Stress effects on mood, HPA axis, and autonomic response: comparison of three psychosocial stress paradigms

The impact of virtual images of coastal landscape features on stress recovery based on EEG

Understanding how coastal landscape features influence stress recovery can provide valuable insights for designing healthier urban environments. This study aims to evaluate the psychological and physiological restorative effects of four types of coastal landscape features-coastal walkway, coastal mountain park, coastal plaza, and coastal beach-using immersive virtual reality simulations. 44 university students participated in a laboratory experiment involving subjective evaluations, heart rate variability, and electroencephalogram (EEG) measurements. The results demonstrated that virtual images of coastal landscape features alleviate mood disturbances and enhance perceived recovery. Specifically, autonomic nervous system (ANS) responses showed significant improvement: low-frequency to high-frequency ratio decreased by 8.47-20.20%, root mean square of successive differences increased by 8.41-27.83%, and the standard deviation of heart intervals increased by 13.05-25.07%. EEG findings further revealed reduced brain energy consumption, with total power decreasing by 0.83-9.10% and α relative power increasing by 2.76-28.51%. The virtual images of coastal walkway demonstrated the strongest restorative effect, especially in promoting optimal neural avalanche activity (12.70-18.17% improvement). Correlation analysis indicated a strong relationship between ANS and brain responses. Notably, this study innovatively introduced neural avalanche parameters to assess brain criticality states, offering a novel approach to evaluating environmental restoration. These findings contribute to environmental psychology by offering scientific evidence for optimizing coastal landscape design to support mental health and stress regulation.

Identifying the most effective acute stress induction methods for producing SAM- and HPA-related physiological responses: a meta-analysis

BACKGROUND AND OBJECTIVES

Laboratory-based stress inductions are commonly used to elicit acute stress but vary widely in their procedures and effectiveness. We compared the effects of stress induction techniques on measures of two major biological stress systems: the early sympathetic-adrenal-medullary (SAM) and the delayed hypothalamic-pituitary-adrenal (HPA) axis response.

DESIGN

A review and meta-analysis to examine the relationship between stress induction techniques on cardiorespiratory and salivary measures of SAM and HPA system activity.

METHODS

A systematic literature search identified 245 reports and 700 effects.

RESULTS

The overall effect of stress induction techniques on the stress response was moderate (Fisher's zr = 0.44), inducing stronger SAM-related (zr = 0.48) versus HPA-related (zr = 0.37) responses. Three factors moderated these associations: the stress system examined (SAM vs HPA), the specific stress induction technique employed (e.g., Cold Pressor), the physiological sampling time relative to the stress induction, and participant sex. Loud music elicited the most robust SAM-related effects, whereas combined stress inductions elicited the most robust HPA-related effects. Men showed stronger stress responses than women.

CONCLUSIONS

Stress induction techniques variably elicit SAM - and HPA-related responses. Results recommend specific induction techniques for targeting stress systems, highlighting the importance of carefully selecting methodologies in laboratory contexts.

The minor allele of the serotonin transporter gene variant rs4251417 is associated with increased resilience in soldiers experiencing acute stress during survival training: preliminary findings

BACKGROUND

Variation in cognitive, emotional and physical performance in response to stress is attributable to environmental and genetic factors. Ability to adapt to stress is resilience.

OBJECTIVES

This study investigated genetic factors associated with resilience in soldiers exposed to severe stress due to intense physical and mental demands at Survive, Evade, Resist and Escape school, a unique environment to study acute stress and resiliency in real-world circumstances.

DESIGN

A preliminary correlational study was conducted to identify genetic markers for resilience to stress.

METHODS

Mood state, resiliency and dissociative state of 73 soldiers were assessed using: Connor-Davidson Resilience Scale (CD-RISC); Profile of Mood States (POMS); and Clinician-Administered Dissociative States Scale (CADSS). Change scores for resilience-related stress markers were computed; 116 single nucleotide polymorphisms (SNPs) associated with stress, depression, anxiety, sleep, or psychiatric disorders were assessed.

RESULTS

A significant association between change in CD-RISC score and SNP rs4251417, present in an intron of SLC6A4, the serotonin transporter gene, was observed.

CONCLUSIONS

Individuals with the minor allele of SNP rs4251417 had a greater positive change in CD-RISC, indicating increased self-assessed resilience. This study suggests the minor allele of SNP rs4251417 of SLC6A4 is associated with resilience when individuals are exposed to high stress.

Left ventromedial prefrontal cortex inhibitory rTMS as an anti-stress intervention in opioid use disorder: Trial design

Background

In people with substance use disorders (SUDs), stress-exposure can impair executive function, and increase craving and likelihood of drug-use recurrence. Research shows that acute stressors increase drug-seeking behavior; however, mechanisms underlying this effect are incompletely understood. The Competing Neurobehavioral Decisions System theory posits that persons with SUDs may have hyperactive limbic reward circuitry and hypoactive executive control circuitry.

Objective

To investigate how inhibitory repetitive transcranial magnetic stimulation (rTMS) targeting the left ventromedial prefrontal cortex (vmPFC) may alter stress-induced executive dysfunction, emotion dysregulation, and drug-seeking in people with opioid use disorder.

Methods

We will examine effects of a psychological stressor combined with inhibitory (1Hz) left vmPFC rTMS in participants (N = 24) receiving opioid agonist treatment. Participants undergo guided imagery of autobiographical stressors paired with 10 sessions of active vmPFC rTMS vs. sham (within-subject randomized crossover). Stress-induced dysfunction will be indexed with cognitive (e.g., executive function), affective (e.g., emotional arousal), and behavioral (e.g., opioid-seeking) measures pre- and post-rTMS. To confirm changes are associated with altered neural activity in targeted regions, we will measure event-related potentials during key tasks using EEG. We hypothesize that stressors will increase executive dysfunction, emotion dysregulation, and drug-seeking, and that left vmPFC inhibitory rTMS will decrease limbic activation, which could translate to reduced craving and drug-seeking.

Conclusion

Our findings should offer insights into how neural networks modulate drug-seeking and associated dysfunctions in people with SUDs. The results of this and similar studies can advance theory and neuromodulation interventions for people with SUDs.

Memory under pressure: The impact of acute stress across different memory tasks

In the present study, we aimed to investigate how acute stress exerts its heterogeneous effects. Based on biophysical network models, we hypothesized that acute stress would improve occipital-mediated ultra-short-term and to a lesser degree affect occipital- and frontal-mediated short-term and working, and impairs hippocampal-mediated long-term memory processes and their respective behavioral measures. To test this, 111 healthy individuals (57 female) underwent both the Trier Social Stress Test (TSST) and a control test. Immediately afterward, participants' performance was measured in four memory tasks (Rapid Serial Visual Presentation, RSVP, Match-to-Sample, MTS, N-Back, NB and Free-Recall, FR tasks). TSST exposure seems to impair long-term memory (ACFR; β = -1.50 ± 0.62; when free recall was tested approx. 80 minutes after initial encoding, immediately after the TSST), and working memory (ACNB; β= -0.42 ± 0.20 %) but did not affect ultra-short-term (ACRSVP; β = -0.03 ± 0.31 %) and short-term (ACMTS; β=-0.18 ± 0.31 %) memory accuracies (ACs). Interestingly, TSST exposure increased the exploratory included measure of response times in MTS (RTMTS; β =16.42 ± 7.18 msec) and impaired T1 detection in the RSVP (ACT1; β=-0.48 ± 0.22 %) tasks. Contrary to the hypothesis, TSST exposure did not have the hypothesized effects on the memory processes. Instead, TSST exposure appeared to affect secondary behavioral indicators of motivation or task instruction adherence.

Automated classification of stress and relaxation responses in major depressive disorder, panic disorder, and healthy participants via heart rate variability

Background

Stress is a significant risk factor for psychiatric disorders such as major depressive disorder (MDD) and panic disorder (PD). This highlights the need for advanced stress-monitoring technologies to improve treatment. Stress affects the autonomic nervous system, which can be evaluated via heart rate variability (HRV). While machine learning has enabled automated stress detection via HRV in healthy individuals, its application in psychiatric patients remains underexplored. This study evaluated the feasibility of using machine-learning algorithms to detect stress automatically in MDD and PD patients, as well as healthy controls (HCs), based on HRV features.

