Elevated repetitive behaviors are associated with lower diurnal salivary cortisol levels in autism spectrum disorder

Disruptions in reproductive health, sex hormonal profiles, and hypothalamic hormone receptors content in females of the C58/J mouse model of autism

Autism Spectrum Disorder (ASD) is characterized by differences in social communication and interaction, as well as areas of focused interests and/or repetitive behaviors. Recent studies have highlighted a higher prevalence of endocrine and reproductive disturbances among females on the autism spectrum, hinting at potential disruptions within the hypothalamus-pituitary-ovary (HPO) axis. This research aims to explore the reproductive health disparities in ASD using an animal model of autism, the C58/J inbred mouse strain, with a focus on reproductive performance and hormonal profiles compared to the C57BL/6J control strain. Our findings revealed that the estrous cycle in C58/J females is disrupted, as evidenced by a lower frequency of complete cycles and a lack of cyclical release of estradiol and progesterone compared to control mice. C58/J females also exhibited poor performance in several reproductive parameters, including reproductive lifespan and fertility index. Furthermore, estrogen receptor alpha content showed a marked decrease in the hypothalamus of C58/J mice. These alterations in the estrous cycle, hormonal imbalances, and reduced reproductive function imply dysregulation in the HPO axis. Additionally, our in-silico study identified a group of genes involved in infertility carrying single-nucleotide polymorphisms (SNPs) in the C58/J strain, which also have human orthologs associated with autism. These findings could offer valuable insights into the molecular underpinnings of neuroendocrine axis disruption and reproductive issues observed in ASD.

Characterising Insistence on Sameness and Circumscribed Interests: A Qualitative Study of Parent Perspectives

Manifestations of insistence on sameness (IS) and circumscribed interests (CI) are complex, with individuals varying considerably, not only in the types of behaviours they express, but also in terms of a behaviour's frequency, intensity, trajectory, adaptive benefits, and impacts. However, current quantitative RRB instruments capture only certain aspects of these behaviours (e.g., mostly frequency or general "severity"). Thus, the current study utilised a semi-structured caregiver interview to provide an in-depth, qualitative characterization of different aspects of IS and CI presentation. Caregivers of 27 autistic children and adolescents displaying IS and/or CI behaviours (3-16 years; 18 males; 9 females) participated in a semi-structured interview. Responses were analysed using thematic framework analysis. Framework analysis identified nine different aspects of IS and CI presentation: (1) intensity, (2) frequency, (3) emergence of behaviour, (4) changes over time, (5) day-to-day fluctuations, (6) purpose/adaptive benefit, (7) experiences of distress, (8) challenges for the individual, their family, and their socialisation, and (9) management strategies and their effectiveness. Autistic children and adolescents were reported to vary greatly on each of these dimensions. Findings demonstrate the complexity of IS and CI presentations and highlight the need for more comprehensive quantitative assessments that independently assess the frequency, intensity, and impact of behaviours. Further, findings reported here emphasize the need for ecologically valid measures that assess the contexts in which these behaviours occur and how their presentations can change within and across days.

Relationship between serum cortisol levels, stereotypies, and the presence of autism spectrum disorder in patients with severe intellectual disability

Stereotypies are one of the diagnostic criteria for autism spectrum disorder (ASD) and are common to both ASD and intellectual disability (ID). Previous studies have been inconclusive, with some showing a positive correlation between stereotypies and cortisol, while others have shown a negative correlation. We hypothesised and investigated the presence of ASD as one of the variables involved in this discrepancy. We tested the following hypotheses on serum cortisol in a total of 84 hospitalised patients with severe ID and ASD with severe ID. Hypothesis (1) Higher levels of stereotypies are associated with higher levels of serum cortisol. Hypothesis (2) The presence of ASD will moderate the association between stereotypies and high serum cortisol levels. The results of the analysis supported hypotheses (1) and (2). We also found that in the population with ID, serum cortisol levels were significantly lower in the ASD group compared to the non-ASD group. The present findings that the association between stereotypies and serum cortisol levels in people with severe ID is moderated by the presence of ASD suggest that the stress response system may function differently in people with ID and ASD than in the general population.

PEERS® for Preschoolers preliminary outcomes and predictors of treatment response

PEERS® for Preschoolers (P4P) is a social skills group program for young autistic children and their caregivers, which provides everyday tools for interacting and communicating with others. Twenty-two caregiver-child dyads participated and completed pre-treatment, post-treatment, and follow-up measures (4-16 weeks after). Using single-subject analyses to examine social skills, 60% demonstrated post-treatment improvement, and 53.85% demonstrated follow-up improvement. Regarding a secondary outcome of behavioral difficulties, 33.33% demonstrated post-treatment reduction, and 7.69% demonstrated follow-up reduction. Using regressions, autistic traits predicted outcomes; fewer social communication difficulties predicted both greater social skills and fewer behavioral difficulties at post-treatment, while fewer repetitive behaviors predicted fewer post-treatment and follow-up behavioral difficulties. These results preliminarily demonstrate the benefits of P4P and how autistic traits may impact P4P outcomes.

