The combined dexamethasone/TSST paradigm--a new method for psychoneuroendocrinology

When virtual reality becomes psychoneuroendocrine reality: A stress(or) review

This review article was awarded the Dirk Hellhammer award from ISPNE in 2023. It explores the dynamic relationship between stressors and stress from a historical view as well as a vision towards the future of stress research via virtual reality (VR). We introduce the concept of a "syncytium," a permeable boundary that blurs the distinction between stress and stressor, in order to understand why the field of stress biology continues to inadequately measure stress alone as a proxy for the force of external stressors. Using Virtual Reality (VR) as an illustrative example to explicate the black box of stressors, we examine the distinction between 'immersion' and 'presence' as analogous terms for stressor and stress, respectively. We argue that the conventional psychological approaches to stress measurement and appraisal theory unfortunately fall short in quantifying the force of the stressor, leading to reverse causality fallacies. Further, the concept of affordances is introduced as an ecological or holistic tool to measure and design a stressor's force, bridging the gap between the external environment and an individual's physiological response to stress. Affordances also serve to ameliorate shortcomings in stress appraisal by integrating ecological interdependencies. By combining VR and psychobiological measures, this paper aims to unravel the complexity of the stressor-stress syncytium, highlighting the necessity of assessing both the internal and external facets to gain a holistic understanding of stress physiology and shift away from reverse causality reasoning. We find that the utility of VR extends beyond presence to include affordance-based measures of immersion, which can effectively model stressor force. Future research should prioritize the development of tools that can measure both immersion and presence, thereby providing a more comprehensive understanding of how external stressors interact with individual psychological states.

Pain of Threatened Self: Explicit and Implicit Self-Esteem, Cortisol Responses to a Social Threat and Pain Perception

Background: Rejection, injustice, and exclusion from meaningful interpersonal relationships are often extremely painful and stress-generating experiences. This study aimed to define the role of explicit and implicit self-esteem in pain perception as a component of the physiological-psychological system that regulates the body's response to stress associated with the threat of social rejection. Methods: In total, 360 individuals participated in this study. The measurement of cortisol in saliva, the assessment of pain thresholds using thermal stimuli, the IAT to assess implicit self-esteem, and a questionnaire on global self-esteem and social pain were used. The study included three measurements: baseline and 15 and 45 min after the application of a laboratory socially threatening stimulus (the Trier Social Stress Test). Results: People experiencing chronic social pain (CSP) are more likely to have fragile self-esteem, higher pain thresholds, and tend to experience reduced pain tolerance in situations of acute social threat than people without CSP experience. In people with CSP and fragile self-esteem, after the introduction of a social threat, an increase in pain tolerance was observed along with a longer-lasting increase in cortisol levels. Conclusions: Fragile self-esteem, along with feelings of chronic exclusion, injustice, and rejection, may prolong stress reactions and produce a hypoalgesic effect.

Hair cortisol concentration and its association with acute stress responses and recovery in a sample of medical students in Germany

INTRODUCTION

Experiencing acute and chronic stress can contribute to adverse health outcomes. Responses to acute stress differ between individuals (i.e., stress reactivity) and the experience of chronic stress has been discussed to be associated with acute stress responses and stress recovery. This study thus aims to investigate whether hair cortisol concentration (HCC), being an indicator for hypothalamus-pituitary-adrenal (HPA) axis activity over a prolonged period of time, is associated with acute stress responses and recovery in a sample of medical students.

MATERIAL AND METHODS

From July 2020 to July 2021, medical students (n = 54) underwent a virtual-reality Trier Social Stress Test in which their blood pressure and heart rate variability (HRV) were measured, and hair samples were taken to determine HCC. Piecewise linear growth analyses were used to investigate whether HCC (categorized into low, medium and high levels) is associated with acute stress responses and recovery regarding blood pressure and HRV.

RESULTS

Significant interaction effects in piecewise linear growth analyses showed that participants with higher levels of HCC had lower systolic and diastolic blood pressure responses compared to participants with medium levels of HCC. No significant interaction effects were observed for HRV responses or for recovery measures.

CONCLUSIONS

The study suggests that higher levels of HCC are associated with a lower cardiovascular response in terms of blood pressure to an acute stressor in medical students. Therefore, long-term HPA-axis activity may contribute to different magnitudes of acute stress responses in the autonomic nervous system. As the shown lower blood pressure responses to acute stress in individuals with increased long-term HPA-axis activity may represent inadequate stress responses, these should be further studied in order to find out more about their interaction and potential subsequent disease risks.