Methods

The study included 147 participants (MDD: 41, PD: 47, HC: 59) who visited the laboratory up to five times over 12 weeks. HRV data were collected during stress and relaxation tasks, with 20 HRV features extracted. Random forest and multilayer perceptron classifiers were applied to distinguish between the stress and relaxation tasks. Feature importance was analyzed using SHapley Additive exPlanations, and differences in HRV between the tasks (ΔHRV) were compared across groups. The impact of personalized longitudinal scaling on classification accuracy was also assessed.

Results

Random forest classification accuracies were 0.67 for MDD, 0.69 for PD, and 0.73 for HCs, indicating higher accuracy in the HC group. Longitudinal scaling improved accuracies to 0.94 for MDD, 0.90 for PD, and 0.96 for HCs, suggesting its potential in monitoring patients' conditions using HRV. The HC group demonstrated greater ΔHRV fluctuation in a larger number of and more significant features than the patient groups, potentially contributing to higher accuracy. Multilayer perceptron models provided consistent results with random forest, confirming the robustness of the findings.

Conclusion

This study demonstrated that differentiating between stress and relaxation was more challenging in the PD and MDD groups than in the HC group, underscoring the potential of HRV metrics as stress biomarkers. Psychiatric patients exhibited altered autonomic responses, which may influence their stress reactivity. This indicates the need for a tailored approach to stress monitoring in these patient groups. Additionally, we emphasized the significance of longitudinal scaling in enhancing classification accuracy, which can be utilized to develop personalized monitoring technologies for psychiatric patients.

Emotional, physiological, biochemical, and behavioral responses to acute stress and uncertainty in military personnel

Stress carries diverse implications for perceptual, cognitive, and affective functions. One population particularly susceptible to acute stress-induced cognitive changes are individuals with high-stress jobs (e.g., military personnel). These individuals are often tasked with maintaining peak cognitive performance, including memory, spatial navigation, and decision-making under threatening and uncertain conditions. Previous research has separately examined decision-making under conditions of stress or uncertainty (i.e., ambiguous discrimination between friends and foes). However, questions remain about how operationally relevant stress impacts memory encoding and recall, or spatial learning, as well as how uncertainty may impact decision-making during stress. To address this gap, we examined the influence of a military-relevant emotional stressor on a series of cognitive tasks including recognition memory task (RMT), spatial orienting task (SOT), and shoot/don't shoot decision making (DMT). To examine the effects of uncertainty and stress we varied the stimulus clarity in the DMT. We utilized threat of shock (TOS) as a high-stakes outcome for decision errors. TOS increased sympathetic arousal but did not affect subjective emotional or HPA responses. TOS influenced decision times and confidence ratings in the DMT, but not response sensitivity or response bias. DMT performance varied by stimulus clarity (uncertainty) but did not differ between stress conditions. TOS did not influence recognition memory or spatial orienting. In sum, high levels of stress and uncertainty characterize military operations, yet stress experienced in military contexts can be difficult to induce in laboratory settings. We discuss several avenues for future research, including methodological considerations to better assess the magnitude and specificity of emotional stress-induction techniques in Soldiers.

No Effects of Omega-3 Supplementation on Kynurenine Pathway, Inflammation, Depressive Symptoms, and Stress Response in Males: A Placebo-Controlled Trial

Background: Increased inflammation and heightened physiological stress reactivity have been associated with pathophysiology of depressive symptoms. The underlying biological mechanisms by which inflammation and stress may influence neurogenesis are changes in the kynurenine (KYN) pathway, which is activated under stress. Supplementation with n-3 polyunsaturated fatty acids (n-3 PUFAs) has anti-inflammatory properties and can increase stress resilience. Whether n-3 PUFAs alter KYN stress response is unknown. Objectives: This placebo-controlled study investigated the effect of n-3 PUFAs on KYN metabolism, inflammation, depressive symptoms, and mood. Moreover, stress-induced changes following a laboratory stressor have been assessed. Methods: In this placebo-controlled study, 47 healthy male adults received either 4 g n-3 PUFAs per day (Omega-3 group) or a placebo (Placebo group) for 12 weeks. Results: A significant group-by-time interaction was found for the inflammatory markers gp130 (F = 7.07, p = 0.011), IL-6R alpha (F = 10.33, p = 0.003), and TNF_RI (F= 10.92, p = 0.002). No significant group-by-time interactions were found for KYN metabolites, depressive symptoms, and mood (except for Hedonic tone (F = 6.50, p = 0.014)), nor for stress-induced changes in KYN metabolites and mood following a laboratory stressor. Conclusions: Overall, increased n-3 PUFA levels in healthy men ameliorate inflammatory markers but do not ameliorate KYN metabolism, depressive symptoms, mood, or KYN metabolism and mood following a stress induction. This study was registered at ClinicalTrials.gov with the identifier NCT05520437 (30/08/2022 first trial registration).

L-type calcium channel regulation of depression, anxiety and anhedonia-related behavioral phenotypes following chronic stress exposure

Exposure to chronic and unpredictable stressors can precipitate mood-related disorders in humans, particularly in individuals with pre-existing mental health challenges. L-type calcium channels (LTCCs) have been implicated in numerous neuropsychiatric disorders, as LTCC encoding genes have been identified as candidate risk factors for neuropsychiatric illnesses. In these sets of experiments, we sought to examine the ability of LTCC blockade to alter depression, anxiety, and anhedonic-related behavioral responses to chronic unpredictable stress (CUS) exposure in female and male rats. Rats first underwent either 21 days of CUS or no exposure to chronic stressors, serving as home cage controls (HCC). Then rats were examined for anhedonia-related behavior, anxiety and depression-like behavioral responses as measured by the sucrose preference test (SPT), elevated plus maze (EPM), and forced swim test (FST). CUS exposed females and males showed anhedonic and anxiogenic-like behavioral responses on the SPT and EPM, respectively, when compared to HCCs. In female and male rats, systemic administration of the LTCC blocker isradipine (0.4 mg/kg and 1.2 mg/kg, I.P.) attenuated the CUS-induced decrease in sucrose preference and reversed the CUS-induced decrease in open arm time. In the FST, systemic isradipine decreased immobility time across all groups, consistent with an antidepressant-like response. However, there were no significant differences in forced swim test immobility time between HCC and CUS exposed animals. Taken together, these data point to a role of LTCCs in the regulation of mood disorder-related behavioral phenotype responses to chronic stress exposure.

Stressing out! Effects of acute stress on prepulse inhibition and working memory

Prepulse inhibition (PPI) of the startle reflex serves as a pre-cognitive marker of sensorimotor gating, and its deficit may predict cognitive impairments. Startle reflex is modulated by many factors. Among them, stress has been a topic of interest, but its effects on both pre-cognitive and cognitive variables continue to yield divergent results. This study aims to analyze the effect of acute stress on PPI of the startle reflex and cognitive function (working memory, attention, inhibition, and verbal fluency). Participants were exposed to the MAST stress induction protocol or a stress-neutral task: stress group (n = 54) or control group (n = 54). Following stress induction, participants' startle responses were recorded, and cognition was assessed. The results revealed that participants in the stress group exhibited greater startle magnitude, lower PPI, and lower scores in working memory tests compared with the control group. Additionally, a correlation was found between working memory and PPI across all the participants, independent of stress group. These findings support the notion that after stress, both greater startle magnitude and diminished PPI could play an adaptive role by allowing for increased processing of stimuli potentially dangerous and stress-related. Similarly, our results lend support to the hypothesis that lower PPI may be predictive of cognitive impairment. Considering the impact of stress on both pre-cognitive (PPI) and cognitive (working memory) variables, we discuss the possibility that the effect of stress on PPI occurs through motivational priming and emphasize the relevance of considering stress in both basic and translational science.

Stress and substance use disorders: risk, relapse, and treatment outcomes

Stress has long been associated with substance misuse and substance use disorders (SUDs). The past two decades have seen a surge in research aimed at understanding the underlying mechanisms driving this association. This Review introduces a multilevel "adaptive stress response" framework, encompassing a stress baseline, acute reaction, and recovery with return-to-homeostasis phase that occurs at varying response times and across domains of analysis. It also discusses evidence showing the disruption of this adaptive stress response in the context of chronic and repeated stressors, trauma, adverse social and drug-related environments, as well as with acute and chronic drug misuse and with drug withdrawal and abstinence sequelae. Subjective, cognitive, peripheral, and neurobiological disruptions in the adaptive stress response phases and their link to inflexible, maladaptive coping; increased craving; relapse risk; and maintenance of drug intake are also presented. Finally, the prevention and treatment implications of targeting this "stress pathophysiology of addiction" are discussed, along with specific aspects that may be targeted in intervention development to rescue stress-related alterations in drug motivation and to improve SUD treatment outcomes.

