Co-activation of SAM and HPA responses to acute stress: A review of the literature and test of differential associations with preadolescents' internalizing and externalizing

Procyanidins and sensory nutrition; do procyanidins modulate homeostasis via astringent taste receptors?

Long-term intake of procyanidins has been suggested to reduce the risk of cardiovascular disease, dementia, and sensory function decline associated with aging. However, most of the ingested procyanidins are not absorbed and are excreted in the feces, so the mechanism of their beneficial impact is unknown. Procyanidins are the components of astringency in plant foods and their stimulation appears to be directly transmitted to the central nervous system via sensory nerves. Recent attention has been focused on the taste receptors expressed in the extra-oral gastrointestinal tract may regulate homeostasis via the neuroendocrine system. In this paper, we have reviewed recent findings on the relationship between the astringency of procyanidins and their bioregulatory effects.

The effects of acute exercise on stress reactivity assessed via a multidimensional approach: a systematic review

Psychological stress is associated with numerous deleterious health effects. Accumulating evidence suggests acute exercise reduces stress reactivity. As stressors activate a wide array of psychological and physiological systems it is imperative stress responses are examined through a multidimensional lens. Moreover, it seems prudent to consider whether stress responses are influenced by exercise intervention characteristics such as modality, duration, intensity, timing, as well as participant fitness/physical activity levels. The current review therefore examined the role of acute exercise on stress reactivity through a multidimensional approach, as well as whether exercise intervention characteristics and participant fitness/physical activity levels may moderate these effects. Stress reactivity was assessed via heart rate, blood pressure, cortisol, catecholamines, and self-report. A systematic search following PRISMA guidelines of five databases was updated in November 2022. Reviewed studies met the following criteria: English language, participants aged ≥ 18, use of acute exercise, use of a validated stress-inducing task, and assessment(s) of stress reactivity. Thirty-one studies (1386 participants) were included. Acute exercise resulted in reliable reductions to blood pressure and cortisol. Acute exercise yielded mostly negligible effects on heart rate reactivity and negligible effects on self-report measures. As for exercise intervention characteristics, intensity-dependent effects were present, such that higher intensities yielded larger reductions to reactivity measures, while limited evidence was present for duration, modality, and timing-dependent effects. Regarding participant fitness/physical activity levels, the effects on stress reactivity were mixed. Future work should standardize the definitions and assessment time points of stress reactivity, as well as investigate the interaction between physiological and psychological stress responses in real-world contexts.

The HPA and SAM axis mediate the impairment of creativity under stress

With the ever-changing social environment, individual creativity is facing a severe challenge induced by stress. However, little is known regarding the underlying mechanisms by which acute stress affects creative cognitive processing. The current research explored the impacts of the neuroendocrine response on creativity under stress and its underlying cognitive flexibility mechanisms. The enzyme-linked immuno sorbent assay was employed to assess salivary cortisol, which acted as a marker of stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis. Eye blink rate (EBR) and pupil diameter were measured as respective indicators of dopamine and noradrenaline released by the activation of the sympathetic-adrenal-medullary (SAM) axis. The Wisconsin card task (WCST) measured cognitive flexibility, while the alternative uses task (AUT) and the remote association task (RAT) measured separately divergent and convergent thinking in creativity. Results showed higher cortisol increments following acute stress induction in the stress group than control group. Ocular results showed that the stress manipulation significantly increased EBR and pupil diameter compared to controls, reflecting increased SAM activity. Further analysis revealed that stress-released cortisol impaired the originality component of the AUT, reducing cognitive flexibility as measured by perseverative errors on the WCST task. Serial mediation analyses showed that both EBR and pupil diameter were also associated with increased perseverative errors leading to poor originality on the AUT. These findings confirm that physiological arousal under stress can impair divergent thinking through the regulation of different neuroendocrine pathways, in which the deterioration of flexible switching plays an important mediating role.