Effects of nonsocial and circumscribed interest images on neural mechanisms of emotion regulation in autistic adults

Introduction

Emotion dysregulation is commonly reported among autistic individuals. Prior work investigating the neurofunctional mechanisms of emotion regulation (ER) in autistic adults has illustrated alterations in dorsolateral prefrontal cortex (dlPFC) activity, as well as concurrent atypical patterns of activation in subcortical regions related to affect during cognitive reappraisal of social images. Whereas most research examining ER in autism has focused on regulation of negative emotions, the effects of regulating positive emotions has been generally understudied. This is surprising given the relevance of positive motivational states to understanding circumscribed interests (CI) in autism.

Methods

Accordingly, the purpose of this study was to use fMRI with simultaneous eye-tracking and pupillometry to investigate the neural mechanisms of ER during passive viewing and cognitive reappraisal of a standardized set of nonsocial images and personalized (self-selected) CI images.

Results

The autistic group demonstrated comparatively reduced modulation of posterior cingulate cortex (PCC) activation during cognitive reappraisal of CI images compared to viewing of CI, although no eye-tracking/pupillometry differences emerged between-groups. Further, the autistic group demonstrated increased PCC connectivity with left lateral occipital and right supramarginal areas when engaging in cognitive reappraisal vs. viewing CI.

Discussion

In autistic adults, CI may be differentially modulated via PCC. Considering the documented role of the PCC as a core hub of the default mode network, we further postulate that ER of CI could potentially be related to self-referential cognition.

Higher scores on autonomic symptom scales in pediatric patients with neurodevelopmental disorders of known genetic etiology

INTRODUCTION

Features of underlying autonomic dysfunction, including sleep disturbances, gastrointestinal problems, and atypical heart rate, have been reported in neurodevelopmental conditions, including autism spectrum disorder (ASD). The current cross-sectional, between-groups study aimed to quantify symptoms of autonomic dysfunction in a neurodevelopmental pediatric cohort characterized by clinical diagnoses as well as genetic etiology.

METHOD

The Pediatric Autonomic Symptom Scales (PASS) questionnaire was used to assess autonomic features across a group of patients with clinical neurodevelopmental diagnoses (NPD; N = 90) and genetic etiologies. Patients were subdivided based on either having a clinical ASD diagnosis (NPD-ASD; n = 37) or other non-ASD neurodevelopmental diagnoses, such as intellectual disability without ASD, speech and language disorders, and/or attention deficit hyperactivity disorder (NPD-OTHER; n = 53). Analyses focused on characterizing differences between the NPD group compared to previously published reference samples, as well as differences between the two NPD subgroups (NPD-ASD and NPD-OTHER).

RESULTS

Our results indicate higher PASS scores in our NPD cohort relative to children with and without ASD from a previously published cohort. However, we did not identify significant group differences between our NPD-ASD and NPD-OTHER subgroups. Furthermore, we find a significant relationship between quantitative ASD traits and symptoms of autonomic function.

CONCLUSION

This work demonstrates the utility of capturing quantitative estimates of autonomic trait dimensions that may be significantly linked with psychosocial impairments and other core clinical features of ASD.

Biological correlates of altered circadian rhythms, autonomic functions and sleep problems in autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by a complex and multifaceted neurobehavioral syndrome. In the last decades, several studies highlighted an increased prevalence of sleep problems in ASD, which would be associated with autonomic system and circadian rhythm disruption. The present review aimed to summarize the available literature about sleep problems in ASD subjects and about the possible biological factors implicated in circadian rhythm and autonomic system deregulation in this population, as well as possible therapeutic approaches. Shared biological underpinnings between ASD symptoms and altered circadian rhythms/autonomic functions are also discussed. Studies on sleep showed how ASD subjects typically report more problems regarding insufficient sleep time, bedtime resistance and reduced sleep pressure. A link between sleep difficulties and irritability, deficits in social skills and behavioral problems was also highlighted. Among the mechanisms implicated, alteration in genes related to circadian rhythms, such as CLOCK genes, and in melatonin levels were reported. ASD subjects also showed altered hypothalamic pituitary adrenal (HPA) axis and autonomic functions, generally with a tendency towards hyperarousal and hyper sympathetic state. Intriguingly, some of these biological alterations in ASD individuals were not associated only with sleep problems but also with more autism-specific clusters of symptoms, such as communication impairment or repetitive behaviors Although among the available treatments melatonin showed promising results, pharmacological studies for sleep problems in ASD need to follow more standardized protocols to reach more repeatable and reliable results. Further research should investigate the issue of sleep problems in ASD in a broader perspective, taking into account shared pathophysiological mechanisms for core and associated symptoms of ASD.

