Stress reactivity: biological and subjective responses to the cold pressor and Trier Social stressors

Sympathetic arousal among depressed college students: Examining the interplay between psychopathology and social activity

Depressed individuals exhibit altered sensitivity to both positive and negative social contact, and may not reap the same psychological and emotional benefits to socializing as non-depressed individuals. Although depressive symptoms and loneliness predict social withdrawal and decreased pleasure, little is currently understood about immediate affective arousal dynamics during real-time socializing. Using a novel ambulatory protocol that tracked both objective features of affective arousal (electrodermal activity) and subjective valence (self-reported) during college students' social interactions, we evaluated the moderating role of depression and loneliness symptoms on the associations between socializing with others (specifically, with a romantic partner, a close friend, or a group of friends) and the arousal and valence dimensions of affect. Among a racially and ethnically diverse sample of 118 college students (64% African American/Black/Continental African, 20% Latinx, 8% Asian, and 8% White) recruited from a large, predominantly White Midwestern university, those lower in depression and loneliness symptomatology evinced decreased average arousal (Β = -0.10, SE = 0.04, p < .01) when in relaxed and intimate socializing contexts (e.g., with a romantic partner and a close friend), consistent with the idea that these contexts facilitate important opportunities for psychological rest and recovery. Those lower in depression and loneliness symptoms also showed higher average arousal when socializing in the energizing context of being with a group of friends. Overall, the results suggest psychopathology is reflected in patterns of sympathetic arousal when socializing, with more depressed and lonely individuals generally feeling worse while receiving fewer psychophysiological rewards in multiple socializing contexts.

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.

Effect of a single session of yoga and meditation on stress reactivity: A systematic review

This systematic review synthesises the evidence for the effectiveness of a single session of yoga or its components including meditation and breathing techniques in reducing acute stress reactivity in healthy adults. Following the PRISMA guidelines, we searched Medline, EMBASE, Cochrane, CINAHL, and PsycINFO on 30th July 2023 for randomised controlled or crossover trials of yoga components and reporting physiological and/or psychological outcome measure(s) related to stress reactivity. Risk of bias (ROB) was assessed using the Cochrane ROB 2 tool. Data were synthesised narratively. Twenty-one out of 28 eligible studies (n = 2574) relating to 31 interventions (meditation [n = 22], breathing [n = 4] and yoga [n = 5]) reported outcomes in favour of the intervention. Stress reactivity was reported to be reduced by 71% of studies measuring physiological outcomes and 65% of studies measuring psychological outcomes. These studies show that a single session of yoga components is effective in reducing acute stress reactivity in adults and could be recommended for stress management. Future studies with larger populations and a more equal representation of genders and age groups are warranted.

App-Based Mindfulness for Attenuation of Subjective and Physiological Stress Reactivity in a Population With Elevated Stress: Randomized Controlled Trial

BACKGROUND

Stress-related mental health disorders have steadily increased and contributed to a worldwide disease burden with up to 50% experiencing a stress-related mental health disorder worldwide. Data suggest that only approximately 20%-65% of individuals receive treatment. This gap in receiving treatment may be attributed to barriers such as limited treatment access, negative stigma surrounding mental health treatment, approachability (ie, not having a usual treatment plan or provider), affordability (ie, lack of insurance coverage and high treatment cost), and availability (ie, long waits for appointments) leaving those who need treatment without necessary care. To mitigate the limited access mental health treatment, there has been a rise in the application and study of digital mental health interventions. As such, there is an urgent need and opportunity for effective digital mental health interventions to alleviate stress symptoms, potentially reducing adverse outcomes of stress-related disorders.

OBJECTIVE

This study examined if app-based guided mindfulness could improve subjective levels of stress and influence physiological markers of stress reactivity in a population with elevated symptoms of stress.

METHODS

The study included 163 participants who had moderate to high perceived stress as assessed by the Perceived Stress Scale (PSS-10). Participants were randomly allocated to 1 of 5 groups: a digital guided program designed to alleviate stress (Managing Stress), a digital mindfulness fundamentals course (Basics), digitally delivered breathing exercises, an active control intervention (Audiobook), and a Waitlist Control group. The 3 formats of mindfulness interventions (Managing Stress, Basics, and Breathing) all had a total duration of 300 minutes spanning 20-30 days. Primary outcome measures were perceived stress using the PSS-10, self-reported sleep quality using the Pittsburgh Sleep Quality Index, and trait mindfulness using the Mindful Attention Awareness Scale. To probe the effects of physiological stress, an acute stress manipulation task was included, specifically the cold pressor task (CPT). Heart rate variability was collected before, during, and after exposure to the CPT and used as a measure of physiological stress.

RESULTS

The results showed that PSS-10 and Pittsburgh Sleep Quality Index scores for the Managing Stress (all P<.001) and Basics (all P≤.002) groups were significantly reduced between preintervention and postintervention periods, while no significant differences were reported for the other groups. No significant differences among groups were reported for Mindful Attention Awareness Scale (P=.13). The physiological results revealed that the Managing Stress (P<.001) and Basics (P=.01) groups displayed reduced physiological stress reactivity between the preintervention and postintervention periods on the CPT. There were no significant differences reported for the other groups.

CONCLUSIONS

These results demonstrate efficacy of app-based mindfulness in a population with moderate to high stress on improving self-reported stress, sleep quality, and physiological measures of stress during an acute stress manipulation task.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05832632; https://www.clinicaltrials.gov/ct2/show/NCT05832632.

Acute stress alters probabilistic reversal learning in healthy male adults

Behavioural adaptation is a fundamental cognitive ability, ensuring survival by allowing for flexible adjustment to changing environments. In laboratory settings, behavioural adaptation can be measured with reversal learning paradigms requiring agents to adjust reward learning to stimulus-action-outcome contingency changes. Stress is found to alter flexibility of reward learning, but effect directionality is mixed across studies. Here, we used model-based functional MRI (fMRI) in a within-subjects design to investigate the effect of acute psychosocial stress on flexible behavioural adaptation. Healthy male volunteers (n = 28) did a reversal learning task during fMRI in two sessions, once after the Trier Social Stress Test (TSST), a validated psychosocial stress induction method, and once after a control condition. Stress effects on choice behaviour were investigated using multilevel generalized linear models and computational models describing different learning processes that potentially generated the data. Computational models were fitted using a hierarchical Bayesian approach, and model-derived reward prediction errors (RPE) were used as fMRI regressors. We found that acute psychosocial stress slightly increased correct response rates. Model comparison revealed that double-update learning with altered choice temperature under stress best explained the observed behaviour. In the brain, model-derived RPEs were correlated with BOLD signals in striatum and ventromedial prefrontal cortex (vmPFC). Striatal RPE signals for win trials were stronger during stress compared with the control condition. Our study suggests that acute psychosocial stress could enhance reversal learning and RPE brain responses in healthy male participants and provides a starting point to explore these effects further in a more diverse population.