Sensory Nutrition and Bitterness and Astringency of Polyphenols

Recent studies have demonstrated that the interaction of dietary constituents with taste and olfactory receptors and nociceptors expressed in the oral cavity, nasal cavity and gastrointestinal tract regulate homeostasis through activation of the neuroendocrine system. Polyphenols, of which 8000 have been identified to date, represent the greatest diversity of secondary metabolites in plants, most of which are bitter and some of them astringent. Epidemiological studies have shown that polyphenol intake contributes to maintaining and improving cardiovascular, cognitive and sensory health. However, because polyphenols have very low bioavailability, the mechanisms of their beneficial effects are unknown. In this review, we focused on the taste of polyphenols from the perspective of sensory nutrition, summarized the results of previous studies on their relationship with bioregulation and discussed their future potential.

Untapped resource: the simulation-based healthcare environment as a means to study human stress

The effects of 'stress' within the healthcare professions are wide-reaching, not least of all within the field of simulation-based healthcare education. Whilst this popular method of experiential learning offers a 'safe space' for participants to develop their skillset, it also has a more surreptitious action; namely, the incubation of simulation-related stress. Currently, research concerning the complex relationship between stress, learning, and performance is ambiguous, leaving fertile ground for simulationists to debate what level of stress is appropriate for an optimised educational experience. In this narrative review, we examine the human response to stress and outline the various methods that have been used by researchers to measure stress in a quantifiable and standardised way. We then provide a brief overview of simulation-based healthcare education before describing why stress responses have been of interest to healthcare educationalists for some time. Finally, we outline how simulation education environments might provide an ideal environment for studying the human response to stress generally, with ramifications extending beyond the field of medical education.

Correlations between negative life events and suicidal ideation among Chinese adolescents: a meta-analysis

Background

Suicide ideation (SI) has become a serious social issue worldwide, and research has found a certain correlation between negative life events (NLE) and SI. Nevertheless, this relationship is still not clear among Chinese adolescents, a special population. Hence, this investigation performed a meta-analysis of observational research on the correlation between NLE and SI among adolescents in China, to further clarify the association.

Methods

We performed an extensive search on seven electronic databases starting from their establishment until March 10, 2023. The research mainly focused on cross-sectional studies conducted on samples of Chinese adolescents. To examine the association between NLE and SI, a meta-analysis model using random effects was utilized. To investigate moderating factors such as age, region, assessment tools for SI, and year of publication, subgroup and meta-regression analyses were performed. The AHRQ evaluated the quality of the study. The synthesis of data was conducted utilizing STATA software (version 16).

Results

Ultimately, a total of 30 cross-sectional studies were selected for this analysis, including 39,602 individuals in the participant sample. The results showed that NLE was moderately positively correlated with SI among Chinese adolescents (r = 0.29, 95% CI: 0.26, 0.32). In addition, this relationship was moderated by regional differences and the measurement tool used for SI. Studies conducted in Western China showed a higher correlation coefficient than those conducted in Eastern and Central China. Moreover, research conducted with the SSIOSS demonstrated a stronger correlation coefficient compared to studies utilizing the BSI-CV or other assessment instruments.

Conclusion

This meta-analysis indicates that NLE is linked to SI in Chinese teenagers, especially those residing in Western regions of China. Identifying and intervening in NLE and associated risk factors are crucial to prevent suicide within this demographic.

Activation of transient receptor potential channels is involved in reactive oxygen species (ROS)-dependent regulation of blood flow by (-)-epicatechin tetramer cinnamtannin A2