Time-dependent effects of acute stress on working memory performance: A systematic review and hypothesis

Laboratory procedures such as the Trier Social Stress Test or the (Socially Evaluated) Cold Pressor Test have been used to investigate working memory performance under stress. Researchers so far have reported a diverse spectrum of stress effects (including the lack thereof) on working memory tasks. We conducted a systematic review of the effect acute stress on working memory performance in standardized laboratory procedures. An overview of the existing literature suggests that acute stress affects working memory in a time-dependent manner, presumably due to the differing time scales of the main stress-reactive hormones involved. Based on the empirical evidence, we hypothesize that the immediate stress-induced release of noradrenaline decreases working memory performance within the first 10 min post stress. In addition, rapid cortisol effects impair working memory at a later time-interval beginning about 25 min post stress. We outline future research directions which could further explore the implications of our insights, as for example combined pharmacological and naturalistic stressor interventions.

Multi-trajectory analysis uncovers latent associations between psychological and physiological acute stress response patterns

Encounter with an acute stressor elicits multiple physiological and psychological response trajectories that spread at different times-scales and directions. Associating a single physiological response trajectory with a specific psychological response has remained a challenge, due to putative interactions between the different stress response pathways. Hence, multidimensional analysis of stress response trajectories may be better suited to account for response variability. To test this, 96 healthy female participants underwent a robust acute laboratory stress induction procedure while their psychological [positive and negative affect (PANAS)] and physiological [heart rate (HR), heart rate variability (HRV), saliva cortisol (CORT)] responses were recorded before, during and after stress. Combining these data using unsupervised group-based multi-trajectory modelling uncovered three latent classes that best accounted for variability across psychological and physiological stress response trajectories. These classes were labelled based on their psychological response patterns as: A prototypical response group that depict a moderate increase in negative and decrease in positive affect during stress, with both patterns recovering after stress offset (n = 55); A heightened response group that depict excessive affective responses during stress that recover after stress offset (n = 24); and a lack of recovery group that depict a moderate increase in negative and decrease in positive affect during stress, with both patterns not recovering after stress offset (n = 17). With respect to physiological acute stress trajectories, all three groups exhibited comparable increases in HR and CORT during stress that recovered after stress offset, yet only the prototypical group expressed the expected stress-induced reduction in HRV, while the other two groups exhibited blunted HRV response. Critically, focusing on a single physiological stress response trajectory, including HRV, did not account for psychological response variability and vice versa. Taken together, a multi-trajectory approach may better account for the multidimensionality of acute stress response and uncover latent associations between psychological and physiological response patterns. Compared to the other two groups, the prototypical group also exhibited significantly lower overall stress scores based on the DASS-21 scale. This, alongside the uncovered response patterns, suggest that latent psycho-physiological associations may shed light on stress response adaptivity or lack thereof.

Opioid-blunted cortisol response to stress is associated with increased negative mood and wanting of social reward

Animal research suggests a central role of the μ-opioid receptor (MOR) system in regulating affiliative behaviors and in mediating the stress-buffering function of social contact. However, the neurochemistry of stress-related social contact seeking in humans is still poorly understood. In a randomized, double-blind, between-subjects design, healthy female volunteers (N = 80) received either 10 mg of the µ-opioid agonist morphine sulfate, or a placebo. Following a standardized psychosocial stress induction, participants engaged in a social reward task, in which the motivation to obtain skin-to-skin social touch and the hedonic reactions elicited by such touch were assessed. Morphine prevented the increase of salivary cortisol typically observed following acute stress exposure. Notably, this altered HPA axis responsivity was associated with increased negative affect in response to psychosocial stress, and with enhanced subjective wanting of highly rewarding social contact. These findings provide novel evidence on the effect of exogenous opioids administration on the reactions to psychosocial stress and point to a state-dependent regulation of social motivation.

The effects of acute stress and stress hormones on social cognition and behavior: Current state of research and future directions

Stress encompasses profound psychological and physiological changes that are observable on all levels, from cellular mechanisms, humoral changes, and brain activation to subjective experience and behavior. While the impact of stress on health has already been studied for decades, a more recent field of research has revealed effects of stress on human social cognition and behavior. Initial studies have attempted to elucidate the underlying biological mechanisms of these stress-induced effects by measuring physiological responses or by using pharmacological approaches. We provide an overview of the current state of research on the effects of acute stress induction or pharmacological manipulations of stress-related neuro circuitry on social cognition and behavior. Additionally, we discuss the methodological challenges that need to be addressed in order to gain further insight into this important research topic and facilitate replicability of results. Future directions may help to disentangle the complex interplay of psychological and biological stress variables and their effects on social cognition and behavior on health and in disorders with social deficits.