Cortisol, testosterone and psychosocial responses in the assessment of stress in police officers: a brief systematic review of the literature

Given the nature of their profession, police officers cannot limit their exposure to stress and trauma, and the endocrine system plays a vital role in regulating and preparing the human body. This study aims to identify studies that have studied the behavior of the hormones cortisol and testosterone in their relationship with the physical and psychological performance of police officers and/or in a training/simulation scenario. The systematic review, limited from 2011 to 2022, was carried out according to the PICO and Preferred Reporting Items for Systematic reviews and Meta-Analyses research strategy, considering seven articles for the critical analysis (classified based on the modified Physiotherapy Evidence Database scale). Of the seven articles considered, (i) five studies are observational, and two are experimental; (ii) 1,475 police officers participated; (iii) three studies evaluated only male participants, and four studies evaluated both sexes; (iv) most studies include salivary collections for hormonal evaluation and questionnaires for behavioral analysis and psychosocial stress; (v) a study analyses salivary collections for hormonal evaluation in response to decision-making tasks; and (vi) a study analyses blood collections for hormonal evaluation. Although studies with proven validity in the association between the hormones cortisol and testosterone and physiological and psychological are scarce, the scientific evidence is consistent and points to these endocrine markers as reliable in quantifying stress levels and performance of police function.

Neurobiology and systems biology of stress resilience

Stress resilience is the phenomenon that some people maintain their mental health despite exposure to adversity or show only temporary impairments followed by quick recovery. Resilience research attempts to unravel the factors and mechanisms that make resilience possible and to harness its insights for the development of preventative interventions in individuals at risk for acquiring stress-related dysfunctions. Biological resilience research has been lagging behind the psychological and social sciences but has seen a massive surge in recent years. At the same time, progress in this field has been hampered by methodological challenges related to finding suitable operationalizations and study designs, replicating findings, and modeling resilience in animals. We embed a review of behavioral, neuroimaging, neurobiological, and systems biological findings in adults in a critical methods discussion. We find preliminary evidence that hippocampus-based pattern separation and prefrontal-based cognitive control functions protect against the development of pathological fears in the aftermath of singular, event-type stressors [as found in fear-related disorders, including simpler forms of posttraumatic stress disorder (PTSD)] by facilitating the perception of safety. Reward system-based pursuit and savoring of positive reinforcers appear to protect against the development of more generalized dysfunctions of the anxious-depressive spectrum resulting from more severe or longer-lasting stressors (as in depression, generalized or comorbid anxiety, or severe PTSD). Links between preserved functioning of these neural systems under stress and neuroplasticity, immunoregulation, gut microbiome composition, and integrity of the gut barrier and the blood-brain barrier are beginning to emerge. On this basis, avenues for biological interventions are pointed out.

Acute psychosocial stress modulates neural and behavioral substrates of cognitive control

Acute psychosocial stress affects learning, memory, and attention, but the evidence for the influence of stress on the neural processes supporting cognitive control remains mixed. We investigated how acute psychosocial stress influences performance and neural processing during the Go/NoGo task-an established cognitive control task. The experimental group underwent the Trier Social Stress Test (TSST) acute stress induction, whereas the control group completed personality questionnaires. Then, participants completed a functional magnetic resonance imaging (fMRI) Go/NoGo task, with self-report, blood pressure and salivary cortisol measurements of induced stress taken intermittently throughout the experimental session. The TSST was successful in eliciting a stress response, as indicated by significant Stress > Control between-group differences in subjective stress ratings and systolic blood pressure. We did not identify significant differences in cortisol levels, however. The stress induction also impacted subsequent Go/NoGo task performance, with participants who underwent the TSST making fewer commission errors on trials requiring the most inhibitory control (NoGo Green) relative to the control group, suggesting increased vigilance. Univariate analysis of fMRI task-evoked brain activity revealed no differences between stress and control groups for any region. However, using multivariate pattern analysis, stress and control groups were reliably differentiated by activation patterns contrasting the most demanding NoGo trials (i.e., NoGo Green trials) versus baseline in the medial intraparietal area (mIPA, affiliated with the dorsal attention network) and subregions of the cerebellum (affiliated with the default mode network). These results align with prior reports linking the mIPA and the cerebellum to visuomotor coordination, a function central to cognitive control processes underlying goal-directed behavior. This suggests that stressor-induced hypervigilance may produce a facilitative effect on response inhibition which is represented neurally by the activation patterns of cognitive control regions.

Omega-3 fatty acid supplementation affects tryptophan metabolism during a 12-week endurance training in amateur runners: a randomized controlled trial

The effects of long-term omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation during endurance training on tryptophan (Trp) metabolism and mental state of healthy individuals have not been evaluated so far. Concentrations of plasma Trp, its metabolites and IL-6 were assessed in 26 male runners before and after a 12-week training program combined with supplementation of n-3 PUFAs (O-3 + TRAIN group) or medium chain triglycerides (MCTs; TRAIN group). After the 12-week program participants' mood before and after stress induction was also assessed. The effects of the same supplementation protocol were evaluated also in 14 inactive subjects (O-3 + SEDEN group). Concentrations of 3-hydroxykynurenine (3-HK) and picolinic acid (PA) significantly increased only in the O-3 + TRAIN group (p = 0.01; [Formula: see text] = 0.22 and p = 0.01; [Formula: see text]= 0.26). Favorable, but not statistically significant changes in the concentrations of kynurenic acid (KYNA) (p = 0.06; [Formula: see text]= 0.14), xanthurenic acid (XA) (p = 0.07; [Formula: see text]= 0.13) and 3-hydroxyanthranilic acid (3-HAA) (p = 0.06; [Formula: see text]= 0.15) and in the ratio of neurotoxic to neuroprotective metabolites were seen also only in the O-3 + TRAIN group. No changes in mood and IL-6 concentrations were observed in either group. Supplementation with n-3 PUFAs during endurance training has beneficial effects on Trp's neuroprotective metabolites.Trial registry: This study was registered at ClinicalTrials.gov with identifier NCT05520437 (14/07/2021 first trial registration and 2018/31/N/NZ7/02962 second trial registration).

Estimating Physical Activity and Sleep using the Combination of Movement and Heart Rate: A Systematic Review and Meta-Analysis

The purpose of this meta-analysis was to quantify the difference in physical activity and sleep estimates assessed via 1) movement, 2) heart rate (HR), or 3) the combination of movement and HR (MOVE+HR) compared to criterion indicators of the outcomes. Searches in four electronic databases were executed September 21-24 of 2021. Weighted mean was calculated from standardized group-level estimates of mean percent error (MPE) and mean absolute percent error (MAPE) of the proxy signal compared to the criterion measurement method for physical activity, HR, or sleep. Standardized mean difference (SMD) effect sizes between the proxy and criterion estimates were calculated for each study across all outcomes, and meta-regression analyses were conducted. Two-One-Sided-Tests method were conducted to metaanalytically evaluate the equivalence of the proxy and criterion. Thirty-nine studies (physical activity k = 29 and sleep k = 10) were identified for data extraction. Sample size weighted means for MPE were -38.0%, 7.8%, -1.4%, and -0.6% for physical activity movement only, HR only, MOVE+HR, and sleep MOVE+HR, respectively. Sample size weighted means for MAPE were 41.4%, 32.6%, 13.3%, and 10.8% for physical activity movement only, HR only, MOVE+HR, and sleep MOVE+HR, respectively. Few estimates were statistically equivalent at a SMD of 0.8. Estimates of physical activity from MOVE+HR were not statistically significantly different from estimates based on movement or HR only. For sleep, included studies based their estimates solely on the combination of MOVE+HR, so it was impossible to determine if the combination produced significantly different estimates than either method alone.

Investigating adverse daily life effects following a psychosocial laboratory stress task, and the moderating role of Psychopathology

Laboratory stress tasks are necessary to closely investigate the stress response in a controlled environment. However, to our knowledge, no study has tested whether participating in such tasks can pose any daily life adverse effect. Fifty-three healthy participants (46 women) took part in a laboratory session where stress was induced using a typical psychosocial stressor: the repeated Montreal Imaging Stress Task (rMIST). Average levels of negative affect (NA), heart rate (HR), root mean square of successive differences (RMSSD), and skin conductance level (SCL), as well as reactivity across all these parameters as measured with the experience sampling method (ESM) in the four days prior to the laboratory session were compared with the four days following the session. We also assessed whether vulnerability to psychopathology moderated these associations. Findings showed that the task did not pose any significant adverse effect on participants. However, there was an unexpected increase in average RMSSD and a decrease in average SCL pre- to post- task. In addition, more vulnerable individuals were more likely to experience an increase in average levels of NA in the days following the task compared to the days preceding it. Our findings suggest that laboratory stress tasks may pose a significant risk to more vulnerable individuals.

