Habituation of cortisol responses to repeated psychosocial stress-further characterization and impact of genetic factors

Resilience as a predictor of habituation

Habituation refers to the physiological adaptation to recurrent stressors, which can be measured by cortisol levels, and is considered a central mechanism in reducing allostatic load. Resilience, a potential factor influencing stress reduction, is the focus of this study. Specifically, the study aims to investigate the impact of resilience, as assessed by the Brief Resilience Scale (BRS), on habituation. The Trier Social Stress Test (TSST) was used as the recurrent stressor, and it was administered to each of the 56 subjects at 4 consecutive measurements. To assess habituation, various physiological parameters including the area under the curve with respect to the ground (AUCg) and with respect to the increase (AUCi), cortisol peak, slope from baseline to peak, and recovery were calculated. Mixed linear models were employed to examine the differences in the influence of resilience on habituation across the different time points. The findings indicate that the influence of resilience significantly varies from the first to the fourth measurement time point for AUCg (p = .048), while no significant differences were observed for the other cortisol parameters. The effects plot suggests that individuals with higher levels of resilience exhibit lower AUCg values throughout the measurements. These findings provide initial evidence supporting resilience as a predictor of cortisol habituation. However, future studies should also consider dynamic resilience models, utilizing longitudinally assessed resilience as a predictor for habituation, to explore whether resilience acts as a determinant of habituation or if habituation itself constitutes a resilience mechanism.

Stress from early life to adulthood: Is there a protective role of cognitive control?

Early life events can have long-lasting effects that may impact the quality of life into adulthood. The link between childhood adversities and adult mental and physical health is well documented, however, the underlying mechanisms remain poorly understood. Executive functions are assumed to be a key factor in successfully dealing with cognitive-emotional challenges thereby contributing to stress resilience and mental health across the lifespan. Here, we examined whether cognitive control moderates the link between early life adversity and depression. Data was available from a sample of 424 participants aged 20-70 years (Clinicaltrials.gov: NCT05155397). They performed in the Stroop task and behavior as well as frontal theta power were recorded. Negative childhood experiences were assessed with the Childhood Trauma Questionnaire (CTQ), chronic stress was measured with the Trier Inventory for Chronic Stress (TICS) and depression symptoms with Beck's Depression Inventory (BDI). The CTQ predicted symptoms of chronic stress and depression. Regression models pointed to the TICS as a crucial mediator in the relationship between CTQ and BDI. However, parameters of cognitive control demonstrated a rather weak effect as moderators. These results indicate that chronic stress is an important mediator linking childhood trauma to depression but suggest only a limited role for cognitive control.

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

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

Left dorsolateral prefrontal cortex activation can accelerate stress recovery: A repetitive transcranial stimulation study

In this study, a single high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) session was applied over the left dorsolateral prefrontal cortex (DLPFC) after a moderate-to-intense stressor to investigate whether left DLPFC stimulation could regulate cortisol concentration after stress induction. Participants were randomly divided into three groups (stress-TMS, stress, and placebo-stress). Stress was induced in both the stress-TMS and stress groups using the Trier Social Stress Test (TSST). The placebo-stress group received a placebo TSST. In the stress-TMS group, a single HF-rTMS session was applied over the left DLPFC after TSST. Cortisol was measured across the different groups, and each group's responses to the stress-related questionnaire were recorded. After TSST, both the stress-TMS and stress groups reported increased self-reported stress, state anxiety, negative affect, and cortisol concentration compared with the placebo-stress group, indicating that TSST successfully induced a stress response. Compared with the stress group, the stress-TMS group exhibited reduced cortisol levels at 0, 15, 30, and 45 min after HF-rTMS. These results suggest that left DLPFC stimulation after stress induction might accelerate the stress recovery.

Psychopathology, cortisol and testosterone responses to traumatic images: differences between urban and suburban citizens in a middle-income country

Background

Living in urban places has been associated with a higher risk of psychopathology as well as with altered hypothalamus-pituitary-adrenal (HPA) axis and consequently altered cortisol response, but studies have concentrated mainly in high-income countries population. The role of other hormones such as testosterone, implicated in stress response and with human social behaviors, have not yet been investigated. The aim of this study was to compare symptoms of psychopathology as well as cortisol and testosterone in response to traumatic images between urban and suburban people in a middle-income country.

