Differences in anticipatory versus reactive stress to social evaluative threat in adults versus adolescents with autism

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.

Cardiac vagal control in response to acute stress during pregnancy: Associations with life stress and emotional support

Life stressors during pregnancy can disrupt maternal stress regulation and negatively impact offspring health. Despite the important role of cardiac vagal control (e.g., heart rate variability; HRV) in stress regulation, few studies have investigated how life stressors and emotional support influence vagal control during pregnancy. This study aimed to (a) characterize patterns of cardiac vagal control in response to a stressor administered in pregnancy, and (b) examine the effects of life stress and emotional support on vagal control during rest, reactivity, and recovery. Participants included 191 pregnant women (79% Black; 21% White) living in an urban U.S. city (73% receiving public assistance). Heart rate (HR) and HRV (indexed by RMSSD) were recorded continually during the preparation, task, and recovery periods of the Trier Social Stress Test (TSST). Participants reported recent life stressors (e.g., relationship problems, financial hardship) and emotional support. Piecewise growth curve modeling was used to model rates of reactivity and recovery, adjusting for gestational age at time of assessment and recent health problems. Life stress predicted greater HR and HRV reactivity to the TSST as well as greater HRV recovery (vagal rebound). However, associations were only evident for women reporting high emotional support. Results suggest that pregnant women living with frequent life stressors may exhibit more rapid autonomic responses to acute stress, including more rapid vagal rebound after stressors, potentially reflecting physiological adaptation to anticipated high-stress environments; emotional support may enhance these responses. Studies are needed to investigate long-term health outcomes related to this stress response pattern.

Developmental effects in physiological stress in early adolescents with and without autism spectrum disorder

INTRODUCTION

Humans place high value on how they are socially evaluated by others. The Trier Social Stress Test (TSST) is a well-established measure of social evaluative threat that promotes activation of the hypothalamic pituitary adrenal (HPA) axis and release of cortisol. Higher cortisol responses in typically developing (TD) adolescents are influenced by age and pubertal development especially in later stages. Children with ASD have been shown to exhibit blunted cortisol in response to the TSST although adults with ASD show a more prototypical response. The current study examined physiological stress in early adolescents with ASD and TD. It was hypothesized that TD youth would show elevated cortisol in response to the TSST influenced by age and pubertal stage. In contrast, youth with ASD would show a more diminished stress response yet still show effects for age and pubertal development METHODS: The sample included 241 youth, 138 with ASD (median age=11.25) and 103 TD (median age=11.67). Standardized diagnostic and pubertal development (genital/breast (GB), and pubic hair (PH) stage) physical exams were performed. Salivary cortisol was collected before and after the TSST. Linear mixed effects models examined the effects of baseline cortisol, time, age, sex, pubertal stage, and diagnosis.

RESULTS

We did not find an effect of early pubertal development stage (GB or PH) on cortisol response. There was an interaction between age and TSST timepoint, showing stronger effects for older children across the timeline especially during the stressor. Finally, there was a significant diagnosis by TSST timepoint interaction characterized by a blunted cortisol stress response in youth with ASD compared to TD participants who showed higher cortisol.

DISCUSSION

We found evidence that age contributes to an increase in cortisol in response to social evaluative threat during early adolescence. TD youth exhibit an adaptive elevated stress response to psychosocial threat whereas youth with ASD do not. There may exist a developmental lag in the perception of and stress responsivity to social evaluation which may emerge in older adolescents with ASD.

Assessment of autism-relevant behaviors in C57BKS/J leptin receptor deficient mice

Gestational diabetes mellitus (GDM) was associated with greater autism risk in epidemiological studies. Disrupted leptin signaling may contribute to their coincidence, as it is found in both disorders. Given this we examined leptin receptor (Lepr) deficient (BKS.Cg-Dock7^m +/+ Lepr^db/J diabetic (db)) heterozygous (db/+) mice for autism-relevant behaviors. BKS db/+ females are lean with normal blood glucose, but they develop GDM while pregnant. We hypothesized BKS db/+ offspring might exhibit physiological and behavior traits consistent with autism. Adolescent body weight, fasting blood glucose, serum corticosterone, social preferences, self-grooming, marble burying, social dominance and cognitive flexibility of BKS db/+ mice was compared to C57BLKS/J (BKS) and C57BL/6J (BL6) mice. Male db/+ weighed more and had higher blood glucose and corticosterone relative to BL6, but not BKS mice. Also, male db/+ lacked social interaction preference, explored arenas less, and buried more marbles than BL6, but not BKS males. Male and female db/+ were more dominant and made more mistakes in water T-mazes locating a sunken platform after its position was reversed than BL6, but not BKS mice. Overall BKS db/+, particularly males, exhibited some autism-like social deficits and restrictive-repetitive behaviors relative to BL6, but BKS strain contributions to BKS db/+ behaviors were evident. Since BKS db/+ and BKS behavioral and physiological phenotypes are already so similar, it will be difficult to use these models in studies designed to detect contributions of fetal GDM exposures to offspring behaviors.

Treatment of Aggression in Adults with Autism Spectrum Disorder: A Review

BACKGROUND

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by markedly impaired social interaction, impaired communication, and restricted/repetitive patterns of behavior, interests, and activities. In addition to challenges caused by core symptoms, maladaptive behaviors such as aggression can be associated with ASD and can further disrupt functioning and quality of life. For adults with ASD, these behaviors can portend adverse outcomes (e.g., harm to others or to the individual with ASD, hindering of employment opportunities, criminal justice system involvement). This article reviews the scientific literature to provide an update on evidence-based interventions for aggression in adults with ASD.

METHOD

A search of the electronic databases CINAHL, EMBASE, and PsycINFO was conducted using relevant search terms. After reviewing titles, abstracts, full-length articles, and reference lists, 70 articles were identified and reviewed.

RESULTS

The strongest (controlled trial) evidence suggests beneficial effects of risperidone, propranolol, fluvoxamine, vigorous aerobic exercise, and dextromethorphan/quinidine for treating aggression in adults with ASD, with lower levels of evidence supporting behavioral interventions, multisensory environments, yokukansan, and other treatments.

CONCLUSIONS

Additional randomized, controlled trials using consistent methodology that adequately addresses sources of bias are needed to determine which treatments are reliably effective in addressing aggression in adults with ASD. In the meantime, considering efficacy and adverse effect/long-term risk profiles, a practical approach could start with functional assessment-informed behavioral interventions along with encouragement of regular, vigorous aerobic exercise to target aggression in adults with ASD, with pharmacotherapy employed if these interventions are unavailable or inadequate based on symptom acuity.