Attenuation of visual exploration following stress

When we explore our surroundings, we frequently move our gaze to collect visual information. Studies have extensively examined gaze behavior in response to different visual scenes. Here, we examined how differences in an individual's state may affect visual exploration, for example, following acute stress. In this study, participants were exposed to either a psychosocial stressor-performing a public speaking task in front of a two-person committee-or a control condition absent stress induction. Elicitation of stress responses was validated using cortisol levels and subjective reports. Stress also led to an extended increase in pupil diameter (a proxy of arousal responses), suggesting it may also affect eye movements. Gaze behavior measures were taken prior and following the stress or control tasks. Acute stress attenuated visual exploration, reflected by fewer saccades and a smaller scanned area. Stress did not have a significant effect on either the tendency to look at social features or at salient regions of the images. These findings diverge from theoretical predictions suggesting that acute stress may facilitate social affiliative behaviors (e.g., Tend-and-Befriend theory). Reduced saccades and a smaller scanned area may be a possible mechanism explaining previous reports showing stress-related effects on various cognitive processes (e.g., visual working memory) that rely on visual exploration.

Stress-mediated dysregulation of the Rap1 small GTPase impairs hippocampal structure and function

The effects of repeated stress on cognitive impairment are thought to be mediated, at least in part, by reductions in the stability of dendritic spines in brain regions critical for proper learning and memory, including the hippocampus. Small GTPases are particularly potent regulators of dendritic spine formation, stability, and morphology in hippocampal neurons. Through the use of small GTPase protein profiling in mice, we identify increased levels of synaptic Rap1 in the hippocampal CA3 region in response to escalating, intermittent stress. We then demonstrate that increased Rap1 in the CA3 is sufficient in and of itself to produce stress-relevant dendritic spine and cognitive phenotypes. Further, using super-resolution imaging, we investigate how the pattern of Rap1 trafficking to synapses likely underlies its effects on the stability of select dendritic spine subtypes. These findings illuminate the involvement of aberrant Rap1 regulation in the hippocampus in contributing to the psychobiological effects of stress.

Detecting Social Contexts from Mobile Sensing Indicators in Virtual Interactions with Socially Anxious Individuals

Mobile sensing is a ubiquitous and useful tool to make inferences about individuals' mental health based on physiology and behavior patterns. Along with sensing features directly associated with mental health, it can be valuable to detect different features of social contexts to learn about social interaction patterns over time and across different environments. This can provide insight into diverse communities' academic, work and social lives, and their social networks. We posit that passively detecting social contexts can be particularly useful for social anxiety research, as it may ultimately help identify changes in social anxiety status and patterns of social avoidance and withdrawal. To this end, we recruited a sample of highly socially anxious undergraduate students (N=46) to examine whether we could detect the presence of experimentally manipulated virtual social contexts via wristband sensors. Using a multitask machine learning pipeline, we leveraged passively sensed biobehavioral streams to detect contexts relevant to social anxiety, including (1) whether people were in a social situation, (2) size of the social group, (3) degree of social evaluation, and (4) phase of social situation (anticipating, actively experiencing, or had just participated in an experience). Results demonstrated the feasibility of detecting most virtual social contexts, with stronger predictive accuracy when detecting whether individuals were in a social situation or not and the phase of the situation, and weaker predictive accuracy when detecting the level of social evaluation. They also indicated that sensing streams are differentially important to prediction based on the context being predicted. Our findings also provide useful information regarding design elements relevant to passive context detection, including optimal sensing duration, the utility of different sensing modalities, and the need for personalization. We discuss implications of these findings for future work on context detection (e.g., just-in-time adaptive intervention development).

ECG and EEG based detection and multilevel classification of stress using machine learning for specified genders: A preliminary study

Mental health, especially stress, plays a crucial role in the quality of life. During different phases (luteal and follicular phases) of the menstrual cycle, women may exhibit different responses to stress from men. This, therefore, may have an impact on the stress detection and classification accuracy of machine learning models if genders are not taken into account. However, this has never been investigated before. In addition, only a handful of stress detection devices are scientifically validated. To this end, this work proposes stress detection and multilevel stress classification models for unspecified and specified genders through ECG and EEG signals. Models for stress detection are achieved through developing and evaluating multiple individual classifiers. On the other hand, the stacking technique is employed to obtain models for multilevel stress classification. ECG and EEG features extracted from 40 subjects (21 females and 19 males) were used to train and validate the models. In the low&high combined stress conditions, RBF-SVM and kNN yielded the highest average classification accuracy for females (79.81%) and males (73.77%), respectively. Combining ECG and EEG, the average classification accuracy increased to at least 87.58% (male, high stress) and up to 92.70% (female, high stress). For multilevel stress classification from ECG and EEG, the accuracy for females was 62.60% and for males was 71.57%. This study shows that the difference in genders influences the classification performance for both the detection and multilevel classification of stress. The developed models can be used for both personal (through ECG) and clinical (through ECG and EEG) stress monitoring, with and without taking genders into account.

Contributions of Parasympathetic Arousal-Related Activity to Cognitive Performance in Patients With First-Episode Psychosis and Control Subjects

BACKGROUND

Cognitive impairment is integral to the pathophysiology of psychosis. Recent findings implicate autonomic arousal-related activity in both momentary fluctuations and individual differences in cognitive performance. Although altered autonomic arousal is common in patients with first-episode psychosis (FEP), its contribution to cognitive performance is unknown.

METHODS

A total of 24 patients with FEP (46% male, age = 24.31 [SD 4.27] years) and 24 control subjects (42% male, age = 27.06 [3.44] years) performed the Multi-Source Interference Task in-scanner with simultaneous pulse oximetry. First-level models included the cardiac-blood oxygen level-dependent regressor, in addition to task (congruent, interference, and error) and nuisance (motion and CompCor physiology) regressors. The cardiac-blood oxygen level-dependent regressor reflected parasympathetic arousal-related activity and was created by convolving the interbeat interval at each heartbeat with the hemodynamic response function. Group models examined the effect of group or cognitive performance (reaction times × error rate) on arousal-related and task activity, while controlling for sex, age, and framewise displacement.

RESULTS

Parasympathetic arousal-related activity was robust in both groups but localized to different regions for patients with FEP and healthy control subjects. Within both groups, arousal-related activity was significantly associated with cognitive performance across occipital and temporal cortical regions. Greater arousal-related activity in the bilateral prefrontal cortex (Brodmann area 9) was related to better performance in healthy control subjects but not patients with FEP.

CONCLUSIONS

Autonomic arousal circuits contribute to cognitive performance and the pathophysiology of FEP. Arousal-related functional activity is a novel indicator of cognitive ability and should be incorporated into neurobiological models of cognition in psychosis.

TRPV6 deficiency attenuates stress and corticosterone-mediated exacerbation of alcohol-induced gut barrier dysfunction and systemic inflammation

Introduction

Chronic stress is co-morbid with alcohol use disorder that feedback on one another, thus impeding recovery from both disorders. Stress and the stress hormone corticosterone aggravate alcohol-induced intestinal permeability and liver damage. However, the mechanisms involved in compounding tissue injury by stress/corticosterone and alcohol are poorly defined. Here we explored the involvement of the TRPV6 channel in stress (or corticosterone) 3and alcohol-induced intestinal epithelial permeability, microbiota dysbiosis, and systemic inflammation.

Methods

Chronic alcohol feeding was performed on adult wild-type and Trpv6-/- mice with or without corticosterone treatment or chronic restraint stress (CRS). The barrier function was determined by evaluating inulin permeability in vivo and assessing tight junction (TJ) and adherens junction (AJ) integrity by immunofluorescence microscopy. The gut microbiota composition was evaluated by 16S rRNA sequencing and metagenomic analyses. Systemic responses were assessed by evaluating endotoxemia, systemic inflammation, and liver damage.

