Stranger Fear and Early Risk for Social Anxiety in Preschoolers with Fragile X Syndrome Contrasted to Autism Spectrum Disorder

Heterogeneity of Autism Characteristics in Genetic Syndromes: Key Considerations for Assessment and Support

Purpose of Review

Elevated prevalence of autism characteristics is reported in genetic syndromes associated with intellectual disability. This review summarises recent evidence on the behavioural heterogeneity of autism in the following syndromes: Fragile X, Cornelia de Lange, Williams, Prader-Willi, Angelman, Down, Smith-Magenis, and tuberous sclerosis complex. Key considerations for assessment and support are discussed.

Recent Findings

The profile and developmental trajectory of autism-related behaviour in these syndromes indicate some degree of syndrome specificity which may interact with broader behavioural phenotypes (e.g. hypersociability), intellectual disability, and mental health (e.g. anxiety). Genetic subtype and co-occurring epilepsy within syndromes contribute to increased significance of autism characteristics. Autism-related strengths and challenges are likely to be overlooked or misunderstood using existing screening/diagnostic tools and criteria, which lack sensitivity and specificity within these populations.

Summary

Autism characteristics are highly heterogeneous across genetic syndromes and often distinguishable from non-syndromic autism. Autism diagnostic assessment practices in this population should be tailored to specific syndromes. Service provisions must begin to prioritise needs-led support.

Early behavioral and physiological markers of social anxiety in infants with fragile X syndrome

Background

Social anxiety is highly prevalent in neurotypical children and children with fragile X syndrome (FXS). FXS is a genetic syndrome that is characterized by intellectual disability and an increased risk for autism spectrum disorder. If social anxiety is left untreated, negative outcomes are highly prevalent later in life. However, early detection of social anxiety is challenging as symptoms are often subtle or absent very early in life. Given the prevalence and impairment associated with childhood social anxiety, efforts have accelerated to identify risk markers of anxiety. A cluster of early features of anxiety have been identified including elevated behavioral inhibition, attentional biases, and physiological dysregulation that index early emerging markers of social anxiety. Infants with FXS provide a unique opportunity to study the earlier predictors of social anxiety. The current study utilized a multi-method approach to investigate early markers of social anxiety in 12-month-old infants with FXS.

Method

Participants included 32 infants with FXS and 41 low-risk controls, all approximately 12 months old. Parent-reported social behavioral inhibition was recorded from the Infant Behavior Questionnaire (IBQ-R). Direct observations of behavioral inhibition and attention were measured during a stranger approach task with respiratory sinus arrhythmia collected simultaneously.

Results

Parent-reported social behavioral inhibition was not significantly different between groups. In contrast, direct observations suggested that infants with FXS displayed elevated behavioral inhibition, increased attention towards the stranger, and a blunted respiratory sinus arrhythmia response.

Conclusions

Findings suggest that infants with FXS show both behavioral and physiological markers of social anxiety at 12 months old using a biobehavioral approach with multiple sources of input. Results highlight the importance of a multi-method approach to understanding the complex early emergent characteristics of anxiety in infants with FXS.

Attend Less, Fear More: Elevated Distress to Social Threat in Toddlers With Autism Spectrum Disorder

Differential emotional reactivity to social and nonsocial stimuli has been hypothesized but rarely examined empirically in ASD despite its potential importance for development of social motivation, cognition, and comorbid psychopathology. This study examined emotional reactivity, regulation, and attention to social and nonsocial threat in toddlers with ASD (n = 42, M_age : 22 months) and typically developing (TD) toddlers (n = 22, M_age : 23 months), and their mutual associations with autism symptom severity. Participants were exposed to social (stranger), nonsocial (mechanical objects), and ambiguous (masks) threats, and their intensity of distress (iDistress), attention to threat (Attention), and presence of emotion regulation (ER) strategies were measured. Autism symptom severity was quantified using the Autism Diagnostic Observation Schedule-2. In response to social threat, toddlers with ASD exhibited elevated iDistress (P < 0.038) but lower Attention (P < 0.002) and a wider variety of ER strategies (P < 0.040) compared to TD controls, though their ER strategies were less likely to be social. However, nonsocial and ambiguous threat elicited lower iDistress in ASD than in TD toddlers (P = 0.012 and P = 0.034, respectively), but comparable Attention and ER strategy use. Autism severity was not associated with iDistress. The study demonstrates elevated emotional salience but diminished attentional salience of social threat in ASD. A failure to attend adequately to social threats may restrict opportunities to appraise their threat value and engender often observed in ASD negative emotional responses to novel social situations. Early atypical emotional reactivity may independently contribute to the shaping of complex autism phenotypes and may be linked with later emerging affective and behavioral symptoms. LAY SUMMARY: Compared to typically developing toddlers, toddlers with ASD show diminished attention yet enhanced distress in response to social threat. Poor attention to potential social threat may limit opportunities to assess its threat value and thus contribute to often observed negative emotional responses to novel social situations. Identifying the precursors of atypical emotional reactivity in infancy and its links with later psychopathology will inform about novel treatment targets and mechanisms of change in the early stages of ASD. Autism Res 2021, 14: 1025-1036. © 2020 International Society for Autism Research, Wiley Periodicals, LLC.

