Human hypothalamus-pituitary-adrenal axis responses to acute psychosocial stress in laboratory settings

Brief Report: An Examination of Curvilinear Relations Between Perceived Mother-Child Closeness and Maternal Hair Cortisol

Interpersonal closeness has important health benefits; however, recent work suggests that in certain contexts, closeness can come at a cost. In the current study, curvilinear relations between mother-child closeness and health (e.g., depressive and anxiety symptoms and hair cortisol concentrations [HCC]) were tested. Our sample consisted of 117 mother (Mage = 36.86) and child (Mage = 73.07 months, 50.86% male) dyads. A quadratic relationship between maternal perceived closeness with their child and self-reported depressive and anxiety symptoms, along with overall hair cortisol output, was hypothesized. Path analysis suggested that the quadratic term was predictive of maternal cortisol (β = 0.28, p = 0.001) and depression (β = 0.23, p = 0.014), such that both high and low perceived closeness predict greater maternal depressive symptoms and HCCs as compared to moderate levels of closeness. Results are discussed in terms of parenting support and burnout.

The Physiological and Clinical-Behavioral Effects of Heart Rate Variability Biofeedback in Adolescents with Autism: A Pilot Randomized Controlled Trial

Adolescents with autism present lower levels of cardiac vagal modulation. It was hypothesized that Heart Rate Variability Biofeedback (HRVB) increases cardiac vagal modulation in adolescents with autism, resulting in positive effects on physiological and psychosocial parameters. It was also hypothesized that home-based HRVB training is feasible. In a single-blind, randomized sham-controlled pilot trial, adolescents with autism performed supervised HRVB (n = 24) or sham training (n = 20). Subsequently, half of the adolescents received HRVB training at home, whereas the other subset did not practice. Physiological, cortisol and behavioral data were collected during stress-provoking assessments before and after each training period. Supervised HRVB resulted in a late increase in cardiac vagal modulation in adolescents with autism. Heart rate increased and cortisol decreased significantly immediately after supervised HRVB, but none of these effects remained after follow-up. Following supervised HRVB, no significant change in psychosocial functioning was found. Home-based HRVB was feasible, adolescents reported lower symptoms of stress, but a significant decrease in compliance rate was found. HRVB is feasible and effective in adolescents with autism given the late-emerging increases in cardiac vagal modulation and decrease in stress symptoms. Replicating this study with a larger sample and further exploration of the working mechanisms of HRVB are recommended. ClinicalTrials.gov , NCT04628715.

Human physiological responses to different types of human-dog interactions: A randomised crossover study

Previous studies of human-dog interventions vary in terms of type of interaction, which is rarely quantified, leading to contradictory findings and limited comparability. To uncover the influence of different types of interactions, the present study investigated if it was possible to detect differences in immediate physiological measurements of healthy humans during different standardised types of interaction with a dog. Thirty-three healthy participants (women = 25, men = 8, >18 years) were exposed to four different test situations with standardised types of interaction intensity with a dog in random order: no dog present (CONTROL), looking at a dog (VISUAL), petting a dog (TACTILE) or performing tricks with a dog (ACTIVE). Each test situation lasted 10 min with a 30-min break between each. Heart rate (HR), heart rate variability (HRV) and skin conductance (tonic level (SCL) and peak counts (SCR)) were continuously recorded. Blood pressure (BP) and salivary cortisol (s-cortisol) were measured before and after each test situation. Linear Mixed Models were applied. HR, HRV, BP, SCL and SCR increased with increased interaction with the dog (for all: p < 0.001). HRV increased with decreased HR (p = 0.002), increased SCL (p = 0.027), and SCR (p < 0.001) depending on the type of interaction. Generally, s-cortisol increased with increased HR (p = 0.042), SCL increased with increased SCR (p < 0.001), and SCR increased with increased HRV (p = 0.013), depending on type of interaction. The physiological measurements HR, HRV, BP, SCL and SCR are influenced by different types of dog interaction, and thus it is important to quantify and report the type of interaction in human-dog interaction studies. (ClinicalTrials.gov ID:NCT04696419).

Comparison of human hair cortisol concentration stability for 1-year and 2-year test-retest intervals

Human hair cortisol concentration (HCC) has previously been found to be highly stable for a 1-year interval (r = 0.73) in terms of a product-moment correlation. The present study aimed to replicate this finding and compare HCC stability regarding 1-year and 2-year test-retest intervals. Female university students (N = 39) provided hair strands twice (t1 and t2) at intervals of 1 (n = 21) or 2 years (n = 18). Multiple regression analysis predicting HCC at t2 revealed a significant interaction term (HCC at t1 × time interval condition). It was determined that HCCs were substantially related for the 1-year interval but unrelated for the 2-year interval. The findings were not attributable to potential influences, such as hair treatment. The product-moment correlation showed nearly identical consistency with previous research regarding the 1-year test-retest interval. There was no significant product-moment correlation for the 2-year interval. Overall, these findings indicate that within a temporal framework of 1 year, HCCs may be stable predictors in correlational studies where the focus is on the rank orders of measured values.

Delirium in Neurocritical Care: Uncovering Undisclosed Psychotropic Substance and Medication Use and Stress Exposure by Hair Analysis

OBJECTIVE

In intensive care, delirium is frequent, prolongs the stay, increases health care costs, and worsens patient outcome. Several substances and medications as well as stress can impact the risk of delirium; however, assessment of previous exposure to psychotropic agents and stress by self-reports or third-party information is not always reliable. Hair analysis can be used to objectively assess medication and substance use (including chronic alcohol consumption), and allows for the determination of stress-related long-term changes in steroid hormones and endocannabinoids.

METHODS

Consecutive adult patients with acute brain injury admitted to the neurocritical care unit were included. Delirium was diagnosed using the Confusion Assessment Method for the Intensive Care Unit. Liquid chromatography coupled with tandem mass spectrometry was used to investigate psychoactive substances and medications, ethyl glucuronide, steroid hormones, and endocannabinoids in hair samples. Univariable and multivariable analyses were used to reveal any associations with the occurrence of delirium.

RESULTS

Of 50 consecutive patients, 21 (42%) were diagnosed with delirium. Detection of antipsychotics or antidepressants in hair was more frequent in patients with delirium (antidepressants: 43% vs. 14%, p = 0.040; antipsychotics: 29% vs. 0%, p = 0.021). These patients also displayed higher ethyl glucuronide levels (p = 0.049). Anandamide (AEA) concentrations were higher in patients with delirium (p = 0.005), whereas oleoylethanolamide (p = 0.045) and palmitoylethanolamide (PEA) (p = 0.017) concentrations were lower in patients with delirium. Backward stepwise logistic regression analysis revealed antidepressants and AEA/PEA to be independent relevant predictors of delirium.

CONCLUSIONS

Hair analysis provides crucial and otherwise unattainable information regarding chronic stress and the use of psychotropic substances and medications. Undisclosed antidepressant/antipsychotic use or intense chronic alcohol consumption is susceptible to treatment (continuation of medication or provision of low-dose benzodiazepines in case of alcohol). Chronic stress can be evaluated using stress markers and endocannabinoids in hair, potentially allowing for personalized delirium risk stratification and preventive measures.

Maltreatment type differences in cortisol stress response trajectories across adolescence

This study examined cortisol stress response trajectories across adolescence in 454 maltreated and comparison youth recruited from Los Angeles County between 2002 and 2005 (66.7% maltreated; 46.7% girls; 39.0% Latino; 37.7% Black; 12.3% Mixed or Biracial; 11.0% White; Mage = 10.9 years, SD = 1.2). Adolescents' peak activation and cortisol reactivity and recovery slopes following the Trier Social Stress Test for Children were calculated at four waves, then used to model peak activation and cortisol reactivity and recovery trajectories arrayed by age. Maltreated youth had blunted cortisol reactivity at age 9 relative to comparison youth (b = -.19, p = .02). Sexually and physically abused youth showed blunted cortisol reactivity and recovery trajectories relative to emotionally abused and neglected youth.