Systematic manipulations of the biological stress systems result in sex-specific compensatory stress responses and negative mood outcomes

Women are twice as likely as men to be diagnosed with anxiety and mood disorders. One potential underlying mechanism is sex differences in physiological and psychological responses to stress; however, no studies to date have investigated this proposed mechanism experimentally. In a double-blind, placebo-controlled design, pharmacological challenges were administered to individually suppress the hypothalamic-pituitary-adrenal (HPA) axis, or the sympathetic nervous system (SNS) prior to stress exposure, to investigate sex differences in the resulting cross talk among the physiological and psychological stress responses. Sex-specific compensatory patterns and psychological effects emerged when the stress systems were manipulated. Men demonstrated heightened SNS reactivity to stress when the HPA axis was suppressed, and greater HPA reactivity after SNS suppression. This ability to react appropriately to the stressor, even with one system, did not lead to significant negative mood effects. In women, higher baseline activation (but dampened reactivity to stress) of SNS or HPA was observed when the other system was suppressed. This was coupled with worsened mood in response to stress when either stress system was compromised. Our results indicate that men and women may be differentially sensitive to fluctuations of their stress systems. This might be a potential link that underlies the sexual dimorphism in vulnerability for psychopathology.

Psychological and Sociodemographic Variables related to Cortisol in Hair in Spanish Healthy Population

Some recent researches have shown the important role of hair cortisol as a retrospective biomarker of chronic stress. The aim of this research was to investigate the relationship between hair cortisol levels and sociodemographic and psychological variables, such as perceived stress levels and psychopathological symptoms on a Spanish population. The sample consisted of 347 healthy people, 230 women and 117 men, with an average age of 33.39 years (SD = 12.63). Hair cortisol levels were measured by obtaining a hair sample. In addition, a psychological assessment composed by: Analogic-Visual Stress Scale, Perceived Stress Scale (PSS), Symptom Checklist 90 Revised (SCL-90-R) and the assessment of vital stressful events suffered, was carried out. The mean cortisol level was 108.93 pg/mg (SD = 66.43) in men, and 120.38 pg/mg (SD = 87.26) in women. The linear hierarchical regression showed that Analogic-Visual Stress Scale and perceived stress levels were related with higher hair cortisol levels (R2 = .032; t = 2.21; p = .029). Due to the relationship between daily stress levels, Analogic-Visual Stress Scale, anxiety sub-scale of SCL 90-R and perceived stress levels with hair cortisol levels, we conclude that there is a relation between perceived yourself stressed and the physiological levels.

The effects of suppressing the biological stress systems on social threat-assessment following acute stress

RATIONALE

Stress is associated with increased sensitivity to threat. Previous investigations examining how stress affects threat processing have largely focused on biomarker responses associated with either the sympathetic-nervous-system (SNS) or the hypothalamus-pituitary-adrenal (HPA) axis.

OBJECTIVES

We pharmacologically suppressed activations of SNS, HPA, or both, prior to stress and investigated how each stress system modulates social threat assessment.

METHODS

One hundred sixty-one healthy men and women were randomized in a between-subject design, to one of four pharmacological or placebo conditions: dexamethasone-placebo, placebo-propranolol, dexamethasone-propranolol, or placebo-placebo. Participants provided threat assessments for angry and neutral human faces on a baseline day, and immediately after stress induction on a testing day.

RESULTS

With both systems responding normally to stress (placebo-placebo), threat assessment was higher for neutral faces compared with angry. Compared with placebo, SNS suppression resulted in increased threat assessment for angry faces. HPA suppression resulted in decreased threat assessment for neutral and angry faces. When both systems were suppressed, there was an increase in threat assessment for angry faces, and no difference from placebo for neutral.

CONCLUSION

Our findings demonstrated that when intact, the biological stress systems adaptively support organisms during stress by focusing attention towards specific stimuli that are relevant to the threat. Dysregulations of the stress systems result in important system specific consequences on threat evaluation, such that suppression of either stress system alone resulted in reduced threat assessment for contextually relevant threatening stimuli, whereas when both systems were suppressed, individuals appear indiscriminately attentive to all potential threats in the environment, resulting in increased threat processing of both contextually relevant and irrelevant stimuli. Given that stress-related psychopathologies have been associated with dysregulations of the stress systems and biased responses to social threat, a systematic understanding of the mechanisms that underlie how stress systems modulate social threat assessment is needed, and can provide important insights into the cognitive processes that are involved in the development and maintenance of stress-related psychopathologies.