Habituation of the stress response multiplex to repeated cold pressor exposure

Humans show remarkable habituation to aversive events as reflected by changes of both subjective report and objective measures of stress. Although much experimental human research focuses on the effects of stress, relatively little is known about the cascade of physiological and neural responses that contribute to stress habituation. The cold pressor test (CPT) is a common method for inducing acute stress in human participants in the laboratory; however, there are gaps in our understanding of the global state changes resulting from this stress-induction technique and how these responses change over multiple exposures. Here, we measure the stress response to repeated CPT exposures using an extensive suite of physiologic measures and state-of-the-art analysis techniques. In two separate sessions on different days, participants underwent five 90 s CPT exposures of both feet and five warm water control exposures, while electrocardiography (ECG), impedance cardiography, continuous blood pressure, pupillometry, scalp electroencephalography (EEG), salivary cortisol and self-reported pain assessments were recorded. A diverse array of adaptive responses are reported that vary in their temporal dynamics within each exposure as well as habituation across repeated exposures. During cold-water exposure there was a cascade of changes across several cardiovascular measures (elevated heart rate (HR), cardiac output (CO) and Mean Arterial Pressure (MAP) and reduced left ventricular ejection time (LVET), stroke volume (SV) and high-frequency heart rate variability (HF)). Increased pupil dilation was observed, as was increased power in low-frequency bands (delta and theta) across frontal EEG electrode sites. Several cardiovascular measures also habituated over repeated cold-water exposures (HR, MAP, CO, SV, LVET) as did pupil dilation and alpha frequency activity across the scalp. Anticipation of cold water induced stress effects in the time-period immediately prior to exposure, indexed by increased pupil size and cortical disinhibition in the alpha and beta frequency bands across central scalp sites. These results provide comprehensive insight into the evolution of a diverse array of stress responses to an acute noxious stressor, and how these responses adaptively contribute to stress habituation.

Is a blunted cortisol response to stress a premorbid risk for insomnia?

STUDY OBJECTIVES

Vulnerability to stress-related sleep disturbances (sleep reactivity) is an established heritable risk factor for insomnia disorder with unclear biological underpinnings. Preliminary research points to a blunted cortisol response to stress as a biological predisposition to familial risk for insomnia, but the role of cortisol response in sleep reactivity is unknown. Therefore, the current studies examined whether sleep reactivity is associated with a blunted cortisol response to two laboratory stressors among participants without insomnia.

METHODS

Two community samples of adults with no lifetime history of insomnia completed the Trier Social Stress Test (N = 35) or the Cold Pressor Task (N = 34). Participants were grouped by insomnia-risk using sleep reactivity scores from the Ford Insomnia Response to Stress Test (FIRST). Physiological responses were measured via markers of the hypothalamic-pituitary-adrenal (HPA) axis (salivary cortisol) and autonomic nervous system (ANS; heart rate, mean arterial pressure, and salivary alpha amylase).

RESULTS

Participants with high insomnia-risk (FIRST score > 18) exhibited blunted cortisol responses to both stressors. There were no group differences in ANS responses across stressors.

CONCLUSIONS

Insomnia-risk as indicated by sleep reactivity is associated with blunted cortisol responses to psychosocial and physical laboratory stressors among premorbid adults without insomnia disorder. This study replicates previous research and supports a blunted cortisol response to stress as a biomarker for insomnia vulnerability that may be detected using the FIRST. Prospective research is needed to elucidate whether a blunted cortisol response to stress is one mechanism by which sleep reactive individuals may be at risk of developing insomnia.

The modulation of acute stress on model-free and model-based reinforcement learning in gambling disorder

BACKGROUND AND AIMS

Experiencing acute stress is common in behavioral addictions such as gambling disorder. Additionally, like most substance-induced addictions, aberrant decision-making wherein a reactive habit-induced response (conceptualized as a Model-free [MF] in reinforcement learning) suppresses a flexible goal-directed response (conceptualized as a Model-based [MB]) is also common in gambling disorder. In the current study we investigated the influence of acute stress on the balance between habitual response and the goal-directed system.

METHODS

A sample of N = 116 problem gamblers (PG) and healthy controls (HC) performed an acute stress task - the Socially Evaluated Cold pressure task (SECPT) - or a control task. Self-reported stress and salivary cortisol were collected as measures of acute stress. Following the SECPT, participants performed the Two-Step Markov Task to account for the relative contribution of MB and MF strategies. Additionally, verbal working memory and IQ measures were collected to account for their mediating effects on the orchestration between MB/MF and the impact of stress.

RESULTS

Both groups had comparable baseline and stress-induced cortisol response to the SECPT. Non-stressed PG displayed lower MB learning than HC. MANOVA and regression analyses showed a deleterious effect of stress-induced cortisol response on the orchestration between MB and MF learning in HC but not in PG. These effects remained when controlling for working memory and IQ.

DISCUSSION AND CONCLUSIONS

We found an abnormal pattern of modulation of stress on the orchestration between MB and MF learning among PG. Several interpretations and future research directions are discussed.

Sex and drug differences in stress, craving and cortisol response to the trier social stress task

RATIONALE

The hypothalamic-pituitary-adrenal (HPA) axis is a critical hormonal system involved in stress response. A number of studies have investigated the HPA axis response of drug-dependent individuals to stressors. Stress-induced vulnerabilities in the HPA axis may differ in response to chronic use of different substances, possibly leading to different target therapies. There has not been a direct comparison of HPA axis and subjective response between individuals with different types of substance use disorders following a laboratory stress intervention.

OBJECTIVES

The primary goal of the current study was to compare subjective and neuroendocrine response to the Trier Social Stress Task (TSST) across multiple primary types of substance use disorders and investigate differential response between males and females.

METHODS

Four hundred participants were drawn from seven studies completed at the Medical University of South Carolina between 2011 and 2021. The TSST was utilized across studies and subjective and neuroendocrine responses measured following completion. Generalized linear mixed effects models and area under the response curve analysis were used to compare both substance type and sex differences.

RESULTS

The study groups involving individuals with cocaine use disorder had blunted stress, craving and cortisol response following the TSST as compared to other substance use groups. Females in the cocaine groups reported higher subjective stress but lower cortisol than males.

CONCLUSIONS

The study results indicate that there may be differential effects of substances on the HPA axis, with cocaine using individuals exhibiting more blunting of the HPA axis response as compared to users of other substances.

Stress Effects on Pharyngeal Air Pressure and Upper Esophageal Sphincter Pressure During Phonation: The Influence of Vocal Tract Semi-Occlusion

OBJECTIVES/HYPOTHESIS

The objective of this study was to determine whether vocal tract semi-occlusion (SOVT) influenced stress effects on pharyngeal air pressure and upper esophageal sphincter (UES) pressure during phonation. Relationships between dysphonia and stress are well recognized but poorly understood. Stress effects act globally on the body, and may be observed beyond intrinsic laryngeal muscles to include pharyngeal muscles and the UES, which contribute to voice modulation. Phonation with SOVT may provide resistance to stress effects on the vocal tract. We hypothesized that stress effects on pharyngeal air pressure and UES pressure would be measurable with a high-resolution, 360° pressure catheter, and that stress effects would be impacted differently by occlusal and non-occlusal phonatory tasks.

METHODS

Ten healthy adults performed sustained vowel tasks (comfortable /a/, and loud /a/), and SOVT tasks (bilabial fricative and straw phonation). Each task was performed during a baseline condition, and during stress induced through a cold pressor task. Pharyngeal air pressure and UES pressure were measured via high-resolution manometry. Changes in pressure between baseline and stress were compared among phonatory tasks.

