The stability of and intercorrelations among cardiovascular, immune, endocrine, and psychological reactivity

Emotion suppression and acute physiological responses to stress in healthy populations: a quantitative review of experimental and correlational investigations

Emotion suppression may be linked to poor health outcomes through elevated stress-related physiology. The current meta-analyses investigate the magnitude of the association between suppression and physiological responses to active psychological stress tasks administered in the laboratory. Relevant articles were identified through Medline, PsychINFO, PubMed, and ProQuest. Studies were eligible if they (a) used a sample of healthy, human subjects; (b) assessed physiology during a resting baseline and active psychological stress task; and (c) measured self-report or experimentally manipulated suppression. Twenty-four studies were identified and grouped within two separate random effects meta-analyses based on study methodology, namely, manipulated suppression (k = 12) and/or self-report (k = 14). Experimentally manipulated suppression was associated with greater physiological stress reactivity compared to controls (Hg = 0.20, 95% CI [0.08, 0.33]), primarily driven by cardiac, hemodynamic, and neuroendocrine parameters. Self-report trait suppression was not associated with overall physiological stress reactivity but was associated with greater neuroendocrine reactivity (r = 0.08, 95% CI [0.01, 0.14]). Significant moderator variables were identified (i.e., type/duration of stress task, nature of control instructions, type of physiology, and gender). This review suggests that suppression may exacerbate stress-induced physiological arousal; however, this may differ based upon the chosen methodological assessment of suppression.

Reliability of repeated exposure to the human elevated plus-maze in virtual reality: Behavioral, emotional, and autonomic responses

Approach-avoidance conflicts are a hallmark of anxiety-related behaviors. A gold standard for assessing anxiety-related behaviors in rodents is the elevated plus-maze (EPM), which was recently translated to humans using immersive virtual reality. Repeated behavioral testing is particularly interesting for clinical and pharmacological research in humans but could be limited by habituation effects. Here, we tested whether comparable strategies that are used in rodents (different environments and inter-trial interval of 28 days) are sufficient to avoid habituation or sensitization effects on the EPM, making it possible to perform repeated measurement of anxiety-related behavior in humans. Moreover, we developed two novel virtual environments for repeated testing to explore whether a scenario resembling the real world is superior to a video game-like EPM in terms of lifelike physiological, emotional, and behavioral responses. On a behavioral level, no significant differences but a high correlation between first and repeated exposure to the human EPM independent of EPM version were found. On a psychophysiological level, salivary alpha-amylase, skin-conductance, and respiratory frequency increased at first and second exposure independent of EPM version. However, at repeated exposure, skin-conductance and heart rate showed indicators for anticipatory anxiety and a small sensitization effect, while no effect of real-world resemblance on these physiological measures was found. This was also reflected in slightly higher subjective anxiety levels at second exposure, although subjective anxiety still correlated strongly between first and second exposure. In conclusion, the human EPM can be used for longitudinal assessments of human anxiety-related behavior when strategies to avoid habituation and sensitization are considered.

Sex, anxiety and the interplay with physiological variables of stress: a clinical study of patients about to undergo bronchoscopy

Women often report more anxiety than men, but there are divergent results regarding the putative correlation between physiological variables, such as cortisol, blood pressure and heart rate and the experienced emotional states. The aim of the present study was to evaluate sex differences in anxiety, and the relation to serum cortisol, blood pressure and heart rate. We used data from two pooled studies with participants from the same population (N = 405) facing a real-life stressor, bronchoscopy, as part of examination for lung cancer. At admission, blood pressure and heart rate were recorded, and a blood sample was taken for analysis of serum cortisol. Participants then completed Spielberger's State Trait Anxiety Inventory (STAI). Patients had elevated anxiety measured with STAI state compared to relevant age and sex stratified norm scores. Women had significantly higher STAI state score than men (M = 44.9, SD = 13.2 vs M = 36.2, SD = 10.7; t(403) = 7.25, p < 0.001). Mean serum cortisol, systolic blood pressure and heart rate showed no significant sex difference. There was a weak but significant correlation between state anxiety and heart rate and cortisol but none between blood pressure and anxiety. This study adds an important confirmation of sex differences in anxiety in a real-life setting, where women report significantly more anxiety than men do. However, the physiological markers only show a weak link with experienced anxiety, and exhibit no sex differences.

Pre-sleep arousal induced by suspenseful series and cliffhangers have only minor effects on sleep: A sleep laboratory study

Pre-sleep arousal impairs sleep. Therefore, watching suspenseful TV series before sleep is not recommended as they increase arousal. In particular, the consumption of multiple episodes of the same suspenseful TV series in one sitting - termed binge-watching - could lead to large increases in physiological arousal delaying sleep onset. Furthermore, abrupt endings during critical scenes - termed cliffhangers - result in unfinished story lines, which further increase cognitive arousal and could negatively impact sleep architecture and the number of awakenings. However, the effects of binge-watching and cliffhangers on objective sleep parameters are still unknown. Here we tested in a controlled sleep-laboratory setting whether pre-sleep arousal induced by watching 3-4 episodes of a suspenseful TV series has negative effects on sleep in 50 healthy young participants (39 females, mean age = 22.62 ± 2.60 (SD)). Watching a neutral TV series served as a control condition, according to a within-subject design. In one group of participants, the suspenseful TV series ended with a cliffhanger. In the other group, the same TV series ended where no ongoing action was interrupted. Pre-sleep arousal was measured both subjectively with the self-reported level of stress and objectively with the mean heart rate and cortisol level. As expected, suspenseful TV series induced higher cognitive and physiological pre-sleep arousal than neutral control TV series, with highest values for TV series with cliffhangers. In spite of the high pre-sleep arousal, participants fell asleep faster after watching the suspenseful compared with the neutral TV series (F_(1,48) = 4.89, p = 0.032, η² = 0.09). Sleep architecture and the number of awakenings remained unaffected. However, in the first two sleep cycles, heart rate was still higher after watching suspenseful TV series (F_(1,48) = 6.76, p = 0.012, η² = 0.12). And only after cliffhangers, objective sleep quality - measured as the ratio between slow-wave and beta activity during sleep - was lower than in the other conditions (interaction effect, F_(1,48) = 5.05, p = 0.029, η² = 0.10). Our results speak against large impairments of pre-sleep watching of multiple episodes of suspenseful TV series and cliffhangers on sleep quality and architecture. However, unfinished narratives might induce more subtle changes in oscillatory power during sleep, possibly reflecting ongoing cognitive processing during sleep.

Acute stress affects peripersonal space representation in cortisol stress responders

Peripersonal space is the representation of the space near the body. It is implemented by a dedicated multisensory-motor network, whose purpose is to predict and plan interactions with the environment, and which can vary depending on environmental circumstances. Here, we investigated the effect on the PPS representation of an experimentally induced stress response and compared it to a control, non-stressful, manipulation. We assessed PPS representation in healthy humans, before and after a stressful manipulation, by quantifying visuotactile interactions as a function of the distance from the body, while monitoring salivary cortisol concentration. While PPS representation was not significantly different between the control and experimental group, a relation between cortisol response and changes in PPS emerged within the experimental group. Participants who showed a cortisol stress response presented enhanced visuotactile integration for stimuli close to the body and reduced for far stimuli. Conversely, individuals with a less pronounced cortisol response showed a reduced difference in visuotactile integration between the near and the far space. In our interpretation, physiological stress resulted in a freezing-like response, where multisensory-motor resources are allocated only to the area immediately surrounding the body.