The Trier Social Stress Test in first episode psychosis patients: Impact of perceived stress, protective factors and childhood trauma

Psychosis has been associated with abnormalities in hypothalamic-pituitary-adrenal axis functioning, which may emerge through heightened stress sensitivity following early life adversity - ultimately resulting in illness onset and progression. The present study assessed cortisol levels during an established psychosocial stress task and their association with current stress perception, putative protective factors and adverse childhood experiences in patients with a first episode of psychosis (FEP). A total of 100 volunteers participated in the study, 57 of whom were patients with a FEP (mean age 23.9 ± 3.8) and 43 healthy community controls (mean age 23.2 ± 3.9). Salivary cortisol, heart rate and blood pressure were measured at eight time points before and after the Trier Social Stress Test. Subjective stress and protective factors were assessed with the Perceived Stress Scale, the Self-Esteem Rating Scale and the Brief COPE. Early life adversity was assessed with the Childhood Trauma Questionnaire. Patients compared to controls showed significantly lower cortisol levels (F = 7.38; p = .008) throughout the afternoon testing period, but no difference in the cortisol response to the TSST. Heart rate was elevated and protective factors were lower in patients compared to controls. Attenuated cortisol levels were associated with higher levels of perceived stress, poor protective factors and more physical neglect during childhood. Our results suggest that attenuated baseline cortisol levels and not a blunted response during an acute stress task might be an indicator of heightened stress vulnerability and poor resilience in psychosis. The possible influence of childhood adversity and antipsychotic medication is discussed.

Basal testosterone's relationship with dictator game decision-making depends on cortisol reactivity to acute stress: A dual-hormone perspective on dominant behavior during resource allocation

The dual-hormone hypothesis proposes that testosterone's relationship with status-seeking behavior is moderated by cortisol. However, research testing this hypothesis has focused on basal cortisol; the potential moderating effect of the acute cortisol response to stress has been largely overlooked. The present research investigated the moderating role of cortisol responses to an acute stressor on basal testosterone's link with dominant, status-relevant decision-making. Also, given the multifaceted nature of the response to acute stress, cardiovascular and affective responses to the stressor were examined as alternative moderators of the testosterone-behavior relationship. Participants (N = 112; 56% female) were exposed to a social-evaluative stressor, and their stress responses were measured. Participants subsequently engaged in a one-shot dictator game, wherein they were asked to split money ($10) with a confederate counterpart. The amount of money participants decided to keep for themselves was treated as a metric of dominant status-seeking behavior. For individuals who demonstrated lower cortisol responses to the stressor, basal testosterone was positively associated with more dominant behavior (i.e., keeping more money for oneself), but for those who showed higher cortisol responses, the testosterone-behavior relationship was suppressed. Moreover, other aspects of the stress response (i.e., cardiovascular and affective responses) did not moderate the relationship between basal testosterone and dictator game behavior. These results provide unique support for the dual-hormone hypothesis using markers of stress-induced cortisol change. The findings also suggest that the antagonistic effects of stress on testosterone's role in motivating status-relevant behavior may be specific to cortisol's role in the acute stress response.

Psychosocial stress promotes food intake and enhances the neuroenergetic level in men

Psychosocial stress may lead to increased food consumption and overweight. In turn, obesity is related to reduced brain energy content. We hypothesized that psychosocial stress influencing food intake may alter the neuroenergetic status in the human brain. We tested 14 healthy normal weight men in a randomized crossover design. A modified version of the Trier Social Stress Test (TSST) was carried out to induce psychosocial stress vs. control in a neuroimaging setting. Cerebral energy content, i.e. high energy phosphates adenosine triphosphate (ATP) and phosphocreatine (PCr), was measured by ³¹phosphorus magnetic resonance spectroscopy. Food intake was quantified by an ad libitum buffet test. Stress hormonal response and alterations in glucose metabolism were monitored by blood sampling. Before data collection, we mainly expected a stress-induced reduction in cerebral high energy phosphates, followed by higher food intake. Psychosocial stress increased serum cortisol concentrations (p = .003) and fat intake of all participants by 25% (p = .043), as well as food intake of "stress-eaters" by 41.1% (p = .003) compared with controls. Blood glucose and insulin concentrations were not affected (p > .174 for both). Cerebral ATP and PCr levels generally increased upon stress-induction (p > = .022 and p = .037, respectively). Our data confirm that psychosocial stress may enhance food intake. Contrary to our expectations, stress induces a distinct increase in the neuroenergetic status. This insight suggests that the underlying central nervous mechanisms of stress-induced overeating may involve the regulation of the brain energy homeostasis.