RESULTS

Stress-induced changes to UES pressure differed by phonatory task (P < 0.01). Stress increased UES pressures during vowels, but had no effect during bilabial fricative, and decreased UES pressures during straw phonation. Change in UES pressure with stress was greater for comfortable /a/ and loud /a/ than straw phonation (P = 0.048 and P = 0.019, respectively), and was not significantly different between comfortable /a/ or loud /a/ and bilabial fricative. Stress-induced changes in pharyngeal air pressure were not significantly different among tasks.

CONCLUSIONS

These findings help identify possible mechanisms underlying the relationship between stress and voice, and point to the utility of SOVT tasks for training vocal tract resistance to stress. This methodology provides a foundation for measuring changes to extra-laryngeal components of the vocal tract during phonation.

The influence of a glucose administration on stress responsivity and memory after a socially evaluated cold pressor test

The nutritional state of participants prior to stress induction via a laboratory stressor has been demonstrated to influence reactivity of the Hypothalamus-Pituitary-Adrenal axis. So far, either primarily psychosocial or primarily physiological stressors have been utilized investigating this effect. In the present study, we aimed to fill this gap in the existing literature by utilizing a stressor that combines both elements, namely the Socially Evaluated Cold Pressor Test. Furthermore, we investigated how glucose consumption and subsequent stress induction influence long-term memory retrieval as well as working memory. In a 2 × 2 design, half of the 72 participants (36 women, 36 men) participated in the laboratory stressor while the other half participated in a control condition after having fasted for at least six hours. Thirty minutes prior to stress or control treatment, fasted participants consumed either 75 g of glucose or stevia-sweetened water. Salivary cortisol levels, systolic and diastolic blood pressure, as well as affect did not significantly differ between participants consuming glucose or the placebo beverage. Acute stress impaired working memory but had no effect on long-term memory retrieval. Glucose consumption did not significantly influence memory. Our results suggest that the intensity of a stressor might be important when determining the effects of a glucose administration on stress reactivity. The nutritional state of participants taking part in studies investigating the effects of acute stress on memory might be less decisive than previously assumed.

Stress and Emotional Intelligence Shape Giving Behavior: Are There Different Effects of Social, Cognitive, and Emotional Stress?

Acute stress has been linked with prosocial behavior, yet it is entirely unexplored how different types of stressors may affect individuals’ willingness to help: This is particularly relevant while people is experiencing multiple sources of stress due to the COVID-19 pandemic. Here we explore whether different types of stress influence peoples’ giving behavior and the moderating role of emotional intelligence (EI). Undergraduate students were exposed to experimentally induced social, cognitive, or emotional stress and were asked to self-report on their willingness to help and donate to a charity raising funds for COVID-19 and flu patients. Results showed that when compared to a control condition, after being exposed to a social stress, participants were more willing to help a person in need. Our results also provide evidence that, after experiencing a social stress, participants with high (vs low) trait EI were more willing to help, and, as a result, donated more. Findings indicate that moderate levels of distress are associated with increased donations. Interestingly, when stress is not too threatening, high EI can regulate it and promote prosocial behaviors.

Volume and Connectivity Differences in Brain Networks Associated with Cognitive Constructs of Binge Eating

Bulimia nervosa (BN) and binge eating disorder (BED) are characterized by episodes of eating large amounts of food while experiencing a loss of control. Recent studies suggest that the underlying causes of BN/BED consist of a complex system of environmental cues, atypical processing of food stimuli, altered behavioral responding, and structural/functional brain differences compared with healthy controls (HC). In this narrative review, we provide an integrative account of the brain networks associated with the three cognitive constructs most integral to BN and BED, namely increased reward sensitivity, decreased cognitive control, and altered negative affect and stress responding. We show altered activity in BED/BN within several brain networks, specifically in the striatum, insula, prefrontal cortex (PFC) and orbitofrontal cortex (OFC), and cingulate gyrus. Numerous key nodes in these networks also differ in volume and connectivity compared with HC. We provide suggestions for how this integration may guide future research into these brain networks and cognitive constructs.

Help or punishment: acute stress moderates basal testosterone's association with prosocial behavior

The gonadal hormone testosterone is well-recognized to facilitate various behaviors for obtaining social status. A good reputation (i.e. competitive, generous, and trustworthy) is of crucial importance for acquiring high social status. It is unclear which type of reputation is preferred by individuals under the influence of testosterone. Given that the recent dual-hormone hypothesis emphasizes the modulating effect of stress (cortisol) on the influence of testosterone, it would be intriguing to test the role of stress-induced cortisol in testosterone-related reputation seeking. To test this hypothesis, we induced acute stress in 93 participants with cold pressor test (CPT) paradigm (vs. control condition), and then they were instructed to play a third-party intervention game, in which they made decisions as an uninvolved, outside the third party to punish a violator, help a victim, or do nothing. Salivary samples were obtained to assess participants' testosterone and cortisol levels. We split the testosterone concentration by median to low endogenous testosterone (LT) and high endogenous testosterone (HT). We found that HT individuals' prosocial preferences did not affect by acute stress. They were more likely to choose punishment than helping under both stress and control conditions. In contrast, individuals with low testosterone were more inclined to help than punish under control conditions. Interestingly, acute stress brought behavior patterns of LT individuals closer to those of HT individuals, that is, they reduced their helping behavior and increased the intensity of punishments. In this preliminary study on the preference inducement of testosterone for different types of prosocial behaviors, we discuss the physiological mechanism of the relationship between testosterone and reputation and the implications of these results for the dual-hormone hypothesis.HIGHLIGHTSLow testosterone (LT) individuals were more inclined to help than punish.High testosterone (HT) individuals were more inclined to punish than help.The HT individuals' preferences for prosocial types were not affected by acute stress.Acute stress brought the behavior patterns of LT individuals closer to those of HT individuals.

A brief video-coaching intervention buffers young children's vulnerability to the impact of caregivers’ depressive symptoms: Examination of differential susceptibility

Informed by the National Institute of Mental Health's Research Domain Criteria (RDoC) and developmental psychopathology frameworks, the current study used cortisol area under the curve with respect to ground (AUCg) as an index of differential sensitivity to context, which was expected to predispose young children with elevated vulnerability to adverse caregiving experiences and adaptive sensitivity to intervention effects. Particularly, the study aimed to determine whether improving caregivers’ responsive parenting through the Filming Interactions to Nurture Development (FIND) intervention would buffer children's biologically embedded vulnerability to caregivers’ depressive symptoms. Data were derived from a randomized controlled trial using pretest–posttest design with low-income families of children aged 4 to 36 months (N = 91). Young children's differential sensitivity was measured using cortisol AUCg during a structured stress paradigm. As hypothesized, children whose cortisol AUCg indicated greater sensitivity to social context exhibited more internalizing and externalizing behaviors in relation to caregivers’ elevated depressive symptoms. Critically, the intervention program was effective in attenuating psychopathology symptoms among the more biologically sensitive children. As proven by rigorous statistical tests, the findings of this study partially supported the differential susceptibility hypotheses, indicating both greater vulnerability to adverse conditions and responsiveness to intervention among children with high levels of cortisol AUCg.