Relationships between daily stress responses in everyday life and nightly sleep

Stress and sleep are related, but the nature and time course of this relation is not well understood. We explored the within-person associations of three components of emotional responses to everyday stressors, indexed by negative affect, reactivity (initial response to a stressor), recovery (persistence of the post-stressor response), and pile-up (accumulation of stress episodes), with sleep indicators. We conducted coordinated analyses of data in several studies employing ecological momentary assessments, which captured naturally occurring, self-reported stress and sleep. We defined proximal reactivity as the emotional response to the stressor moment in question compared to an immediate pre-stressor state, and distal reactivity as the emotional response to the stressor moment in question compared to a typical stressor-free state for that person. Results in two of three studies showed that people reported significantly lower sleep quality following days on which they experienced higher levels of distal reactivity to stressors. Days with greater distal reactivity also predicted significantly more difficulty falling asleep in one of two studies. There was no clear association between proximal reactivity and subsequent sleep. Associations of recovery or pile-up with subsequent sleep emerged only in single studies. Poorer sleep quality was significantly related to higher next day levels of negative affect in all three studies, but there were no consistent relations between sleep and next day stress reactivity, recovery, or pile-up. These exploratory analyses suggest that distal reactivity is associated with a heightened risk of experiencing poor sleep quality the following night, and as such the former may serve as a candidate for potential targets for the remediation of the negative effects of stress on sleep.

Physiological reactions to acute stressors and subjective stress during daily life: A systematic review on ecological momentary assessment (EMA) studies

Objective

This review aims to provide an overview of ecological momentary assessment (EMA) studies analyzing stress reactivity during daily life in terms of direct and moderated influence of acute stress on physiological responses.

Materials and methods

A systematic literature search was performed on November 29, 2021 using Web of Science, MEDLINE and PsycINFO to identify prospective EMA studies targeting acute stressors or stress under naturalistic conditions, without restrictions of publication date or population. Study quality was assessed for multiple EMA-specific sources of bias.

Results

Out of 4285 non-duplicate records, 107 publications involving 104 unique studies were included. The majority of studies assessed acute physiological stress responses primarily through salivary cortisol (n = 59) and cardiovascular outcomes (n = 32). Most studies performed at least three measurements per day (n = 59), and had a moderate risk of recall bias (n = 68) and confounding (n = 85). Fifty-four studies reported a compliance of ≥80%. Direct, non-moderated positive associations were observed between acute stress exposure and concurrent cortisol levels (44%, n = 11/25), systolic (44%, 8/18) and diastolic blood pressure (53%, 8/15) and heart rate (53%, 9/17). Several inter- and intra-individual moderators were identified, such as age, gender, health status, chronic stress, work-related resources, physical activity and stress coping indicators.

Conclusions

About half of the reviewed EMA studies demonstrated direct associations between everyday acute stress exposure and physiological responses, including increased cortisol levels, blood pressure and heart rate. Results further suggested various moderator variables that could help develop tailored prevention strategies and identify groups at higher risk for dysfunctional stress responses.

Registration

PROSPERO—Reg.-No.: PROSPERO 2020 CRD42020163178.

Impact of Federal, State, and Local Housing Policies on Disparities in Cardiovascular Disease in Black/African American Men and Women: From Policy to Pathways to Biology

Racist and discriminatory federal, state, and local housing policies significantly contribute to disparities in cardiovascular disease incidence and mortality for individuals that self-identify as Black or African American. Here we highlight three key housing policies - "redlining," zoning, and the construction of highways - which have wrought a powerful, sustained, and destructive impact on cardiovascular health in Black/African American communities. Redlining and highway construction policies have restricted access to quality health care, increased exposure to carcinogens such as PM2.5, and increased exposure to extreme heat. At the root of these policy decisions are longstanding, toxic societal factors including racism, segregation, and discrimination, which also serve to perpetuate racial inequities in cardiovascular health. Here, we review these societal and structural factors and then link them with biological processes such as telomere shortening, allostatic load, oxidative stress, and tissue inflammation. Lastly, we focus on the impact of inflammation on the immune system and the molecular mechanisms by which the inflamed immune microenvironment promotes the formation of atherosclerotic plaques. We propose that racial residential segregation and discrimination increases tissue inflammation and cytokine production, resulting in dysregulated immune signaling, which promotes plaque formation and cardiovascular disease. This framework has the power to link structural racism not only to cardiovascular disease, but also to cancer.

Mental but no bio-physiological long-term habituation to repeated social stress: A study on soldiers and the influence of mission abroad

Soldiers regularly participate in missions abroad and subjectively adapt to this situation. However, they have an increased lifetime cardiovascular risk compared to other occupational groups. To test the hypothesis that foreign deployment results in different stress habituation patterns, we investigated long-term psychological and bio-physiological stress responses to a repeated social stress task in healthy soldiers with and without foreign deployment. Ninety-one female and male soldiers from the BEST study (German armed forces deployment and stress) participated three times in the Trier Social Stress Test for groups (TSST-G) prior to, 6-8 weeks after and 1 year after the mission abroad and were compared to a control group without foreign deployment during the study period. They completed the State-Trait-Anxiety Inventory scale (STAI), the Primary Appraisal Secondary Appraisal questionnaire (PASA) and the Multidimensional Mood State Questionnaire (MDBF). Salivary cortisol and α-amylase, blood pressure, heart rate and heart rate variability were determined. Soldiers showed mental habituation over the three times with a significant decrease after the TSST-G in anxiousness (STAI) and cognitive stress appraisal (PASA), they were calmer and reported better mood (MDBF). Prior to the social stress part, the mood (MDBF) declined significantly. None of the biological and physiological markers showed any adaptation to the TSST-G. Mission abroad did not significantly influence any measured psychobiological marker when compared to soldiers without foreign deployment. Foreign deployment does not result in alterations in psychobiological social stress response patterns over 1 year after mission abroad which indicates that adaptation to acute social stress is highly maintained in healthy soldiers. The discrepancy between subjective perception and objective stress response has numerous clinical implications and should receive more attention.

Daily Stressors, Emotion Dynamics, and Inflammation in the MIDUS Cohort

BACKGROUND

The current study (1) examined links between daily stressors and inflammation and (2) tested whether negative emotion dynamics (emotional variability) is one pathway through which stressors are linked to inflammation.

METHOD

A cross-sectional sample of 986 adults (aged 35-86 years, 57% female) from MIDUS reported daily stressor frequency and severity and negative emotions on 8 consecutive nights. Negative emotion variability (intraindividual standard deviation), controlling for overall mean level (intraindividual mean), was the focus of the current study. Interleukin-6 (IL-6) and C-reactive protein (CRP) were assayed from blood drawn at a clinic visit. Regression models adjusted for demographics, health factors, and the time between assessments.

RESULTS

More severe daily stressors were associated with higher CRP, but this effect was accounted for by covariates. More frequent daily stressors were associated with lower IL-6 and CRP. In follow-up analyses, significant interactions between stressor severity and frequency suggested that participants with lower stressor severity and higher stressor frequency had the lowest levels of IL-6 and CRP, whereas those with higher stressor severity had the highest levels of IL-6 and CRP, regardless of frequency. Daily stressor frequency and severity were positively associated with negative emotion variability, but variability was not linearly associated with inflammation and did not operate as a mediator.

CONCLUSION

Among midlife and older adults, daily stressor frequency and severity may interact and synergistically associate with inflammatory markers, potentially due to these adults being advantaged in other ways related to lower inflammation, or in a pattern aligning with hormetic stress, where frequent but manageable stressors may yield physiological benefits, or both. Negative emotion variability does not operate as a mediator. Additional work is needed to reliably measure and test other emotion dynamic metrics that may contribute to inflammation.