Hypothalamic-Pituitary-Adrenal Reactivity to Acute Stress: an Investigation into the Roles of Perceived Stress and Family Resources

Rurally situated African Americans suffer from chronic exposure to stress that may have a deleterious effect on health outcomes. Unfortunately, research on potential mechanisms that underlie health disparities affecting the African American community has received limited focus in the scientific literature. This study investigated the relationship between perceived stress, family resources, and cortisol reactivity to acute stress. A rural sample of African American emerging adults (N = 60) completed a battery of assessments, the Trier Social Stress Test (TSST), and provided four samples of salivary cortisol: prior to receiving TSST instructions, prior to conducting the speech task, immediately following the TSST, and 15-20 min following the TSST. As predicted, cortisol levels increased in response to a controlled laboratory inducement of acute stress. Moreover, diminished levels of family resources were associated with blunted cortisol reactivity to acute stress. Of note, higher levels of perceived stress over the past month and being male were independently associated with lower levels of cortisol at baseline. Lack of family resources had a blunting relationship on the hypothalamic-pituitary-adrenal axis reactivity. These findings provide biomarker support for the relationship between family resources-an indicator associated with social determinants of health-and stress physiology within a controlled laboratory experiment. Identifying mechanisms that work toward explanation of within-group differences in African American health disparities is both needed and informative for culturally informed prevention and intervention efforts.

Psychosocial stress affects the acquisition of cerebellar-dependent sensorimotor adaptation

Despite being overlooked in theoretical models of stress-related disorders, differences in cerebellar structure and function are consistently reported in studies of individuals exposed to current and early-life stressors. However, the mediating processes through which stress impacts upon cerebellar function are currently unknown. The aim of the current experiment was to test the effects of experimentally-induced acute stress on cerebellar functioning, using a classic, forward saccadic adaptation paradigm in healthy, young men and women. Stress induction was achieved by employing the Montreal Imaging Stress Task (MIST), a task employing mental arithmetic and negative social feedback to generate significant physiological and endocrine stress responses. Saccadic adaptation was elicited using the double-step target paradigm. In the experiment, 48 participants matched for gender and age were exposed to either a stress (n = 25) or a control (n = 23) condition. Saliva for cortisol analysis was collected before, immediately after, and 10, and 30 min after the MIST. Saccadic adaptation was assessed approximately 10 min after stress induction, when cortisol levels peaked. Participants in the stress group reported significantly more stress symptoms and exhibited greater total cortisol output compared to controls. The stress manipulation was associated with slower learning rates in the stress group, while control participants acquired adaptation faster. Learning rates were negatively associated with cortisol output and mood disturbance. Results suggest that experimentally-induced stress slowed acquisition of cerebellar-dependent saccadic adaptation, related to increases in cortisol output. These 'proof-of-principle' data demonstrate that stress modulates cerebellar-related functions.

Blunted cortisol response to acute pre-learning stress prevents misinformation effect in a forced confabulation paradigm

Research examining the effects of stress on false memory formation has been equivocal, partly because of the complex nature of stress-memory interactions. A major factor influencing stress effects on learning is the timing of stress relative to encoding. Previous work has shown that brief stressors administered immediately before learning enhance long-term memory. Thus, we predicted that brief stress immediately before learning would decrease participants' susceptibility to subsequent misinformation and reduce false memory formation. Eighty-four male and female participants submerged their hand in ice cold (stress) or warm (no stress) water for 3min. Immediately afterwards, they viewed an 8-min excerpt from the Disney movie Looking for Miracles. The next day, participants were interviewed and asked several questions about the video, some of which forced them to confabulate responses. Three days and three weeks later, respectively, participants completed a recognition test in the lab and a free recall test via email. Our results revealed a robust misinformation effect, overall, as participants falsely recognized a significant amount of information that they had confabulated during the interview as having occurred in the original video. Stress, overall, did not significantly influence this misinformation effect. However, the misinformation effect was completely absent in stressed participants who exhibited a blunted cortisol response to the stress, for both recognition and recall tests. The complete absence of a misinformation effect in non-responders may lend insight into the interactive roles of autonomic arousal and corticosteroid levels in false memory development.

The Clinic for Assessment of Youth at Risk (CAYR): 10 years of service delivery and research targeting the prevention of psychosis in Montreal, Canada

AIM

In the context of an increasing focus on indicated prevention of psychotic disorders, we describe the operation of the Clinic for Assessment of Youth at Risk (CAYR) over 10 years, a specialized service for identification, monitoring and treatment of young individuals who meet ultra-high risk (UHR) criteria for psychosis, and its integration within the Prevention and Early Intervention Program for Psychosis (PEPP) in Montreal, Canada.

METHODS

We outline rationale, development, inclusion and exclusion criteria, assessment, services offered, community outreach and liaison with potential referral sites, and our research focus on risk and protective factors related to the neural diathesis-stress model of psychosis.

RESULTS

Between January 2005 and December 2014, CAYR has received 370 referrals and accepted 177 patients who met UHR criteria based on the Comprehensive Assessment for At Risk Mental States. Conversion rates to a first episode of psychosis were 11%. Our research findings point to high subjective stress levels, poor self-esteem, social support and coping skills, and a dysregulation of the hypothalamus-pituitary-adrenal axis during the high-risk phase.