Quantifying the subjective cost of self-control in humans

Since Odysseus committed to resisting the Sirens, mechanisms to limit self-control failure have been a central feature of human behavior. Psychologists have long argued that the use of self-control is an effortful process and, more recently, that its failure arises when the cognitive costs of self-control outweigh its perceived benefits. In a similar way, economists have argued that sophisticated choosers can adopt "precommitment strategies" that tie the hands of their future selves in order to reduce these costs. Yet, we still lack an empirical tool to quantify and demonstrate the cost of self-control. Here, we develop and validate an economic decision-making task to quantify the subjective cost of self-control by determining the monetary cost a person is willing to incur in order to eliminate the need for self-control. We find that humans will pay to avoid having to exert self-control in a way that scales with increasing levels of temptation and that these costs appear to be modulated both by motivational incentives and stress exposure. Our psychophysical approach allows us to index moment-to-moment self-control costs at the within-subject level, validating important theoretical work across multiple disciplines and opening avenues of self-control research in healthy and clinical populations.

Self-beneficial belief updating as a coping mechanism for stress-induced negative affect

Being confronted with social-evaluative stress elicits a physiological and a psychological stress response. This calls for regulatory processes to manage negative affect and maintain self-related optimistic beliefs. The aim of the current study was to investigate the affect-regulating potential of self-related updating of ability beliefs after exposure to social-evaluative stress, in comparison to non-social physical stress or no stress. We assessed self-related belief updating using trial-by-trial performance feedback and described the updating behavior in a mechanistic way using computational modeling. We found that social-evaluative stress was accompanied by an increase in cortisol and negative affect which was related to a positive shift in self-related belief updating. This self-beneficial belief updating, which was absent after physical stress or control, was associated with a better recovery from stress-induced negative affect. This indicates that enhanced integration of positive self-related feedback can act as a coping strategy to deal with social-evaluative stress.

Laboratory-induced stress and craving predict opioid use during follow-up among individuals with prescription opioid use disorder

BACKGROUND

Opioid use disorder (OUD) remains a public health crisis in the USA. Although stress and craving are common precipitants of substance use, no research to date has investigated the impact of laboratory-induced stress and craving on subsequent opioid use.

METHOD

Participants (N = 31) were individuals with prescription OUD who completed a human laboratory study followed by a one-month follow-up visit. Participants were randomly assigned to either a stress task (i.e., Trier Social Tress Task; TSST) or a no-stress condition, and then all participants completed an opioid cue paradigm. Measures of subjective (e.g., stress, craving), and neuroendocrine (e.g., cortisol, dehydroepiandrosterone) reactivity were assessed before and after each task. Survival and regression models tested the association between reactivity to the laboratory tasks and a) time to first opioid use and b) amount of opioid use during follow-up.

RESULTS

On average, participants first used opioids 3.65 (SD = 2.08) days following the study. Craving after the opioid cue paradigm (B = 0.44, Exp(B) = 1.55, 95 % CI [1.06, 2.28], p = .02) and after the TSST/no-stress condition plus opioid cue paradigm (B = 1.06, Exp(B) = 2.88, 95 % CI [1.70, 4.85], p < .001) predicted time to first use. Additionally, there was a significant interaction between randomization to the TSST, stress reactivity, and amount of opioids used.

CONCLUSIONS

Findings demonstrate that elevated cue-induced craving, either in the context of a stressor or not, is associated with shortened time to opioid use, whereas stress reactivity impacts the amount of opioids consumed. Preliminary findings add to the literature on stress, craving and opioid use and implicate treatment.

Short intense psychological stress induced by skydiving does not impair intestinal barrier function

Background and aim

Psychological stress has been shown to increase intestinal permeability and is associated with the development of gastrointestinal disorders. This study aimed to investigate skydiving as an alternative model to analyse the effect of acute psychological stress on intestinal barrier function.

Materials and methods

Twenty healthy subjects participated in a tandem skydive followed by a negative control visit, of which 19 (9 females and 10 males, 25.9 ± 3.7 years) were included in the study. Intestinal permeability was assessed by a multi-sugar urinary recovery test. Sucrose recovery and lactulose/rhamnose ratio in 0-5h urine indicated gastroduodenal and small intestinal permeability, respectively, and sucralose/erythritol ratio in 5-24h urine indicated colonic permeability. Blood samples were taken to assess markers associated with barrier function. This study has been registered at ClinicalTrials.gov (NCT03644979) on August 23, 2018.

Results

Skydiving resulted in a significant increase in salivary cortisol levels directly after skydiving compared to the control visit. Cortisol levels were still increased two hours after landing, while cortisol levels before skydiving were not significantly different from the baseline at the control visit. Skydiving did not induce a significant increase in gastroduodenal, small intestinal or colonic permeability. There was also no significant increase in plasma intestinal and liver fatty acid-binding proteins, suggesting no damage to the enterocytes.

Discussion

These results show that the acute intense psychological stress induced by skydiving does not affect intestinal permeability in healthy subjects. Future models aiming to investigate the effect of stress on human intestinal barrier function should consider a more sustained exposure to the psychological stressor.

Allostatic load: Developmental and conceptual considerations in a multi-system physiological indicator of chronic stress exposure

Developmental researchers studying how stress affects health have often focused on specific, individual, physiological parameters such as cortisol. Yet, recent theories of stress biology emphasize that the stress response is multi-faceted and engages distinct yet interconnected physiological systems, including metabolic, immune, and cardiovascular systems that respond to one another. Moreover, advocates of a systems approach also argue that the confluence of changes across several physiological systems presents a health risk, even when one indicator alone is not predictive of health outcomes. Allostatic load is one potential multi-system indicator of stress, capturing the cumulative, physiological burden of chronic stress exposure on the body. At the same time, studying allostatic load during early development raises several issues, including how allostatic load is operationalized, the clinical importance of commonly used biomarkers during distinct periods of development, and the fundamental role of timing. In this review paper, we discuss the potential of allostatic load in the context of studies of stress in developmental science, review developmental studies that have assessed allostatic load, and articulate critical conceptual questions regarding the study of allostatic load during the childhood years.

Pain and Stress Detection Using Wearable Sensors and Devices-A Review

Pain is a subjective feeling; it is a sensation that every human being must have experienced all their life. Yet, its mechanism and the way to immune to it is still a question to be answered. This review presents the mechanism and correlation of pain and stress, their assessment and detection approach with medical devices and wearable sensors. Various physiological signals (i.e., heart activity, brain activity, muscle activity, electrodermal activity, respiratory, blood volume pulse, skin temperature) and behavioral signals are organized for wearables sensors detection. By reviewing the wearable sensors used in the healthcare domain, we hope to find a way for wearable healthcare-monitoring system to be applied on pain and stress detection. Since pain leads to multiple consequences or symptoms such as muscle tension and depression that are stress related, there is a chance to find a new approach for chronic pain detection using daily life sensors or devices. Then by integrating modern computing techniques, there is a chance to handle pain and stress management issue.

Stress and information processing: acute psychosocial stress affects levels of mental abstraction

BACKGROUND

One mechanism by which acute psychosocial stress effects health-related cognitions and behaviors is through changes in the level of mental abstraction when processing information. However, it is unclear whether levels of mental abstraction would be higher or lower after an acute psychosocial stressor.

OBJECTIVES

This research examined acute psychosocial stress's impact on levels of mental abstraction.

DESIGN

Randomized between-subjects experimental design.

METHODS

A diverse sample of 164 undergraduate students aged 18-24 years old were randomly assigned to an acute psychosocial stressor or non-stressful control condition. Blood pressure (BP), heart rate (HR), and negative affect were monitored throughout the study and mental abstraction was measured at the end of each condition.