An Observational Study of Social Interaction Skills and Behaviors in Cornelia de Lange, Fragile X and Rubinstein-Taybi Syndromes

We directly assessed the broader aspects of sociability (social enjoyment, social motivation, social interaction skills and social discomfort) in individuals with Cornelia de Lange (CdLS), fragile X (FXS) and Rubinstein-Taybi syndromes (RTS), and their association with autism characteristics and chronological age in these groups. Individuals with FXS (p < 0.01) and RTS (p < 0.01) showed poorer quality of eye contact compared to individuals with CdLS. Individuals with FXS showed less person and more object attention than individuals with CdLS (p < 0.01). Associations between sociability and autism characteristics and chronological age differed between groups, which may indicate divergence in the development and aetiology of different components of sociability across these groups. Findings indicate that individuals with CdLS, FXS and RTS show unique profiles of sociability.

A Scoping Review of Anxiety in Young Children with Autism Spectrum Disorder

Research on anxiety in children and adolescents with autism spectrum disorder (ASD) has burgeoned in the past 15 years. Most of the research has focused on school-age children, ages 6 to 18 years. Yet, recent studies suggest that anxiety can emerge in young children, under 6 years, with ASD. This scoping review synthesized the literature on anxiety in young children with ASD. Three domains of anxiety research were reviewed: (a) prevalence/severity, phenomenology, and course; (b) correlates; and (c) treatment. Four online databases were searched from the start of the database until March 2020. Keywords pertaining to anxiety, autism, and young children were entered. The search identified 44 articles for inclusion. These studies varied with respect to sample source, informants, and measures to assess anxiety. The overall prevalence of anxiety ranged from 1.6 to 62%. Sixteen of 17 studies found that young children with ASD had higher levels of anxiety compared to various control groups. A variety of DSM anxiety symptoms and disorders were present in young children with the most common symptoms being specific, social, and generalized fears. Correlates of anxiety included sensory over-responsivity, sleep disturbance, aggression/defiance, and attention deficit/hyperactivity disorder. Three cognitive behavioral treatment studies for anxiety and one developmental intervention targeting ASD symptoms showed promise in reducing anxiety. Findings indicate an early emergence of anxiety in some children with ASD. Further research on the measurement, pathophysiology, and treatment of anxiety in early childhood is critical to improving outcomes in children with ASD. LAY SUMMARY: This scoping review synthesizes the literature on anxiety in young children with autism spectrum disorder (ASD). Results indicate that children with ASD have higher levels of anxiety than children without ASD. Potential factors that could be contributing to anxiety include sensory, sleep, and behavioral problems. Preliminary studies show that anxiety can improve with cognitive behavioral treatment. These findings suggest that research on anxiety in young children with ASD should be prioritized to improve mental health outcomes.

Atypical Emotional Electrodermal Activity in Toddlers with Autism Spectrum Disorder

Past studies in autism spectrum disorder (ASD) indicate atypical peripheral physiological arousal. However, the conditions under which these atypicalities arise and their link with behavioral emotional expressions and core ASD symptoms remain uncertain. Given the importance of physiological arousal in affective, learning, and cognitive processes, the current study examined changes in skin conductance level (ΔSCL) in 41 toddlers with ASD (mean age: 22.7 months, SD: 2.9) and 32 age-matched toddlers with typical development (TD) (mean age: 21.6 months, SD: 3.6) in response to probes designed to induce anger, joy, and fear emotions. The magnitude of ΔSCL was comparable during anger (P = 0.206, d = 0.30) and joy (P = 0.996, d = 0.01) conditions, but significantly lower during the fear condition (P = 0.001, d = 0.83) in toddlers with ASD compared to TD peers. In the combined samples, ΔSCL positively correlated with intensity of behavioral emotional expressivity during the anger (r[71] = 0.36, P = 0.002) and fear (r[68] = 0.32, P = 0.007) conditions, but not in the joy (r[69] = -0.15, P = 0.226) condition. Finally, ΔSCL did not associate with autism symptom severity in any emotion-eliciting condition in the ASD group. Toddlers with ASD displayed attenuated ΔSCL to situations aimed at eliciting fear, which may forecast the emergence of highly prevalent internalizing and externalizing problems in this population. The study putatively identifies ΔSCL as a dimension not associated with severity of autism but with behavioral responses in negatively emotionally challenging events and provides support for the feasibility, validity, and incipient utility of examining ΔSCL in response to emotional challenges in very young children. LAY SUMMARY: Physiological arousal was measured in toddlers with autism exposed to frustrating, pleasant, and threatening tasks. Compared to typically developing peers, toddlers with autism showed comparable arousal responses to frustrating and pleasant events, but lower responses to threatening events. Importantly, physiological arousal and behavioral expressions were aligned during frustrating and threatening events, inviting exploration of physiological arousal to measure responses to emotional challenges. Furthermore, this study advances the understanding of precursors to emotional and behavioral problems common in older children with autism. Autism Res 2020, 13: 1476-1488. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.