Results

Corticosterone and CRS disrupted TJ and AJ, increased intestinal mucosal permeability, and caused endotoxemia, systemic inflammation, and liver damage in wild-type but not Trpv6-/- mice. Corticosterone and CRS synergistically potentiated the alcohol-induced breakdown of intestinal epithelial junctions, mucosal barrier impairment, endotoxemia, systemic inflammation, and liver damage in wild-type but not Trpv6-/- mice. TRPV6 deficiency also blocked the effects of CRS and CRS-mediated potentiation of alcohol-induced dysbiosis of gut microbiota.

Conclusions

These findings indicate an essential role of TRPV6 in stress, corticosterone, and alcohol-induced intestinal permeability, microbiota dysbiosis, endotoxemia, systemic inflammation, and liver injury. This study identifies TRPV6 as a potential therapeutic target for developing treatment strategies for stress and alcohol-associated comorbidity.

Effects of neuromodulation on cognitive and emotional responses to psychosocial stressors in healthy humans

Physiological and psychological stressors can exert wide-ranging effects on the human brain and behavior. Research has improved understanding of how the sympatho-adreno-medullary (SAM) and hypothalamic-pituitary-adrenocortical (HPA) axes respond to stressors and the differential responses that occur depending on stressor type. Although the physiological function of SAM and HPA responses is to promote survival and safety, exaggerated psychobiological reactivity can occur in psychiatric disorders. Exaggerated reactivity may occur more for certain types of stressors, specifically, psychosocial stressors. Understanding stressor effects and how the body regulates these responses can provide insight into ways that psychobiological reactivity can be modulated. Non-invasive neuromodulation is one way that responding to stressors may be altered; research into these interventions may provide further insights into the brain circuits that modulate stress reactivity. This review focuses on the effects of acute psychosocial stressors and how neuromodulation might be effective in altering stress reactivity. Although considerable research into stress interventions focuses on treating pathology, it is imperative to first understand these mechanisms in non-clinical populations; therefore, this review will emphasize populations with no known pathology and consider how these results may translate to those with psychiatric pathologies.

Green Spaces with Fewer People Improve Self-Reported Affective Experience and Mood

Calm and quiet green spaces provide health benefits for urban residents. Yet as cities become more densely populated, increasing public users to green spaces may reduce or moderate these benefits. We examine how increased pedestrian density in a green street changes self-reported wellbeing. We use a between subject experimental design that added public users as confederates in randomly selected periods over three weeks. We collect data on mood and affective response from pedestrians moving through the green street (n = 504), with and without our public user treatment in randomly selected periods. Mood and affective response are improved when experiencing the green street with fewer people. We find that an increased number of public users in the green space has a negative effect on mood, especially among women. We provide experimental evidence that self-reported wellbeing in urban green spaces depends on social context, and that there are gender inequities associated with changes in affective response. Although we only measure immediate impacts, our results imply that the health benefits of green spaces may be limited by the total number of users. This research contributes additional evidence that greener cities are also healthier cities, but that the benefits may not be equally shared between women and men and will depend on the social context of use.

Toward an Understanding of Cognitive Mapping Ability Through Manipulations and Measurement of Schemas and Stress

Daily function depends on an ability to mentally map our environment. Environmental factors such as visibility and layout, and internal factors such as psychological stress, can challenge spatial memory and efficient navigation. Importantly, people vary dramatically in their ability to navigate flexibly and overcome such challenges. In this paper, we present an overview of "schema theory" and our view of its relevance to navigational memory research. We review several studies from our group and others, that integrate manipulations of environmental complexity and affective state in order to gain a richer understanding of the mechanisms that underlie individual differences in navigational memory. Our most recent data explicitly link such individual differences to ideas rooted in schema theory, and we discuss the potential for this work to advance our understanding of cognitive decline with aging. The data from this body of work highlight the powerful impacts of individual cognitive traits and affective states on the way people take advantage of environmental features and adopt navigational strategies.

Mood and judgment in a dyadic stress context

The 1980s and 1990s witnessed a surge of psychological research addressing the role of affect in social judgments. Evaluations of others were shown to be shaped, at least in part, by a person's incidental mood in the moment of social evaluation; while negative moods instigated negative interpersonal evaluations, positive moods instigated positive interpersonal evaluations. Interestingly, these effects only emerged when the reason for the evaluator's mood was not obvious. Over 30 years later, we expand these findings to the dyadic domain. Rather than conceptualize interpersonal evaluations as occurring solely within an individual, we introduce the Dyadic Affect Infusion/Diffusion (DAID) model to suggest that interpersonal evaluations occur as fundamentally dyadic phenomena. Using 6 weeks of daily diary data from 311 couples in which one member approached a stressful event, we show that (a) mood influences relationship evaluations at both the intraindividual (i.e., affect infusion) and interindividual (i.e., affect diffusion) levels, (b) both affect infusion and affect diffusion are turned off by the availability of attributional information, and (c) these effects are better explained by affect infusion/diffusion rather than by several alternative mechanisms. Taken together, the DAID model bolsters the view that individualistic approaches to emotion and social cognition are insufficient and require theory and data at the dyadic and group levels of analysis. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Hormonal contraceptive usage influences stress hormone effects on cognition and emotion

Men and women partially differ in how they respond to stress and how stress in return affects their cognition and emotion. The influence of hormonal contraceptives (HCs) on this interaction has received little attention, which is surprising given the prevalence of HC usage. This selective review illustrates how HC usage modulates the effects of stress hormones on cognition and emotion. As three examples, we discuss stress hormone effects on episodic memory, fear conditioning and cognitive emotion regulation. The identified studies revealed that stress effects on cognitive-emotional processes in women using HCs were at times reduced or even absent when compared to men or naturally cycling women. Especially striking were the few examples of reversed effects in HC women. As underlying neuroendocrine mechanisms, we discuss influences of HCs on the neuroendocrine stress response and effects of HCs on central glucocorticoid sensitivity. The summarized findings emphasize the need for additional translational research.

Coordination of autonomic and endocrine stress responses to the Trier Social Stress Test in adolescence

Dysregulations in autonomic and endocrine stress responses are linked to the emergence of psychopathology in adolescence. However, most studies fail to consider the interplay between these systems giving rise to conflicting findings and a gap in understanding adolescent stress response regulation. A multisystem framework-investigation of parasympathetic (PNS), sympathetic (SNS), and hypothalamic pituitary adrenal (HPA) axis components and their coordination-is necessary to understand individual differences in stress response coordination which contribute to stress vulnerabilities. As the first investigation to comprehensively evaluate these three systems in adolescence, the current study employed the Trier Social Stress Test in 72 typically developing adolescents (mean age = 13) to address how PNS, SNS, and HPA stress responses are coordinated in adolescence. Hypotheses tested key predictions of the Adaptive Calibration Model (ACM) of stress response coordination. PNS and SNS responses were assessed via heart rate variability (HRV) and salivary alpha amylase (sAA) respectively. HPA responses were indexed by salivary cortisol. Analyses utilized piecewise growth curve modeling to investigate these aims. Supporting the ACM theory, there was significant hierarchical coordination between the systems such that those with low HRV had higher sAA and cortisol reactivity and those with high HRV had low-to-moderate sAA and cortisol responsivity. Our novel results reveal the necessity of studying multisystem dynamics in an integrative fashion to uncover the true mechanisms of stress response and regulation during development. Additionally, our findings support the existence of characteristic stress response profiles as predicted by the ACM model.

Comparing two psychosocial stress paradigms for imaging environments - ScanSTRESS and fNIRS-TSST: correlation structures between stress responses

The present post-hoc analysis of two independent studies conducted in different laboratories aimed at comparing reactions of stress activation systems in response to two different psychosocial stress induction paradigms. Both paradigms are based on the Trier Social Stress Test and suited for neuroimaging environments. In an in-depth analysis, data from 67 participants (36 men, 31 women) from a functional magnetic resonance imaging study implementing ScanSTRESS were compared with data from a functional near-infrared spectroscopy (fNIRS) study implementing the so-called 'fNIRS-TSST' including 45 participants (8 men, 37 women). We tested the equivalence of correlation patterns between the stress response measures cortisol, heart rate, affect, and neural responses in the two samples. Moreover, direct comparisons of affective and neural responses were made. Similar correlation structures were identified for all stress activation systems, except for neural contrasts of paradigm conditions (stress vs. control) showing significant differences in association with cortisol, heart rate, and affective variables between the two samples. Furthermore, both stress paradigms elicited comparable affective and cortical stress responses. Apart from methodological differences (e.g., procedure, timing of the paradigms) the present analysis suggests that both paradigms are capable of inducing moderate acute psychosocial stress to a comparable extent with regard to affective and cortical stress responses. Moreover, similar association structures between different stress response systems were found in both studies. Thus, depending on the study objective and the respective advantages of each imaging approach, both paradigms have demonstrated their usefulness for future studies.