The Relationship of Steroid Hormones, Genes Related to Testosterone Metabolism and Behavior in Boys With Autism in Slovakia

OBJECTIVE

Purpose of the study was to identify the relationship among actual plasmatic levels of steroid hormones and behavioral manifestations in boys with autism and to assess the genetic contribution to these manifestations.

METHODS

172 boys with autism under 10 years of age and 135 neurotypical boys attended the study. ADI-R and ADOS-2 were used to evaluate the core symptom severities. Problem behavior was assessed using BPI-01 questionnaire. Levels of testosterone, estradiol, dehydroepiandrosterone, dehydroepiandrosterone-sulfate and sex hormone binding globulin (SHBG) were measured in plasma of autistic boys. Three SNPs (in ESR1, SHBG, SRD5A2 genes) and one STR in AR gene (number of CAG repeats in first exon) were assessed. Hormonal levels and number of CAG repeats in AR gene were used for correlation analysis with behavioral measures. Genotype and allelic frequencies were compared among autistic and neurotypical boys.

RESULTS

We found negative relationship among SHBG levels and restricted, repetitive behaviors (measured by ADOS-2) and positive relationship among actual testosterone levels and frequency of stereotyped behavior (measured by BPI-01).

CONCLUSION

Actual levels of SHBG and testosterone are related to severities of restricted and repetitive behaviors in boys with autism. Mechanisms of action of these hormones in brain require further investigation.

Stress System Activation in Children and Adolescents With Autism Spectrum Disorder

The mission of the human stress system is the maintenance of homeostasis in the presence of real or perceived, acute or chronic stressors. The hypothalamic–pituitary–adrenal (HPA) axis and the autonomic nervous system (ANS) are the stress system-related neuroendocrine pathways. There is abundant evidence that children and adolescents with autism spectrum disorder (ASD) may exhibit atypical function within the HPA axis and the ANS both at the resting state and during the presence of social and/or non-social stressors. The aim of this review is to provide an up-to-date summary of the findings regarding stress system alterations in children and adolescents with ASD. We focus on the variations of stress hormones circadian rhythms, specifically cortisol and alpha-amylase (i.e., a surrogate index of epinephrine/norepinephrine secretion), and on the alterations of stress system responsivity to different stressors. Also, we present imaging and immunological findings that have been associated with stress system dysregulation in children and adolescents with ASD. Finally, we review the pivotal role of HPA axis-ANS coordination, the developmental trajectory of the stress system in ASD, and the possible role of early life stress in the dysregulation of the stress system demonstrated in children and adolescents with ASD. This synthesis will hopefully provide researchers with a foundation for an integrated approach to future research into stress system variations in children and adolescents with ASD.

Relationships Between Emotion Regulation, Social Communication and Repetitive Behaviors in Autism Spectrum Disorder

The relationship between emotion regulation, social interaction and different types of restricted and repetitive behaviors is poorly understood. In the present study, structural equation modeling based on information about 239 individuals with autism was used to examine whether emotion regulation and social communication were associated with self-injury and stereotyped behaviors. Results showed that poor emotion regulation had a unique association with self-injury while difficulties with social communication was uniquely associated with stereotyped behaviors. Emotion regulation and social communication were strongly associated and self-injury and stereotyped behaviors moderately associated. This implies that these types of behaviors are often expressions of broader negative emotional states in autism. Treatments that help improve coping and social communication strategies may benefit individuals with autism.

The effects of two stressors on working memory and cognitive flexibility in zebrafish (Danio rerio): The protective role of D1/D5 agonist on stress responses

Acute stressors are recurrent in multiple species' lives and can facilitate or impair cognition. The use of zebrafish (Danio rerio) as a translational species to understand the mechanisms by which stress induces different behavioral phenotypes has been widely studied. Two acute stressors are recognized when using this species: (1) conspecific alarm substance (CAS); and (2) net chasing. Here, we tested if CAS or net chasing would affect working memory and cognitive flexibility by testing performance in the FMP Y-maze after exposure to stress. We observed that CAS altered zebrafish behavioral phenotypes by increasing repetitive behavior; meanwhile, animals showed different patterns of repetitive behavior when exposed to net chasing, depending on the chasing direction. Because D1 receptors were previously studied as a potential mechanism underlying stress responses in different species, here, we pretreated fish with a D1/D5 agonist (SKF-38393) to assess whether this system plays a role in repetitive behavior in the FMP Y-maze. The pretreatment with D1/D5 agonist significantly decreased repetitive behavior in CAS exposed animals, and cortisol levels for both stressed groups, suggesting that the dopaminergic system plays an important role in zebrafish stress-related responses.