Relationship between heart rate variability and differential patterns of cortisol response to acute stressors in mid-life adults: A data-driven investigation

Cortisol and heart rate variability (HRV) are well-established biomarkers of the human stress response system. While a relationship between cortisol and HRV is assumed, few studies have found evidence of their correlation within single study designs. One complication for isolating such a relationship may lie in individual variability in the cortisol response to stress such that atypical cortisol responding (i.e., elevated or blunted) occurs. To-date, studies on the cortisol response have employed traditional mean-difference-based approaches to examine average magnitude change in cortisol over time. Alternatively, data-driven trajectory modelling, such as latent growth mixture modelling, may be advantageous for quantifying cortisol based on patterns of response over time. Latent growth mixture modelling was used in N = 386 adults to identify subgroups based on trajectories of cortisol responses to stress. The relationship between cortisol and HRV was tested within subgroups. Results revealed a 'prototypical' subgroup characterised by expected rise and fall in cortisol response to stress (n = 309), a 'decline' subgroup (n = 28) that declined in cortisol after stress, and a 'rise' subgroup (n = 49) that increased in cortisol after stress. Within the 'prototypical' subgroup, greater HRV during stress was associated with decline in cortisol after stress from its maximum (r (306) = 0.19, p < 0.001). This relationship failed to emerge in the 'decline' and 'rise' subgroups (p > 0.271). Results document different patterns of cortisol response to stress; among those who exhibit a 'prototypical' response, changes in HRV during stress are related to changes in cortisol after stress.

Ramifications of Precarious Employment for Health and Health Inequity: Emerging Trends from the Americas

Precarious employment (PE), which encompasses the power relations between workers and employers, is a well-established social determinant of health that has strong ramifications for health and health inequity. In this review, we discuss advances in the measurement of this multidimensional construct and provide recommendations for overcoming continued measurement challenges. We then evaluate recent evidence of the negative health impacts of PE, with a focus on the burgeoning studies from North America and South America. We also establish the role of PE in maintaining and perpetuating health inequities and review potential policy solutions to help alleviate its health burden. Last, we discuss future research directions with a call for a better understanding of the heterogeneity within PE and for research that focuses both on upstream drivers that shape PE and its impacts on health, as well as on the mechanisms by which PE causes poor health.

Comprehensive assessment of memory function, inhibitory control, neural activity, and cortisol levels in late pregnancy

A considerable proportion of women subjectively perceive a detriment to their cognitive capacity during pregnancy, with decreased memory functions being the most frequently self-reported concerns. However, objective investigation of these perceived cognitive deficits has yielded inconsistent results. This study focused on memory functions during late pregnancy using multiple tasks designed to assess various memory indices, for example, working memory, learning rate, immediate recall, proactive and retroactive interference, delayed recall, retrieval efficiency, visuospatial constructional ability, recognition, and executive function. Additionally, sustained attention and inhibitory control were examined using a combined recognition stop-signal task. Electrophysiological brain activity during this task was recorded using a 128-channel electroencephalographic-event-related potential system. Salivary cortisol levels were assessed both prior to and following the experimental session. In contrast to the widely held belief, results demonstrated that women in late pregnancy did not exhibit a decline in their performance across the various memory tests. In terms of accuracy, there was not a single task in which poorer performance was found for pregnant women. The quality of memory performance was comparable, and in some cases even superior, among women in the pregnancy group. On the stop-signal task, pregnant women exhibited significantly better performance, and their electrophysiological data revealed greater centrally distributed P300 amplitude to "stop" signs, which may signify an enhanced neural efficiency in the domains of inhibitory executive control. Endocrine results revealed that pregnant women exhibited significantly lower levels of salivary cortisol, suggesting an attenuation of hypothalamic-pituitary-adrenocortical axis activity, which may contribute to the optimization of fetal development and growth.

Bridging childhood to adulthood: the impact of early life stress on acute stress responses

Background

Childhood trauma exerts enduring impacts on the physical and psychological well-being of individuals in adulthood, influencing their daily functioning. This study aims to investigate the impact of childhood trauma on stress recovery in adults, concentrating on heart rate variations during acute stress exposure.

Methods

A cohort of 126 participants completed the Childhood Trauma Questionnaire (CTQ) and underwent the Trier Social Stress Test (TSST) to elicit acute stress, with continuous heart rate (HR) monitoring for stress recovery assessment.

Results

The results revealed a negative correlation between childhood trauma and stress recovery, prominently observed in instances of emotional neglect and abuse. Individuals with heightened childhood trauma exhibited protracted stress recovery following acute stress exposure.

Conclusion

Childhood traumatic experiences were associated with the recovery from acute stress, as indicated by heart rate indices. These findings contribute to the foundational framework for psychological interventions tailored to individuals with a history of childhood trauma.

Can scent-detection dogs detect the stress associated with trauma cue exposure in people with trauma histories? A proof-of-concept study

Introduction

Post-traumatic stress disorder (PTSD) is an impairing mental health condition with high prevalence among military and general populations alike. PTSD service dogs are a complementary and alternative intervention needing scientific validation. We investigated whether dogs can detect putative stress-related volatile organic compounds (VOCs) in the breath of people with trauma histories (54% with PTSD) exposed to personalized trauma cues.

Methods

Breath samples were collected from 26 humans over 40 experimental sessions during a calm (control breath sample) and stressed state induced by trauma cue exposure (target breath sample). Two scent detection canines were presented with the samples in a two alternative forced choice (2AFC) discrimination and yes/no detection task. The 2AFC task assessed the dogs' ability to discriminate between the two states within the breath samples of one individual. The detection task determined their ability to generalize the target odour across different individuals and different stressful events of one individual. Signal Detection Theory was applied to assess dogs' sensitivity, specificity, precision, and response bias.

Results

The dogs performed at ∼90% accuracy across all sample sets in the discrimination experiment, and at 74% and 81% accuracy, respectively, in the detection experiment. Further analysis of dog olfactory performance in relation to human donor self-reported emotional responses to trauma cue exposure suggested the dogs may have been detecting distinct endocrine stress markers. One dog's performance correlated with the human donors' self-reported fear responses and the other dog's performance correlated with the human donors' self-reported shame responses. Based on these correlations between dog performance and donor self-report measures, we speculate that the VOCs each dog was detecting likely originated from the sympathetico-adreno-medullary axis (SAM; adrenaline, noradrenaline) in the case of the first dog and the hypothalamo-pituitary-adrenal axis (HPA; glucocorticoids) in the case of the second dog.

Conclusion

Our proof-of-concept study is the first to demonstrate that some dogs can detect putative VOCs emitted by people with trauma histories when experiencing distress theoretically associated with the intrusion and arousal/reactivity symptoms of PTSD. Results have potential to improve the effectiveness and training protocol of PTSD service dogs with a focus on enhancing their alert function.

Gene‒environment interaction effect of hypothalamic‒pituitary‒adrenal axis gene polymorphisms and job stress on the risk of sleep disturbances

Background

Studies have shown that chronic exposure to job stress may increase the risk of sleep disturbances and that hypothalamic‒pituitary‒adrenal (HPA) axis gene polymorphisms may play an important role in the psychopathologic mechanisms of sleep disturbances. However, the interactions among job stress, gene polymorphisms and sleep disturbances have not been examined from the perspective of the HPA axis. This study aimed to know whether job stress is a risk factor for sleep disturbances and to further explore the effect of the HPA axis gene × job stress interaction on sleep disturbances among railway workers.

Methods

In this cross-sectional study, 671 participants (363 males and 308 females) from the China Railway Fuzhou Branch were included. Sleep disturbances were evaluated with the Pittsburgh Sleep Quality Index (PSQI), and job stress was measured with the Effort-Reward Imbalance scale (ERI). Generalized multivariate dimensionality reduction (GMDR) models were used to assess gene‒environment interactions.