Sex-Specific Interaction Between Cortisol and Striato-Limbic Responses to Psychosocial Stress

Although women and men differ in psychological and endocrine stress responses as well as in the prevalence rates of stress-related disorders, knowledge on sex differences regarding stress regulation in the brain is scarce. Therefore, we performed an in-depth analysis of data from 67 healthy participants (31 women, taking oral contraceptives), who were exposed to the ScanSTRESS paradigm in a functional magnetic resonance imaging study. Changes in cortisol, affect, heart rate and neural activation in response to psychosocial stress were examined in women and men as well as potential sex-specific interactions between stress response domains. Stress exposure led to significant cortisol increases, with men exhibiting higher levels than women. Depending on sex, cortisol elevations were differently associated with stress-related responses in striato-limbic structures: higher increases were associated with activations in men but with deactivations in women. Regarding affect or heart rate responses, no sex differences emerged. Although women and men differ in their overall stress reactivity, our findings do not support the idea of distinct neural networks as the base of this difference. Instead, we found differential stress reactions for women and men in identical structures. We propose considering quantitative predictors such as sex-specific cortisol increases when exploring neural response differences of women and men.

Individual differences in the neuroendocrine response of male rats to emotional stressors are not trait-like and strongly depend on the intensity of the stressors

Biological response to stressors is critical to understand stress-related pathologies and vulnerability to psychiatric diseases. It is assumed that we can identify trait-like characteristics in biological responsiveness by testing subjects in a particular stressful situation, but there is scarce information on this issue. We then studied, in a normal outbred population of adult male rats (n = 32), the response of well-characterized stress markers (ACTH, corticosterone and prolactin) to different types of stressors: two novel environments (open-field, OF1 and OF2), an elevated platform (EP), forced swim (SWIM) and immobilization (IMO). Based on both plasma ACTH and prolactin levels, the OF1 was the lowest intensity situation, followed by the OF2 and the EP, then SWIM and finally IMO. When correlations between the individual responses to the different stressors were studied, the magnitude of the correlations was most dependent on the similarities in intensity rather than on other characteristics of stressors, with good correlations between similar intensity stressors and no correlations at all were found between stressors markedly differing in intensity. In two additional confirmatory experiments (n = 37 and n = 20) with HPA hormones, we observed good correlation between the response to restraint and IMO, which were close in intensity, and no correlation between OF1 and SWIM. The present results suggest that individual neuroendocrine response to a particular stressor does not predict the response to another stressor greatly differing in intensity, thus precluding characterization of low or high responsive individuals to any stressor in a normal population. The present data have important implications for human studies.

Psychological Reactivity to Daily Family Experiences During Adolescence: Individual Differences and Developmental Stability

The current study examined adolescent psychological reactivity to daily family experiences, an important feature of emotion regulation that could have significant implications for psychopathology. A total of 428 Mexican-heritage adolescents (M_age  = 15.02 years, range: 13-18 years) completed daily diary checklists for 14 days and again 1 year later. Results revealed that adolescents' family experiences were associated with negative mood, positive mood, and role fulfillment on a daily basis. Only role fulfillment reactivity was stable across 1 year, suggesting instability in individual differences in positive and negative mood reactivity. Sex moderated the relation between positive and negative mood reactivity during the second year of study, with males exhibiting broad psychological reactivity to daily family experiences. However, females who experienced higher negative mood reactivity exhibited less positive mood reactivity. Implications for possible sex differences in depression risk during the high school years are discussed.

Working with Children with ADHD—A Latent Profile Analysis of Teachers’ and Psychotherapists’ Attitudes

A positive attitude of teachers and psychotherapists towards children with ADHD can both support their mutual relationship and support reducing ADHD-related symptoms. According to Fishbein and Ajzen’s rational-choice approach, attitude formation is based on a person’s expectations and the appraisal of these, thus attitude, therefore, differs individually. The present study aimed to identify different attitude profiles based on our participants’ answer patterns on the ADHD-school-expectation questionnaire’s (ASE) subscales, and to examine which attitude profile would be desirable for professionals working with children with ADHD. We conducted a latent profile analysis and investigated differences between the latent profiles. Our analysis revealed three attitude profiles characterized by negative, moderate and extreme ratings of expectations. The attitude profiles differed in further variables such as the use and effectiveness of rating classroom management strategies, knowledge of ADHD, perceived control, stress and strain, as well as some personality traits. The extreme rating profile seems to be beneficial for children with ADHD, whereas the moderate rating profile might appeal to certain professionals.

Racial discrimination and disability among Asian and Latinx populations in the United States

Purpose: This study examined the association between perceived racial discrimination and disability among Asian and Latinx residents of the United States, as the link between discrimination and disability has gone largely ignored in analyses of these populations.Materials and methods: Nationally representative samples included 2046 Asian Americans and 2515 Latinx Americans from the National Latino and Asian American Study (NLAAS). We used multivariable logistic regression and multivariable negative binomial regression to analyze the association between racial discrimination and five different disability domains as well as racial discrimination and a count of simultaneous functional limitations, respectively. The disability domains included: self-care, cognition, mobility, time out of role, and social interaction.Results and conclusions: Perceived racial discrimination positively and significantly predicted impairments across a variety of disability domains for both Asian and Latinx populations. The estimated associations between racial discrimination and disability were heterogeneous across Asian and Latinx ethnicities. Racial discrimination may contribute to stress for Asians and Latinxs in the United States, potentially increasing the possibility these populations develop disabilities. Rehabilitation efforts should consider the social contexts in which people of color live, recognizing that discrimination may differentially affect risk profiles for disabilities across racial and ethnic groups.IMPLICATIONS FOR REHABILITATIONAcross Asian and Latinx populations, racial discrimination is associated with impairments in self-care, cognition, mobility, time out of role, and social interaction.Future translational research can explore the utility of brief racial discrimination screens in clinical settings to assess risk for disability in various domains.Professionals should attend to the stress and overall impact of racial discrimination, as it is conceivable that racial discrimination may result in the exclusion or hindrance of people of color who are pursuing meaningful participation in places of work, public spaces, and civic life.Society bears the collective obligation to reduce discrimination against Asian and Latinx populations, particularly against those who experience disability.

Establishing the validity of a novel passive stress task

Laboratory tasks used to elicit a cardiovascular stress response in the laboratory can involve either active or passive coping. However, in previous work, passive stress tasks often incorporate a distinct physical stress element, such as the handgrip or cold pressor task, meaning observed changes in cardiovascular parameters may be the result of the physical element of the stressor rather than truly reflecting psychological stress. The present study aimed to establish the validity of a psychological passive stressor; one more analogous to active tasks than those previously employed in laboratory studies. Twenty-six young, healthy adults completed a speech task in the laboratory following a resting baseline period. Twelve months later, they were invited back to the laboratory and watched the video recording of their speech. Analyses confirmed that while both tasks elicited significant SBP and DBP change (all ps < .001), only the active task was associated with HR and CO reactivity (both ps < .001), while only the passive task was associated with TPR reactivity (p = .028). Furthermore, the passive stressor was associated with a mixed hemodynamic profile, whereas the active stressor was associated with a clear myocardial profile. This study confirms that watching a video recording of oneself complete a speech task is associated with a more vascular response profile, a response associated with passive coping contexts.

Positive Emotions Experienced on Days of Stress are Associated with Less Same Day and Next Day Negative Emotion

Positive emotions help us during times of stress. They serve to replenish resources and provide relief from stressful experiences. Positive emotions may be particularly beneficial during times of stress by dampening negative emotional reactivity and quickening recovery from stressful events. In this study, we used a daily diary design to examine how positive emotions experienced on days with minor stressful events are associated with same day and next day stressor-related negative emotions. We combined data from the National Study of Daily Experiences II (NSDE II) and the Midlife in the United States survey (MIDUS II), resulting in 1,588 participants who answered questions about daily stressors and emotion across 8 consecutive days. On days when people experienced a stressor and had higher than their average level of positive emotion, they experienced less of a same day increase in negative emotion. Additionally, they experienced less subsequent negative emotion the following day and were less likely to experience a stressor the next day. Results held when adjusting for trait measures of positive and negative emotion. These results suggest that daily positive emotions experienced on days of stress help regulate our negative emotion during times of stress.