Methods

A sample of 67 women and 55 men (N = 122, 18-45 years) from urban and suburban places of Mexico participated in the study. We quantified salivary cortisol and testosterone in response to images with traumatic and violent content (basal, 15, 30, and 45 min after images). Participants answered a general information questionnaire and the Symptom Checklist-90-R to assess their psychopathological traits. We performed Generalized Estimating Equation Models to analyze hormonal levels and MANOVAs to compare differences in participants' psychopathology symptoms. Area under the curve respect to ground (AUC_G) of hormonal levels and sex differences were also compared.

Results

Suburban citizens showed no cortisol response, whereas urban people showed a cortisol peak 15 min after the image's exposure; however, suburban people had higher AUC_G and basal levels compared to urban ones. Contrastingly, testosterone levels declined in all participants excepting the urban women, who showed no testosterone response. Although similar testosterone profile, AUC_G levels were higher in urban than suburban men. Participants living in suburban areas had higher scores of somatizations, obsessive-compulsive, and interpersonal sensitivity, as well as more sleep disorders than participants living in urban areas.

Conclusion

This study offers novel evidence about differences in cortisol and testosterone responses to a social stressor and in mental health indicators between a population of urban and suburban citizens, highlighting the impact of urbanization process on physiological and psychological outcomes in a middle-income country.

Sex differences in electrophysiological properties and voltage-gated ion channel expression in the paraventricular thalamic nucleus following repeated stress

Background

Habituation to repeated stress refers to a progressive reduction in the stress response following multiple exposures to the same, predictable stressor. We previously demonstrated that the posterior division of the paraventricular thalamic nucleus (pPVT) nucleus regulates habituation to 5 days of repeated restraint stress in male rats. Compared to males, female rats display impaired habituation to 5 days of restraint. To better understand how activity of pPVT neurons is differentially impacted in stressed males and females, we examined the electrophysiological properties of pPVT neurons under baseline conditions or following restraint.

Methods

Adult male and female rats were exposed to no stress (handling only), a single period of 30 min restraint or 5 daily exposures to 30 min restraint. 24 h later, pPVT tissue was prepared for recordings.

Results

We report here that spontaneous excitatory post-synaptic current (sEPSC) amplitude was increased in males, but not females, following restraint. Furthermore, resting membrane potential of pPVT neurons was more depolarized in males. This may be partially due to reduced potassium leakage in restrained males as input resistance was increased in male, but not female, rats 24 h following 1 or 5 days of 30-min restraint. Reduced potassium efflux during action potential firing also occurred in males following a single restraint as action potential half-width was increased following a single restraint. Restraint had limited effects on electrophysiological properties in females, although the mRNA for 10 voltage-gated ion channel subunits was altered in the pPVT of female rats.

Conclusions

The results suggest that restraint-induced changes in pPVT activation promote habituation in males. These findings are the first to describe a sexual dimorphism in stress-induced electrophysiological properties and voltage-gated ion channel expression in the pPVT. These results may explain, at least in part, why habituation to 5 days of restraint is disrupted in female rats.

Male, but not female, pPVT neurons display increases in EPSC amplitude and decay time 24 h following one and five restraints.

Input resistance is increased 24 h following one and five restraints in male, but not female, pPVT neurons.

Afterhyperpolarization potential is greater in pPVT neurons of females compared to males, regardless of restraint.

Restraint alters the expression of 10 voltage-gated ion channel transcripts in the pPVT of females, but only 3 in males.