Intervention trials confirmed that blood flow-mediated dilatation increases significantly after intake of astringent (-)-epicatechin (EC) oligomers (procyanidins)-rich foods, but the mechanism remains unclear. We have previously found that procyanidins can activate the sympathetic nervous and subsequently increase blood flow. Here, we examined whether procyanidin-derived reactive oxygen species (ROS) activate transient receptor potential (TRP) channels in gastrointestinal sensory nerves and consequently induce sympathoexcitation. We evaluated the redox properties of EC and its tetramer cinntamtannin A2 (A2) at pH 5 or 7, mimicking plant vacuole or oral cavity/small intestine using a luminescent probe. At pH 5, A2 or EC showed O₂^･- scavenging ability, but they promoted O₂^･- generation at pH 7. We observed blood flow in rat cremaster arterioles using laser Doppler, a single oral dose of 10 µg/kg A2 markedly increased blood flow, while EC showed little activity. This change with A2 was significantly dampened by co-administration of adrenaline blocker, ROS scavenger N-acetyl-L-cysteine (NAC), TRP vanilloid 1, or ankyrin 1 antagonist. We also performed a docking simulation of EC or A2 with the binding site of a typical ligand for each TRP channel and calculated the respective binding affinities. The binding energies were notably higher for A2 than typical ligands, suggesting that A2 is less likely to bind to these sites. ROS produced at neutral pH following the orally administered A2 to the gastrointestinal tract could activate TRP channels, triggering sympathetic hyperactivation and causing hemodynamic changes.

On the Stress of Being a Woman: The synergistic contribution of sex as a biological variable and gender as a psychosocial one to risk of stress-related disorders

Stress-related disorders (SRD) disproportionately affect women. Cortisol blunting, a failure to demonstrate a typical rise and fall of cortisol in response to stress, is associated with SRDs and has been found to be more pronounced among women. Cortisol blunting relates to both sex as a biological variable (SABV; e.g., estrogens and their fluctuations, impact on neural circuits) and gender as a psychosocial variable (GAPSV; e.g., discrimination, harassment, gender roles). I suggest a theoretical model linking experience, sex- and gender-related factors, and neuroendocrine substrates of SRD to the heightened risk among women. The model thus bridges multiple gaps in the literature to create a synergistic conceptual framework with which to understand the stress of being a woman. Utilizing such a framework in research may allow identifying targeted, sex-and gender-dependent risk factors, informing psychological treatment, medical advice, educational and community programming, and policy. DATA AVAILABILITY: All references are cited as required, no other data is reported.

Difference in endocrine and behavior between short-term single- and paired-housing mice in metabolic cage

Metabolic cage housing which is exposed to a number of environmental stressors is often used in pharmacokinetic studies. In this study, we compared the difference in stress response between single- and paired-housing in metabolic cages by evaluating the alteration of urinary stress hormones and behavior. Mice were randomly divided into single- or paired-housing groups and placed in a metabolic cage with wire mesh. Their urine was collected every 24 hours for consecutive 4 days to determine excreted catecholamine and corticosterone. The change in body weight was significantly decreased at 3 and 4 days in the single-housing group compared with that before the experiment, but not paired-housing group. The level of urinary catecholamines, such as noradrenaline, adrenaline, and their metabolite vanillylmandelic acid, was significantly increased in the single-housing compared with paired housing group and urinary corticosterone increased as well. Next, for the two similarly housed groups, we observed spontaneous behavior on the fourth day and conducted an elevated plus-maze test on the fifth day. Spontaneous behavior was not different between experimental groups. In the elevated plus-maze test, the proportion of time spent in the open arms was significantly prolonged in the paired-housing group compared to that of the single-housing group. Short-term social isolation stress loading in metabolic cages was suggested to exhibit endocrinological and behavioral changes in mice. To reduce such interference due to stress exposure, it was suggested to keep two mice in a metabolic cage.