RESULTS

Mental abstraction was statistically significantly higher (i.e., more abstract) after the stress condition than after the control condition (p = 0.005, d = 0.44). This association was partially explained by negative affect (p = 0.017), but not BP or HR (ps > 0.60).

CONCLUSIONS

Acute psychosocial stress is associated with higher levels of mental abstraction after the stressor. These findings may have implications for stress-relevant interventions as accounting for the level of mental abstraction may enhance the efficacy of the intervention.

Decision Outcomes in Sport: Influence of Type and Level of Stress

In two experiments, the authors investigated the influence of stress type (i.e., low/no stress, mental, and physical), level (i.e., low, moderate, and high), and Type × Level interaction on intuitive decision frequency, decision quality, and decision speed. Participants were exposed to mental (i.e., color word task, mental arithmetic) and/or physical stress (i.e., running) and then required to make decisions regarding videotaped offensive situations in basketball. Intuitive decision frequency, decision quality, and decision speed were measured for each trial. Study 1 used a between-subjects design whereby 20 participants were randomly assigned to each of the five stress conditions. Results revealed that moderate stress was associated with faster decisions. Study 2 replicated the design and aim of Study 1 using a within-subject methodology (n = 42). Results suggested that moderate stress levels produced better, faster decisions. In conclusion, moderate levels of stress were associated with the most desirable decision outcomes.

Acute stress impairs reward learning in men

Acute stress is ubiquitous in everyday life, but the extent to which acute stress affects how people learn from the outcomes of their choices is still poorly understood. Here, we investigate how acute stress impacts reward and punishment learning in men using a reinforcement-learning task. Sixty-two male participants performed the task whilst under stress and control conditions. We observed that acute stress impaired participants' choice performance towards monetary gains, but not losses. To unravel the mechanism(s) underlying such impairment, we fitted a reinforcement-learning model to participants' trial-by-trial choices. Computational modeling indicated that under acute stress participants learned more slowly from positive prediction errors - when the outcomes were better than expected - consistent with stress-induced dopamine disruptions. Such mechanistic understanding of how acute stress impairs reward learning is particularly important given the pervasiveness of stress in our daily life and the impact that stress can have on our wellbeing and mental health.

PASS: A Multimodal Database of Physical Activity and Stress for Mobile Passive Body/ Brain-Computer Interface Research

With the burgeoning of wearable devices and passive body/brain-computer interfaces (B/BCIs), automated stress monitoring in everyday settings has gained significant attention recently, with applications ranging from serious games to clinical monitoring. With mobile users, however, challenges arise due to other overlapping (and potentially confounding) physiological responses (e.g., due to physical activity) that may mask the effects of stress, as well as movement artifacts that can be introduced in the measured signals. For example, the classical increase in heart rate can no longer be attributed solely to stress and could be caused by the activity itself. This makes the development of mobile passive B/BCIs challenging. In this paper, we introduce PASS, a multimodal database of Physical Activity and StresS collected from 48 participants. Participants performed tasks of varying stress levels at three different activity levels and provided quantitative ratings of their perceived stress and fatigue levels. To manipulate stress, two video games (i.e., a calm exploration game and a survival game) were used. Peripheral physical activity (electrocardiography, electrodermal activity, breathing, skin temperature) as well as cerebral activity (electroencephalography) were measured throughout the experiment. A complete description of the experimental protocol is provided and preliminary analyses are performed to investigate the physiological reactions to stress in the presence of physical activity. The PASS database, including raw data and subjective ratings has been made available to the research community at http://musaelab.ca/pass-database/. It is hoped that this database will help advance mobile passive B/BCIs for use in everyday settings.

The physiological responses to acute stress in alcohol-dependent patients: A systematic review

Dysregulation of physiological stress reactivity plays a key role in the development and relapse risk of alcohol dependence. This article reviews studies investigating physiological responses to experimentally induced acute stress in patients with alcohol dependence. A systematic search from electronic databases resulted in 3641 articles found and after screening 62 articles were included in our review. Studies are analyzed based on stress types (i.e., social stress tasks and nonsocial stress tasks) and physiological markers (i.e., the nervous system, the endocrine system, somatic responses and the immune system). In studies applying nonsocial stress tasks, alcohol-dependent patients were reported to show a blunted stress response compared with healthy controls in the majority of studies applying markers of adrenocorticotropic hormone and cortisol. In studies applying social stress tasks, findings are inconsistent, with less than half of the studies reporting altered physiological stress responses in patients. We discuss the impact of duration of abstinence, comorbidities, baseline physiological arousal and intervention on the discrepancy of study findings. Furthermore, we review evidence for an association between blunted physiological stress responses and the relapse risk among patients with alcohol dependence.

Moderated mediation for exercise maintenance in pain and posttraumatic stress disorder: A randomized trial

This study utilizes the Science of Behavior Change (SOBC) experimental medicine approach to evaluate the effects of a 3-month, individually prescribed progressive exercise training program on neurobiological, cognitive and motivational mechanisms by which our exercise-training paradigm may foster exercise maintenance. We will investigate hypothesized relationships between exercise-training associated augmentation of neuropeptide Y (NPY) system function and improvements in self-regulation and reward sensitivity-cognitive control and motivational processes posited to promote self-efficacy and intrinsic motivation, which have been shown to predict exercise maintenance. This study will recruit Veterans with chronic low back pain and posttraumatic stress disorder (PTSD). Procedures include a baseline, acute cardiopulmonary exercise challenge assessment that will inform the exercise prescription for a 12-week progressive exercise training program comprised of three 45-minute aerobic exercise sessions per week-all of which will be supervised by an exercise physiologist. Additionally, a week-7 and week-14 exercise challenge assessment will track changes in NPY system function and the variables of interest. We hypothesize that increases in the capacity to release NPY in response to acute exercise testing will be associated with improvements in self-regulation and reward sensitivity, which will in turn be associated with self-efficacy and intrinsic motivation to maintain regular exercise. Ninety participants will be randomized either to the "active exercise training condition" or to the "wait list symptom monitoring condition". The study aims to demonstrate the feasibility of procedures and elucidate mechanisms relevant to developing individually prescribed, motivationally based exercise regimens to reduce negative consequences of PTSD and low back pain over the long-term. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Stress & executive functioning: A review considering moderating factors

A multitude of studies investigating the effects of stress on cognition has produced an inconsistent picture on whether - and under which conditions - stress has advantageous or disadvantageous effects on executive functions (EF). This review provides a short introduction to the concept of stress and its neurobiology, before discussing the need to consider moderating factors in the association between stress and EF. Three core domains are described and discussed in relation to the interplay between stress and cognition: the influence of different paradigms on physiological stress reactivity, individual differences in demographic and biological factors, and task-related features of cognitive tasks. Although some moderating variables such as the endocrine stress response have frequently been considered in single studies, no attempt of a holistic overview has been made so far. Therefore, we propose a more nuanced and systematic framework to study the effects of stress on executive functioning, comprising a holistic overview from the induction of stress, via biological mechanisms and interactions with individual differences, to the influence of stress on cognitive performance.