Chronic stress-driven glucocorticoid receptor activation programs key cell phenotypes and functional epigenomic patterns in human fibroblasts

Chronic environmental stress can profoundly impact cell and body function. Although the underlying mechanisms are poorly understood, epigenetics has emerged as a key link between environment and health. The genomic effects of stress are thought to be mediated by the action of glucocorticoid stress hormones, primarily cortisol in humans, which act via the glucocorticoid receptor (GR). To dissect how chronic stress-driven GR activation influences epigenetic and cell states, human fibroblasts underwent prolonged exposure to physiological stress levels of cortisol and/or a selective GR antagonist. Cortisol was found to drive robust changes in cell proliferation, migration, and morphology, which were abrogated by concomitant GR blockade. The GR-driven cell phenotypes were accompanied by widespread, yet genomic context-dependent, changes in DNA methylation and mRNA expression, including gene loci with known roles in cell proliferation and migration. These findings provide insights into how chronic stress-driven functional epigenomic patterns become established to shape key cell phenotypes.

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Physiological stress levels of cortisol drive robust changes in key cell phenotypes

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Stress-driven changes in cell phenotypes are abrogated by concomitant GR blockade

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GR activation induces functional and phenotypically relevant epigenomic changes

Arc-Mediated Plasticity in the Paraventricular Thalamic Nucleus Promotes Habituation to Stress

BACKGROUND

Habituation is defined as a progressive decline in response to repeated exposure to a familiar and predictable stimulus and is highly conserved across species. Disrupted habituation is a signature of posttraumatic stress disorder. In rodents, habituation is observed in neural, neuroendocrine, and behavioral responses to repeated exposure to predictable and moderately intense stress or restraint. We previously demonstrated that lesioning the posterior paraventricular thalamic nucleus (pPVT) impairs habituation. However, the underlying molecular mechanisms and specific neural connections among the pPVT and other brain regions that underlie habituation are unknown.

METHODS

Behavioral and neuroendocrine habituation was assessed in adult male Sprague Dawley rats using the repeated restraint paradigm. Pan-neuronal and Cre-dependent DREADDs (designer receptors exclusively activated by designer drugs) were used to chemogenetically inhibit the pPVT and the subpopulation of pPVT neurons that project to the medial prefrontal cortex (mPFC), respectively. Activity-regulated cytoskeleton-associated protein (Arc) expression was knocked down in the pPVT using small interfering RNA. Structural plasticity of pPVT neurons was assessed using Golgi staining. Local field potential recordings were used to assess coherent neural activity between the pPVT and mPFC. The attentional set shifting task was used to assess mPFC-dependent behavior.

RESULTS

Here, we show that Arc promotes habituation by increasing stress-induced spinogenesis in the pPVT, increasing coherent neural activity with the mPFC, and improving mPFC-mediated cognitive flexibility.

CONCLUSIONS

Our results demonstrate that Arc induction in the pPVT regulates habituation and mPFC function. Therapies that improve synaptic plasticity during posttraumatic stress disorder therapy may enhance habituation and the efficacy of posttraumatic stress disorder treatment.

Neuroendocrine Response and State Anxiety Due to Psychosocial Stress Decrease after a Training with Subject's Own (but Not Another) Virtual Body: An RCT Study

Previous research involving healthy participants has reported that seeing a moving virtual body from the first person perspective induces the illusion of ownership and agency over that virtual body. When a person is sitting and the virtual body runs, it is possible to measure physiological, behavioral and cognitive reactions that are comparable to those that occur during actual movement. Capitalizing on this evidence, we hypothesized that virtual training could also induce neuroendocrine effects that prompt a decreased psychosocial stress response, as occurs after physical training. While sitting, 26 healthy young adults watched a virtual avatar running for 30 min from the first person perspective (experimental group), while another 26 participants watched the virtual body from the third person perspective (control group). We found a decreased salivary alpha-amylase concentration (a biomarker for the stress response) after the virtual training among the experimental group only, as well as a decreased subjective feeling of state anxiety (but no difference in heart rate). We argue that the virtual illusion of a moving body from the first person perspective can initiate a cascade of events, from the perception of the visual illusion to physiological activation that triggers other biological effects, such as the neuroendocrine stress response.

