groups, namely later born siblings of children with autism and/or infants referred because of developmental concerns. This knowledge has been useful in improving early identification and establishing the feasibility of targeted interventions for infant risk groups before symptoms arise. However, key knowledge gaps remain, such as the discovery of protective factors (biological or environmental) that may mitigate the impact of risk. Also, the dynamic mechanisms that underlie the associations between risk factors and outcomes need further research. These include the processes of resilience, which may explain why some individuals at risk for autism achieve better than expected outcomes. Bridging these knowledge gaps would help to provide tools for early identification and intervention that reflect dynamic developmental pathways from risk to outcomes.

Infant rhesus macaque (Macaca mulatta) personality and subjective well-being

Infant temperament is theorized to lay the foundation for adult personality; however, many questions remain regarding personality in infancy, including the number of dimensions, extent to which they are adult-like, and their relation to other outcomes, such as mental and physical health. Here we tested whether adult-like personality dimensions are already present in infancy in a nonhuman primate species. We measured personality and subjective well-being in 7-month-old rhesus macaques (N = 55) using the Hominoid Personality Questionnaire and Subjective Well-Being Questionnaire, both of which were developed for adult primates based on human measures. Multiple human raters, who provided infants with daily care since birth, independently rated each infant. We found high interrater reliability. Results from a parallel analysis and scree plot indicated a five component structure, which, using principal components analysis, we found to be comprised of dimensions relating to Openness (e.g., curiosity, inquisitive, playfulness), Assertiveness (e.g., dominance, bullying, aggressive), Anxiety (e.g., vigilance, fearful), Friendliness (e.g., sociable, affectionate, sympathetic), and Intellect (e.g., organized, not erratic). These components are largely analogous to those in adult macaques, suggesting remarkably stable structural personality components across the lifespan. Infant macaques' subjective well-being positively correlates with Openness and Assertiveness and negatively correlated with Anxiety, similar to findings in adult macaques and other primates. Together, these findings suggest that, in macaques, infant personality dimensions may be conceptually related to adult personality and challenge the view that infant temperament may be disorganized and not as meaningful as adult personality. Further research is necessary to explore the antecedents, predictive validity, and stability of these personality components across situations and with development.

Changes in temperament over time in young children with autism spectrum disorder and other developmental delays: a follow-up comparison study

BACKGROUND

Although in the last decade some research has emerged on temperament in autism spectrum disorder (ASD), this research has primarily focused on the differences between children with ASD and their typically developing peers rather than the stability or change in temperament in this population. Thus, the goal of this study was to examine temperament over time in children with ASD, developmental delays (DD) and typical development (TD). Temperament differences were also compared among the three groups.

METHODS

To accomplish this, parents rated children's temperament at Time 1 (T1) and Time 2 (T2) using the Carey Temperament Scales (CTS).

RESULTS

Results from the study showed that at T1, parents of children with ASD rated their children as more withdrawn (i.e. approach), and emotionally negative (i.e. mood), and less distractible and adaptable than parents of children with TD and DD. Also, children with ASD were rated as more intense and children with DD as less distractible than their TD peers. Similarly, at T2, children with ASD were rated more withdrawn, and emotionally negative, and less persistent, rhythmic, adaptable and distractible than children with TD and DD. Also, children with ASD were rated as more active than their DD peers. Regarding stability, parent ratings of temperament appeared stable over time in the TD group, but ratings varied substantially in the ASD or DD groups. That is, for the ASD group, activity and approach at T1 were significantly associated with their corresponding dimensions at T2. However, for the TD group, rhythmicity, approach, intensity and mood at T1 were significantly associated with those dimensions at T2. No associations were found in the DD group. Regarding change, parents reported change in rhythmicity, persistence and threshold between T1 and T2 in the ASD group. Similarly, parents reported change in rhythmicity, approach and threshold between T1 and T2 in the DD group. Lastly, parents of TD children reported change in adaptability, persistence and distractibility between T1 and T2.

CONCLUSIONS

These findings are novel in that children with ASD appear to have less stable temperament profile and different change patterns than children with TD or DD. Similar to previous research, children with ASD were described by their parents as experiencing more temperamental difficulties.