Trait impulsivity and acute stress interact to influence choice and decision speed during multi-stage decision-making

Impulsivity and stress exposure are two factors that are associated with changes in reward-related behavior in ways that are relevant to both healthy and maladaptive decision-making. Nonetheless, little empirical work has examined the possible independent and joint effects of these factors upon reward learning. Here, we sought to examine how trait impulsivity and acute stress exposure affect participants' choice behavior and decision speed in a two-stage sequential reinforcement-learning task. We found that more impulsive participants were more likely to repeat second-stage choices after previous reward, irrespective of stress condition. Exposure to stress, on the other hand, was associated with an increased tendency to repeat second-stage choices independent of whether these choices previously led to a reward, and this tendency was exacerbated in more impulsive individuals. Such interaction effects between stress and impulsivity were also found on decision speed. Stress and impulsivity levels interacted to drive faster choices overall (again irrespective of reward) at both task stages, while reward received on the previous trial slowed subsequent first-stage choices, particularly among impulsive individuals under stress. Collectively, our results reveal novel, largely interactive effects of trait impulsivity and stress exposure and suggest that stress may reveal individual differences in decision-making tied to impulsivity that are not readily apparent in the absence of stress.

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.

Good vibrations: An observational study of real-life stress induced by a stage performance

Stressors induce physiological changes in the brain and periphery that support adaptive defensive responses. The consequences of psychological stress on cognitive functioning are often measured in laboratory settings using experimentally induced stress that leads to mainly negative subjective feelings. There is a need for verification of these studies using real-life stressors that may potentially induce both positive and negative subjective feelings. In an observational study, we investigated real-life stress induced by voluntary stage performance at a large-scale music festival, including 126 participants (60 female, age range = 16-57 years). Our primary measurements involved salivary cortisol, heart rate, blood pressure, and positive and negative affect. In addition, participants completed a 2-back working memory task and a speeded decision-making task. We found that stage performance significantly increased salivary cortisol - with a particularly low number of cortisol non-responders - and heart rate, even when controlling for potential confounding factors, such as sleep, movement, and alcohol use. Interestingly, stage performance significantly decreased negative affect while increasing positive affect. This positively experienced stressor ("eustressor") was related to impaired working memory performance: the stronger the increases in cortisol, the slower participants responded to targets. Decision-making, however, was not affected. In conclusion, we show how stressful experiences in real-life can lead to positive affect, but still have a similar negative impact on cognitive functioning. We suggest that future research should focus more on the consequences of real-life stressors, and the consequences of eustress, in order to extend our understanding of the concept of psychological stress.

Investigation of cortisol dynamics in human sweat using a graphene-based wireless mHealth system

Understanding and assessing endocrine response to stress is crucial to human performance analysis, stress-related disorder diagnosis, and mental health monitoring. Current approaches for stress monitoring are largely based on questionnaires, which could be very subjective. To avoid stress-inducing blood sampling and to realize continuous, non-invasive, and real-time stress analysis at the molecular levels, we investigate the dynamics of a stress hormone, cortisol, in human sweat using an integrated wireless sensing device. Highly sensitive, selective, and efficient cortisol sensing is enabled by a flexible sensor array that exploits the exceptional performance of laser-induced graphene for electrochemical sensing. Herein, we report the first cortisol diurnal cycle and the dynamic stress response profile constructed from human sweat. Our pilot study demonstrates a strong empirical correlation between serum and sweat cortisol, revealing exciting opportunities offered by sweat analysis toward non-invasive dynamic stress monitoring via wearable and portable sensing platforms.

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.

Trauma- and Stress-Induced Craving for Alcohol in Individuals Without PTSD

AIMS

The main objective of the study was to compare the differences in craving following trauma and stress scripts in individuals with alcohol dependence (AD) who have experienced trauma but did not meet criteria for post-traumatic stress disorder (PTSD).

METHODS

Twenty-eight men and women who participated in a treatment trial were included in this study before starting treatment. All had to meet criteria for AD and had experienced trauma at some point of their lives but were never diagnosed with PTSD. All participants had one laboratory session and were exposed to stress, trauma and neutral scripts randomly assigned. Main measures of craving, anxiety and mood were administered before, during and after each script.

RESULTS

Stress and trauma scripts induced significantly more craving and anxiety than the neutral scripts. Interestingly, stress scripts produced stronger craving and anxiety than the trauma scripts but only with some measures. Stress and trauma scripts produced significantly more fear, anger and sadness and significantly lower ratings of joy and relaxation than the neutral script. Again, there were no differences between stress and trauma scripts for any of the emotional subscales.

CONCLUSIONS

Trauma scripts did not result in stronger craving than stress scripts. These findings suggest that trauma in the absence of PTSD diagnosis does not lead to stronger craving for alcohol.

Neural correlates of enhanced response inhibition in the aftermath of stress

Life stress has been shown to impact cognitive functions, including inhibitory control. However, the immediate effects of acute stress on inhibitory control and the underlying neural mechanisms remain unclear. In a behavioral pilot study (N = 30) and a within-subject functional magnetic resonance imaging study (N = 30), we examined how acute stress induced by Trier Social Stress Test influenced inhibitory control in a stop signal task. Behavioral results across two studies showed that stress consistently improved inhibitory control. Shorter stop signal reaction time (SSRT) in stress as compared with control condition was associated with stronger connectivity between the superior/middle frontal gyrus (SFG/MFG) and striatum. Dynamic causal modeling revealed distinct best models under stress and control condition, with an enhanced interaction between the SFG/MFG and the striatum after stress exposure. This research identified the SFG/MFG-striatum network as a key circuit underlying acute stress-elicited enhancement of inhibitory control in a stop signal task.

Hippocampal connectivity in the aftermath of acute social stress

The hippocampus is a core brain region that responds to stress. Previous studies have found a dysconnectivity between hippocampus and other brain regions under acute and chronic stress. However, whether and how acute social stress influences the directed connectivity patterns from and to the hippocampus remains unclear. In this study, using a within-subject design and Granger causal analysis (GCA), we investigated the alterations of resting state effective connectivity from and to hippocampal subregions after an acute social stressor (the Trier Social Stress Test). Participants were engaged in stress and control conditions spaced approximately one month apart. Our findings showed that stress altered the information flows in the thalamus-hippocampus-insula/midbrain circuit. The changes in this circuit could also predict with high accuracy the stress and control conditions at the subject level. These hippocampus-related brain networks have been documented to be involved in emotional information processing and storage, as well as habitual responses. We speculate that alterations of the effective connectivity between these brain regions may be associated with the registering and encoding of threatening stimuli under stress. Our investigation of hippocampal functional connectivity at a subregional level may help elucidate the functional neurobiology of stress-related psychiatric disorders.

Can verbal suggestions strengthen the effects of a relaxation intervention?