Stressed in afterthought: Neuroendocrine effects of social self-threat during physical effort are counteracted by performance feedback after stress exposure

Social self-threat during physical stress, such as exposure to the cold pressor test and isometric handgrip test, has been shown to induce activation of the HPA axis, in addition to autonomic responses. However, previous research has suggested that dysfunctional post-event processing may play a major role in neuroendocrine reactivity at initial as well as subsequent social stress exposure. In the present study, we investigated how the interplay of context (i.e. performance feedback) with state (i.e., self-esteem) as well as trait-like factors (i.e., ruminative tendencies) affects stress responses to repeated, short bouts of physical activity. On two sessions, 1 week apart, 53 participants (27 women) performed an isometric handgrip task for 3 min, during which they were exposed to social-evaluative threat. In addition, participants received fake feedback on their performance immediately after the task, labeling it as either 'above' (positive) or 'below average' (negative). In addition to neuroendocrine (cortisol), cardiovascular (heart rate, blood pressure) and subjective stress reactivity, performance-related and social dimensions of state self-esteem were assessed before and after stress induction. Substantial increases in cardiovascular parameters were found on both days, regardless of feedback condition. However, positive feedback led to significantly diminished neuroendocrine responses on day 1, whereas baseline cortisol on session 2 was significantly higher in the negative feedback group. Conversely, social self-esteem decreased after stress induction on both days only for participants who had received negative feedback. Changes in self-esteem reported on day 1 were associated with increased baseline cortisol at the second session, while interindividual differences in self-reported (trait) rumination were associated with cortisol reactivity at session 1. Taken together, the results suggest that effects of social evaluation during short periods of physical stress rely on post-event processing and might be counteracted by positive appraisal directly after stress exposure. Post-hoc framing (in terms of success vs. failure) may predict subsequent stress-related hormonal effects better than task demands per se, which should be considered as a potential moderator in future acute stress research, but might also be relevant to many practical applications in fields ranging from sports/performance to health psychology.

How does risk preference change under the stress of COVID-19? Evidence from Japan

In this study, we investigated whether the risk preference systematically changed during the spread of COVID-19 in Japan. Traditionally, risk preference is assumed to be stable over one's life, though it differs among individuals. While recent studies have reported that it changes with a large event like natural disasters and financial crisis, they have not reached a consensus on its direction, risk aversion, or tolerance. We collected panel data of Japanese individuals in five waves from March to June 2020, which covered the period of the first cycle when COVID-19 spread rapidly and then dwindled. We measured risk preference through questions on the willingness to pay for insurance. The main results are as follows: First, people became more risk tolerant throughout the period; and second, people were more averse to mega risk than moderate risk, with the former correlating more strongly with the individual's perception of COVID-19. The first result may be interpreted as "habituation" to repeated stress, as is understood in neuroscience.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11166-022-09374-z.

The anticipatory response to stress and symptoms of depression and anxiety in early adulthood

BACKGROUND

Whilst cortisol reactivity has been associated with depression and anxiety disorders, research examining cortisol reactivity with early symptoms of these conditions in males and females is limited.

METHODS

At age 18, 748 males and females from Gen2 of the Raine Study were assessed for their salivary cortisol response to a psychosocial stressor using the Trier Social Stress Test (TSST). Participants later completed the Depression Anxiety Stress Scale (DASS-21) at age 20 which was used as the outcome measure in regression models.

RESULTS

We found differences in DASS-21 across TSST responder categories in females but not males. Female reactive-responders (RR) and non-responders (NR) had increased symptoms of depression and anxiety compared to anticipatory-responders (AR). AR were associated with the lowest symptomology in females. We found limited evidence for an association between salivary cortisol summary measures (C_BL, C_MAX, C_MIN, C_RANGE, AUC_G and AUC_R) and depression/anxiety symptoms at age 20.

CONCLUSIONS

This study sheds new light on adaptive and maladaptive physiological responses to psychosocial stress in terms of depression and anxiety symptoms. These preliminary findings indicate the pattern of response to a psychosocial stressor may contribute to individual vulnerability for stress-related diseases in a sex-specific manner.

Determinants and Mechanisms of the Renin-Aldosterone Stress Response

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Increased Cortisol Response and Low Quality of Life in Women Exposed to Intimate Partner Violence With Severe Anxiety and Depression

BACKGROUND

Intimate partner violence (IPV) is one of the most prevalent forms of violence against women globally and it is considered a public health problem. Because the experience of IPV is stressful and traumatic for victims, they are at high risk of developing alteration of the Hypothalamus-Pituitary-Adrenal (HPA) axis functioning as well as anxiety and depression symptoms. The aim of this study was to compare the quality of life and changes in cortisol response to an acute stressor between women exposed to IPV and non-exposed women. Differences according to symptoms of anxiety and depression including the risk of suicide thoughts, were also analyzed.