Social-evaluative threat: Stress response stages and influences of biological sex and neuroticism

Social-evaluative threat (SET) - when the self could be negatively judged by others - can cause pronounced responses in the different stress systems: threat/challenge appraisal, the sympathetic (SNS) and parasympathetic (PNS) nervous systems, experienced motivation and affect, and the hypothalamus-pituitary-adrenal (HPA) axis. Here, we utilize a four-stage stress response model to shed light on the complex associations between different stress responses, where earlier stages are hypothesized to predict later stages. Additionally, we take into account important moderators, such as biological sex (controlling for menstrual cycle phase), personality traits (neuroticism and extraversion), and baseline stress levels. Thirty-seven men and 30 women in their luteal phase participated in an impromptu public speaking task to induce SET. Stress responses in four different stages were measured using: self-reported appraisal (threat or challenge, stage 1: S1), cardiovascular measures (pre-ejection period as SNS index, respiratory sinus arrhythmia as PNS index, S2), self-reported motivation and affect (state approach motivation, state anxiety, S3) and endocrine measures (cortisol as HPA index, S4). Stress reactivity was calculated by subtracting individual peaks from baseline. Results showed that SET induced pronounced stress reactivity in stages two to four. Against expectations, self-reported appraisal (S1) or motivation and affect (S3) did not predict later stress reactivity. As hypothesized, increased SNS (but not PNS) reactivity (S2) predicted increased HPA reactivity (S4). Bayesian model comparison confirmed the absence of sex differences in stress reactivity, likely due to controlling for menstrual cycle phase and sex differences in neuroticism levels. Higher trait neuroticism predicted blunted SNS (S2) and HPA (S4) reactivity, while higher baseline stress levels predicted blunted stages two and three reactivity overall. In conclusion, this rigorously controlled experiment partly supports and partly contradicts previous findings regarding associations between stress response stages, and offers new insight into the causes of blunted HPA responses in women.

Predictors of ccf-mtDNA reactivity to acute psychological stress identified using machine learning classifiers: A proof-of-concept

OBJECTIVE

We have previously found that acute psychological stress may affect mitochondria and trigger an increase in serum mitochondrial DNA, known as circulating cell-free mtDNA (ccf-mtDNA). Similar to other stress reactivity measures, there are substantial unexplained inter-individual differences in the magnitude of ccf-mtDNA reactivity, as well as within-person differences across different occasions of testing. Here, we sought to identify psychological and physiological predictors of ccf-mtDNA reactivity using machine learning-based multivariate classifiers.

METHOD

We used data from serum ccf-mtDNA concentration measured pre- and post-stress in 46 healthy midlife adults tested on two separate occasions. To identify variables predicting the magnitude of ccf-mtDNA reactivity, two multivariate classification models, partial least-squares discriminant analysis (PLS-DA) and random forest (RF), were trained to discriminate between high and low ccf-mtDNA responders. Potential predictors used in the models included state variables such as physiological measures and affective states, and trait variables such as sex and personality measures. Variables identified across both models were considered to be predictors of ccf-mtDNA reactivity and selected for downstream analyses.

RESULTS

Identified predictors were significantly enriched for state over trait measures (X2 = 7.03; p = 0.008) and for physiological over psychological measures (X2 = 4.36; p = 0.04). High responders were more likely to be male (X2 = 26.95; p < 0.001) and differed from low-responders on baseline cardiovascular and autonomic measures, and on stress-induced reduction in fatigue (Cohen's d = 0.38-0.73). These group-level findings also accurately accounted for within-person differences in 90% of cases.

CONCLUSION

These results suggest that acute cardiovascular and psychological indices, rather than stable individual traits, predict stress-induced ccf-mtDNA reactivity. This work provides a proof-of-concept that machine learning approaches can be used to explore determinants of inter-individual and within-person differences in stress psychophysiology.

Associations between heart rate, perceived heart rate, and anxiety during acute psychological stress

Background: Acute psychological stress elicits increases in heart rate (HR) and anxiety. Theories propose associations between HR, perceived HR, and anxiety during stress. However, anxiety is often measured as a unidimensional construct which limits a comprehensive understanding of these relationships. Objectives: This research explored whether HR reactivity or perceived HR change was more closely associated with cognitive and somatic anxiety during acute psychological stress. Design: Two laboratory-based studies were conducted. Methods: In a single laboratory session, healthy male (N = 71; study 1) and female (N = 70; study 2) university students completed three laboratory psychological stress tasks (counterbalanced), each with a preceding baseline. Heart rate, perceived HR change, and cognitive and somatic anxiety intensity and interpretation of anxiety symptoms were assessed immediately following each task. Data were aggregated across tasks. Results: Actual HR change was unrelated to anxiety intensity, but was associated with more debilitative interpretations of anxiety (study 2). Perceptions of HR change were consistently associated with greater intensity of cognitive (study 1) and somatic (study 1 and 2) anxiety. Conclusions: Perceived HR rather than actual HR is more closely associated with anxiety intensity during psychological stress. The findings have implications for stress management and the clinical treatment of anxiety symptoms.

The role of bicultural adaptation, familism, and family conflict in Mexican American adolescents' cortisol reactivity

Scarce research has examined stress responsivity among Latino youths, and no studies have focused on the role of acculturation in shaping cortisol stress response in this population. This study assessed Mexican American adolescents' Mexican and Anglo cultural orientations and examined prospective associations between their patterns of bicultural orientation and hypothalamic-pituitary-adrenal cortisol reactivity to an adapted Trier Social Stress Test. The sample included 264 youths from a longitudinal birth cohort study who completed the Trier Social Stress Test and provided saliva samples at age 14. The youths completed assessments of cultural orientation at age 12, and family conflict and familism at age 14. Analyses testing the interactive effects of Anglo and Mexican orientation showed significant associations with cortisol responsivity, including the reactivity slope, peak levels, and recovery, but these associations were not mediated by family conflict nor familism values. Findings revealed that bicultural youth (high on both Anglo and Mexican orientations) showed an expected pattern of high cortisol responsivity, which may be adaptive in the context of a strong acute stressor, whereas individuals endorsing only high levels of Anglo orientation had a blunted cortisol response. Findings are discussed in relation to research on biculturalism and the trade-offs and potential recalibration of a contextually responsive hypothalamic-pituitary-adrenal axis for acculturating adolescents.

Cardiovascular Reactivity During Marital Conflict in Laboratory and Naturalistic Settings: Differential Associations with Relationship and Individual Functioning Across Contexts

Cardiovascular reactivity during spousal conflict is considered to be one of the main pathways for relationship distress to impact physical, mental, and relationship health. However, the magnitude of association between cardiovascular reactivity during laboratory marital conflict and relationship functioning is small and inconsistent given the scope of its importance in theoretical models of intimate relationships. This study tests the possibility that cardiovascular data collected in laboratory settings downwardly bias the magnitude of these associations when compared to measures obtained in naturalistic settings. Ambulatory cardiovascular reactivity data were collected from 20 couples during two relationship conflicts in a research laboratory, two planned relationship conflicts at couples' homes, and two spontaneous relationship conflicts during couples' daily lives. Associations between self-report measures of relationship functioning, individual functioning, and cardiovascular reactivity across settings are tested using multilevel models. Cardiovascular reactivity was significantly larger during planned and spontaneous relationship conflicts in naturalistic settings than during planned relationship conflicts in the laboratory. Similarly, associations with relationship and individual functioning variables were statistically significantly larger for cardiovascular data collected in naturalistic settings than the same data collected in the laboratory. Our findings suggest that cardiovascular reactivity during spousal conflict in naturalistic settings is statistically significantly different from that elicited in laboratory settings both in magnitude and in the pattern of associations with a wide range of inter- and intrapersonal variables. These differences in findings across laboratory and naturalistic physiological responses highlight the value of testing physiological phenomena across interaction contexts in romantic relationships.