Stress and risk — Preferences versus noise

We analyze the impact of acute stress on risky choice in a pre-registered laboratory experiment with 194 participants. We test the causal impact of stress on the stability of risk preferences by separating noise in decision-making from an actual shift in preferences. We find no significant differences in risk attitudes across conditions on the aggregate, using both descriptive analyses as well as structural estimations for risk aversion and different noise structures. Additionally, in line with the previous literature, we find statistically significant evidence for lower cognitive abilities being correlated with more noise in decision-making in general. We do not find a significant interaction effect between cognitive abilities and stress on noise levels.

Does Training Motivation Influence Resilience Training Outcome on Chronic Stress? Results from an Interventional Study

Resilience is understood as an acquired skill which aids in coping with acute and chronic stress. Accordingly, the present study aimed to determine the effect of resilience training on mental health problems during chronic stress. To this end, we conducted a quasi-experimental study with 127 male cadets (mean age: 21 years) of the Swiss Armed Forces officers' school. Whereas the intervention group (IG) received resilience training in addition to the standard officer's education program, the control group (CG) completed the officers' school as usual. Data assessment included pre- and post- measurement of chronic stress, symptoms of depression, and vital exhaustion in both groups. Motivation for training was collected before the first training session. Those who received the resilience training reported no change in chronic stress, whereas participants in the CG showed a significant increase in chronic stress over time (η_p² = 0.025). Furthermore, significant differences between IG and CG were only found for symptoms of depression: Participants in the IG reported significantly decreased symptoms of depression, while this was not the case for participants in the CG. Within the IG, participants' training motivation strongly influenced the effectiveness of the resilience training. More specifically, motivated individuals were more likely to benefit from the resilience training than unmotivated ones. Outcome data suggest that resilience training appeared to favorably affect chronic stress and related mental health symptoms; however, the motivation for the training seemed to be an essential prerequisite.

Stress and the gut-brain axis: Cognitive performance, mood state, and biomarkers of blood-brain barrier and intestinal permeability following severe physical and psychological stress

BACKGROUND

Physical and psychological stress alter gut-brain axis activity, potentially causing intestinal barrier dysfunction that may, in turn, induce cognitive and mood impairments through exacerbated inflammation and blood brain barrier (BBB) permeability. These interactions are commonly studied in animals or artificial laboratory environments. However, military survival training provides an alternative and unique human model for studying the impacts of severe physical and psychological stress on the gut-brain axis in a realistic environment.

PURPOSE

To determine changes in intestinal barrier and BBB permeability during stressful military survival training and identify relationships between those changes and markers of stress, inflammation, cognitive performance, and mood state.

MATERIALS AND METHODS

Seventy-one male U.S. Marines (25.2 ± 2.6 years) were studied during Survival, Evasion, Resistance, and Escape (SERE) training. Measurements were conducted on day 2 of the 10-day classroom phase of training (PRE), following completion of the 7.5-day field-based simulation phase of the training (POST), and following a 27-day recovery period (REC). Fat-free mass (FFM) was measured to assess the overall physiologic impact of the training. Biomarkers of intestinal permeability (liposaccharide-binding protein [LBP]) and BBB permeability (S100 calcium-binding protein B [S100B]), stress (cortisol, dehydroepiandrosterone sulfate [DHEA-S] epinephrine, norepinephrine) and inflammation (interleukin-6 [IL-6], high-sensitivity C-reactive protein [hsCRP]) were measured in blood. Cognitive performance was assessed by psychomotor vigilance (PVT) and grammatical reasoning (GR) tests, and mood state by the Profile of Mood States (total mood disturbance; TMD), General Anxiety Disorder-7 (GAD-7), and Patient Health (PHQ-9) questionnaires.

RESULTS

FFM, psychomotor vigilance, and LBP decreased from PRE to POST, while TMD, anxiety, and depression scores, and S100B, DHEA-S, IL-6, norepinephrine, and epinephrine concentrations all increased (all p ≤ 0.01). Increases in DHEA-S were associated with decreases in body mass (p = 0.015). Decreases in FFM were associated with decreases in LBP concentrations (p = 0.015), and both decreases in FFM and LBP were associated with increases in TMD and depression scores (all p < 0.05) but not with changes in cognitive performance. Conversely, increases in S100B concentrations were associated with decreases in psychomotor vigilance (p < 0.05) but not with changes in mood state or LBP concentrations.

CONCLUSIONS

Evidence of increased intestinal permeability was not observed in this military survival training-based model of severe physical and psychological stress. However, increased BBB permeability was associated with stress and cognitive decline, while FFM loss was associated with mood disturbance, suggesting that distinct mechanisms may contribute to decrements in cognitive performance and mood state during the severe physical and psychological stress experienced during military survival training.

Determinants and Mechanisms of the Renin-Aldosterone Stress Response

OBJECTIVE

The renin-angiotensin-aldosterone system (RAAS) plays a relevant role in regulating blood pressure and thus maintaining cardiovascular homeostasis. Although it was recently shown that RAAS parameters are responsive to acute psychosocial stress, the psychobiological determinants of the acute stress-induced RAAS activation have not yet been investigated. In a randomized placebo-controlled design, we investigated potential psychological and physiological determinants of the RAAS response and underlying mechanisms.

METHODS

Fifty-seven young healthy male participants underwent either an acute standardized psychosocial stress test or a nonstress placebo task. We measured aldosterone in plasma and saliva, as well as renin, and the stress-reactive endocrine measures adrenocorticotropic hormone (ACTH), epinephrine, and norepinephrine in plasma at rest, immediately after the task and several times up to 3 hours thereafter. Moreover, we assessed stress-reactive psychological (anticipatory cognitive stress appraisal, mood, physical discomfort) and basal demographic-physiological measures (age, body mass index, blood pressure).

RESULTS

Acute psychosocial stress elicited changes in all assessed endocrine (p values ≤ .028, ηp2 values ≥ 0.07) and stress-reactive psychological measures (p values ≤ .003, ηp2 values ≥ 0.15). The basal parameter body mass index, the stress-reactive endocrine parameters ACTH and norepinephrine, and the psychological parameter anticipatory stress appraisal were identified as determinants of higher RAAS parameter reactivity to acute psychosocial stress. The association between anticipatory cognitive stress appraisal and plasma RAAS measures was fully mediated by ACTH increases (p values ≤ .044, ηp2 values ≥ 0.05).

CONCLUSIONS

Cognitive stress appraisal processes seem to modulate RAAS stress reactivity. This points to potential clinical implications for psychoeducative therapeutical interventions targeting stress appraisal processes to reduce endocrine stress reactivity.

Effects of Lactococcus lactis subsp. cremoris YRC3780 daily intake on the HPA axis response to acute psychological stress in healthy Japanese men

BACKGROUND

Lactococcus lactis subsp. cremoris (YRC3780), which is isolated from kefir, has been associated with anti-allergic effects in humans. However, it remains unknown whether daily intake of YRC3780 attenuates the response to psychological stress in humans in parallel with changes to the gut microbiome. We examined the fundamental role of YRC3780 in the gut microbiome, stress response, sleep, and mental health in humans.

METHODS

Effects of daily intake of YRC3780 on the hypothalamic-pituitary-adrenal (HPA) axis response to acute psychological stress were investigated in a double-blind, placebo-controlled clinical trial involving 27 healthy young men (mean age and body mass index: 23.5 years and 21.5 kg/m²) who were randomly assigned to placebo (n = 13) or YRC3780 (n = 14) groups. The HPA axis response to acute psychological stress, the diurnal rhythm of HPA axis activity, and gut microbiome were assessed and compared between the two groups.

RESULTS

The results showed that daily intake of YRC3780 significantly lowered morning salivary cortisol levels compared with placebo. In addition, salivary cortisol levels following a social stress test significantly decreased +40 min after beginning the TSST in the YRC3780-treated group compared to placebo. There were no significant differences between the two groups in terms of actigraphy-based sleep quality, but the subjective sleep quality and mental health were significantly improved in the YRC3780-treated group compared to placebo.

CONCLUSIONS

Our study suggests that daily intake of YRC3780 improves the HPA axis response to acute psychological stress, which might be associated with a decrease in morning cortisol levels.