METHOD

Our sample size consisted of 130 women (ages 18-68) grouped as follows: 71 women experiencing IPV and 59 women without history of IPV as control group. All participants completed a battery of questionnaires including IPV exposure, anxiety, and depression symptoms (Beck Inventories), as well as quality of life (WHOQOL-BREF). Salivary cortisol levels in response to a cognitive test with verbal, mathematical, and abstract reasoning were measured at four time points.

RESULTS

Women exposed to IPV, with severe anxiety and depression symptoms as well as suicide thoughts, exhibited heightened cortisol response after the cognitive test and reported lower quality of life compared to (i) women experiencing IPV with moderate symptoms of anxiety and depression, who showed a blunted response, and (ii) women without history of IPV with minimal to moderate symptoms, who showed a decreased cortisol profile. Social relationships dimension was in particular the most affected aspect of quality of life.

CONCLUSIONS

Our findings highlight the role of cortisol responses as a complementary biological marker to be associated with severe psychiatric disturbances in women exposed to IPV.

FKBP51 in the Oval Bed Nucleus of the Stria Terminalis Regulates Anxiety-Like Behavior

The cochaperone FKBP51, encoded by the Fkbp5 gene, has been identified as central risk factor for anxiety-related disorders and stress system dysregulation. In the brain, the oval bed nucleus of the stria terminalis (ovBNST) has been implicated in stress-induced anxiety. However, the role of Fkbp5 in the ovBNST and its impact on anxiety-like behavior have remained unknown. Here, we show in mice that Fkbp5 in the ovBNST is reactive to acute stress and coexpressed with the stress-regulated neuropeptides Tac2 and Crh Subsequently, results obtained from viral-mediated manipulation indicate that Fkbp5 overexpression (OE) in the ovBNST results in an anxiolytic-like tendency regarding behavior and endocrinology, whereas a Fkbp5 knock-out (KO) exposed a clear anxiogenic phenotype, indicating that native ovBNST expression and regulation is necessary for normal anxiety-related behavior. Notably, our data suggests that a stress-induced increase of Fkbp5 in the ovBNST may in fact have a protective role, leading to a transient decrease in anxiety and suppression of a future stress-induced hypothalamic-pituitary-adrenal (HPA) axis activation. Together, our findings provide a first insight into the previously unknown relationship and effects of Fkbp5 and the ovBNST on anxiety-like behavior and HPA axis functioning.

Gender roles are related to cortisol habituation to repeated social evaluative stressors in adults: secondary analyses from a randomized controlled trial

Masculine and feminine gender roles influence stressor appraisals and coping in everyday life, but their effect on stress response systems like the hypothalamic-pituitary-adrenocortical axis is unclear. Accordingly, the present study tested the association between gender roles and cortisol responses to repeated stress as part of secondary analyses of data from a randomized controlled trial examining the effects of stress management interventions on cortisol habituation. Participants (N_final = 86; 72% female) completed a baseline survey assessing gender role endorsement using the Bem Sex Role Inventory, from which 4 groups were derived: masculine (n = 20), feminine (n = 20), androgynous (high masculinity, high femininity; n = 22), and undifferentiated (low masculinity, low femininity; n = 24). Following the stress management intervention (mindfulness-based stress reduction or cognitive-behavioral skills training) or waitlist period control, participants completed the Trier Social Stress Test on two laboratory visits (48 h apart). Salivary cortisol was assessed 0, 25, 35, and 60 min post-stressor during both laboratory visits. Androgynous and undifferentiated individuals both exhibited a significant decrease in total cortisol from visit 1 to visit 2 (i.e. habituation) whereas feminine and masculine individuals did not. Undifferentiated individuals exhibited greater habituation than feminine and masculine individuals, whereas androgynous individuals only exhibited greater habituation than the feminine group. Controlling for study condition assignment did not alter these results. Results imply that gender roles may be implicated in stress-related disease because of their association with HPA axis functioning during episodes of acute stress.