Salivary cortisol and alpha-amylase daily profiles and stress responses to an academic performance test and a moral cognition task in children with neurodevelopmental disorders

There is evidence that children with neurodevelopmental disorders may exhibit atypical responses to stress and alterations in concentrations and diurnal secretion of stress hormones. We assessed diurnal profiles and stress responses of salivary cortisol and alpha-amylase (sAA) in children with attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and specific learning disorder (SLD) compared to typically developing children (TD). A total of 157 children of both sexes, aged between 6 and 12 years old, took part in the study distributed into four groups: ADHD (N = 34), ASD (N = 56), SLD (N = 43) and TD (N = 24). Salivary samples were collected at three time points during a day, as well as before and 5 min after an academic performance test and a moral cognition task. ADHD children had lower evening and diurnal sAA levels, adjusted for age. Also, ASD children showed lower diurnal sAA secretion, adjusted for age. The mean percentage change for salivary cortisol and sAA after both tests did not differ between the groups. In conclusion, we demonstrated alterations in diurnal autonomic functioning in children with ADHD and ASD, while hypothalamic-pituitary-adrenal axis functioning did not differ between the clinical and the comparison groups.

Using Prevent Teach Reinforce for Young Children to Manage Challenging Behaviors in Public Specialized Early Intervention Services for Autism

This proof-of-concept study assessed the feasibility of implementing Prevent-Teach-Reinforce-for-Young-Children (PTR-YC) program to address challenging behaviors in children with autism within the context of public, specialized early intensive behavioral intervention (EIBI) services offered in community settings. Following a 2-day training and with brief weekly supervision meetings, children's EIBI educators acted as facilitators in 35 families' home environments. Small and moderate effect sizes were observed for children's behavioral outcomes and parenting stress. Recruitment and retention rates, implementation fidelity, as well as treatment acceptability from the perspective of participating parents and the organization attested to the feasibility and relevance of implementing and evaluating this program on a larger scale as part of a multi-center randomized controlled trial.

Sleep Problems and Trajectories of Restricted and Repetitive Behaviors in Children with Neurodevelopmental Disabilities

Sleep problems are prevalent in children with neurodevelopmental disabilities and are associated with the expression of restricted and repetitive behaviors (RRBs). Children (n = 57) with autism spectrum disorder (ASD, n = 38) or developmental delay (DD, n = 19) participated in multiple assessments of intellectual ability, ASD symptoms, and RRBs (3 timepoints for ASD, 2 for DD). Sleep problems assessed at age 4 via parent report were associated with trajectories of higher-order RRBs (sameness/ritualistic/compulsive behaviors) from age 2-6 in the ASD group, and from age 2-4 in the DD group, even after controlling for intellectual ability, social-affective symptoms, and anxiety. Trajectories of stereotyped/restricted behaviors were unrelated to sleep problems. Sleep problems were associated with trajectories of higher-order (but not lower-order) RRBs in a transdiagnostic sample.

Increasing compliance with wearing a medical device in children with autism

Health professionals often recommend the use of medical devices to assess the health, monitor the well-being, or improve the quality of life of their patients. Children with autism may present challenges in these situations as their sensory peculiarities may increase refusals to wear such devices. To address this issue, we systematically replicated prior research by examining the effects of differential reinforcement of other behavior (DRO) to increase compliance with wearing a heart rate monitor in 2 children with autism. The intervention increased compliance to 100% for both participants when an edible reinforcer was delivered every 90 s. The results indicate that DRO does not require the implementation of extinction to increase compliance with wearing a medical device. More research is needed to examine whether the reinforcement schedule can be further thinned.

Cortisol awakening response in children and adolescents with autism spectrum disorder: a systematic review and meta-analysis

BACKGROUND

The cortisol awakening response (CAR) is characterised by an increase in cortisol in the 30 to 60 min after waking. Research has found significant associations between an atypical CAR and symptoms of stress and anxiety in typically developing (TD) children and adolescents. A number of studies have explored the CAR in autism spectrum disorder (ASD), but no evidence synthesis is available to date.