CONCLUSIONS

Our efforts at community outreach have resulted in increasing numbers of referrals and patients accepted to CAYR, highlighting the relevance of and need for a high-risk programme in the Montreal area. Patients with psychotic symptoms can be immediately assigned to the first-episode psychosis clinic within PEPP, which has likely contributed to the low conversion rates observed in the UHR group. Our research findings on stress and protective factors emphasize the importance of psychosocial interventions for high-risk patients.

Suppressing the endocrine and autonomic stress systems does not impact the emotional stress experience after psychosocial stress

Acute psychosocial stress activates the physiological and endocrine stress systems and increases the subjective emotional experience of stress. While considerable efforts have been made to link changes in the activity of the biological stress systems with changes in the subjective emotional experience of stress, results so far have been mixed, at best. To investigate this association in a study employing experimental manipulation, we pharmacologically suppressed both the autonomic and the endocrine stress responses, and investigated the effects of acute psychosocial stress on the emotional stress experience. 22 healthy men and women received dexamethasone (2mg) the day before, and propranolol (80mg) one hour before psychosocial stress induction. A control group (n=24) received placebo pills on each occasion. Salivary cortisol, alpha-amylase and heart-rate responses to stress were assessed before, during and after stress induction. Subjective stress, mood, and state self-esteem assessments were made before and after stress. In the pharmacological manipulation group, subjects demonstrated no increase in autonomic or endocrine stress response, after exposure to psychosocial stress. Despite these effects, the emotional stress experience was intact in this group and identical to the control group. Participants in the experimental group showed an increase in subjective stress, greater mood dysregulation, and lower state self-esteem following stress exposure, with the response magnitude comparable to the control group. Our findings suggest that at least acutely, the physiological stress arousal systems and the emotional experience of stress are dissociated. This raises important questions about the efficacy of our measurement of subjective stress, and the unique contributions of the autonomic and endocrine responses in the subjective stress experience.

Salivary cortisol and α-amylase: subclinical indicators of stress as cardiometabolic risk

Currently, the potential for cardiovascular (CV) stress-induced risk is primarily based on the theoretical (obvious) side effects of stress on the CV system. Salivary cortisol and α-amylase, produced respectively by the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic-adrenomedullary (SAM) system during stress response, are still not included in the routine evaluation of CV risk and require additional and definitive validation. Therefore, this article overviews studies published between 2010 and 2015, in which salivary cortisol and α-amylase were measured as stress biomarkers to examine their associations with CV/CMR (cardiometabolic risk) clinical and subclinical indicators. A comprehensive search of PubMed, Web of Science and Scopus electronic databases was performed, and 54 key articles related to the use of salivary cortisol and α-amylase as subclinical indicators of stress and CV/CMR factors, including studies that emphasized methodological biases that could influence the accuracy of study outcomes, were ultimately identified. Overall, the biological impact of stress measured by salivary cortisol and α-amylase was associated with CV/CMR factors. Results supported the use of salivary cortisol and α-amylase as potential diagnostic tools for detecting stress-induced cardiac diseases and especially to describe the mechanisms by which stress potentially contributes to the pathogenesis and outcomes of CV diseases.

Cortisol, salivary alpha-amylase and children's perceptions of their social networks

In recent years there has been a growing interest in the use of social network analysis in biobehavioral research. Despite the well-established importance of social relationships in influencing human behavior and health, little is known about how children's perception of their immediate social relationships correlates with biological parameters of stress. In this study we explore the association between two measures of children's personal social networks, perceived network size and perceived network density, with two biomarkers of stress, cortisol and salivary alpha-amylase. Forty children (mean age = 8.30, min age = 5, and max age = 12) were interviewed to collect information about their friendships and three samples of saliva were collected. Our results show that children characterized by a lower pre-interview cortisol concentration and a lower salivary alpha-amylase reactivity to the interview reported the highest density of friendships. We discuss this result in light of the multisystem approach to the study of children's behavioral outcomes, emphasizing that future work of this kind is needed in order to understand the cognitive and biological mechanisms underlying children's and adolescents' social perceptual biases.