HPA-SAM co-activation among racially diverse, economically disadvantaged early adolescents: Secondary analysis with a preliminary test of a multisystem, person-centered approach

Investigating the co-activation of hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenomedullary (SAM) responses to acute stress can provide insight into how risk might become biologically embedded during early adolescence and improve understanding of what distinguishes physiological dysregulation from normative/expected physiological responses to stress. Evidence has thus far been mixed as to whether symmetric or asymmetric co-activation patterns are associated with higher exposure to chronic stress and poorer mental health outcomes during adolescence. This study expands on a prior multisystem, person-centered analysis of lower-risk, racially homogenous youth by focusing on HPA-SAM co-activation patterns in a higher-risk, racially diverse sample of early adolescents from low-income families (N = 119, Mage=11.79 years, 55.5% female, 52.7% mono-racial Black). The present study was conducted by performing secondary analysis of data from the baseline assessment of an intervention efficacy trial. Participants and caregivers completed questionnaires; youth also completed the Trier Social Stress Test-Modified (TSST-M) and provided six saliva samples. Multitrajectory modeling (MTM) of salivary cortisol and alpha-amylase levels identified four HPA-SAM co-activation profiles. In accordance with the asymmetric-risk model, youth exhibiting Low HPA-High SAM (n = 46) and High HPA-Low SAM (n = 28) profiles experienced more stressful life events, posttraumatic stress, and emotional and behavioral problems relative to Low HPA-Low SAM (n = 30) and High HPA-High SAM (n = 15) youth. Findings highlight potential differences in biological embedding of risk during early adolescence based on individuals' exposure to chronic stress and illustrate the utility of multisystem and person-centered approaches in understanding how risk might get "underneath the skin" across systems.

Psychological and Physical Abuse and Cortisol Response to Stress: The Moderating Role of Psychosocial Resources

Child abuse is associated with alterations in the hypothalamic-pituitary-adrenal (HPA) axis functioning. However, the unique effects of psychological and physical abuse and protective factors against these effects remain largely unknown. To close these gaps, the present study examined the unique effects of psychological and physical abuse on cortisol stress response and explored the moderating role of psychosocial resources in these associations among a sample of Chinese preadolescent children (N = 150; aged 9-13 years; M_age = 10.69 years; 51% boys). The results showed that both psychological and physical abuse were associated with blunted cortisol reactivity slopes. Psychological abuse, but not physical abuse, was associated with lower peak cortisol values and flatter cortisol recovery slopes. Further, psychosocial resources moderated the association between abuse and hyporesponsiveness of the HPA axis. The association between psychological abuse and lower peak cortisol values and the association between physical abuse and steeper cortisol recovery slopes (faster cortisol recovery following the stressor) were observed only among children with low levels of psychosocial resources. These findings indicate the differential effects of psychological and physical abuse on various phases of cortisol stress response, and the protective role of psychosocial resources. This study also has practical implications, given that preadolescence serves as a critical period for maximizing benefit of interventions of adversity.

Empathy Modulates the Effect of Stress Reactivity on Generous Giving

How does acute stress influence the degree to which we cooperate with others? Research on the effects of stress on social decision-making is guided by two seemingly contrasting theories. Acute stress may trigger a Fight-or-Flight response, manifested by increased anxiety, and more egocentric or selfish behavior. Alternatively, according to the Tend-and-Befriend model, acute stress may induce affiliative behaviors, marked by increased prosociality in an effort to seek and receive social support and protection. Extant studies on the topic do not provide consistent support for either pattern of behavior, with studies showing evidence for both Fight-or-Flight or Tend-and-Befriend like responses. One possibility, may be the nature of social responses to stressful situations differ as a function of the individual. In the current study, we demonstrate an example of such a person-by-situation interaction, showing that acute stress can cause either pro-social or selfish responses, contingent on individual differences in trait empathy. One hundred and twenty three participants (60 F) were assessed for trait empathy using the Interpersonal Reactivity Index; consequently, they underwent either the Trier Social Stress Test-a well-validated paradigm for eliciting acute psychosocial stress-or a non-stress inducing control condition. Following exposure to either the stress or control condition, participants played a one-shot Dictator Game to evaluate their generosity levels. Statistical analyses revealed that acute stress by itself did not affect the amount transferred in the Dictator Game. Rather, individual differences in trait empathy moderated the effects of stress on giving. Elevations in stress-induced cortisol resulted in more generous behavior, but only in individuals high in empathy. In contrast, in individuals low in empathy, a greater rise in stress-induced cortisol resulted in more selfish behavior. Effects were more pronounced in females than males. Our findings highlight the necessity of integrating personality traits as important moderators of the link between stress and sociality.