Short stress management interventions such as relaxation therapy have demonstrated preliminary effectiveness in reducing stress-related problems. A promising tool to strengthen the effectiveness of relaxation-based interventions is the use of verbal suggestions, as previous research provided evidence that verbal suggestions can induce positive outcome expectancies, facilitate adaptive responses to stress and improve health outcomes. The present experimental proof-of-concept study aimed to investigate the effects of a brief relaxation intervention and specifically the role of verbal suggestions on stress-related outcomes assessed by self-report questionnaires and psychophysiological data. 120 participants (mean age = 22.1 years) were randomized to one of four intervention conditions: a brief relaxation intervention plus verbal suggestions condition, a brief relaxation intervention only condition, a verbal suggestions only condition, and a control condition. Afterwards, participants were subjected to a psychosocial stress challenge to assess reactivity to a stressful event. Immediately after both relaxation interventions (with and without verbal suggestions), lower self-reported state anxiety was found compared to the control condition, but no differences were observed in response to the stressor. The verbal suggestions only condition did not impact state anxiety. No significant effects were found for verbal suggestion interventions on cortisol, alpha amylase, heart rate and skin conductance. This is the first study investigating the role of verbal suggestions in the effectiveness of a brief relaxation intervention. Although this experimental proof-of-concept study provides support for the effectiveness of a brief relaxation intervention in lowering state anxiety directly after the intervention, the effects did not impact the response to a subsequent stressor and we did not observe any evidence for the add-on effectiveness of verbal suggestions. The effectiveness of brief relaxation interventions on stress responses should be investigated further in future research by incorporating interventions that are tailored to the specific stress challenge and various types of verbal suggestions.

Preliminary examination of the orexin system on relapse-related factors in cocaine use disorder

RATIONALE

Current evidence and literature reviews provide a strong justification for examining the orexin receptor (OXR) system as a therapeutic target in substance use disorders, including cocaine and other psychostimulants.

OBJECTIVES

In this preliminary, proof-of-concept examination of orexin modulation in humans with cocaine use disorder, we measured changes in domains tied to relapse: stress, sleep, cue reactivity, and inhibitory control. Additionally, mood symptoms (anxiety, depression), medication compliance, and side effects were assessed.

METHODS

Twenty non-treatment seeking subjects with cocaine use disorder (CUD) received either the OX₁R / OX₂R antagonist suvorexant PO or placebo at 10 PM daily for two weeks (10 mg week 1, 20 mg week 2). Using psychometrics, smart-watch actigraphy, a cold-pressor stress challenge, and eye-tracking technology, the following domains were examined: sleep, stress/anxiety, cue-reactivity (attentional bias, craving), and inhibitory control. Psychometric data were collected every M/W/F (7 time points). Laboratory data were collected weekly (3 time points).

RESULTS

Bayesian and frequentist generalized linear models were employed in parallel to examine the effects of suvorexant compared to placebo, with a Bayesian posterior probability threshold >80% as evidence of a signal for suvorexant. Notable results favoring suvorexant over placebo included fewer total anti-saccade errors, improved sleep actigraphy (sleep/awake periods), pre/post cold-pressor change in heart rate and salivary cortisol (all posterior probabilities >94%), and craving (posterior probability >87%).

CONCLUSIONS

Initial but restricted evidence is provided supporting the orexin system as a modulator of relapse-related processes in cocaine use disorder. Baseline differences in the main outcome variables were not experimentally controlled and differences in craving were observed at baseline. This, in combination with a limited sample size, constrain the nature of the project. The results may serve to inform more comprehensive future research.

Acute stress improves long-term reward maximization in decision-making under uncertainty

Acute stress influences reward-seeking tendencies and risky decision-making. However, it is unclear how acute stress influences decision-making in situations in which individuals must learn to either maximize long-term or immediate rewards from experience. Consequently, this study sought to investigate whether acute stress enhances salience of small, immediate or large, delayed rewards on decision-making under uncertainty. The Socially Evaluated Cold Pressor Task (SECPT) was used to induce acute stress. Participants in Experiment 1 (N = 50) were exposed to either the SECPT or a warm-water control condition and then completed a decision-making task in which participants needed to learn to forego immediate rewards in favor of larger delayed rewards. The results demonstrated that acute stress enhanced decisions that maximized long-term, large rewards over immediate, small rewards. Experiment 2 (N = 50) included an assessment of salivary cortisol. Results replicated the behavioral findings in Experiment 1 and demonstrated that the acute stress manipulation increased salivary cortisol, thus providing a potential physiological mechanism for these results. This work suggests that moderate acute stress can improve decision-making under uncertainty that depends on learning to maximize long-term rewards from experience.

Delayed effects of psychosocial stress on risk taking

Several studies found that acute stress leads to increased risk taking in humans. However, this effect appears to be time-dependent because the few studies that examined delayed (>40 min after stress onset) stress effects show in fact a decrease in risk taking. In 32 young healthy women, we intra-individually examined whether psychosocial stress decreases risk taking 80 min after stress induction. All participants performed the Balloon Analog Risk Task (BART) twice: once after exposure to the Trier social stress test (TSST) and once after a control condition Placebo-TSST (P-TSST). The experimental order was randomized across participants. The psychophysiological stress response increased after the TSST compared to the P-TSST, indicated by elevated cortisol concentrations, elevated alpha-amylase activity, and elevated blood pressure. We found a significant interaction of stress condition and experimental order. Compared to the control condition psychosocial stress decreased risk taking in novel decision situations but not when participants were already familiar with the BART from the prior condition. Delayed effects of psychosocial stress lead to a decrease in risk taking in unfamiliar but not familiar conditions 80 min after stress exposure. Lay summary It has been suggested that stress exerts delayed effects on risk taking propensity. We found that individuals who are exposed to psychosocial stress take less risk when confronted with novel decisions even 80 min after the stressor compared to individuals who are not stressed.

Post-Mortem Immunohistochemical Evidence of β2-Adrenergic Receptor Expression in the Adrenal Gland

The evidence from post-mortem biochemical studies conducted on cortisol and catecholamines suggest that analysis of the adrenal gland could provide useful information about its role in human pathophysiology and the stress response. Authors designed an immunohistochemical study on the expression of the adrenal β2-adrenergic receptor (β2-AR), a receptor with high-affinity for catecholamines, with the aim to show which zones it is expressed in and how its expression differs in relation to the cause of death. The immunohistochemical study was performed on adrenal glands obtained from 48 forensic autopsies of subjects that died as a result of different pathogenic mechanisms using a mouse monoclonal β2-AR antibody. The results show that immunoreactivity for β2-AR was observed in all adrenal zones. Furthermore, immunoreactivity for β2-AR has shown variation in the localization and intensity of different patterns in relation to the original cause of death. To the best of our knowledge, this is the first study that demonstrates β2-AR expression in the human cortex and provides suggestions on the possible involvement of β2-AR in human cortex hormonal stimulation. In conclusion, the authors provide a possible explanation for the observed differences in expression in relation to the cause of death.

Sex Differences in the Association between Heavy Drinking and Behavioral Distress Tolerance and Emotional Reactivity Among Non-Depressed College Students

Background

Heavy episodic drinking (HED) is a common behavior among college students that is associated with severe negative consequences. Negative reinforcement processes have been applied to elucidate mechanisms underlying relationships between consumption of alcohol and the desire to alleviate negative feelings. Distress tolerance (DT) and emotional reactivity are two mechanisms that are consistent with the self-medication model that may contribute to HED. The current study investigated relationships between DT, emotional reactivity, defined as frustration reactivity and irritability reactivity, and HED in a non-depressed college population. Given differential patterns of consumption and motivation for drinking between males and females, sex differences were also examined.

Short Summary

The study examined two constructs consistent with negative reinforcement processes, behavioral distress tolerance (DT) and emotional reactivity (frustration reactivity and irritability reactivity), to explain heavy episodic drinking (HED) among non-depressed college students. Behavioral DT and frustration reactivity independently predicted HED. Higher HED was associated with higher frustration reactivity and lower behavioral DT in women, but nor in men.