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

Social evaluative threat is a potent activator of the hypothalamic-pituitary-adrenocortical (HPA) axis in typically developing (TD) populations. Studies have shown that children and adolescents with autism spectrum disorder (ASD) show a blunted cortisol response to this type of stressor; yet, a previous study in adults with ASD reported a more prototypical stress response. The current study compared 24 adolescents and 17 adults with ASD to investigate a possible developmental lag in autism resulting in a more adaptive stress response to social evaluation with development. Participants were exposed to the trier social stress test (TSST), and salivary cortisol was collected before and after stress induction. Multilevel modeling revealed that relative to adolescents, young adults with ASD evidenced a significant increase in cortisol in response to anticipatory stress, and 23.5% were classified as anticipatory responders. Adolescents, however, had a significant change in slope in response to the TSST, with 37.5% classified as reactive responders. In both groups, the majority of participants did not have a robust stress response to the TSST as would be expected in TD participants. Findings suggest significant differences in the cortisol trajectory; adults with ASD were more likely to show an anticipatory response to being socially evaluated, which was maintained throughout the stressor, whereas the adolescents had a more reactive response pattern with no anticipatory response. Further research is needed to determine if such patterns are adaptive or deleterious, and to determine underlying factors that may contribute to distinct stress profiles and to the overall diminished stress responses. Autism Res 2018, 11: 1276-1285. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Many individuals have increased stress when being socially evaluated. The current study shows that adults with ASD have increased stress in anticipation of a task in which individuals are required to give a speech to unfamiliar raters, while adolescents with ASD tend to show a stress response only during the task itself. Further research is necessary to understand whether developmental influences on stress response in ASD have significant impacts on other areas of functioning often affected by stress.

Perceived discrimination and cardiovascular health disparities: a multisystem review and health neuroscience perspective

There are distinct racial disparities in cardiovascular disease (CVD) risk, with Black individuals at much greater risk than White individuals. Although many factors contribute to these disparities, recent attention has focused on the role of discrimination as a stress-related factor that contributes to racial disparities in CVD. As such, it is important to understand the mechanisms by which discrimination might affect CVD. Recent studies have examined these mechanisms by focusing on neurobiological mediators of CVD risk. Given this increase in studies, a systematic review of perceived discrimination and neurobiological mediators of CVD risk is warranted. Our review uses a multisystem approach to review studies on the relationship between perceived discrimination and (1) cardiovascular responses to stress, (2) hypothalamic-pituitary-adrenocortical axis function, and (3) the immune system, as well as (4) the brain systems thought to regulate these parameters of peripheral physiology. In addition to summarizing existing evidence, our review integrates these findings into a conceptual model describing multidirectional pathways linking perceived discrimination with a CVD risk.

During stress, heart rate variability moderates the impact of childhood adversity in women with breast cancer

Childhood adversity has long-lasting neuro-biological effects that can manifest as exaggerated stress responsivity to environmental challenge. These manifestations include a dysregulated hypothalamic-pituitary-adrenocortical (HPA) axis as well as increased levels of inflammatory mediators in response to stress. In this investigation, vagal parasympathetic activity was assessed for its capacity to moderate the relationship between childhood adversity and stress responsivity (cortisol and inflammation) during an acute laboratory challenge (Trier Social Stress Test-TSST). Thirty women recently diagnosed with breast cancer underwent the TSST during which their heart rate was recorded and saliva samples collected for measurement of cortisol and the proinflammatory cytokine, IL-6. Vagal activity during the TSST was calculated as the high-frequency (HF) component of heart rate variability (HRV). Vagal activity during the TSST moderated the effect of childhood adversity on both the cortisol and the IL-6 response. Women who had lower vagal stress-reactivity during the TSST and reported greater childhood adversity showed a larger rise in cortisol and IL-6 when compared to women with lower childhood adversity. The findings demonstrate that women with exposure to childhood adversity and low vagal stress-reactivity (reduced parasympathetic activity) exhibit an elevated stress response characterized by greater cortisol and proinflammatory cytokine release. Inflammatory burden and HPA dysregulation subsequent to stress may impair cancer control.

Age differences in negative emotional responses to daily stressors depend on time since event

Research on age differences in the experience of negative emotional states have produced inconsistent results, particularly when emotion is examined in the context of daily stress. Strength and vulnerability integration (SAVI; Charles, 2010) theory postulates that age differences in emotional states are contingent upon whether a stressor occurred, and whether sufficient time has passed since the stressor to allow older adults to benefit from theorized strengths. The present study uses an ecological momentary assessment design to examine how timing of daily stressors relates to age differences in negative emotional responses. Participants (N = 199, aged 25-65) completed mobile surveys up to 5 times daily for 14 days. They reported current mood and stressor exposure, as well as how long ago the stressor occurred. As expected, no age differences were observed in current negative affect (NA) for stressors which occurred in the previous 0-10 min. As predicted, older age was associated with less of a stressor-related increase in NA when a greater time had passed (i.e., 10 min to 2.5 hours) since stressor exposure. Consistent with previous results, there were no age differences in the effects of more distal stressors that occurred 2.5 to 5 hr ago, although NA remained significantly elevated. The present findings are consistent with SAVI's predictions and advance understanding age differences in the time course relating everyday stressors to emotional responses. (PsycINFO Database Record

The psychology of HPA axis activation: Examining subjective emotional distress and control in a phobic fear exposure model

The HPA axis plays a key role in mediating the effects of "stress" on health, but clarifying mechanisms requires an understanding of psycho-biological linkages. There has long been an implicit assumption that subjective emotional distress (e.g., fear) should activate the HPA axis. Although this assumption was challenged 25 years ago (Curtis, 1976), laboratory studies in humans are limited. In this study we sought to replicate Curtis' findings and extend it by investigating if presence or absence of stressor control shapes HPA axis reactivity in a phobic fear exposure model. We recruited 19-45-year-old specific phobia participants (n=32 spider/snake phobia; n=14 claustrophobia) and gradually exposed them to their feared object or situation while measuring hormonal (ACTH and cortisol) and subjective (emotional distress, perceived control) responses. Utilizing a dyadic yoked design, we compared HPA reactivity when the pace of exposure was controlled by participants to identical exposure given to matched participants in the absence of control. Results showed that phobic fear exposure generated intense emotional distress without a corresponding increase in HPA axis activity. Although our actual manipulation of control failed to impact HPA responses, perceived control during exposure was associated with lower cortisol, an effect that was moderated by actual availability of stressor control. Our findings replicate Curtis' findings and challenge the still common but unsupported assumption that HPA axis activity reflects subjective distress. These results also highlight the importance of both perceived and actual aspects of stressor control in understanding what is truly "stressful" to the HPA axis system.