An Empirical Approach to Analyzing the Effects of Stress on Individual Creativity in Business Problem-Solving: Emphasis on the Electrocardiogram, Electroencephalogram Methodology

In this study, experiments were conducted on 30 subjects by means of electrocardiogram (ECG) and electroencephalogram (EEG) methodologies as well as a money game to examine the effects of stress on creativity in business problem-solving. The study explained the relationship between creativity and human physiological response using the biopsychosocial model of challenge and threat. The subjects were asked to perform a cognitive mapping task. Based on the brain wave theory, we identified the types of brain waves and locations of brain activities that occurred during the creative problem-solving process in a business environment and studied the effects of stress on creativity. The results of the experiments showed significant differences in creativity in business problem-solving depending on whether or not stress was triggered. Differences were found in the time domain (SDNN, RMSSD) and frequency domain (HF, LF/HF ratio) of heart rates, a physiological stress indicator, between the stress group and the no-stress group. A brain wave analysis confirmed that alpha waves increased in the frontal lobe of the brain during creative business problem-solving but decreased when the subjects were under stress, during which beta waves in the brain increased. This study seeks to examine creativity in business problem-solving by studying the effects of stress on human physiological response and cognitive functions in the hope of providing a new and objective interpretation of existing research results.

Therapeutic potential of nociceptin/orphanin FQ peptide (NOP) receptor modulators for treatment of traumatic brain injury, traumatic stress, and their co-morbidities

The nociceptin/orphanin FQ (N/OFQ) peptide (NOP) receptor is a member of the opioid receptor superfamily with N/OFQ as its endogenous agonist. Wide expression of the NOP receptor and N/OFQ, both centrally and peripherally, and their ability to modulate several biological functions has led to development of NOP receptor modulators by pharmaceutical companies as therapeutics, based upon their efficacy in preclinical models of pain, anxiety, depression, Parkinson's disease, and substance abuse. Both posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI) are debilitating conditions that significantly affect the quality of life of millions of people around the world. PTSD is often a consequence of TBI, and, especially for those deployed to, working and/or living in a war zone or are first responders, they are comorbid. PTSD and TBI share common symptoms, and negatively influence outcomes as comorbidities of the other. Unfortunately, a lack of effective therapies or therapeutic agents limits the long term quality of life for either TBI or PTSD patients. Ours, and other groups, demonstrated that PTSD and TBI preclinical models elicit changes in the N/OFQ-NOP receptor system, and that administration of NOP receptor ligands alleviated some of the neurobiological and behavioral changes induced by brain injury and/or traumatic stress exposure. Here we review the past and most recent progress on understanding the role of the N/OFQ-NOP receptor system in PTSD and TBI neurological and behavioral sequelae. There is still more to understand about this neuropeptide system in both PTSD and TBI, but current findings warrant further examination of the potential utility of NOP modulators as therapeutics for these disorders and their co-morbidities. We advocate the development of standards for common data elements (CDE) reporting for preclinical PTSD studies, similar to current preclinical TBI CDEs. That would provide for more standardized data collection and reporting to improve reproducibility, interpretation and data sharing across studies.

Fight or flight: The effect of heart rate reactivity on acute stress-induced food intake

The 'fight-or-flight-reaction' describes the suppression of all irrelevant functions like food intake during the acute stress response. However, heart rate reactivity and food intake under acute stress has not been investigated. Therefore, the aim of this study was to investigate the effect of high and low heart rate reactivity on food intake following an acute laboratory stress paradigm in individuals with healthy weight. Fifty-six men and women with healthy weight (BMI: M = 21.82 ± 1.53 kg/m²) were categorized into high heart rate reactors (H-HRR) and low heart rate reactors (L-HRR). After the stress paradigm of the Trier Social Stress Test (TSST), total energy intake was measured in a standardized laboratory meal. H-HRR demonstrated a significantly lower appetite (z = -3.133, p≤ 0.01) and food intake (t(49.13) = 2.253, p≤ 0.05, d= 0.68) after the TSST compared to the L-HRR. No differences in the stress perception and cognitive appraisal could be found between the two reactor groups. These results suggest that the stress-induced heart rate reactivity might be a responsible factor in the stress-eating paradox. In view of the divergent results of stress-induced eating studies in laboratory setting with acute stressors, it is highly important to control the effect of the heart rate reactivity on food intake.