Results

We found a significant positive correlation between job stress and sleep disturbances (P < 0.01). The FKBP5 rs1360780-T and rs4713916-A alleles and the CRHR1 rs110402-G allele were associated with increased sleep disturbance risk, with adjusted ORs (95% CIs) of 1.75 [1.38-2.22], 1.68 [1.30-2.18] and 1.43 [1.09-1.87], respectively. However, the FKBP5 rs9470080-T allele was a protective factor against sleep disturbances, with an OR (95% CI) of 0.65 [0.51-0.83]. GMDR analysis indicated that under job stress, individuals with the FKBP5 rs1368780-CT, rs4713916-GG, and rs9470080-CT genotypes and the CRHR1 rs110402-AA genotype had the greatest risk of sleep disturbances.

Conclusions

Individuals carrying risk alleles who experience job stress may be at increased risk of sleep disturbances. These findings may provide new insights into stress-related sleep disturbances in occupational populations.

A randomised controlled trial assessing the effects of weather sensitivity profile and walking in nature on the psychophysiological response to stress in individuals with coronary artery disease. A study protocol

BACKGROUND

The following protocol pertains to a pioneer study, aiming to investigate how weather sensitivity and walking in different environments affects the psychophysiological responses to the stress of individuals with coronary artery disease (CAD) during rehabilitation (WE_SENSE_THE_NATURE). This randomised control trial will provide fresh insight on the influence of the environmental exposure in CAD patients, as it is seldom investigated in association to the disease. Additionally, findings on the link between personality traits and cognitive functions (especially cognitive flexibility), and weather sensitivity may help reveal a fine-grained perspective on the treatment possibilities for individuals with CAD at risk to stress-vulnerability.

METHODS

The proposed protocol is for a randomised control trial among individuals attending a cardiac rehabilitation program. We aim to recruit 164 individuals, collecting information related to demographic characteristics, weather sensitivity, functional capacity, personality traits, subjective mental health status, cognitive function, and basal cortisol level of participating individuals. Basal cortisol level refers to cortisol concentration in saliva and will be tested in the morning and the afternoon prior to the day of the experiment. After baseline measurements, the patients will be randomly assigned to either walking outdoors or walking indoors. All measures and their sequential order will remain the same within each group, while the treatment condition (i.e., walking environment) will vary between groups. On the day of the experiment, hemodynamic parameters (assessed via 6-hour blood pressure measurements), stress level (consisting of assessments of cortisol level), and mood (assessed using visual analogues scale) will be registered. Cold stress test will be administered to evaluate the effect of walking in different environments.

DISCUSSION

The outcomes of this study may have direct clinical applications for the use of different types of exercise environments in cardiac rehabilitation programs. Awareness about the potential influence of weather sensitivity on the psychophysiological reactions to stress in individuals with CAD may contribute to a timely planning and implementation of actions leading to improved medical care services and preventive measures, especially considering the expected weather oscillations and extreme weather events due to unfolding of the climate change.

TRIAL REGISTRATION

This protocol has been retrospectively registered in ClinicalTrials.gov with identifier code: NCT06139705 on November 20, 2023.

Long-term cortisol secretion in attention deficit hyperactivity disorder: roles of sex, comorbidity, and symptom presentation

Low activity of the hypothalamic-pituitary-adrenal axis (HPAA) has been found in children with attention deficit hyperactivity disorder (ADHD). The condition may be related to the reduced attention regulation capacity and/or to comorbid oppositional defiant or conduct disorder (ODD/CD). Sex differences are probable but not sufficiently studied. We analyzed the HPAA activity and sympathetic nervous system reactivity (SR) in children with ADHD while accounting for ADHD symptom presentation, comorbidity, and sex differences. The sample comprised 205 children, 98 (61 boys, 37 girls) with ADHD and 107 (48 boys, 59 girls) healthy controls. DSM-5 phenotypic symptom presentation and comorbid ODD/CD were assessed using clinical interviews. Hair cortisol concentration (HCC) was used to assess the long-term, cumulative activity of the HPAA. SR was assessed via skin conductance response (SCR). For control purposes, comorbid internalizing symptoms and indicators of adverse childhood experiences (ACE) were assessed. Children were medication naive. Boys presenting with predominantly inattentive symptoms (ADHD-I) showed lower HCC than healthy boys. Girls presenting with combined symptoms (ADHD-C) showed higher HCC than did healthy girls (p's < 0.05, sex-by-group interaction, F (2,194) = 4.09, p = 0.018). Boys with ADHD plus ODD/CD showed a blunted SR (p < 0.001, sex-by-group interaction, F (2,172) = 3.08, p = 0.048). Adjustment for ACE indicators led to non-significant differences in HCC but did not affect differences in SR. HCC constitutes an easily assessable, reliable, and valid marker of phenotypic ADHD-related features (i.e. symptom presentation and comorbidity). It indicates more homogenous subgroups of ADHD and might point to specifically involved pathophysiological processes.

Wearable and Implantable Cortisol-Sensing Electronics for Stress Monitoring

Cortisol is a steroid hormone that is released from the body in response to stress. Although a moderate level of cortisol secretion can help the body maintain homeostasis, excessive secretion can cause various diseases, such as depression and anxiety. Conventional methods for cortisol measurement undergo procedures that limit continuous monitoring, typically collecting samples of bodily fluids, followed by separate analysis in a laboratory setting that takes several hours. Thus, recent studies demonstrate wearable, miniaturized sensors integrated with electronic modules that enable wireless real-time analysis. Here, the primary focus is on wearable and implantable electronic devices that continuously measure cortisol concentration. Diverse types of cortisol-sensing techniques, such as antibody-, DNA-aptamer-, and molecularly imprinted polymer-based sensors, as well as wearable and implantable devices that aim to continuously monitor cortisol in a minimally invasive fashion are discussed. In addition to the cortisol monitors that directly measure stress levels, other schemes that indirectly measure stress, such as electrophysiological signals and sweat are also summarized. Finally, the challenges and future directions in stress monitoring and management electronics are reviewed.

The cortisol switch between vulnerability and resilience

In concert with neuropeptides and transmitters, the end products of the hypothalamus-pituitary-adrenal (HPA) axis, the glucocorticoid hormones cortisol and corticosterone (CORT), promote resilience: i.e., the ability to cope with threats, adversity, and trauma. To exert this protective action, CORT activates mineralocorticoid receptors (MR) and glucocorticoid receptors (GR) that operate in a complementary manner -as an on/off switch- to coordinate circadian events, stress-coping, and adaptation. The evolutionary older limbic MR facilitates contextual memory retrieval and supports an on-switch in the selection of stress-coping styles at a low cost. The rise in circulating CORT concentration after stress subsequently activates a GR-mediated off-switch underlying recovery of homeostasis by providing the energy for restraining the primary stress reactions and promoting cognitive control over emotional reactivity. GR activation facilitates contextual memory storage of the experience to enable future stress-coping. Such complementary MR-GR-mediated actions involve rapid non-genomic and slower gene-mediated mechanisms; they are time-dependent, conditional, and sexually dimorphic, and depend on genetic background and prior experience. If coping fails, GR activation impairs cognitive control and promotes emotional arousal which eventually may compromise resilience. Such breakdown of resilience involves a transition to a chronic stress construct, where information processing is crashed; it leads to an imbalanced MR-GR switch and hence increased vulnerability. Novel MR-GR modulators are becoming available that may reset a dysregulated stress response system to reinstate the cognitive flexibility required for resilience.

Effects of physical exercise, LEGO, and Minecraft activities on anxiety in underserved children with autism: Study design and methodological strategies

Anxiety is a common comorbidity for individuals with ASD, and there is some preliminary data about the efficacy of physical exercise to alleviate anxiety. However, we are not aware of any studies that have compared the effects of a physical exercise program on anxiety in underserved children with ASD using a randomized controlled research design. This paper describes a method to evaluate and compare the efficacy of an 8-week physical exercise intervention with a sedentary play intervention to alleviate anxiety in young children with autism spectrum disorders (ASD) from underserved backgrounds. We assessed anxiety and its physical symptoms using the parent-rated Child Behavior Checklist DSM-5 anxiety (CBCL DSM-5) subscale, the child-rated Screen for Childhood Anxiety Related Emotional Disorder (SCARED), the parent-rated Child's Sleep Habits Questionnaire (CSHQ), and salivary cortisol. We also utilized the Physical Activity Questionnaire for Older Children (PAQ-C) to assess physical activity level and identify compounds. Unique components of this study include: •Implementation of novel physical exercise and sedentary play interventions that have been designed for children with ASD.•Recruitment of predominantly underserved and non-English speaking families.