The effects of acute psychological stress on circulating and stimulated inflammatory markers: A systematic review and meta-analysis

Inflammatory reactivity to acute laboratory stress is thought to reflect individual differences in responsivity to environmental stressors and may confer future health risk. To characterize this response, we conducted a meta-analysis of 34 studies that measured circulating inflammatory markers and 15 studies that measured stimulated production of inflammatory markers before and after exposure to laboratory challenge. Results showed significant stress-related increases in circulating interleukin (IL)-1β (d=0.66, p<0.001), IL-6 (d=0.35, p<0.001), IL-10 (d=0.69, p<0.001), and tumor necrosis factor(TNF)-α (d=0.28, p<0.001), but not IL-1ra, IL-2, interferon-γ, or C-reactive protein. There were sufficient data to assess the time course of IL-6, IL-1β, and TNF-α reactivity. IL-6 increased from baseline to measures taken 40-50, 60-75, 90, and 120min following stress, with the largest effect at 90min post-stress (d=0.70, p<0.001). IL-1β increased from baseline to 20-30, 40-50, and 60-70min following stress, with the largest effect between 40 and 50min post-stress (d=0.73, p=0.02). For TNF-α, there was a significant increase from baseline to 31-50min post stress (d=0.44, p=0.01), but not at later times. There was no difference in magnitude of IL-6 reactivity as a function of type of stress (social-evaluative versus other). For stimulated inflammatory markers, results showed stress-related increases in IL-1β when measured 20-120min post-stress (d=1.09, p<0.001), and in IL-4 and interferon-γ when measured 0-10min post stressor (d=-0.42, p<0.001 and d=0.47, p<0.001). These results extend findings from a prior meta-analysis (Steptoe et al., 2007) to show reliable increases in circulating IL-6, IL-1β, IL-10 and TNF-α and stimulated IL-1β, IL-4 and interferon-γ in response to acute stress. It is possible that these responses contribute to associations between exposure to life challenges and vulnerability to inflammatory disease.

La escucha de música antes del TSST regula los niveles de cortisol en saliva independiente de la preferencia musical

El presente estudio evaluó si la escucha de música preferida por los participantes o la música relajante elegida por los investigadores previa al protocolo de estrés social modificado TSST (Trier Social Stress Test) afectaba el desempeño de las actividades realizadas durante el propio test, modulaba la respuesta de estrés que este induce, y en conjunto con el estresor, afectaba el desempeño en una tarea de atención en setenta y seis estudiantes universitarios asignados a uno de seis grupos: música relajante del investigador, música preferida por el participante y silencio, con o sin TSST. Los resultados mostraron que la escucha de ambos tipos de música provocó un incremento más lento en los niveles de cortisol en saliva luego del TSST, mientras que el aumento en la ansiedad estado evaluada con el IDARE (Inventario de Ansiedad Rasgo-Estado) fue semejante en todos los grupos. No se encontraron diferencias debidas a la música en el desempeño de las tareas evaluadas. Se discute sobre la modulación de la escucha de música en la respuesta fisiológica de estrés por la posible inducción de reacciones emocionales de manera independiente de la preferencia musical.

Psychophysiological Assessment of Social Stress in Natural and Laboratory Situations

Abstract. Experience sampling and psychophysiological ambulant assessment methods were employed to compare reactions to social stress using a laboratory stressor (The Trier Social Stress Test [TSST]) or a corresponding real-life condition (seminar presentation). Stress reactions were assessed by self-report as well as additional heart rate (AHR, i.e., heart rate increases corrected for physical activity and initial values) and were compared to a control condition in each group. Twenty-five participants gave a talk in a university seminar course and twenty-two participants took part in the TSST. The TSST elicited a greater overall physiological stress reaction as compared to the seminar presentation. However, analyses of dynamic AHR levels revealed that the groups of speakers showed different response profiles during the time course of the stress situations. AHR levels of both groups were similar at the beginning of the free speech. During the course of their presentation, seminar speakers downregulated their arousal level. The arousal level of TSST participants showed a further increase in the later portion of the TSST during the mental arithmetic task. Thus, the more prominent overall physiological stress reaction during the TSST as compared to the seminar presentation appeared to depend on different demand characteristics rather than on differences of laboratory versus real-life situations per se. The experience of emotional strain was greater in response to the social stressors than in response to control situations in both the TSST and seminar speaker group with no differential effects of the experimental setting (laboratory vs. real life). During the TSST procedure, salivary cortisol concentrations were also assessed. Significant correlations of AHR with cortisol level and subjective experience indicate that AHR measurement provides a valid psychophysiological indicator of social stress. These findings suggest that ambulatory assessment techniques successfully contribute to the validation of a common social stress task.

Perception of Life as Stressful, Not Biological Response to Stress, is Associated with Greater Social Disability in Adults with Autism Spectrum Disorder

This study examined differences between adults with autism spectrum disorder (ASD; N = 40) and typical community volunteers (N = 25) on measures of stressful life events, perceived stress, and biological stress response (cardiovascular and cortisol reactivity) during a novel social stress task. Additional analyses examined the relationship between stress and social functioning as measured by the Social Adjustment Scale-II and the Waisman Activities of Daily Living scale. Results indicated that adults with ASD experienced significantly more stressful life events and perceived stress, and greater systolic blood pressure reactivity than typical community volunteers. Results also indicated that perceived stress and stressful life events were significantly associated with social disability. Interventions targeting stress management might improve social function in adults with ASD.

Moderate alcohol consumption after a mental stressor attenuates the endocrine stress response

Alcohol is often consumed to reduce tension and improve mood when exposed to stressful situations. Previous studies showed that moderate alcohol consumption may reduce stress when alcohol is consumed prior to a stressor, but data on the effect of alcohol consumption after a mental stressor is limited. Therefore, our objective was to study whether moderate alcohol consumption immediately after a mental stressor attenuates the stress response. Twenty-four healthy men (age 21-40 y, BMI 18-27 kg/m²) participated in a placebo-controlled trial. They randomly consumed 2 cans (660 mL, ∼26 g alcohol) of beer or alcohol-free beer immediately after a mental stressor (Stroop task and Trier Social Stress Test). Physiological and immunological stress response was measured by monitoring heart rate and repeated measures of the hypothalamic-pituitary-adrenal axis (HPA-axis), white blood cells and a set of cytokines. After a mental stressor, cortisol and adrenocorticotropic hormone (ACTH) concentrations were 100% and 176% more reduced at 60 min (P = 0.012 and P = 0.001, respectively) and 92% and 60% more reduced at 90 min (P < 0.001 and P = 0.056, respectively) after beer consumption as compared to alcohol-free beer consumption. Heart rate and dehydroepiandrosterone (DHEA) were not influenced by alcohol consumption. Plasma IL-8 concentrations remained lower during the stress recovery period after beer consumption than after alcohol-free beer consumption (P < 0.001). In conclusion, consumption of a moderate dose of alcohol after a mental stressor may facilitate recovery of the endocrine stress response as reflected by decreasing plasma ACTH and cortisol.

Sex differences in the association between stressor-evoked interleukin-6 reactivity and C-reactive protein

Individuals differ consistently in the magnitude of their inflammatory responses to acute stressors, with females often showing larger responses than males. While the clinical significance of these individual differences remains unclear, it may be that greater inflammatory responses relate to increased systemic inflammation and thereby risk for chronic inflammatory disease. Here, we examined whether acute stressor-evoked interleukin (IL)-6 responses associate with resting levels of C-reactive protein (CRP), a marker of systemic inflammation, and whether this association differs by sex. Subjects were 57 healthy midlife adults (30-51years; 33% female; 68% white). Blood was drawn before and 30-min after two mental stress tasks: a multisource interference task and a Stroop color word task. Hierarchical regressions controlling for age, sex, race, and BMI tested whether stressor-evoked IL-6 responses were associated with resting CRP and whether this association differed by sex. Results indicated that sex and stressor-evoked IL-6 responses interacted to predict CRP (ΔR²=0.08, B=-1.33, β=-0.39, p=0.02). In males, larger stressor-evoked IL-6 responses associated with higher CRP, whereas in females, stressor-evoked IL-6 responses showed a non-significant negative association with CRP. These findings indicate that inflammatory responses to acute stressors associate with resting levels of CRP; however, this association differs by sex. Previous literature suggests that there are sex differences in stressor-evoked IL-6 responses, but this is the first study to show sex differences in the relationship between acute inflammatory responses and systemic inflammation. The contribution of these sex differences to inflammatory disease risk warrants further investigation.