OBJECTIVE AND METHODS

Based on a preregistered protocol (PROSPERO: CRD42017051187), we carried out a systematic review (SR) and meta-analysis (MA) of CAR studies to explore potential significant differences between children and adolescents with ASD and TD controls. Web of Science, PubMed and PsychInfo were searched until January 2019. A random-effects model was used to pool studies and we used the Newcastle-Ottawa scale (NOS) to assess study quality and risk of bias.

FINDINGS

The SR retrieved a total of nine studies, with mixed findings on the comparison of the CAR between children and adolescents with ASD and TD controls. The MA, based on four studies (ASD; n=117 and TD n=118), suggested no differences between the CAR in ASD and TD populations (SMD: -0.21, 95% CI -0.49 to 0.08). In terms of NOS items, no study specified Representativeness of the cases and Non-response rate. DISCUSSION AND CLINICAL IMPLICATIONS: Given the relatively few studies and lack of appropriately matched TD controls, additional research is needed to further understand and recommend the utility of the CAR as a reliable marker to differentiate ASD and TD.

Background cortisol versus social anxiety as correlates of HPA-axis recovery from stress in boys with Autism Spectrum Disorder

Children with Autism Spectrum Disorder (ASD) show dysregulation of the expected Hypothalamus-Pituitary-Adrenal (HPA) axis and elevated cortisol responses to stress and response patterns, but little has been reported regarding their recovery from stress in terms of cortisol concentrations. This response was investigated in a sample of 32 young males with ASD aged between 9 and 18 years (M = 14.3 yr, SD = 2.7 yr), using a standardised experimental protocol combined with individualised stressor and non-stressor tasks. Results indicated that about half of the sample demonstrated unexpected HPA axis response patterns, and that recovery from stress cortisol concentrations were significantly associated with a single symptom of Social Phobia and Morning cortisol. These findings suggest that one of the key diagnostic criteria for ASD may be strongly influential in the HPA axis responses of boys with ASD and that training regimesto assist them to form less fearful associations with their non-ASD peers may be central to the academic and social progress of these boys.

Measuring Cortisol in the Classroom with School-Aged Children-A Systematic Review and Recommendations

The collection of salivary cortisol has been chosen as one of the least intrusive, easiest to collect, analyze, and store methods of obtaining information on physiological changes. It is, however, not clear what the best practice is when collecting salivary cortisol from children within the school setting. The aim of this systematic review is to evaluate the feasibility of cortisol collection in schools for future research and to make recommendations for best practice. The review included 25 peer-reviewed articles from seven databases. The hypotheses of the included studies vary, but they all use cortisol as a diurnal, baseline, or acute measure, or to measure the effect of an intervention. Two methods of salivary cortisol collection were preferred by most of the research, i.e., passive drool or cotton Salivettes. The review has concluded that cortisol is a physiological marker that can be successfully measured in school-based research. However, there are discrepancies across studies when evaluating the collection guidelines, protocols, and instructions to participants as well as transparency of the success rate of obtaining all samples. Recommendations are made for future research to address and avoid such discrepancies and improve cross-study comparisons by implementing standard protocol guidelines.

Autism: a transdiagnostic, dimensional, construct of reasoning?

The concept of autism has changed across time, from the Bleulerian concept, which defined it as one of several symptoms of dementia praecox, to the present-day concept representing a pervasive development disorder. The present theoretical contribution to this special issue of EJN on autism introduces new theoretical ideas and discusses them in light of selected prior theories, clinical examples, and recent empirical evidence. The overall aim is to identify some present challenges of diagnostic practice and autism research and to suggest new pathways that may help direct future research. Future research must agree on the definitions of core concepts such as autism and psychosis. A possible redefinition of the concept of autism may be a condition in which the rationale of an individual's behaviour differs qualitatively from that of the social environment due to characteristic cognitive impairments affecting reasoning. A broad concept of psychosis could focus on deviances in the experience of reality resulting from impairments of reasoning. In this light and consistent with recent empirical evidence, it may be appropriate to redefine dementia praecox as a developmental disorder of reasoning. A future challenge of autism research may be to develop theoretical models that can account for the impact of complex processes acting at the social level in addition to complex neurobiological and psychological processes. Such models could profit from a distinction among processes related to (i) basic susceptibility, (ii) adaptive processes and (iii) decompensating factors involved in the development of manifest illness.