Neural habituation during acute stress signals a blunted endocrine response and poor resilience

BACKGROUND

A blunted hypothalamic-pituitary-adrenal (HPA) axis response to acute stress is associated with psychiatric symptoms. Although the prefrontal cortex and limbic areas are important regulators of the HPA axis, whether the neural habituation of these regions during stress signals both blunted HPA axis responses and psychiatric symptoms remains unclear. In this study, neural habituation during acute stress and its associations with the stress cortisol response, resilience, and depression were evaluated.

METHODS

Seventy-seven participants (17-22 years old, 37 women) were recruited for a ScanSTRESS brain imaging study, and the activation changes between the first and last stress blocks were used as the neural habituation index. Meanwhile, participants' salivary cortisol during test was collected. Individual-level resilience and depression were measured using questionnaires. Correlation and moderation analyses were conducted to investigate the association between neural habituation and endocrine data and mental symptoms. Validated analyses were conducted using a Montreal Image Stress Test dataset in another independent sample (48 participants; 17-22 years old, 24 women).

RESULTS

Neural habituation of the prefrontal cortex and limbic area was negatively correlated with cortisol responses in both datasets. In the ScanSTRESS paradigm, neural habituation was both positively correlated with depression and negatively correlated with resilience. Moreover, resilience moderated the relationship between neural habituation in the ventromedial prefrontal cortex and cortisol response.

CONCLUSIONS

This study suggested that neural habituation of the prefrontal cortex and limbic area could reflect motivation dysregulation during repeated failures and negative feedback, which might further lead to maladaptive mental states.

Hypothalamic-pituitary-adrenal axis responsivity during adolescence in relation to psychopathic personality traits later in life

Psychopathic personality traits have been linked to low physiological arousal, particularly among high risk and forensic samples. A core indicator of physiological arousal is the activity of the hypothalamic-pituitary-adrenal (HPA) axis; however, findings of a link between HPA axis functioning and psychopathic personality traits have been inconsistent. Furthermore, given sex differences in both HPA axis responsivity and psychopathic personality traits, the association may be expected to differ between men and women. The aim of this study was to investigate the association between HPA axis responsivity in mid-adolescence and psychopathic personality traits in early adulthood and determine whether the association was moderated by sex. We examined this link in a general population sample of twins (N = 556). Adolescents participated in a psychosocial stress task during which samples of salivary cortisol were collected (11-15 years) and reported psychopathic personality traits using the Triarchic Psychopathy Measure (19-20 years). Multilevel linear regression models were estimated in which psychopathic personality traits (boldness, meanness and disinhibition), and their interactions with sex, were regressed on HPA axis responsivity. The study was pre-registered on the Open Science Framework (osf.io/gs2a8). Preliminary analyses showed that cortisol levels did not increase significantly during the stressor task but decreased during recovery. Results showed that there was no association between HPA axis responsivity in mid-adolescence and psychopathic personality traits in early adulthood. The associations were not moderated by sex. Findings suggest that HPA axis responsivity in mid-adolescence did not serve as a biological marker for psychopathic personality traits among young adults from the general population.

Total cortisol output during an acute stressor predicts youths' internalizing symptoms during the COVID-19 pandemic

Individual differences in cortisol output may influence adolescents' adjustment to the COVID-19 pandemic; however, boys and girls may differ in terms of associations between cortisol output and internalizing symptoms in the context of COVID-19-related stress. We examined whether pre-pandemic cortisol output during an acute stressor, assessed approximately three years prior to the pandemic, predicted change in adolescents' internalizing symptoms early during the COVID-19 pandemic. Consistent with previous work on other life stressors, girls' cortisol output was positively associated with anxious and somatic symptoms early in the pandemic. Conversely, cortisol output and depressive symptoms were negatively associated for boys; boys with higher cortisol had depressive symptoms which significantly decreased over time. Findings suggest that hypothalamic-pituitary-adrenal axis stress functioning plays a role in shaping differences between adolescent boys' and girls' adjustment during the experience of a ubiquitous chronic stressor.

From childhood adversity to latent stress vulnerability in adulthood: the mediating roles of sleep disturbances and HPA axis dysfunction

Childhood adversity is a prominent predisposing risk factor for latent stress vulnerability, expressed as an elevated likelihood of developing stress-related psychopathology upon subsequent exposure to trauma in adulthood. Sleep disturbances have emerged as one of the most pronounced maladaptive behavioral outcomes of childhood adversity and are also a highly prevalent core feature of stress-related psychopathology, including post-traumatic stress disorder (PTSD). After reviewing the extensive literature supporting these claims, the current review addresses the notion that childhood adversity-induced sleep disturbances may play a causal role in elevating individuals' stress vulnerability in adulthood. Corroborating this, sleep disturbances that predate adult trauma exposure have been associated with an increased likelihood of developing stress-related psychopathology post-exposure. Furthermore, novel empirical evidence suggests that sleep disturbances, including irregularity of the sleep-wake cycle, mediate the link between childhood adversity and stress vulnerability in adulthood. We also discuss cognitive and behavioral mechanisms through which such a cascade may evolve, highlighting the putative role of impaired memory consolidation and fear extinction. Next, we present evidence to support the contribution of the hypothalamic-pituitary-adrenal (HPA) axis to these associations, stemming from its critical role in stress and sleep regulatory pathways. Childhood adversity may yield bi-directional effects within the HPA stress and sleep axes in which sleep disturbances and HPA axis dysfunction reinforce each other, leading to elevated stress vulnerability. To conclude, we postulate a conceptual path model from childhood adversity to latent stress vulnerability in adulthood and discuss the potential clinical implications of these notions, while highlighting directions for future research.

Network analysis of acute stress reaction in a sample of Chinese male military college students

Background

Acute stress reaction (ASR) following a stressful event is associated with stress-related mental disorders. However, no studies have investigated the relationships between ASR symptom clusters. The present study aimed to provide a fine-grained understanding of the complex relationships among symptom clusters and identify the central symptom clusters of ASR using network analysis.

Methods

The Acute Stress Reaction Scale (ASRS) was used to investigate the network structure of ASR in 1792 Chinese male military college students who were about to participate in an important physical fitness test. We calculated the weights of the edges connecting different symptom clusters and the central indices of 25 symptom clusters in the final network.

Results

There were five strongest edges with significantly higher weights than most other edge weights, including the edges between "Less communication" and "Isolated from others." The symptom clusters of "Somatic symptoms," "Hypoprosexia," and "Anxiety" were found to be the central nodes with the highest expected influences (primary centrality index).

Conclusion

The present study explored the network structure of ASR, revealed complex connections between symptom clusters, and identified central clusters. These findings have important clinical implications, and it is suggested that the three central symptom clusters may be potential targets for effective interventions for ASR.

Exercise training improves blood pressure reactivity to stress: a systematic review and meta-analysis

Blood pressure (BP) reactivity to stress is associated with cardiovascular events and the incidence of hypertension, therefore, tolerance to stressors is important for better management of cardiovascular risks. Exercise training is among the strategies that have been investigated as blunting the peak response to stressors, however, its efficacy is poorly explored. The aim was to explore the effects of exercise training (at least four weeks) on BP responses to stressor tasks in adults. A systematic review was performed in five electronic databases (MEDLINE, LILACS, EMBASE, SPORTDiscus, and PsycInfo). Twenty-three studies and one conference abstract was included in the qualitative analysis, totaling 1121 individuals, and k = 17 and 695 individuals in the meta-analysis. Favorable results (random-effects) for exercise training were found, with attenuated peak responses in systolic (standardized mean difference (SMD) = -0.34 [-0.56; -0.11], representing average reductions of 2.5 ± 3.6 mmHg) and null effects on diastolic BP (SMD = -0.20 [-0.54; 0.14], representing average reductions of 2.0 ± 3.5 mmHg). The analysis removing outliers' studies improved the effects for diastolic (SMD = -0.21 [-0.38; -0.05]) but not systolic BP (SMD = -0.33 [-0.53; -0.13]). In conclusion, exercise training seems to lower stress-related BP reactivity, therefore has the potential to improve patients' ability to better respond to stressful situations.