Current psychosocial stress, childhood trauma and cognition in patients with schizophrenia and healthy participants

BACKGROUND

Cognitive difficulties are experienced frequently in schizophrenia (SZ) and are strongly predictive of functional outcome. Although severity of cognitive difficulties has been robustly associated with early life adversity, whether and how they are affected by current stress is unknown. The present study investigated whether acute stress reactivity as measured by heart rate and mood changes predict cognitive performance in patients with schizophrenia and healthy individuals, and whether this is moderated by diagnosis and previous childhood trauma exposure.

METHODS

One hundred and four patients with schizophrenia and 207 healthy participants were administered a battery of tasks assessing cognitive performance after psychosocial stress induction (Trier Social Stress Test; TSST). Mood states (Profile of Mood States; POMS) and heart rate were assessed at baseline, immediately before, and after the TSST.

RESULTS

Both healthy participants and patients showed increases in POMS Tension and Total Mood Disturbance scores between Time Point 2 (pre-TSST) and Time Point 3 (post-TSST). These changes were not associated with variation in cognition. Although childhood trauma exposure was associated with higher stress reactivity and poorer cognitive function in all participants, childhood trauma did not moderate the association between stress reactivity and cognition. Neither was diagnosis a moderator of this relationship.

DISCUSSION

These findings suggest that while chronic stress exposure explains significant variation in cognition, acute stress reactivity (measured by changes in Tension and Total Mood Disturbance) did not. In the context of broader developmental processes, we conclude that stressful events that occur earlier in development, and with greater chronicity, are likely to be more strongly associated with cognitive variation than acute transient stressors experienced in adulthood.

Toward Predicting Human Performance Outcomes From Wearable Technologies: A Computational Modeling Approach

Wearable technologies for measuring digital and chemical physiology are pervading the consumer market and hold potential to reliably classify states of relevance to human performance including stress, sleep deprivation, and physical exertion. The ability to efficiently and accurately classify physiological states based on wearable devices is improving. However, the inherent variability of human behavior within and across individuals makes it challenging to predict how identified states influence human performance outcomes of relevance to military operations and other high-stakes domains. We describe a computational modeling approach to address this challenge, seeking to translate user states obtained from a variety of sources including wearable devices into relevant and actionable insights across the cognitive and physical domains. Three status predictors were considered: stress level, sleep status, and extent of physical exertion; these independent variables were used to predict three human performance outcomes: reaction time, executive function, and perceptuo-motor control. The approach provides a complete, conditional probabilistic model of the performance variables given the status predictors. Construction of the model leverages diverse raw data sources to estimate marginal probability density functions for each of six independent and dependent variables of interest using parametric modeling and maximum likelihood estimation. The joint distributions among variables were optimized using an adaptive LASSO approach based on the strength and directionality of conditional relationships (effect sizes) derived from meta-analyses of extant research. The model optimization process converged on solutions that maintain the integrity of the original marginal distributions and the directionality and robustness of conditional relationships. The modeling framework described provides a flexible and extensible solution for human performance prediction, affording efficient expansion with additional independent and dependent variables of interest, ingestion of new raw data, and extension to two- and three-way interactions among independent variables. Continuing work includes model expansion to multiple independent and dependent variables, real-time model stimulation by wearable devices, individualized and small-group prediction, and laboratory and field validation.

Trier Social Stress Test Elevates Blood Pressure, Heart Rate, and Anxiety, But a Singing Test or Unsolvable Anagrams Only Elevates Heart Rate, among Healthy Young Adults

The Trier Social Stress Test (TSST) is a psychosocial stressor that effectively stimulates the stress response but is labor and time intensive. Although other psychological stressors are often used experimentally, none are known to comparably elevate stress. Two stressors that may potentially elevate stress are a singing task (ST) and unsolvable anagrams, but there are not enough data to support their effectiveness. In the current experiment, 53 undergraduate males and females (mean age = 21.9 years) were brought into the laboratory, and baseline blood pressure, heart rate, self-rated anxiety, and salivary cortisol were recorded. Then, participants were randomly assigned to one of three stress conditions: TSST (n = 24), ST (n = 14), or an unsolvable anagram task (n = 15). Stress measures were taken again after the stressor and during recovery. The TSST significantly elevated systolic blood pressure, diastolic blood pressure, heart rate, and self-rated anxiety from pre-stress levels, replicating its stress-inducing properties. However, the ST and unsolvable anagrams only elevated heart rate, indicating that these methods are not as able to stimulate physiological or psychological stress. Overall, results indicate that out of these three laboratory stressors, the TSST clearly engages the stress response over the ST or unsolvable anagrams.

The Lausanne Infant Crying Stress Paradigm: Validation of an Early Postpartum Stress Paradigm with Women at Low vs. High Risk of Childbirth-Related Posttraumatic Stress Disorder

Stress reactivity is typically investigated in laboratory settings, which is inadequate for mothers in maternity settings. This study aimed at validating the Lausanne Infant Crying Stress Paradigm (LICSP) as a new psychosocial stress paradigm eliciting psychophysiological stress reactivity in early postpartum mothers (n = 52) and to compare stress reactivity in women at low (n = 28) vs. high risk (n = 24) of childbirth-related posttraumatic stress disorder (CB-PTSD). Stress reactivity was assessed at pre-, peri-, and post-stress levels through salivary cortisol, heart rate variability (high-frequency (HF) power, low-frequency (LF) power, and LF/HF ratio), and perceived stress via a visual analog scale. Significant time effects were observed for all stress reactivity outcomes in the total sample (all p < 0.01). When adjusting for perceived life threat for the infant during childbirth, high-risk mothers reported higher perceived stress (p < 0.001, d = 0.91) and had lower salivary cortisol release (p = 0.023, d = 0.53), lower LF/HF ratio (p < 0.001, d = 0.93), and marginally higher HF power (p = 0.07, d = 0.53) than low-risk women. In conclusion, the LICSP induces subjective stress and autonomic nervous system (ANS) reactivity in maternity settings. High-risk mothers showed higher perceived stress and altered ANS and hypothalamic-pituitary-adrenal reactivity when adjusting for infant life threat. Ultimately, the LICSP could stimulate (CB-)PTSD research.

Mild-to-moderate schizotypal traits relate to physiological arousal from social stress

Schizotypy denotes psychosis-like experiences, such as perceptual aberration, magical ideation, and social anxiety. Altered physiological arousal from social stress is found in people with high schizotypal traits. Two experiments aimed to determine the relationship of schizotypy to physiological arousal from social stress. Experiment 1 tested the hypotheses that heart rate from social stress would be greater in high, than mild-to-moderate, schizotypal traits, and disorganized schizotypy would explain this effect because of distress from disorganisation. Experiment 1 tested social stress in 16 participants with high schizotypal traits and 10 participants with mild-to-moderate schizotypal traits. The social stress test consisted of a public speech and an informal discussion with strangers. The high schizotypal group had a higher heart rate than the mild-to-moderate schizotypal group during the informal discussion with strangers, but not during the public speech. Disorganized schizotypy accounted for this group difference. Experiment 2 tested the hypothesis that mild-to-moderate schizotypal traits would have a linear relationship with physiological arousal from social stress. Experiment 2 tested 24 participants with mild-to-moderate schizotypal traits performing the abovementioned social stress test while their heart rate and skin conductance responses were measured. Mild-to-moderate schizotypal traits had a linear relationship with physiological arousal during the discussion with strangers. Distress in disorganized schizotypy may explain the heightened arousal from close social interaction with strangers in high schizotypy than mild-to-moderate schizotypy. Mild-to-moderate schizotypal traits may have a linear relationship with HR during close social interaction because of difficulty with acclimatizing to the social interaction.

Concordant pattern of the HPA axis response to visceral stimulation and CRH administration

The physiological and psychological mechanisms explaining the individual variability in the stress response are poorly understood. We tested the hypothesis that hypothalamic-pituitary- adrenal (HPA) axis responses to colorectal stimulation affect HPA axis reactivity to corticotropin-releasing hormone (CRH), the visceral pain threshold, and perceived stress. We examined 31 healthy volunteers and 27 individuals with irritable bowel syndrome. According to the ACTH response to colorectal stimulation, the participants were classified into three groups: flattened, decreased, and increased. We found significant differences in the abdominal pain threshold, discomfort threshold, and sensitivity to anxiety among the groups. There were significant differences in the ACTH change and peak level after CRH administration among the groups. The area under the curve of the cortisol response to CRH was significantly different among the groups. The increased group showed a higher basal ACTH level, earlier peak level in the CRH administration test, and higher stress rating during the experiment. The increased group had an exaggerated psychological and physiological stress response, whereas the decreased group had a higher anticipatory endocrine response, stress, and sensitivity to anxiety. Further studies are needed to determine factors including gut microbiota on the individual difference in HPA response.