Understanding oral stereotypies in calves: alternative strategies, hypothalamic-pituitary-adrenal axis (re)activity and gene by environment interactions

Stereotypies are used as indicators of poor animal welfare and it is, therefore, important to understand underlying factors mediating their development. In calves, two oral stereotypies, that is, tongue playing and object manipulation, result mostly from insufficient structure in the diet. Three hypotheses were studied: (1) oral stereotypies in calves are one of two alternative strategies, the alternative being hypo-activity; (2) stereotyping and non-stereotyping calves differ in terms of cortisol secretion; (3) oral stereotypy development in calves rests on a gene by environment interaction. Eight-week-old bull calves (n=48) were assigned to one of four solid feed allowances (0, 9, 18 or 27 g dry matter/kg metabolic weight per day) with the following composition: 50% concentrate, 25% maize silage and 25% straw on dry matter basis. The calves received milk replacer in buckets, the provision of which was adjusted to achieve equal growth rates. At 14 to 18 weeks of age, calves were exposed to a challenge, that is, tethering inside cages. Oral stereotypies and inactivity were recorded in the home pens in the 4 weeks before the challenge using instantaneous scan sampling. Salivary cortisol levels were measured at -120, +40, +80, +120 min and +48 h relative to the challenge. Individual differences in behaviour were recorded in the first 30 min after challenge implementation using focal animal sampling and continuous recording, and these elements were entered into a principal component (PC) analysis to extract PCs. Regression analyses were performed to find relationships between stereotypies and inactivity, stereotypies and cortisol, and stereotypies and PCs (individual differences, genes) and solid feed (environment). Relationships between PCs and cortisol were also investigated to help with the interpretation of PCs. Hypotheses 1 and 2 were rejected. Hypothesis 3, however, was supported: calves with a zero solid feed allowance, that is, in the most barren environment, showed links between stereotypies and two of the PCs. Calves that displayed high levels of idle and rapid locomotion and low levels of oral contact with the cage during the challenge also displayed high levels of object manipulation in the home pens. Calves that displayed low levels of stepping and turning attempts during the challenge also displayed high levels of tongue playing in the home pens. This study corroborates the gene by environment interaction on the development of oral stereotypies in calves.

ASD Validity

ASD research is at an important crossroads. The ASD diagnosis is important for assigning a child to early behavioral intervention and explaining a child’s condition. But ASD research has not provided a diagnosis-specific medical treatment, or a consistent early predictor, or a unified life course. If the ASD diagnosis also lacks biological and construct validity, a shift away from studying ASD-defined samples would be warranted. Consequently, this paper reviews recent findings for the neurobiological validity of ASD, the construct validity of ASD diagnostic criteria, and the construct validity of ASD spectrum features. The findings reviewed indicate that the ASD diagnosis lacks biological and construct validity. The paper concludes with proposals for research going forward.

Age-related differences in the association between stereotypic behaviour and salivary cortisol in young males with an Autism Spectrum Disorder

To identify if age influenced the relationship between one of the central symptoms of Autism Spectrum Disorder (ASD) and physiological stress, the association between stereotypic behaviour (SB) and stress-related cortisol concentrations was examined in a sample of 150 young males with an ASD. Parent-rated SB was significantly correlated with cortisol concentrations for boys aged 6 years to 12 years but not for adolescents aged 13 years to 18 years. This age-related difference in this association was not a function of cortisol concentrations but was related to differences in SB across these two age groups. IQ did not have a significant effect on this relationship, suggesting that age-related learning may have been a possible pathway for reduced SB during adolescence. The aspect of SB that was most powerfully related to cortisol was general repetitive behaviour rather than movements of specific body parts. Explanations of these findings are raised for further investigation.

Neuroendocrine and behavioral response to social rupture and repair in preschoolers with autism spectrum disorders interacting with mother and father

Background

Preschoolers with autism spectrum disorder (ASD) exhibit difficulties in handling social stress and utilizing efficient emotion regulation (ER) strategies to manage high arousal. While researchers called to assess ER in ASD, few studies utilized direct observations. We tested children’s behavioral and cortisol response to maternal and paternal unavailability and hypothesized that children with ASD will employ less complex ER strategies and their parents would show increased regulation facilitation effort to accommodate their child’s difficulties.

Methods

Forty preschoolers with ASD were matched with 40 typically developing (TD) preschoolers. Children were seen twice for identical battery with mother or father in the face-to-face-still-face paradigm, a three-episode paradigm where parent-child play (free play (FP)) is interrupted by elimination of communication (still face (SF)) followed by resuming play (reunion (RE)). Micro-coding of parent and child’s social behavior and ER strategies was conducted. Parent and child’s cortisol was assessed at baseline, following stress, and at recovery.