Victimization and Biological Stress Responses in Urban Adolescents: Emotion Regulation as a Moderator

Associations between urban adolescents' victimization experiences and biological stress responses were examined, as well as emotion regulation as a moderator of these associations. Data from a 4-wave longitudinal study with a low-income, community-based sample (n = 242; 91 % African American; 57 % female; M = 11.98, SD = 1.56 years at baseline) revealed that victimization, assessed over 3 study waves, was associated with an attenuated cortisol response to a stress interview at the final study wave, indicating that responses of the Hypothalamus-Pituitary-Adrenal (HPA) axis were dysregulated. Cortisol responses were moderated by caregiver-reported adolescent emotion regulation, suggesting that this modifiable protective factor that is taught in many school-based prevention programs could help reduce harm associated with HPA axis dysregulation linked to victimization.

HRQoL impact of stressful life events in children beginning primary school: results of a prospective study in Poland

Purpose

To evaluate the relationship between recent stressful life events (SLEs), stress-related symptoms (SRSs), and health-related quality of life (HRQoL) in children beginning primary school.

Methods

A community-based sample of 6- to 8-year-old children (176 boys and 175 girls at baseline) participated in a prospective longitudinal study with three waves of data collection and 1-year interval between subsequent surveys, conducted in the Wielkopolska Province, Poland. Main exposures included nine recent stressful life events and psychosomatic and behavioural symptoms related to stress (SRSs), both self-reported by children. The outcome was total HRQoL assessed by a Polish version of the PedsQL™ 4.0 (Pediatric Quality of Life Inventory) Generic Core Scales questionnaire, 5- to 7-year-old version. To evaluate the relationship between total HRQoL and predictor variables, a latent growth curve (LGC) model using multiple group design (boys and girls) with three waves and two time-varying covariates, the SLEs and SRSs, was applied.

Results

An unconditional multi-group LGC model revealed that the total HRQoL changed over time in a linear trajectory. After incorporating to the model, two time-varying covariates, SLEs and SRSs, the first predictor for HRQoL was only significant at the last wave in girls and at two subsequent waves, except for baseline, in boys. The second predictor revealed significant negative impacts on HRQoL over the entire period of time in both boys and girls suggesting that the pathway underlying the association of SLEs with HRQoL may be mediated by SRSs. Mean values of HRQoL at each time points did not show gender differences.

Conclusions

The findings of the present study may help to develop and implement a health and safety protection training programmes addressed to parents, caregivers, and practitioners to make children’s lives easier.

Adolescent neurobiological susceptibility to social context

Adolescence has been characterized as a period of heightened sensitivity to social contexts. However, adolescents vary in how their social contexts affect them. According to neurobiological susceptibility models, endogenous, biological factors confer some individuals, relative to others, with greater susceptibility to environmental influences, whereby more susceptible individuals fare the best or worst of all individuals, depending on the environment encountered (e.g., high vs. low parental warmth). Until recently, research guided by these theoretical frameworks has not incorporated direct measures of brain structure or function to index this sensitivity. Drawing on prevailing models of adolescent neurodevelopment and a growing number of neuroimaging studies on the interrelations among social contexts, the brain, and developmental outcomes, we review research that supports the idea of adolescent neurobiological susceptibility to social context for understanding why and how adolescents differ in development and well-being. We propose that adolescent development is shaped by brain-based individual differences in sensitivity to social contexts - be they positive or negative - such as those created through relationships with parents/caregivers and peers. Ultimately, we recommend that future research measure brain function and structure to operationalize susceptibility factors that moderate the influence of social contexts on developmental outcomes.

Resting heart rate, physiological stress and disadvantage in Aboriginal and Torres Strait Islander Australians: analysis from a cross-sectional study

Background

Lower socioeconomic status has been linked to long-term stress, which can manifest in individuals as physiological stress. The aim was to explore the relationship between low socioeconomic status and physiological stress in Aboriginal and Torres Strait Islander Australians.

Methods

Using data from the eGFR Study (a cross-sectional study of 634 Indigenous Australians in urban and remote areas of northern and central Australia), we examined associations between resting heart rate and demographic, socioeconomic, and biomedical factors. An elevated resting heart rate has been proposed as a measure of sustained stress activation and was used as a marker of physiological stress. Relationships were assessed between heart rate and the above variables using univariate and multiple regression analyses.

Results

We reported a mean resting heart rate of 74 beats/min in the cohort (mean age 45 years). On multiple regression analysis, higher heart rate was found to be independently associated with Aboriginal ethnicity, being a current smoker, having only primary level schooling, higher HbA1c and higher diastolic blood pressure (model R² 0.25).

Conclusions

Elevated resting heart rate was associated with lower socioeconomic status and poorer health profile in Aboriginal and Torres Strait Islander Australians. Higher resting heart rate may be an indicator of stress and disadvantage in this population at high risk of chronic diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0211-9) contains supplementary material, which is available to authorized users.

Heritability and Temporal Stability of Ambulatory Autonomic Stress Reactivity in Unstructured 24-Hour Recordings

OBJECTIVE

Measurements of ambulatory autonomic reactivity can help with our understanding of the long-term health consequences of exposure to psychosocial stress in real-life settings.

METHODS

In this study, unstructured 24-hour ambulatory recordings of cardiac parasympathetic and sympathetic control were obtained in 1288 twins and siblings, spanning both work time and leisure time. These data were used to define two ambulatory baseline (sleep, leisure) and four stress conditions (wake, work, work_sitting, work_peak) from which six ambulatory stress reactivity measures were derived. The use of twin families allowed for estimation of heritability and testing for the amplification of existing or emergence of new genetic variance during stress compared with baseline conditions.

RESULTS

Temporal stability of ambulatory reactivity was assessed in 62 participants and was moderate to high over a 3-year period (0.36 < r < 0.91). Depending on the definition of ambulatory reactivity used, significant heritability was found, ranging from 29% to 40% for heart rate, 34% to 47% for cardiac parasympathetic control (indexed as respiratory sinus arrhythmia), and 10% to 19% for cardiac sympathetic control (indexed as the preejection period). Heritability of ambulatory reactivity was largely due to newly emerging genetic variance during stress compared with periods of rest. Interestingly, reactivity to short standardized stressors was poorly correlated with the ambulatory reactivity measures implying poor laboratory-real-life correspondence.

CONCLUSIONS

Ambulatory autonomic reactivity extracted from an unstructured real-life setting shows reliable, stable, and heritable individual differences. Real-life situations uncover a new and different genetic variation compared with that seen in resting baseline conditions, including sleep.

Cognitive Bias Modification for Interpretation in Major Depression: Effects on Memory and Stress Reactivity

Interpreting ambiguous stimuli in a negative manner is a core bias associated with depression. Investigators have used cognitive bias modification for interpretation (CBM-I) to demonstrate that it is possible to experimentally induce and modify these biases. This study extends previous research by examining whether CBM-I affects not only interpretation, but also memory and physiological stress response in individuals diagnosed with Major Depressive Disorder (MDD). We found that CBM-I was effective in inducing an interpretive bias. Participants also exhibited memory biases that corresponded to their training condition and demonstrated differential physiological responding in a stress task. These results suggest that interpretation biases in depression can be modified, and that this training can lead to corresponding changes in memory and to decreases in stress reactivity. Findings from this study highlight the importance of examining the relations among different cognitive biases in MDD and the possibility of modifying cognitive biases.