Infrared thermography is an effective, noninvasive measure of HPA activation

Infrared thermography (IRT) is increasingly applied as a noninvasive technique for measuring surface body temperature changes related to physiological stress. As a basis for validation of IRT as a tool for diagnostic use, we need to assess its potential to measure hypothalamic-pituitary-adrenal (HPA) axis reactivity. We used experimental manipulations of the HPA axis in house sparrows (Passer domesticus), i.e. adrenal tissue responsiveness to exogenous adrenocorticotropin (ACTH) and the efficacy of negative feedback using the synthetic glucocorticoid dexamethasone (DEX), to test whether IRT is an effective tool for measuring HPA reactivity. Experimental birds showed a pronounced decrease in skin temperatures after ACTH injection and an increase in temperature after DEX injection. However, individual variation in glucocorticoid levels were not related to skin temperatures except after ACTH injection in experimental birds. We show that IRT can be used to measure HPA reactivity but that skin-temperature is not a good index for glucocorticoid secretion at baseline levels. These results suggest that while IRT of skin temperatures is a useful, noninvasive measure of HPA axis reactivity under acute activation, this technique might not be suitable for measuring natural variation of circulating glucocorticoid levels.

Differential responses of salivary cortisol, amylase, and chromogranin A to academic stress

Salivary biomarkers have been widely used to help diagnose stress, anxiety, and/or depression. This study aimed to compare the responses of three commonly investigated salivary stress biomarkers that represent the hypothalamic-pituitary-adrenal activity (cortisol; sCort) and the sympathetic activity (alpha-amylase; sAA and chromogranin A; sCgA), using academic oral presentation as a model of stress. Twenty postgraduate dental students attended the seminar class as presenter and audience. The presenters' performances were evaluated by the instructors suggesting more stress than the audience. The saliva was collected two times: before attending class and after an academic presentation (for presenters) or during the class (for audience). The pulse rates (PR) were also recorded. The results showed that the levels of all three biomarkers, as well as PR, were significantly higher in the presenter group compared with the audience group; however, the changes were most prominent with sCort and sAA (99.56 ± 12.76% for sCort, 93.48 ± 41.29% for sAA, 16.86 ± 6.42% for sCgA, and 15.06 ± 3.41% for PR). When compared between pre-post presentation, the levels of sCgA were not different, while those of sCort and sAA were significantly increased. These results suggest more sensitive reactivity to academic stress of sCort and sAA compared with sCgA and that the response of sCgA did not necessarily follow sAA pattern even though both are claimed to reflect the sympathetic activity. More studies are needed to elucidate the roles of sCgA in stress.

Fathers' Heightened Stress Responses to Recounting their NICU Experiences Months after Discharge: A Mixed Methods Pilot Study

OBJECTIVE

 The acute and traumatic events associated with having a newborn who requires admission to the neonatal intensive care unit (NICU) may elicit long-term concerns for parents postdischarge. Cognitive processing of taxing events influences recurring stress responses, which can be inferred via biomarkers such as salivary cortisol (sCort) and skin conductance (SC). In addition, personal narratives provide an important insight into individual perceptions and coping strategies. The current pilot study aimed to (1) test the hypotheses that fathers' sCort and SC would peak in response to stress induction and decrease during recovery, (2) examine associations among stress biomarkers and stress perceptions, (3) explore fathers' narratives using thematic analysis, and (4) integrate fathers' narrative themes with their stress responsivity.