Results

Children with ASD exhibited the typical SF effect, indexed by an increase in negative affect and decrease in positive communications, but employed more simple regulatory behavior (self-soothing, proximity-seeking) and less complex strategies involving attention redirection and substitutive play. Their parents used more regulation-facilitation behavior, both simple and complex. All children showed initial cortisol response to novelty, which declined over time. However, maternal presence suppressed initial cortisol response in children with ASD.

Conclusions

Children with ASD form typical expectations of parental availability and their parents increase effort to help repair social rupture. Among children with ASD, maternal presence and regulation facilitation provide social buffering for the child’s HPA stress response in a manner similar to mammalian neonates. Results highlight the importance of assessing ER by combining direct observations and physiological measures and including fathers in empirical studies and intervention efforts for children with ASD during sensitive periods for social growth.

Electronic supplementary material

The online version of this article (doi:10.1186/s13229-015-0007-2) contains supplementary material, which is available to authorized users.

Autism as a disorder of biological and behavioral rhythms: toward new therapeutic perspectives

There is a growing interest in the role of biological and behavioral rhythms in typical and atypical development. Recent studies in cognitive and developmental psychology have highlighted the importance of rhythmicity and synchrony of motor, emotional, and interpersonal rhythms in early development of social communication. The synchronization of rhythms allows tuning and adaptation to the external environment. The role of melatonin in the ontogenetic establishment of circadian rhythms and the synchronization of the circadian clocks network suggests that this hormone might be also involved in the synchrony of motor, emotional, and interpersonal rhythms. Autism provides a challenging model of physiological and behavioral rhythm disturbances and their possible effects on the development of social communication impairments and repetitive behaviors and interests. This article situates autism as a disorder of biological and behavioral rhythms and reviews the recent literature on the role of rhythmicity and synchrony of rhythms in child development. Finally, the hypothesis is developed that an integrated approach focusing on biological, motor, emotional, and interpersonal rhythms may open interesting therapeutic perspectives for children with autism. More specifically, promising avenues are discussed for potential therapeutic benefits in autism spectrum disorder of melatonin combined with developmental behavioral interventions that emphasize synchrony, such as the Early Start Denver Model.

Hypothalamic-pituitary-adrenocortical axis: neuropsychiatric aspects

Evidence of aberrant hypothalamic-pituitary-adrenocortical (HPA) activity in many psychiatric disorders, although not universal, has sparked long-standing interest in HPA hormones as biomarkers of disease or treatment response. HPA activity may be chronically elevated in melancholic depression, panic disorder, obsessive-compulsive disorder, and schizophrenia. The HPA axis may be more reactive to stress in social anxiety disorder and autism spectrum disorders. In contrast, HPA activity is more likely to be low in PTSD and atypical depression. Antidepressants are widely considered to inhibit HPA activity, although inhibition is not unanimously reported in the literature. There is evidence, also uneven, that the mood stabilizers lithium and carbamazepine have the potential to augment HPA measures, while benzodiazepines, atypical antipsychotics, and to some extent, typical antipsychotics have the potential to inhibit HPA activity. Currently, the most reliable use of HPA measures in most disorders is to predict the likelihood of relapse, although changes in HPA activity have also been proposed to play a role in the clinical benefits of psychiatric treatments. Greater attention to patient heterogeneity and more consistent approaches to assessing treatment effects on HPA function may solidify the value of HPA measures in predicting treatment response or developing novel strategies to manage psychiatric disease.

Altered circadian patterns of salivary cortisol in low-functioning children and adolescents with autism

BACKGROUND

Reports of higher stress responsivity, altered sleep-wake cycle and a melatonin deficit in autism have stimulated interest in the cortisol circadian rhythm in individuals with autism.

METHODS

The study was conducted on 55 low-functioning children and adolescents with autism (11.3 ± 4.1 years-old) and 32 typically developing controls (11.7 ± 4.9 years-old) matched for age, sex and puberty. Behavioral assessment was performed using the Autism Diagnostic Observation Schedule (ADOS). Salivary samples for measurement of cortisol were collected during a 24-h period (at least 0800 h-Day 1, 1600 h, 0800 h-Day 2 for 46 individuals with autism and 27 controls, and 0800 h-Day 1, 1100 h, 1600 h, 2400 h, 0800 h-Day 2 for 13 individuals with autism and 20 controls). Overnight (2000 h-0800 h) urinary cortisol excretion was also measured.

RESULTS

The autism group displayed significantly higher levels of salivary cortisol at all time-points, flatter daytime and nighttime slopes, higher 0800 h cortisol levels on Day 2 compared to Day 1, and greater variances of salivary and urinary cortisol. There was a significant relationship between salivary cortisol levels and impairments in social interaction and verbal language. Overnight urinary cortisol excretion was similar in the autism and control groups.