The Trier Social Stress Test as a paradigm to study how people respond to threat in social interactions

In our lives, we face countless situations in which we are observed and evaluated by our social interaction partners. Social-evaluative threat is frequently associated with strong neurophysiological stress reactions, in particular, an increase in cortisol levels. Yet, social variables do not only cause stress, but they can also buffer the neurophysiological stress response. Furthermore, social variables can themselves be affected by the threat or the threat-induced neurophysiological stress response. In order to study this complex interplay of social-evaluative threat, social processes and neurophysiological stress responses, a paradigm is needed that (a) reliably induces high levels of social-evaluative threat and (b) is extremely adaptable to the needs of the researcher. The Trier Social Stress Test (TSST) is a well-established paradigm in biopsychology that induces social-evaluative threat in the laboratory by subjecting participants to a mock job-interview. In this review, we aim at demonstrating the potential of the TSST for studying the complex interplay of social-evaluative threat, social processes and neurophysiological stress responses.

Premenstrual syndrome is associated with blunted cortisol reactivity to the TSST

This study assessed the effects of premenstrual syndrome (PMS) and menstrual phases on the hypothalamic-pituitary-adrenal (HPA) axis, sympathetic nervous system axis and psychological responses to the Trier Social Stress Test (TSST). Thirty-six PMS women (mean age 21.69 ± 2.16 years) and 36 control women (mean age 22.03 ± 2.48 years) participated in the TSST task, either in the follicular phase or in the late luteal phase (each group N = 18). Saliva samples, heart rate and subjective stress levels were collected for seven time points throughout the test (10, 20, 30, 40, 55, 70 and 100 min). The results indicated that in comparison with control women, PMS women displayed blunted cortisol stress responses to the TSST irrespective of the menstrual phases, as indexed by the cortisol levels across time, area under the curve with respect to ground (AUCg) and peak change scores of cortisol. The results also demonstrated that the measurements indexed by cortisol levels across time, AUCg and peak change scores of heart rate were smaller in women tested during the late luteal phase than during the follicular phase. Correlation results indicated that AUCg was negatively correlated with PMS scores. These results suggest that measures of cortisol, rather than heart rate or subjective responses to stress, may be most closely associated with PMS. Furthermore, hypo-reactivity of the HPA axis may be pathologically relevant to PMS because it predicts heightened PMS severity.

Sex differences in cardiovascular and subjective stress reactions: prospective evidence in a realistic military setting

Evidence points to heightened physiological arousal in response to acute stress exposure as both a prospective indicator and a core characteristic of posttraumatic stress disorder (PTSD). Because females may be at higher risk for PTSD development, it is important to evaluate sex differences in acute stress reactions. This study characterized sex differences in cardiovascular and subjective stress reactions among military survival trainees. One hundred and eighty-five military members (78% males) were studied before, during, and 24 h after stressful mock captivity. Cardiovascular (heart rate [HR], systolic blood pressure [SBP], diastolic blood pressure [DBP]) and dissociative states were measured at all three time points. Psychological impact of mock captivity was assessed during recovery. General linear modeling with repeated measures evaluated sex differences for each cardiovascular endpoint, and causal steps modeling was used to explore interrelationships among sex, cardiovascular reactions and psychological impact of mock captivity. Although females had lower SBP than males at all three time points, the difference was most pronounced at baseline and during stress. Accordingly, females showed greater residual elevation in SBP during recovery. Females had lower DBP at all three time points. In addition, females reported greater psychological impact of mock captivity than males. Exploratory causal steps modeling suggested that stress-induced HR may partially mediate the effect of sex on psychological impact of mock captivity. In conclusion, this study demonstrated sex-specific cardiovascular stress reactions in military personnel, along with greater psychological impact of stress exposure in females. This research may elucidate sex differences in PTSD development.

Association between subjective and cortisol stress response depends on the menstrual cycle phase

The relation between the physiologic and subjective stress responses is inconsistently reported across studies. Menstrual cycle phases variations have been found to influence the psychophysiological stress response; however little is known about possible cycle phase differences in the relationship between physiological and subjective stress responses. This study examined the effect of menstrual cycle phase in the association between subjective stress and physiological response. Forty-five women in either the follicular (n=21) or the luteal phase of the menstrual cycle were exposed to a psychosocial stress task. Salivary cortisol, cardiovascular, and subjective stress were assessed throughout the experiment. Results revealed a significant group difference in the association between peak levels of cortisol and post task subjective stress. In women in the follicular phase a negative association was observed (r(2)=0.199, p=0.04), while this relation was positive in the group of women in the luteal phase (r(2)=0.227, p=0.02). These findings suggest a possible role of sex hormones in modulating the cortisol stress response function in emotion regulation.