STUDY DESIGN

 Using a convergent mixed methods approach, we enrolled 10 fathers of infants formerly cared for in NICU who underwent a Trier Social Stress Test including recounting their NICU experience months postdischarge. Stress responsivity was measured via sCort and SC, while stress perceptions were identified by using the Perceived Stress Scale and Distress Thermometer-Parent. Personal narratives were explored by using thematic analysis.

RESULTS

 The significant rise in fathers' sCort and SC in response to stress induction was reflected in narrative themes including loss, worry, and role strain. Subsequently, fathers' sCort and SC returned to baseline, which was illustrated by themes such as role strength, coping, and medical staff interactions. Fathers' stress measured by PSS was lower than that required for mental health referral, and did not correlate with stress biomarkers.

CONCLUSION

 Salivary cortisol and skin conductance are useful biomarkers of paternal stress responsivity and recovery. Thematic analysis identified fathers' NICU stressors and coping strategies that mirrored their stress responsivity patterns. Further studies are needed to more broadly examine the sociodemographic variables that influence stress reactivity and perceptions in parents of infants formerly cared for in NICU.

KEY POINTS

· Stress associated with NICU stay is impactful on fathers and may have long-term implications.. · Salivary cortisol and skin conductance are useful noninvasive stress biomarkers.. · Fathers' coping strategies included infant bonding, partner relationship, and trust building..

Only time will tell: Acute stress response patterns with time series analysis

Acute stress is often conceptualized as a response pattern that activates the fight-or-flight response via the sympathetic nervous system (SNS). However, other stress response patterns can manifest as well, such as parasympathetic nervous system (PNS) shutdown, and SNS-PNS coactive hypervigilance. Each response pattern engages many dimensions, including physiological, emotional, and behavioral. As stress unfolds over time, these patterns can change to adjust to the changing nature of the stressor. This proof of concept study introduces novel time series methodology to track the multidimensional patterns of acute stress. The defense cascade provides a model with which to understand and predict response patterns over the time course of an acute stressor. The time series methodology introduced in this study holds promise for identifying mechanisms of change in therapy and clinical settings.

Environmental determinants of physiological reactivity to stress: The interacting effects of early life deprivation, caregiving quality, and stressful life events

Children who spend their early lives in institutions experience profound psychosocial deprivation that is associated with altered stress response system development. Here, we used data from a longitudinal randomized controlled trial of foster care for institutionally reared children to examine whether caregiving quality and stressful life events (SLEs) in early adolescence (age 12) influence patterns of hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) reactivity. Controlling for the effect of institutional care, higher caregiving quality at age 12 was associated with heightened cortisol and SNS reactivity. However, moderation analysis revealed that the latter effect was only observed among never-institutionalized children, whereas ever-institutionalized children demonstrated a persistently blunted SNS response regardless of recent caregiving quality. Among institutionally reared children, SLEs interacted with prior random assignment to foster care, such that those placed in foster care early in development had a SNS response that approximated never-institutionalized children when SLEs at age 12 were low. In contrast, SNS reactivity was persistently blunted among those with prolonged deprivation, regardless of recent SLEs. Early-life deprivation is associated with persistent blunting of stress response systems, but normalization may be achievable if SLEs are limited following placement into enriched family-based care.

Externalizing behavior and stress system functioning in infants exposed to early adversity: A multi-system exploration

Children who experience early adversity often show alterations across multiple stress response systems, including the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS). Changes in the diurnal rhythm of salivary cortisol (a marker of HPA axis functioning) and alpha-amylase (a marker of ANS functioning) may increase their probability of developing behavior problems. The goal of this study is to examine how these analytes may interact to predict externalizing behavior in infants exposed to early stress. Participants included 179 parents and their 6- to 20-month old infants recruited from a low-income neighborhood. Parents reported on their infants' externalizing behaviors and collected saliva samples from their children at wake-up and bedtime over three days. Diurnal cortisol and alpha-amylase were modeled using latent difference scores. Four models were tested examining the effects of cortisol and alpha-amylase morning values and slopes, as well as their interactions, on externalizing behavior. Results showed a significant interaction effect of cortisol and alpha-amylase morning values, such that low morning cortisol was associated with decreased externalizing behavior when morning alpha-amylase was high but not low. These findings highlight the importance of examining multiple systems when characterizing the physiological correlates of externalizing behavior among infants experiencing adversity.