Non-randomized controlled trial examining the effects of livestock on motivation and anxiety in patients with chronic psychiatric disorders

Objectives

Patients with chronic schizophrenia exhibit negative symptoms, including decreased work motivation. Animal-assisted therapy programs have been reported to benefit such patients; hence, there is a possibility that sheep-rearing, rather than conventional employment training, may motivate these patients. Therefore, we investigated the effects of a one-day experiential learning program of sheep-rearing on the work motivation and anxiety of patients with chronic schizophrenia.

Methods

Fourteen patients were included in a non-randomized controlled trial conducted between August 2018 and October 2018. The patients' participation in the sheep-rearing experiential learning (one day; intervention day) and normal day care (one day; control day) programs were compared. The salivary cortisol and testosterone levels and State-Trait Anxiety Inventory (STAI) scores of the patients were analyzed.

Results

The patients' salivary testosterone was significantly higher on the intervention day (p = 0.04) than on the control day (p = 0.02). Their salivary cortisol was lower on the control day than on the intervention day, although the difference was not significant. Regression analysis was performed based on the change in salivary cortisol levels and STAI-Trait scores (p = 0.006), and a regression equation was established.

Conclusions

The study revealed that participation in sheep-rearing may have promoted the testosterone production but did not increase anxiety in patients with schizophrenia. Additionally, regression equations for salivary cortisol levels in such patients may provide information on individual differences in anxiety levels.

Menstrual cycle-related changes in HPA axis reactivity to acute psychosocial and physiological stressors - a systematic review and meta-analysis of longitudinal studies

Sex disparities are evident in the biological response to acute stressors, with a suggested influence of ovarian hormones on hypothalamic-pituitary-adrenal (HPA) axis functioning. This systematic review and meta-analysis investigates differences in HPA axis reactivity to acute psychosocial or physiological stressors between menstrual cycle phases. A systematic literature search of six databases resulted in 12 longitudinal studies (n = 182) examining HPA axis reactivity in healthy, naturally-cycling, non-breastfeeding participants aged between 18 and 45 years in at least two cycle phases. The quality of cortisol and menstrual cycle assessment was rated and a descriptive synthesis and meta-analysis of HPA axis reactivity between two broader and five more precise cycle phases was conducted. Three studies provided sufficient data for the meta-analysis and showed a significant, small-sized effect, indicating higher cortisol reactivity in the luteal than in the follicular cycle phase. More primary studies with high-quality menstrual cycle and cortisol assessment are needed. The review did not receive funding and was pre-registered (PROSPERO; CRD42020181632).

Interactive teaching enhances students' physiological arousal during online learning

The pure transfer of face-to-face teaching to a digital learning environment can be accompanied by a significant reduction in the physiological arousal of students, which in turn can be associated with passivity during the learning process, often linked to insufficient levels of concentration and engagement in the course work. Therefore, the aim of this study was to investigate whether students' psychobiological stress responses can be enhanced in the context of anatomical online learning and how increased physiological parameters correlate with characteristics of learning experiences in a digital learning environment. Healthy first-year medical students (n = 104) experienced a regular practical course in Microscopic Anatomy either in face-to-face learning, in passive online learning or in an interaction-enhanced version of online learning. Compared to passive online learning, students engaged in the interaction-enhanced version of online learning displayed a significantly reduced Heart Rate Variability (P 0.001, partial η² = 0.381) along with a strong increase in salivary cortisol (P 0.001, partial η² = 0.179) and salivary alpha-amylase activity (P 0.001, partial η² = 0.195). These results demonstrated that the physiological arousal of students engaged in online learning can be enhanced via interactive teaching methods and pointed towards clear correlations between higher physiological responses and elementary criteria of learning experience such as engagement and attention.

Individual differences in social homeostasis

The concept of “social homeostasis”, introduced by Matthews and Tye in 2019, has provided a framework with which to consider our changing individual needs for social interaction, and the neurobiology underlying this system. This model was conceived as including detector systems, a control center with a setpoint, and effectors which allow us to seek out or avoid additional social contact. In this article, we review and theorize about the many different factors that might contribute to the setpoint of a person or animal, including individual, social, cultural, and other environmental factors. We conclude with a consideration of the empirical challenges of this exciting new model.

Identity affirmation is associated with adaptive cardiovascular flexibility in response to stress among sexual and gender minority people of color

BACKGROUND

Research with sexual and gender minority (e.g., lesbian, gay, bisexual, queer, asexual, trans, non-binary) people of Color (SGM-PoC) has largely focused on risk and negative health outcomes. The existing strengths-based mental health research suggests that identity affirmation may be associated with psychological resilience and good mental health among SGM-PoC, but little is known about predictors of physiological resilience and biomarkers of physical health in this population. Adaptive cardiovascular flexibility is an indicator of physiological resilience and physical health in that it enables the body to mobilize resources to adapt to challenges. This study explored the association between identity affirmation and physiological resilience, observed through cardiovascular flexibility in response to stress among SGM-PoC.

METHODS

Participants were 95 SGM-PoC of varying ethnoracial backgrounds, sexual orientations, and gender identities, residing in Canada. Participants completed questionnaires on sociodemographic and psychosocial variables, including a measure of identity affirmation, the Queer People of Color Identity Affirmation Scale (QPIAS). In a laboratory setting, we induced stress using the Trier Social Stress Test and measured heart rate variability (HRV) over time using wearable electrocardiogram devices.

RESULTS

Results from multilevel modeling analyses revealed that high QPIAS scores were associated with adaptive cardiovascular flexibility, as evidenced by reduced HRV during stress exposure, followed by HRV increase during recovery. As QPIAS scores increased, the shape of HRV trajectory increasingly reflected our predicted pattern of adaptive cardiovascular flexibility. Meanwhile, low QPIAS scores were not associated with this pattern and appeared to predict a more flatlined HRV activity during the experiment.

CONCLUSIONS

Findings indicate that Queer People of Color identity affirmation may be related to physiological resilience, observed through a more adaptive cardiovascular profile when responding to stress. Identity affirmation may thus be a protective factor for SGM-PoC, pointing to the critical importance of affirming resources and strengths-based health research.

Associations between HPA axis reactivity and PTSD and depressive symptoms: Importance of maltreatment type and puberty

The functioning of the hypothalamic-pituitary-adrenal (HPA) axis is implicated in the etiology and maintenance of depressive and posttraumatic stress disorder (PTSD) symptoms. However, different maltreatment experiences as well as the increased sensitivity of the HPA axis during puberty may alter associations between the HPA axis and mental health. To address these gaps, the current study examined the potential bidirectional associations between cortisol reactivity to a stressor, PTSD symptoms, and depressive symptoms among early adolescents across two time points, 1 year apart (n = 454; Mage = 10.98 at Time 1 and Mage = 12.11 at Time 2). Multiple-group path models tested the pathways between cortiol reactivity and mental health prior to and during puberty, for different types of maltreatment . Overall, the results showed that associations between cortisol output and symptoms of PTSD and depression were driven by those in the midst of puberty. Specifically, higher cortisol output at Time 1 was linked with higher levels of subsequent PTSD and depressive symptoms for neglected youth who had reached puberty. However, depressive symptoms predicted subsequent lower cortisol output for the physical abuse and emotional abuse groups. These findings demonstrate longitudinal links between cortisol, depressive symptoms, and PTSD symptoms among youth with different types of maltreatment histories and highlight the need to consider the reorganization of the stress system during puberty in order to advance our understanding of the HPA axis and mental health.