Early negative affect in males and females with fragile X syndrome: implications for anxiety and autism

Background

Fragile X syndrome (FXS) is a genetic disorder that is highly comorbid with anxiety and autism spectrum disorder (ASD). Elevated negative affect in young children has been associated with increased risk for both anxiety and ASD; however, these relations remain poorly understood in FXS.

Methods

The present prospective longitudinal study examined the trajectory of negative affect from infancy through preschool in males and females with FXS and typical development and its relation to anxiety and ASD.

Results

Results indicate a complex association reflecting group, developmental, and sex effects. Specifically, the group with FXS displayed a trajectory of increasing negative affect across age that was distinct from the typical controls. This atypical trajectory of negative affect in FXS was driven by sex effects in that males showed lower negative affect during infancy followed by steep increases across the toddler and preschool years whereas the females displayed a flatter trajectory. Finally, elevated negative affect predicted anxiety symptoms in males, but not females, with no relationship to ASD in males or females with FXS.

Conclusions

The current work addresses the importance of studying the development of psychopathology in a specific neurogenetic population. Temperamental negative affect was shown to be an important early marker for anxiety in young children with FXS, with subtle differences observed between males and females.

Infant Social Avoidance Predicts Autism but Not Anxiety in Fragile X Syndrome

Objective: Autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and anxiety are three of the most common childhood psychiatric disorders. Early trajectories of social avoidance have been linked with these psychiatric disorders in previous studies, but it remains unclear how social avoidance differentially predicts comorbid disorders in a high-risk genetic subgroup. Here, we delineate the association between trajectories of social avoidance from infancy and subsequent ASD, ADHD, and anxiety outcomes at preschool in children with fragile X syndrome (FXS), a well-characterized single-gene disorder highly associated with social avoidance as well as elevated rates of ASD, ADHD, and anxiety. Method: Males with FXS (n = 78) aged 4-62 months participated in a longitudinal study resulting in 201 assessments. The Social Avoidance Scale (SAS) documented socially avoidant behaviors from infancy in three domains-physical movement, facial expression, and eye contact during both the first minute and the last hour of an interaction. ASD, ADHD, and anxiety symptom outcomes at preschool were measured via parent-report questionnaires. Results: Increased social avoidance across infancy and preschool predicted elevated ASD symptom severity but reduced ADHD and anxiety symptom severity in males with FXS. Conclusion: ASD, ADHD, and anxiety symptoms relate inconsistently to social avoidance behaviors, providing new insight toward the debate of independence or overlap among these disorders in FXS and other disorders (i.e., ASD). The results suggest that the nuanced profile of the developmental and temporal aspects of social avoidance may inform more the accuracy of differential diagnoses of comorbid psychiatric disorders in FXS.

Emotional Expressivity in Toddlers With Autism Spectrum Disorder

OBJECTIVE

There is a prevailing notion that children with autism spectrum disorder (ASD) exhibit intense negative and attenuated positive emotions, although the empirical evidence regarding their emotional expressiveness (EE) is limited. Given the importance of emotions in shaping social and cognitive development, we examined intensity and valence of EE and links between EE and autism severity and parent-reported temperament in ASD.

METHOD

Toddlers (aged 21.2 months) with ASD (n = 43), developmental delay (DD, n = 16), and typical development (TD, n = 40) underwent standardized probes designed to induce anger, joy, and fear. Intensity of EE through facial and vocal channels were coded offline. Autism severity and temperament were quantified using the Autism Diagnostic Observation Schedule-2 (ADOS-2) and Early Childhood Behavior Questionnaire (ECBQ).

RESULTS

The ASD group exhibited less intense fear compared to both the DD and TD groups, more intense anger than DD but not TD, with no differences in joy intensity. All groups showed similar levels of incongruous negative EE. Intensity of fear and anger were not associated with severity of autism symptoms, but lower intensity of joy was related to greater autism severity. Expressed fear and joy were associated with temperament.

CONCLUSION

The study provides no support for a negative emotionality bias in ASD. Instead, toddlers with ASD display a muted response to threat and an accentuated response to goal blockage, whereas the ability to express positive emotions appears intact. Negative emotionality and social disability dimensions are independent. The study demonstrates the complexity of EE in ASD and motivates investigations into underlying mechanisms as well as its role in shaping complex phenotypes of affected children.

Behavioral Markers of Emergent Stranger Anxiety in Infants and Toddlers with Fragile X Syndrome

Studying anxiety in neurogenetic syndromes may inform the intersection of biological and developmental risks, facilitating effective and targeted interventions. We longitudinally examined stranger fear in infants and toddlers with fragile X syndrome (FXS; n = 46) and typical controls (n = 33), as well as associations between observed stranger fear and rating scales of anxiety, withdrawal and autism features within FXS. Results indicated atypical facial fear in FXS, although facial fear did not index anxiety, autistic symptoms or social withdrawal. Instead, lower withdrawal was associated with decreased distress vocalizations across age, and higher autistic symptoms were associated with lower intensity escape behaviors. Early stranger fear in FXS reflects both typical and atypical dimensions and may help index emergence of social anxiety in this population.