Biological and psychological markers of stress in humans: focus on the Trier Social Stress Test

Validated biological and psychological markers of acute stress in humans are an important tool in translational research. The Trier Social Stress Test (TSST), involving public interview and mental arithmetic performance, is among the most popular methods of inducing acute stress in experimental settings, and reliably increases hypothalamic-pituitary-adrenal axis activation. However, although much research has focused on HPA axis activity, the TSST also affects the sympathetic-adrenal-medullary system, the immune system, cardiovascular outputs, gastric function and cognition. We critically assess the utility of different biological and psychological markers, with guidance for future research, and discuss factors which can moderate TSST effects. We outline the effects of the TSST in stress-related disorders, and if these responses can be abrogated by pharmacological and psychological treatments. Modified TSST protocols are discussed, and the TSST is compared to alternative methods of inducing acute stress. Our analysis suggests that multiple readouts are necessary to derive maximum information; this strategy will enhance our understanding of the psychobiology of stress and provide the means to assess novel therapeutic agents.

Reflections on the interaction of psychogenic stress systems in humans: the stress coherence/compensation model

Although stress simultaneously affects and causes changes in central nervous system systems together with the sympathetic nervous system and the hypothalamus-pituitary-adrenal axis, this interaction and its behavioral consequences are rarely assessed. The current paper first describes the different systems involved in the perception and processing of stressful stimuli on an anatomical and functional level, and the available measures to assess changes in these systems. It then explores, based on theoretical and empirical grounds, the interaction of the systems. This is followed by a review of previous stress models, and how these attempted to integrate the interaction of these systems. Then, it complements previous models by suggesting a complementary regulation of the stress systems, and discusses potential behavioral consequences. Finally, based on the three-system approach to assess stress it is argued that psychological measures, together with physiological and endocrine measures are indispensable. However, the lack of consensus on how to best assess the central and sympathetic nervous system components of stress make it more difficult to include measures of all systems routinely in future stress studies. Thus, the paper closes by giving some recommendations on how to include a minimum of feasible stress measures for all systems involved in stress processing and regulation.

Attenuated cortisol response to acute psychosocial stress in individuals at ultra-high risk for psychosis

We recently reported that individuals at ultra-high risk for the development of psychosis (UHR) have elevated levels of chronic stress and deficits in the putative protective factors self-esteem, social support and coping skills. The aim of the present study was to assess endocrine and autonomic responses to acute psychosocial stress and their associations with self-ratings of stress and protective factors in individuals at UHR. Twenty-one patients diagnosed with an "at risk mental state" (12 male, 9 female; mean age 20.8 ± 3.27) and 21 healthy age and gender matched community controls were exposed to the Trier Social Stress Test (TSST). Saliva samples for cortisol assessment and measurements of heart rate and blood pressure were taken throughout the testing period. Levels of perceived chronic stress, protective factors and depression were assessed with reference to the preceding month and year (stress only). Compared to healthy controls, individuals at UHR reported significantly higher levels of depression, deficits in protective factors, and a trend for higher chronic stress levels. Cortisol levels and systolic blood pressure during the TSST were significantly lower in the UHR group, while heart rate changes were comparable to controls. Lower cortisol levels in the UHR group were associated with higher self-ratings of stress in the past year and a lower level of education. Attenuated cortisol responses to acute psychosocial stress in the presence of high chronic stress could indicate a desensitization of the HPA axis. Associated poor metabolic and psychological adjustment to stress might increase vulnerability for the development of psychosis.

The combined propranolol/TSST paradigm--a new method for psychoneuroendocrinology

Upon perception of a stimulus as stressful, the human brain reacts with the activation of the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS), to mobilize energy resources to better cope with the stressor. Since the perception of the stressor is the initial stimulus, a synchronicity between the subjective perception of stress and the physiological stress reactivity should be expected. However, according to a recent meta-analysis, these associations are weak and inconsistent. The goal of the current study was to investigate the interaction between the SNS, HPA and subjective stress perceptions, by introducing an experimental manipulation of this interaction. For this purpose, we combined the SNS inhibitor propranolol with the Trier Social Stress Test, and measured endocrinological and psychological responses to the stressor. Thirty healthy male participants were recruited and randomly assigned to either a propranolol (PROP; n = 15) or placebo (PLC; n = 15) group. All subjects were administered 80 mg of propranolol 60 minutes prior to exposure to psychosocial stress. Salivary cortisol and alpha amylase (sAA), heart rate, blood pressure and subjective stress responses were assessed throughout the study. We observed significantly reduced sAA levels and heart rate increases in the PROP group in response to stress, with no effects of the drug on systolic or diastolic blood pressure changes. In line with previous studies, a significant increase in cortisol was seen in response to the stress exposure. Importantly, the cortisol increase was significantly higher in the PROP group. A typical increase in subjective stress could be seen in both groups, with no significant group differences emerging. Complementing previous work, this study further demonstrates a significant interaction between the HPA and the SNS during acute stress. The HPA activity was found to be elevated in the presence of a suppressed SNS in reactivity to the TSST.