Methods

One-hundred-ten college students without depressive symptoms completed alcohol use measures and the Paced Auditory Serial Attention Task (PASAT-C) to assess behavioral DT and emotional reactivity.

Results

DT and frustration reactivity independently predicted HED. The association between DT and HED was moderated by sex such that higher levels of DT predicted higher HED among females, but not among males. Higher frustration reactivity scores were associated with a greater number of HED.

Conclusions

Results provide supporting evidence that DT and emotional reactivity are distinct factors, and that they predict HED independently. Results underscore the importance of examining sex differences when evaluating the association between HED and negative reinforcement processes in this population.

Activación emocional en sujetos humanos: procedimientos para la inducción experimental de estrés

Resumen El estudio de los efectos del estrés sobre la cognición y el comportamiento es un área de especial interés y desarrollo científico, tanto para la Psicología como para las Neurociencias. La inducción de estrés constituye un elemento fundamental en estos estudios, pues permite la manipulación de esta forma de activación emocional, como variable independiente, para observar su efecto sobre la conducta; no obstante, esta inducción debe ser suficiente para generar incrementos significativos en los niveles de cortisol y cumplir los estándares éticos establecidos para la experimentación con humanos. El presente artículo tiene como propósito aportar una revisión general sobre la activación emocional, para profundizar en el conocimiento acerca de los procedimientos utilizados en la inducción experimental de estrés en sujetos humanos. Se concluye que se requiere el diseño de protocolos más eficaces, para lo cual, el uso de las simulaciones y otras herramientas tecnológicas puede ser de gran utilidad.

Past-year relational victimization is associated with a blunted neural response to rewards in emerging adults

Anhedonia is associated with multiple forms of psychopathology, yet relatively, little is known about how anhedonia develops. Emerging evidence suggests that anhedonia is the result of interactions between life stress and the brain's reward systems, and that social stress, in particular, may drive these processes. One potent form of social stress is peer victimization, but very little research has focused on peer victimization beyond adolescence, and even less has examined the associations between peer victimization and neural response to rewards. The present study sought to identify associations between past-year history of peer victimization and neural response to rewards in emerging adults (N = 61). Relational and physical forms of victimization were assessed separately since these distinct types of social stress have different trajectories across development and different associations with psychopathology. Reward sensitivity was indexed with the event-related potential component known as the reward positivity, which was elicited using a forced-choice monetary reward guessing task. Results demonstrated that past-year relational, but not physical, victimization was associated with a blunted neural response to rewards. These findings provide insight into one potential mechanism in the etiology of anhedonia, which may, in turn, help us to better identify pathways to multiple psychopathologies.

Neutral is negative enough-Peer victimization influences cardiac, facial-muscular and experiential reactions to both negative evaluative and neutral social stimuli

Physiological stress responses vary as a function of adverse childhood experiences. However, previous studies concentrate on familial sources of childhood adversity. Potential long-term effects of peer victimization on physiology and affective responses are less known. This study examined cardiac, facial-muscular, and experiential responses to social evaluative stimuli in ninety-four healthy subjects with various degrees of experienced peer victimization. In a social conditioning task, peer victimization was associated with similarly attenuated cardiac and facial-muscular responses to negative and neutral stimuli, while differentiated physiological responses to negative and neutral stimuli were found in subjects without peer victimization. Overall, increased ratings of arousal, valence and disapproval for negative compared to neutral stimuli were found. Contrary to the physiological response, peer victimization was associated with more negative ratings of negative stimuli one month after acquisition. The results suggest that the physiological and experiential reactivity towards both negative and neutral social stimuli is affected by the experience of peer victimization. Peer victimization causes generalized autonomic dysregulation and memory recall biases during social learning impeding adequate response preparation to social stressors.

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

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

Gender, stressful life events and interactions with sleep: a systematic review of determinants of adiposity in young people

OBJECTIVES

Overweight and obesity among young people are high and rising. Social stressors and sleep are independently associated with obesity, but are rarely studied together or examined for gender-specific effects. The literature regarding adolescent populations is especially lacking. This review assesses whether experiencing stressful life events results in greater adiposity in young women and young men compared with those who do not experience stressful life events, and whether the relationship is modified by sleep problems.

DESIGN

We systematically searched six bibliometric databases (Web of Science, Embase Ovid, PsycINFO, CINHAL, PubMed, ProQuest Dissertations) supplemented by hand searches. Longitudinal prospective studies or reviews were eligible for inclusion when they examined gender-specific changes in adiposity in young adults (age 13-18 years) as a function of stressful life event alone or in combination with sleep problems.

RESULTS

We found one study eligible for inclusion reporting mixed impact of stressful life events on body mass index (BMI) between genders. The study assessed specific life events and showed significantly lower BMI at follow-up among young men who experienced a residence change, but significantly higher BMI among young women who experienced setting up a family and who reported internal locus of control.

CONCLUSIONS

Despite ample research on social stressors or sleep problems and weight, we still know little about the role of stressful life events, or combined effects with sleep, on obesity risk in adolescents from a gender perspective. Existing evidence suggests specific life events affect weight differently between the genders. Robust, high-quality longitudinal studies to decipher this dual burden on obesity during adolescence should be prioritised, as firm conclusions remain elusive.

Glucocorticoid and inflammatory reactivity to a repeated physiological stressor in insomnia disorder

Despite known associations of insomnia disorder with alterations in cytokine and glucocorticoid (GC) production, neither the sensitivity of immune cells to a GC signal nor the reactivity of the hypothalamus-pituitary-adrenal (HPA) axis and inflammatory system to stress, or adaptation of these systems to repeated stress have been assessed in patients with insomnia. To investigate potential dysregulation in stress reactivity and adaptation to repeated exposure, a physiological stressor (the cold pressor test; CPT) was repeatedly administered to N = 20 participants with insomnia disorder (based on DSM-V, 18 females, age 30 ± 2.5 years) and N = 20 sex-matched healthy controls following an at-home actigraphy and in-laboratory PSG. HPA and inflammatory markers (serum cortisol, plasma interleukin [IL]-6) were measured at baseline/resting levels and following each of the three CPTs. In addition, sensitivity of monocytes to the synthetic GC dexamethasone was assessed in-vitro at baseline levels in order to examine the cortisol-IL-6 interplay at the cell level. Compared to healthy controls, individuals with insomnia disorder exhibited shorter sleep duration as assessed by actigraphy and PSG (p ≤ 0.05). HPA, but not inflammatory reactivity to the repeated CPT challenge was greater in insomnia disorder (p ≤ 0.05 for group effect), due to greater cortisol responses to the initial CPT (p ≤ 0.05). There were no between-group differences in the ability of the HPA to adapt to stress repetition nor in basal/resting levels of cortisol, IL-6, and GC sensitivity. These findings suggest that insomnia disorder potentiates HPA axis reactivity to initial/novel stressors, which may constitute a pathway underlying adverse health consequences in the long term.

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Insomnia disorder potentiates HPA, but not inflammatory reactivity to a novel stressor.

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The ability of the HPA axis to adapt to the repeated exposure to the same stressor is unchanged in insomnia.

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Basal/resting levels of cortisol, IL-6, and their interplay at cell level (i.e., GC sensitivity of monocytes) are unchanged in insomnia.