A Review of Biophysiological and Biochemical Indicators of Stress for Connected and Preventive Healthcare

Stress is a known contributor to several life-threatening medical conditions and a risk factor for triggering acute cardiovascular events, as well as a root cause of several social problems. The burden of stress is increasing globally and, with that, is the interest in developing effective stress-monitoring solutions for preventive and connected health, particularly with the help of wearable sensing technologies. The recent development of miniaturized and flexible biosensors has enabled the development of connected wearable solutions to monitor stress and intervene in time to prevent the progression of stress-induced medical conditions. This paper presents a review of the literature on different physiological and chemical indicators of stress, which are commonly used for quantitative assessment of stress, and the associated sensing technologies.

Stress and long-term memory retrieval: a systematic review

Introduction

The experience of stressful events can alter brain structures involved in memory encoding, storage and retrieval. Here we review experimental research assessing the impact of the stress-related hormone cortisol on long-term memory retrieval.

Method

A comprehensive literature search was conducted on PubMed, Web of Science and PsycNet databases with the following terms: “stress,” “long-term memory,” and “retrieval.” Studies were included in the review if they tested samples of healthy human participants, with at least one control group, and with the onset of the stress intervention occurring after the encoding phase and shortly (up to one hour) before the final memory test.

Results

Thirteen studies were included in the qualitative synthesis (N = 962) and were classified according to the time elapsed between stress induction and memory retrieval (stress-retrieval delay), the stress-inducing protocol (stressor), the time of day in which stress induction took place, sex, and age of participants. Most studies induced stress with the Trier Social Stress Test (TSST) between 15 and 25 minutes before the final memory (mostly recall) test and showed significant increases in cortisol levels and memory impairment.

Discussion

The reviewed studies indicate that stress does impair retrieval, particularly when induced with the TSST, in the afternoon, up to 45 minutes before the onset of the final memory test, in healthy young men. These results may inform future research on the impact of stress-induced cortisol surges on memory retrieval.

A systematic review of the Trier Social Stress Test methodology: Issues in promoting study comparison and replicable research

Since its development in 1993, the Trier Social Stress Test (TSST) has been used widely as a psychosocial stress paradigm to activate the sympathetic nervous system and hypothalamic-pituitary-adrenal axis (HPAA) stress systems, stimulating physiological functions (e.g. heart rate) and cortisol secretion. Several methodological variations introduced over the years have led the scientific community to question replication between studies. In this systematic review, we used the Preferred Reporting Items of Systematic Reviews and Meta-Analysis (PRISMA) to synthesize procedure-related data available about the TSST protocol to highlight commonalities and differences across studies. We noted significant discrepancies across studies in how researchers applied the TSST protocol. In particular, we highlight variations in testing procedures (e.g., number of judges, initial number in the arithmetic task, time of the collected saliva samples for cortisol) and discuss possible misinterpretation in comparing findings from studies failing to control for variables or using a modified version from the original protocol. Further, we recommend that researchers use a standardized background questionnaire when using the TSST to identify factors that may influence physiological measurements in tandem with a summary of this review as a protocol guide. More systematic implementation and detailed reporting of TSST methodology will promote study replication, optimize comparison of findings, and foster an informed understanding of factors affecting responses to social stressors in healthy people and those with pathological conditions.

Higher perceived stress is associated with lower cortisol concentrations but higher salivary interleukin-1beta in socially evaluated cold pressor test

The relationship between subjective stress perception and the objective stress response to acute stress stimuli is not sufficiently understood. The aim of the present study was to test the hypothesis that the neuroendocrine response in socially evaluated cold pressor test (CPT) depends on the extent of perceived stressfulness of the stimulus. The test was performed in 24 healthy male volunteers. Subjective stress perception was assessed using nine visual analog scales. The subjects were divided to low and high stress perception groups according to the median split of the scores. Subjects with high stress perception exhibited slightly lower values of systolic blood pressure and lower overall concentrations of salivary cortisol compared to subjects with low stress perception. Salivary alpha-amylase activity did not show significant changes. Salivary aldosterone decreased in time in subjects with low but increased early after the test in subjects with high stress perception. Interestingly, salivary concentrations of the pro-inflammatory cytokine interleukin-1beta were considerably higher in subjects with high stress perception, particularly immediately before the test. The differences in salivary cortisol and interleukin-1beta were confirmed by the analysis with distress as a continuous covariate. Distress scores correlated negatively with salivary cortisol and positively with interleukin-1beta. The rate pressure product, which is a global measure of energy consumption by the heart, was significantly higher immediately before than after the stress exposure. The present findings show that concentrations of interleukin-1beta are a sensitive component of the stress response at the time before the stressful event.Lay summaryIt is generally expected that higher perceived stressfulness of a stimulus is accompanied by higher activation of stress-related systems. This study evaluating a combined psychosocial and physical stress situation in healthy men provides evidence that individual parameters of the stress response are differently related to perceived stress intensity. Subjects with high stress perception exhibited lower systolic blood pressure and salivary cortisol, higher interleukin-1beta, marginal differences in alpha amylase and aldosterone compared to subjects with low stress perception, which might be important for stress coping.

Multi-Modal Acute Stress Recognition Using Off-the-Shelf Wearable Devices

Monitoring stress and, in general, emotions has attracted a lot of attention over the past few decades. Stress monitoring has many applications, including high-risk missions and surgical procedures as well as mental/emotional health monitoring. In this paper, we evaluate the possibility of stress and emotion monitoring using off-the-shelf wearable sensors. To this aim, we propose a multi-modal machine-learning technique for acute stress episodes detection, by fusing the information careered in several biosignals and wearable sensors. Furthermore, we investigate the contribution of each wearable sensor in stress detection and demonstrate the possibility of acute stress recognition using wearable devices. In particular, we acquire the physiological signals using the Shimmer3 ECG Unit and the Empatica E4 wristband. Our experimental evaluation shows that it is possible to detect acute stress episodes with an accuracy of 84.13%, for an unseen test set, using multi-modal machinelearning and sensor-fusion techniques.

Stress-related changes in financial risk taking: Considering joint effects of cortisol and affect

Many decisions under risk and uncertainty are made under physical or emotional stress. A recent meta-analysis suggested that stress reliably influences risk taking but did not find a relation between single measures of stress such as cortisol and risk taking. One reason for the conflicting findings could be that the influence of stress on risk taking depends not only on physiological but also on psychological stress responses, in particular affective valence. We tested this hypothesis in an exploratory empirical study: Seventy participants worked on a financial risk-taking task. In half of the participants acute stress was induced with a cold pressor task. For all participants we measured cortisol and α-amylase levels, blood pressure, subjective arousal, and affective valence before and after the task. The stress induction increased participants' levels of cortisol, subjective arousal, and systolic blood pressure but did not directly influence negative affect or risky decision making. Examining the interplay between physiological and psychological stress responses, a moderation analysis revealed an interaction between stress induction and affect valence: Negative affect predicted an increase in risk-seeking decision making in the stress condition, but not in the control group. A similar moderation was found with cortisol reactivity, that is, negative affect predicted an increase in risk-seeking decision making in participants with high cortisol reactivity but not in participants with low cortisol reactivity. These results suggest that the effect of stress on risky decision making depends on the interplay of affective valence and cortisol reactivity.

Association of salivary alpha-amylase and salivary flow rate with working memory functioning in healthy children

The aim of this study was to examine the association between auditory and visual working memory (WM) performance and salivary alpha-amylase (sAA) and salivary flow rate (SFR) in a sample of 63 children (38 boys). WM was assessed by means of WISC-V subtests: four auditory subtests (Digit Span and Letter-Number Sequencing) and one visual subtest (Picture Span). SAA activity, output, and SFR were measured at baseline (10 min prior to testing), one minute prior to testing, one minute after the end of the auditory WM subtests and one minute after the end of the visual WM subtest. Our statistical analyses showed an association among SAA activity, output and SFR levels and the number of recalled digits in the last attempt score in Letter-Number Sequencing subtest. Specifically, our results showed that working performance in this task was associated with a concurrent decrease in SFR (r(63) = -0.423, p < .05). This salivary measure was the best predictor of this specific index of working memory performance (β = -0.423, p < .05). These results show that the changes in SFR, which represents changes in parasympathetic tone, could be employed in future studies as a noninvasive marker of working memory performance in child studies.