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.

Psychosomatic response to acute emotional stress in healthy students

The multidimensionality of the stress response has shown the complexity of this phenomenon and therefore the impossibility of finding a unique biomarker among the physiological variables related to stress. An experimental study was designed and performed to guarantee the correct synchronous and concurrent measure of psychometric tests, biochemical variables and physiological features related to acute emotional stress. The population studied corresponds to a group of 120 university students between 20 and 30 years of age, with healthy habits and without a diagnosis of chronic or psychiatric illnesses. Following the protocol of the experimental pilot, each participant reached a relaxing state and a stress state in two sessions of measurement for equivalent periods. Both states are correctly achieved evidenced by the psychometric test results and the biochemical variables. A Stress Reference Scale is proposed based on these two sets of variables. Then, aiming for a non-invasive and continuous approach, the Acute Stress Model correlated to the previous scale is also proposed, supported only by physiological signals. Preliminary results support the feasibility of measuring/quantifying the stress level. Although the results are limited to the population and stimulus type, the procedure and methodological analysis used for the assessment of acute stress in young people can be extrapolated to other populations and types of stress.

Impact of IV-line Insertion on Salivary Cortisol Levels as a Stress Biomarker in Children

BACKGROUND: Children with leukemia will be treated for a quite long period of time that they will be subjected to multiple invasive procedures, one of which is IV-line insertion. This procedure can cause stress, which increases cortisol levels in the body. AIM: This study aimed to investigate how IV-line insertion affected cortisol levels as a stress biomarker in children. METHODS: This is a single-group pre-test and post-test design pre-experimental study. The study enrolled 30 children undergoing IV line insertion, aged from 6 to 18 years, who had not been eating or drinking for 30 min before the saliva sampling was scheduled to get IV-line insertion. The ELISA test was used to measure the salivary cortisol. If the difference in the cortisol levels is > 0.05 ng/ml, it is clinically significant. Furthermore, the Wilcoxon test was used to analyze the data. Cortisol changes were considered statistically significant if the p-value was <0.05. RESULTS: The cortisol levels were 3.43 (0.19–16.67) ng/ml and 4.14 (0.19–16.67) ng/ml before and after IV-Line insertion, respectively. The difference in the median was 0.71 ng/ml. The > 0.05 ng/ml difference indicates that IV-line insertion affects cortisol elevation. The Wilcoxon test showed a value of p = 0.34 (p > 0.05) indicating that IV-line insertion had no statistically significant effect on cortisol. CONCLUSION: Although an IV-line insertion does not have a statistically significant effect on cortisol, it clinically influences the increase of cortisol in children with leukemia.

Dynamics of personality: The Zurich model of motivation revived, extended, and applied to personality

Personality researchers are increasingly interested in the dynamics of personality, that is, the proximal causal mechanisms underlying personality and behavior. Here, we review the Zurich Model of Social Motivation concerning its potential to explain central aspects of personality. It is a cybernetic model that provides a nomothetic structure of the causal relationships among needs for security, arousal, and power, and uses them to explain an individual's approach-avoidance or "proximity-distance" behavior. We review core features of the model and extend them by adding features based on recent behavioral and neuroscientific evidence. We close by discussing the model considering contemporary issues in personality science such as the dynamics of personality, five-factor personality traits and states, and personality growth.

Need strength, perceived need support, stress symptomatology, and performance in the context of oral exams: A typological approach

Introduction

Based on self-determination theory, we investigated whether examinees are classifiable into profiles based on basic need strength and perceived need support that differ in stress parameters and achievement in the context of a standardized oral exam.

Methods

92 students reported their basic need strength before and perceived need support provided by the examiner once after the exam. Students indicated their emotions and stress perception at four measurement points and we measured their saliva cortisol concurrently, analyzing stress-related changes over time.

Results

Latent class analyses revealed two higher-quality (low/high, high/high) and two lower-quality (low/low, high/low) need strength/need support classes. Physio-affective stress development was typical of exam situations. Higher-quality classes that met or exceeded the needs displayed more beneficial stress and emotion response patterns than lower-quality classes. Gain-related emotions mediated achievement in the higher-quality classes.

Discussion

Need-supportive examiners can promote student well-being and achievement when they succeed in providing high need satisfaction.

Vagus activation by Cold Face Test reduces acute psychosocial stress responses

Chronic stress is linked to dysregulations of the two major stress pathways-the sympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis, which could for example result from maladaptive responses to repeated acute stress. Improving recovery from acute stress could therefore help to prevent this dysregulation. One possibility of physiologically interfering with an acute stress reaction might be provided by applying a cold stimulus to the face (Cold Face Test, CFT) which activates the parasympathetic nervous system (PNS), leading to immediate heart rate decreases. Therefore, we investigated the use of the CFT protocol as an intervention to reduce acute stress responses. Twenty-eight healthy participants were exposed to acute psychosocial stress via the Montreal Imaging Stress Task (MIST) in a randomized between-subjects design while heart rate (HR), heart rate variability (HRV), and salivary cortisol were assessed. While both groups were equally stressed during the procedure, participants with CFT intervention showed better recovery, indicated by significant ([Formula: see text]) differences in HR(V). We additionally found a significantly ([Formula: see text]) lower cortisol response to the MIST and less overall cortisol secretion in the CFT condition. Both findings indicate that the CFT can successfully stimulate the PNS and inhibit the HPA axis. To the best of our knowledge, our experiment is the first to successfully use the CFT as a simple and easy-to-apply method to modify biological responses to acute stress.

Pro- and anti-inflammatory cytokines Interleukin-6 and Interleukin-10 predict therapy outcome of female patients with posttraumatic stress disorder

PTSD patients show alterations of the immune system, mainly a 'low-grade inflammation'. Psychotherapeutic treatments are meant to reduce symptom burden of PTSD patients but 30-50% of PTSD patients do not benefit from psychotherapy. Therefore, in this study, the predictive effect of cytokine levels on therapy outcome are investigated. Pro- (IL-6) and anti-inflammatory (IL-10) cytokines in female PTSD patients (N = 17) were assessed under acute stress during a Trier social stress test (TSST) before therapeutic treatment. The predictive effects of IL-6 and IL-10 on therapy outcome (SCL_GSI, BDI) after an inpatient psychotherapeutic treatment at the University Medical Center Carl Gustav Carus, Technische Universität Dresden was investigated. Areas under the curve with respect to ground (AUC_G) and increase (AUC_I) for IL-6 and IL-10 levels during the TSST were calculated and used as predictors in regression analyses with pre-treatment scores. Models including all three predictors show good model fits (R² = 0.255 to 0.744). Models including AUC_G and AUC_I scores show superior fits compared with models including pre-treatment scores alone (ΔR² = 0.196 to 0.444). IL-6 AUC_G and AUC_I scores are significant predictors for post-treatment SCL-GSI and BDI (β = -0.554 to 0.853), whereas IL-10 AUC_G significantly predicts SCL-GSI and BDI (β = -0.449 to -0.509). Therefore, pro- and anti-inflammatory IL-6 and IL-10 levels under acute stress before therapy predict therapy outcome of female PTSD patients regarding general symptom burden and depressive symptoms. Future studies should further address the link between inflammation and therapy outcome, especially underlying mechanisms and influencing factors.

Stress and reward: A multimodal assessment of childhood sexual abuse

Background

Childhood adversity has been found to impact stress and brain reward systems but it is unclear whether interactions between these systems might explain resilient vs. non-resilient trajectories following childhood sexual abuse (CSA). To address this gap, we adopted a multimodal approach in which cortisol reactivity to an acute stressor was assessed in conjunction with behavioral and neural measures of reward responsiveness in females with major depressive disorder (MDD) or no psychiatric disorders (i.e., resilient) who experienced CSA compared to females with and without MDD who did not experience abuse.

Methods

Latent Class Mixed Modelling (LCMM) identified classes of adults (n = 62; MAge = 26.48, SD = 5.68) characterized by distinct cortisol trajectories in response to a combined social evaluative cold pressor task. Classes were examined for their history of CSA and resilience as well as behavioral and neural measures of reward responsiveness using 128-channel electroencephalography (event-related potentials and source localization analysis).