Stress Monitoring and Recent Advancements in Wearable Biosensors

The stress response allows the body to overcome obstacles and prepare for threats, but sustained levels of stress can damage one's health. Stress has long been measured through physical tests and questionnaires that rely primarily on user-inputted data, which can be subjective and inaccurate. To quantify the amount of stress that the body is experiencing biologically, analytical detection of biomarkers associated with the stress response recently have been developed. Novel stress sensing devices focus on cortisol sweat sensing as a part of wearable, flexible devices. These devices promise a real-time, continuous collection of stress data that can be used in clinical diagnoses or for personal stress monitoring and mediation.

Reactivity of salivary uric acid in response to social evaluative stress in African Americans

High uric acid (UA) is associated with hypertension and cardiovascular disease (CVD), both of which occur disproportionately among African Americans. High UA also predicts greater blood pressure reactivity responses to acute social stress. However, whether UA itself shows reactivity in response to stress is unknown. We evaluated salivary uric acid (sUA) and blood pressure reactivity in response to acute social stress. Healthy African Americans (N = 103; 32 % male; M age = 31.36 years), completed the Trier Social Stress Test. sUA and blood pressure measurements were taken before, during and after the stressor task. sUA showed significant reactivity and recovery, especially among older African Americans. Total sUA activation was also associated with systolic and diastolic blood pressure total activation. Findings illuminate that acute stress may be a way in which UA is implicated in hypertension and CVD, suggesting a critical need to explore UA reactivity as a novel parameter of the acute stress response.

Daily Mood Reactivity to Stress during Childhood Predicts Internalizing Problems Three Years Later

The mental health toll of common school problems that many children encounter every day is not well understood. This study examined individual differences in mood reactivity to naturally occurring school problems using daily diaries, and assessed their prospective associations with youth mental health, three years later. At baseline, 47 children ages 8 to 13 years described common problems at school and mood on a daily basis, for 8 weeks. Thirty-three youth returned for follow-up three years later at ages 11 to 17 years. Children and parents also completed one-time questionnaires about youth mental health at baseline and follow-up. There were individual differences in the within-person associations between school problems and same-day and next-day mood. A greater tendency to react to school problems with more negative mood or less positive mood on the same day predicted more parent-rated internalizing and externalizing problems and child ratings of depression symptoms three years later, relative to baseline levels of symptoms. Daily diaries can help to identify specific targets of psychosocial interventions in real world settings.

Stress sensitization among severely neglected children and protection by social enrichment

Childhood adversity may sensitize certain individuals to later stress which triggers or amplifies psychopathology. The current study uses data from a longitudinal randomized controlled trial to examine whether severe early neglect among children reared in institutions increases vulnerability to the effects of later stressful life events on externalizing problems in adolescence, and whether social enrichment in the form of high-quality foster care buffers this risk. Children abandoned to Romanian institutions were randomly assigned to a foster care intervention or care-as-usual during early childhood. A sample of never-institutionalized children served as a comparison group. Here we report that, among those with prolonged institutional rearing, more stressful life events in preadolescence predicted higher externalizing problems in adolescence. This effect was not observed for never-institutionalized children or those in foster care, thus providing experimental evidence that positive caregiving experiences protect against the stress-sensitizing effects of childhood neglect on externalizing problems in adolescence.

Early adversity may sensitize people to the effects of later stress, amplifying psychopathology risk. Here, the authors show this stress sensitization effect for adolescents who experienced prolonged institutional deprivation in childhood, but not those assigned to foster care intervention.