Acute stress and working memory in older people

Several studies have shown that acute stress affects working memory (WM) in young adults, but the effect in older people is understudied. As observed in other types of memory, older people may be less sensitive to acute effects of stress on WM. We performed two independent studies with healthy older men and women (from 55 to 77 years old) to investigate the effects of acute stress (Trier Social Stress Test; TSST) and cortisol on WM. In study 1 (n = 63), after the TSST women (but not men) improved their performance on Digit Span Forward (a measure of the memory span component of WM) but not on Digit Span Backward (a measure of both memory span and the executive component of WM). Furthermore, in women, cortisol levels at the moment of memory testing showed a positive association with the memory span component of WM before and after the TSST, and with the executive component of WM only before the stress task. In study 2 (n = 76), although participants showed a cortisol and salivary alpha-amylase (sAA) response to the TSST, stress did not affect performance on Letter-Number Sequencing (LNS; a task that places a high demand on the executive component of WM). Cortisol and sAA were not associated with WM. The results indicate that circulating cortisol levels at the moment of memory testing, and not the stress response, affect memory span in older women, and that stress and the increase in cortisol levels after stress do not affect the executive component of WM in older men and women. This study provides further evidence that older people may be less sensitive to stress and stress-induced cortisol response effects on memory processes.

Anger responses to psychosocial stress predict heart rate and cortisol stress responses in men but not women

While previous research has suggested that anger and fear responses to stress are linked to distinct sympathetic nervous system (SNS) stress responses, little is known about how these emotions predict hypothalamus-pituitary-adrenal (HPA) axis reactivity. Further, earlier research primarily relied on retrospective self-report of emotion. The current study aimed at addressing both issues in male and female individuals by assessing the role of anger and fear in predicting heart rate and cortisol stress responses using both self-report and facial coding analysis to assess emotion responses. We exposed 32 healthy students (18 female; 19.6±1.7 yr) to an acute psychosocial stress paradigm (TSST) and measured heart rate and salivary cortisol levels throughout the protocol. Anger and fear before and after stress exposure was assessed by self-report, and video recordings of the TSST were assessed by a certified facial coder to determine emotion expression (FACS). Self-reported emotions and emotion expressions did not correlate (all p>.23). Increases in self-reported fear predicted blunted cortisol responses in men (β=0.41, p=.04). Also for men, longer durations of anger expression predicted exaggerated cortisol responses (β=0.67 p=.004), and more anger incidences predicted exaggerated cortisol and heart rate responses (β=0.51, p=.033; β=0.46, p=.066, resp.). Anger and fear did not predict SNS or HPA activity for females (all p>.23). The current differential self-report and facial coding findings support the use of multiple modes of emotion assessment. Particularly, FACS but not self-report revealed a robust anger-stress association that could have important downstream health effects for men. For women, future research may clarify the role of other emotions, such as self-conscious expressions of shame, for physiological stress responses. A better understanding of the emotion-stress link may contribute to behavioral interventions targeting health-promoting ways of responding emotionally to stress.

Two-year stability of individual differences in (para)sympathetic and HPA-axis responses to public speaking in childhood and adolescence

Long-term stability of individual differences in stress responses has repeatedly been demonstrated in adults, but few studies have investigated the development of stability in adolescence. The present study was the first to investigate the stability of individual differences in heart rate, parasympathetic (RMSSD, pNN50, HF), sympathetic (LF/HF, SC), and HPA-axis (salivary cortisol) responses in a youth sample (8-19 years). Responses to public speaking were measured twice over 2 years. Stability was moderate for absolute responses and task delta responses of HR, RMSSD, pNN50, and HF. Stability was lower for SC and task delta responses of LF/HF and cortisol. Anticipation delta responses showed low stability for HR and cortisol. The latter was moderated by age or puberty, so that individual differences were more stable in more mature individuals. The results support the suggestion that stress responses may be reset during adolescence, but only for the HPA axis.

Mental health outcomes in emerging adults exposed to childhood maltreatment: the moderating role of stress reactivity

Childhood maltreatment is an established risk factor for varying configurations of psychological problems in emerging adulthood. The current study tested associations between childhood maltreatment, cortisol reactivity, and current mental health symptoms in emerging adulthood. Eighty-eight participants (aged 18-22) completed measures of childhood maltreatment and current internalizing and externalizing symptoms and participated in a 10-min conflict role-play task. Salivary cortisol was sampled throughout the task, and a residualized change score between baseline and peak time points was computed to capture reactivity. Results from robust regression analyses indicated that cortisol reactivity moderated the association between childhood maltreatment and mental health symptoms as hypothesized. Childhood maltreatment was related to greater internalizing problems among participants with higher cortisol reactivity, whereas maltreatment was associated with greater externalizing problems among participants who exhibited lower cortisol reactivity. Results suggest that patterns of cortisol reactivity in emerging adulthood may help elucidate mental health outcomes associated with childhood maltreatment.

Exposure to violence predicting cortisol response during adolescence and early adulthood: understanding moderating factors

Previous research on the association between violence and biological stress regulation has been largely cross-sectional, and has also focused on childhood. Using longitudinal data from a low-income, high-risk, predominantly African-American sample (n = 266; 57 % female), we tested hypotheses about the influence of cumulative exposure to violence during adolescence and early adulthood on cortisol responses in early adulthood. We found that cumulative exposure to violence predicted an attenuated cortisol response. Further, we tested whether sex, mothers' support, or fathers' support moderated the effect of exposure to violence on cortisol responses. We found that the effect of cumulative exposure to violence on cortisol was modified by sex; specifically, males exposed to violence exhibited a more attenuated response pattern. In addition, the effect of cumulative exposure to violence on cortisol was moderated by the presence of fathers' support during adolescence. The findings contribute to a better understanding of how cumulative exposure to violence influences biological outcomes, emphasizing the need to understand sex and parental support as moderators of risk.

Mood and autonomic responses to repeated exposure to the Trier Social Stress Test for Groups (TSST-G)

INTRODUCTION

A group version of the Trier Social Stress Test (TSST-G) was introduced as a standardized, economic and efficient tool to induce a psychobiological stress response simultaneously in a group of subjects. The aim of the present study was to examine the efficacy of the TSST-G to repeatedly induce an affective and autonomic stress response while comparing two alternative protocols for the second examination.

METHODS AND MATERIALS

Healthy young male recruits participated twice in the TSST-G 10 weeks apart. In the first examination, the TSST-G consisted of a combination of mental arithmetic and a fake job interview (TSST-G-1st; n=294). For the second examination, mental arithmetic was combined with either (a) a defensive speech in response to a false shoplifting accusation (TSST-G-2nd-defence; n=105), or (b) a speech on a more neutral topic selected by the investigators (TSST-G-2nd-presentation; n=100). Affect ratings and salivary alpha-amylase (sAA) were determined immediately before and after the stress test, while heart rate (HR) and heart rate variability (HRV) were measured continuously.

RESULTS

TSST-G-1st resulted in a significant increase of negative affect, HR, and sAA, and a significant decrease in positive affect and HRV. TSST-G-2nd, overall, resulted in a significant increase of HR and sAA (the latter only in response to TSST-G-2nd-defence) and a decrease in HRV, while no significant affect alterations were found. When comparing both, TSST-G-2nd-defence and -2nd-presentation, the former resulted in a stronger stress response with regard to HR and HRV.

DISCUSSION

The findings reveal that the TSST-G is a useful protocol to repeatedly evoke an affective and autonomic stress response, while repetition leads to affective but not necessarily autonomic habituation. When interested in examining repeated psychosocial stress reactivity, a task that requires an ego-involving effort, such as a defensive speech, seems to be significantly superior to a task using an impersonal speech.