Results

LCMM analysis identified two distinct classes of individuals with increased (Responders) or blunted (Non-Responders) cortisol reactivity to an acute stressor. Unlike Responders, Non-Responders did not modulate reward responses throughout the stress manipulation. No differences emerged between Responders and Non-Responders in terms of CSA or resilience. However, exploratory results showed that blunted cortisol response and non-modulation of reward responses emerged for those who experienced CSA at a younger age.

Conclusions

Co-occurring blunted stress and reward reactivity emerged irrespective of adults' experience of CSA or resilience. However, preliminary findings showed that CSA ending during peripubertal development was associated with blunted cortisol and reward responsiveness. Future research needs to replicate findings in larger samples and could investigate if increasing reward responsiveness during critical times of neurodevelopment could normalize stress reactivity to future stressors and thus promote resilience.

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

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

Resting-state heart rate variability (HRV) mediates the association between perceived chronic stress and ambiguity avoidance

Chronic stress is associated with profound behavioral and physiological alterations, including intolerance to uncertainty and reduced resting-state heart-rate-variability (HRV). Critically, uncertainty may arise in situations with known probabilities (risk) or unknown probabilities (ambiguity). Whether associations between chronic stress and decision-making under uncertainty are dependent on the specific type of uncertain decisions, and whether physiological alterations play a role in these putative associations is not yet clear. Here, ninety-two healthy adults that exhibit various levels of perceived chronic stress underwent resting-state HRV recording before completing a behavioral task that involves decision-making under either risk or ambiguity. Computational modelling quantified participants' behavioral attitudes of approach and avoidance separately for risk and ambiguity. Results indicate, as expected, that perceived chronic stress is positively associated with intolerance to uncertainty and negatively associated with resting-state HRV. Contrary to expectations, behavioral attitudes towards risk and ambiguity were not directly associated with perceived chronic stress, yet HRV fully mediated the association between chronic stress and ambiguity avoidance. Taken together and given the direction of the associations, elevated HRV despite chronic stress may foster adaptive behavior in the form of avoiding ambiguous situations, and hence contribute to reduced exposure to uncertainty and to lower levels of allostatic load.

Dogs can discriminate between human baseline and psychological stress condition odours

Previous research suggests that dogs can detect when humans are experiencing stress. This study tested whether baseline and stress odours were distinguishable to dogs, using a double-blind, two-phase, three-alternative forced-choice procedure. Combined breath and sweat samples were obtained from participants at baseline, and after a stress-inducing (mental arithmetic) task. Participants’ stress was validated with self-report and physiological measures recorded via a Biopac MP150 system. Thirty-six participants’ samples were presented to four dogs across 36 sessions (16, 11, 7 and 2 sessions, respectively). Each session consisted of 10 Phase One training trials and 20 Phase Two discrimination trials. In Phase One, the dog was presented with a participant’s stress sample (taken immediately post-task) alongside two blanks (the sample materials without breath or sweat), and was required to identify the stress sample with an alert behaviour. In Phase Two, the dog was presented with the stress sample, the same participant’s baseline sample (taken pre-task), and a blank. Which sample (blank, baseline, or stress) the dog performed their alert behaviour on was measured. If dogs can correctly alert on the stress sample in Phase Two (when the baseline sample was present), it suggests that baseline and stress odours are distinguishable. Performance ranged from 90.00% to 96.88% accuracy with a combined accuracy of 93.75% (N trials = 720). A binomial test (where probability of success on a single trial was 0.33, and alpha was 0.05) showed that the proportion of correct trials was greater than that expected by chance (p < 0.001). Results indicate that the physiological processes associated with an acute psychological stress response produce changes in the volatile organic compounds emanating from breath and/or sweat that are detectable to dogs. These results add to our understanding of human-dog relationships and could have applications to Emotional Support and Post Traumatic Stress Disorder (PTSD) service dogs.

Salivary testosterone in male and female youth with and without autism spectrum disorder: considerations of development, sex, and diagnosis

BACKGROUND

Puberty is characterized by significant physical, hormonal, and psychological changes, which may be especially challenging for individuals with autism spectrum disorder (ASD). Although the etiology of ASD remains uncertain, studies suggest imbalances in hormones, such as testosterone, may modulate the autism phenotype. While differences in fetal and postnatal testosterone have been reported, there is limited literature regarding testosterone variations during adolescence in ASD. We investigated morning salivary testosterone levels in youth with ASD and typical development (TD) to explore hypothesized differences, expecting elevated hormonal levels in ASD compared to TD.

METHODS

Youth with ASD (n = 140) and TD (n = 104), ages 10 to 13 years, were enrolled as part of a longitudinal study on pubertal development. Pubertal stage was determined by gold standard physical examination, and salivary testosterone was collected in the morning immediately upon waking and 30 min after waking and averaged across 3 days. Diagnostic (ASD/TD) and sex (male/female) differences, as well as interactions with age and puberty, were examined using robust linear mixed effect models.

RESULTS

Youth with ASD showed significantly elevated testosterone concentrations compared to same-age TD peers. After the inclusion of natural cubic splines to account for nonlinearity in age, a significant age-by-sex interaction emerged with distinct developmental slopes for males and females. At younger ages, females had higher testosterone, until about 11.5 years of age, when levels began to plateau, while male testosterone concentrations continued to rapidly increase and surpass females. As expected, more advanced pubertal development was associated with elevated testosterone. In contrast, no significant effect of parent-reported social communication symptoms was observed.

LIMITATIONS

Limitations include an unequal sex distribution, non-representative sample (e.g., cognition and race/ethnicity), and inability to examine afternoon/evening testosterone due to detection limits.

CONCLUSIONS

Testosterone may play a unique role in the presentation of ASD, especially during periods of dynamic hormonal changes including puberty. Inherent developmental (age, puberty) and sex-based (male, female) factors play a more prominent role in changes in testosterone levels during adolescence. Even so, future research is warranted to determine the differential expression and impact of exposure to excess testosterone during the pubertal transition for youth with ASD.

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.

Dynamic behavior of cell-free mitochondrial DNA in human saliva

Mitochondria contain their own genome that can be released in multiple biofluids such as blood and cerebrospinal fluid, as cell-free mitochondrial DNA (cf-mtDNA). In clinical studies, blood cf-mtDNA predicts mortality and higher cf-mtDNA levels are associated with mental and physical stress. However, the dynamics of cf-mtDNA has not been defined, and whether it can be measured non-invasively like other neuroendocrine markers in saliva has not been examined. Here we report cf-mtDNA in human saliva and establish its natural within-person dynamic behavior across multiple weeks. In a small proof-of-principle cohort of healthy adults, we first develop an approach to rapidly quantify salivary cf-mtDNA without DNA isolation, and demonstrate the existence of salivary cf-mtDNA. We then deploy this approach to perform an intensive repeated-measures analysis of two healthy men studied at 4 daily timepoints over 53-60 consecutive days (n = 212-220 observations each) with parallel measures of steroid hormones, self-reported daily mood, and health-related behaviors. Salivary cf-mtDNA exhibited a robust awakening response reaching up to two orders of magnitude 30-45 min after awakening, varied from day-to-day, and moderately correlated with the cortisol awakening response. In exploratory analyses, no consistent association with self-reported daily mood/health-related behaviors were found, although this requires further examination in future studies. Dynamic variation in cf-mtDNA was inversely related with salivary interleukin 6 (IL-6), inconsistent with a pro-inflammatory effect of salivary cf-mtDNA. The highly dynamic behavior of salivary cf-mtDNA opens the door to non-invasive studies examining the relevance of mtDNA signaling in relation to human health.