CONCLUSION

Anticipation of the stressful collection procedure appears to contribute to the higher 0800 h-Day 2 versus 0800 h-Day 1 salivary cortisol levels in autism. This sensitization to stressors might be as, or even more, important clinically than exposure to novelty in autism. The similar group means for overnight urinary cortisol excretion indicate that basal HPA axis functioning is unaltered in low-functioning autism. The elevated salivary cortisol levels observed in autism over the 24-h period in a repeated stressful condition, flattened diurnal cortisol patterns and the apparent effect of anticipation are consistent with prior findings in high trait anxiety.

Redox Regulation and the Autistic Spectrum: Role of Tryptophan Catabolites, Immuno-inflammation, Autoimmunity and the Amygdala

The autistic spectrum disorders (ASD) form a set of multi-faceted disorders with significant genetic, epigenetic and environmental determinants. Oxidative and nitrosative stress (O&NS), immuno-inflammatory pathways, mitochondrial dysfunction and dysregulation of the tryptophan catabolite (TRYCATs) pathway play significant interactive roles in driving the early developmental etiology and course of ASD. O&NS interactions with immuno-inflammatory pathways mediate their effects centrally via the regulation of astrocyte and microglia responses, including regional variations in TRYCATs produced. Here we review the nature of these interactions and propose an early developmental model whereby different ASD genetic susceptibilities interact with environmental and epigenetic processes, resulting in glia biasing the patterning of central interarea interactions. A role for decreased local melatonin and N-acetylserotonin production by immune and glia cells may be a significant treatment target.

Self-injurious behaviour in autistic children: a neuro-developmental theory of social and environmental isolation

RATIONALE

Self-injurious behaviour is not one of the three core symptoms that define autism. However, children on the autism spectrum appear to be particularly vulnerable. Afflicted children typically slap their faces, punch or bang their heads, and bite or pinch themselves. These behaviours can be extremely destructive, and they interfere with normal social and educational activities. However, the neurobiological mechanisms that confer vulnerability in children with autism have not been adequately described.

OBJECTIVES

This review explores behavioural and neurobiological characteristics of children with autism that may be relevant for an increased understanding of their vulnerability for self-injurious behaviour.

METHODS

Behavioural characteristics that are co-morbid for self-injurious behaviour in children with autism are examined. In addition, the contributions of social and environmental deprivation in self-injurious institutionalized orphans, isolated rhesus macaques, and additional animal models are reviewed.

RESULTS

There is extensive evidence that social and environmental deprivation promotes self-injurious behaviour in both humans (including children with autism) and animal models. Moreover, there are multiple lines of convergent neuroanatomical, neurophysiological, and neurochemical data that draw parallels between self-injurious children with autism and environmentally deprived humans and animals.

CONCLUSIONS

A hypothesis is presented that describes how the core symptoms of autism make these children particularly vulnerable for self-injurious behaviour. Relevant neurodevelopmental pathology is described in cortical, limbic, and basal ganglia brain regions, and additional research is suggested.

A systematic review of sensory processing interventions for children with autism spectrum disorders

Children with autism spectrum disorders often exhibit co-occurring sensory processing problems and receive interventions that target self-regulation. In current practice, sensory interventions apply different theoretic constructs, focus on different goals, use a variety of sensory modalities, and involve markedly disparate procedures. Previous reviews examined the effects of sensory interventions without acknowledging these inconsistencies. This systematic review examined the research evidence (2000-2012) of two forms of sensory interventions, sensory integration therapy and sensory-based intervention, for children with autism spectrum disorders and concurrent sensory processing problems. A total of 19 studies were reviewed: 5 examined the effects of sensory integration therapy and 14 sensory-based intervention. The studies defined sensory integration therapies as clinic-based interventions that use sensory-rich, child-directed activities to improve a child's adaptive responses to sensory experiences. Two randomized controlled trials found positive effects for sensory integration therapy on child performance using Goal Attainment Scaling (effect sizes ranging from .72 to 1.62); other studies (Levels III-IV) found positive effects on reducing behaviors linked to sensory problems. Sensory-based interventions are characterized as classroom-based interventions that use single-sensory strategies, for example, weighted vests or therapy balls, to influence a child's state of arousal. Few positive effects were found in sensory-based intervention studies. Studies of sensory-based interventions suggest that they may not be effective; however, they did not follow recommended protocols or target sensory processing problems. Although small randomized controlled trials resulted in positive effects for sensory integration therapies, additional rigorous trials using manualized protocols for sensory integration therapy are needed to evaluate effects for children with autism spectrum disorders and sensory processing problems.