Reward sensitivity modulates the brain reward pathway in stress resilience via the inherent neuroendocrine system

In the previous 10 years, researchers have suggested a critical role for the brain reward system in stress resilience. However, no study has provided an empirical link between activity in the mesostriatal reward regions during stress and the recovery of cortisol stress response. Moreover, although reward sensitivity as a trait has been demonstrated to promote stress resilience, it remains unclear whether it modulates the brain reward system in stress resilience and how this effect is achieved by the inherent neuroendocrine system. To investigate these uncertainties, 70 young adults were recruited to participate in a ScanSTRESS task, and their brain imaging data and saliva samples (for cortisol assay) were collected during the task. In addition, we assessed reward sensitivity, cortisol awakening response, and intrinsic functional connectivity of the brain in all the participants. We found that left putamen activation during stress exposure positively predicted cortisol recovery. In addition, reward sensitivity was positively linked with activation of the left putamen, and this relationship was serially mediated by the cortisol awakening response and right hippocampus-left inferior frontal gyrus intrinsic connectivity. These findings suggest that reward sensitivity modulates reward pathways in stress resilience through the interplay of the diurnal stress response system and network of the hippocampus-prefrontal circuitry. Summarily, the current study built a model to highlight the dynamic and multifaceted interaction between pertinent allostatic factors in the reward-resilience pathway and uncovered new insight into the resilience function of the mesostriatal reward system during stress.

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Cortisol recovery can be predicted by activation of the left putamen in stress.

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Activation of the left putamen was positively linked with reward sensitivity.

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This relationship was serially mediated by the cortisol awakening response and right hippocampus-left inferior frontal gyrus intrinsic coupling.

Social Support as a Stress Buffer or Stress Amplifier and the Moderating Role of Implicit Motives: Protocol for a Randomized Study

BACKGROUND

Previous research shows that providing social support in socioevaluative stress situations reduces participants' stress responses. This stress-buffer effect, however, does not hold for everybody, and some studies even found a stress-amplifying effect of social support. Motive disposition research suggests that social motives (affiliation and power) lead to differential and sometimes even opposing affective and physiological responses to interpersonal interaction processes. We here integrate both lines of research and hypothesize that participants with strong affiliation motives benefit, while participants with strong power motives do not benefit from social support in terms of psychobiological responses to a given stressor. Further, participants with strong affiliation and power motives are expected to respond to social support with the arousal of motive-specific affects and reproductive hormone responses (affiliation: progesterone; power: estradiol and testosterone). In addition, we test sex differences in the response to social support and in the strengths of social motives.

OBJECTIVE

The main objective of this study is to test whether social motives and participants' sex moderate the effects of social support in stressful situations.

METHODS

We aim to collect data from 308 participants recruited at our local university. Participants' social motives are assessed using a standardized measure in motive research (Picture Story Exercise). Then, the Trier Social Stress Test for Groups (TSST-G) is used to experimentally induce psychosocial stress. One group of participants receives social support from an associate of the experimenter, while the control group does not receive social support. Stress responses will be assessed by a modified version of the state anxiety scale of the State-Trait Anxiety Inventory and by physiological indicators of stress (cortisol and α-amylase from saliva samples) at 7 measurement points. Reproductive hormones will be analyzed in 4 of these 7 saliva samples. Heart rate and heart rate variability will be assessed continuously. We will additionally measure participants' performance in an interview (part of the TSST-G) using a self-developed categorization system.

RESULTS

The Ethics Committee of the University of Constance approved the application to conduct the study on December 18, 2018. Furthermore, the study was retrospectively registered in the German Clinical Trials Register (DKRS; ID: DRKS00028503) on March 09, 2022. The start of the experiment was planned for the beginning of 2019, but was postponed to June 2021 due to COVID-19. Publication of the first results is planned for spring 2023.

CONCLUSIONS

Our theory-driven integration of social motives in social support research and the precise analysis of sex differences might disentangle inconsistent findings in TSST research. The more faceted view on individual differences has direct implications for applied contexts as it provides a framework for tailored conceptualizations of social support programs.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00028503; https://tinyurl.com/5a87x4da.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/39509.

Attachment style dimensions are associated with neural activation during projection of mental states

The aim of the present study was to investigate the association between attachment dimensions and neural correlates in response to the Rorschach inkblots. Twenty-seven healthy volunteers were recruited for the electroencephalographic registration during a visual presentation of the Rorschach inkblots and polygonal shapes. The Attachment Style Questionnaire (ASQ) was administered to participants. Correlations between the ASQ scores and standardized low-resolution brain electromagnetic tomography (sLORETA) intensities were performed. The Rorschach inkblots elicited several projective responses greater than the polygonal shapes (distortions, human and total movements, and embellishments). Only during the Rorschach inkblots presentation, discomfort with closeness and relationships as secondary subscales were negatively correlated with the activation of right hippocampus, parahippocampus, amygdala, and insula; need for approval subscale was negatively correlated with the activation of orbital and prefrontal cortex and left hippocampus. Moreover, the correlations between attachment dimensions and neural activation during the Rorschach inkblots were significantly higher compared to the same correlations in response to polygonal shapes. These findings suggest that attachment style can modulate brain activation during the projective activity of the Rorschach inkblots.

Decreased sympathetic cardiovascular influences and hormone-physiological changes in response to Covid-19-related adaptations under different learning environments

To examine the implications of the transition from face-to-face to online learning from a psychobiological perspective, this study investigated potential differences in physiological stress parameters of students engaged in online or face-to-face learning and determined whether these can be identified as possible mediators between learning experience and achievement emotions. In a randomized experimental field study, medical students (n = 82) attended either regular face-to-face classes of the microscopic anatomy course or the same practical course online using Zoom videoconferencing platform. The present study investigated Heart Rate Variability (HRV) and salivary cortisol concentration as stress correlates, within the contexts of online and face-to-face learning and compared these parameters with a control group that was measured at rest. Additionally, participants completed a standardized questionnaire about their experienced emotions in relation to task achievement and subjective stress levels. A significant reduction in HRV was found in face-to-face learning, suggesting stronger stress responses in the face-to-face learning environment (η²  = 0.421, P < 0.001). Furthermore, participants engaged in face-to-face learning showed significantly higher cortisol concentrations (η²  = 0.115, P = 0.032). Additionally, increased sympathetic activation correlated with the discrete positive emotion of enjoyment exclusively within the face-to-face condition (r = 0.365, P = 0.043). These results indicate that the transfer of a face-to-face practical course in microscopic anatomy to an online learning environment is associated with decreased sympathetic and enhanced vagal cardiovascular influences, together with lower cortisol concentrations in healthy medical students.

Additive serotonergic genetic sensitivity and cortisol reactivity to lab-based social evaluative stress: Influence of severity across two samples

Prior work demonstrates that an additive serotonergic multilocus genetic profile score (MGPS) predicts amplified risk for depression following significant life stress, and that it interacts with elevations in the cortisol awakening response to predict depression. The serotonin system and HPA-axis have bidirectional influence, but whether this MGPS predicts acute cortisol reactivity, which might then serve as a mechanism for depression, is unknown. Our prior work suggests that depression risk factors predict blunted cortisol reactivity to explicit negative evaluative lab-based stress. Thus, we hypothesized that a 4-variant serotonergic MGPS (three SNPs from the original 5-variant version plus 5HTTLPR) would predict blunted cortisol reactivity to explicit negative evaluative stress versus a control. In Sample 1, growth curve modeling showed that the MGPS predicted heightened cortisol reactivity (p = 0.0001) in an explicitly negative evaluative Trier Social Stress Test variant (TSST) versus a control condition among non-depressed emerging adults (N = 152; 57% female). In Sample 2, 125 males completed the Socially Evaluative Cold Pressor Test (SECPT), an ambiguously negative evaluative manipulation; findings displayed a similar pattern but did not reach statistical significance (ps.075-.091). A participant-level meta-analysis of the two samples demonstrated a significant effect of negative evaluation severity, such that the MGPS effect size on reactivity increased linearly from control to SECPT to an explicitly negative evaluative TSST. Findings indicate that this MGPS contributes to sensitivity to social threat and that cortisol dysregulation in the context of social stress may be one mechanism by which this MGPS contributes to depression.