Stability and test-retest reliability of different hormonal stress markers upon exposure to psychosocial stress at a 4-month interval

The Trier Social Stress Test (TSST) has been shown to reliably induce physiological stress responses in the hypothalamus-pituitary-adrenal (HPA) and in the sympathetic-adrenal-medullary (SAM) axis in cross-sectional studies. However, it was also reported that repeated exposure to the TSST might be associated with habituation, mainly of the HPA axis responsivity. Thus, in all longitudinal stress studies involving repeated TSST administration, potential habituation of the HPA axis response complicates the interpretation of results. The goal of the present study was therefore to assess stability and test-retest reliability of a number of different endocrinological stress markers as well as subjective stress responses after two exposures to the TSST four months apart. We assessed salivary and plasma cortisol profiles, plasma ACTH and noradrenaline profiles, as well as subjective stress ratings in healthy volunteers before, during, and after the TSST at six time-points both at test-day 1 (TSST_1, n = 42) and test-day 2 (TSST_2, n = 34) 4-months later. Half of the participants received the TSST in the early, the other half in the late afternoon. Discontinuous growth models were applied to model three phases of the stress response (preTSST, reactivity, recovery) for each marker. Subsequently, the stability of these phases was analyzed. Stability and test-retest reliability of standard physiological stress markers such as Area-under-the-Curve (AUC_G, AUC_I), Absolute Peak Change, and Relative Peak Change (RPC) were analyzed as well. We did not observe strong test-retest effects in any of the endocrinological measures. In contrast, test-retest effects in subjective stress were characterized by a faster drop directly after the second TSST, whereas the initial increase before the test period was the same for both test-days. Regarding test-retest-reliability, AUC_G was the most reliable measure across all endocrinological and subjective stress markers (range: r = .606 to .858), while AUC_I and RPC (range: r = - .146 to .548) were least reliable. A 4-month interval is a sufficient time interval between two repeated TSST exposures to largely reinstate the physiological stress response, which was also true for the initial psychological stress response. Thus, the TSST is well applicable in longitudinal studies.

Acute social and somatic stress alters cortical metaplasticity probed with non-invasive brain stimulation in humans

Studying the neuronal mechanisms that govern the cortical adaptations to acute stress is critical for understanding the development of neuropsychiatric diseases. Homeostatic plasticity stabilizes the neural activity in which a previous synaptic event drives subsequent synaptic plasticity. In this study, we evaluated the effect of acute stress induced with the socially evaluated cold pressor test (SECPT) on cortical metaplasticity in humans using a non-invasive brain stimulation protocol. After being exposed to the SECPT and control stress conditions, 30 healthy participants were tested for cortical metaplasticity assessed with changes in the amplitude of the motor evoked potential (MEP) induced by a single-pulse transcranial magnetic stimulation (TMS). Cortical metaplasticity was induced by combining priming with cathodal tDCS (cTDCS) followed by a sub-threshold 1-Hz repetitive stimulation (rTMS) test session. Our results showed that SECPT induced cardiovascular adaptations (increase in systolic, diastolic blood pressure, and heart rate), indicating that SECPT effectively induced acute stress. Also, in our experiments stimulation of subjects with 1-Hz rTMS after they had undergone the SECPT condition induced inhibition of MEP whereas 1-Hz rTMS administered after the control condition induced a facilitatory (physiologic) response pattern. Here we observed that acute stress impairs homeostatic metaplasticity. The dysfunctional regulation of cortical plastic changes after stress could play a pivotal role in the pathogenesis of neurological and psychiatric diseases.

Dysregulated by stigma: Cortisol responses to repeated psychosocial stress in gay and heterosexual men

BACKGROUND

Research on pathways linking stigma with health inequalities affecting sexual minority populations, focused predominantly on exploring the hypothalamic-pituitary-adrenocortical (HPA) dysregulation profiles associated with chronic stress. One of such profiles reflecting a state of increased susceptibility to disease, and not yet studied among sexual minority individuals, is impaired habituation to repeated stress of the same type. In this study we explored whether sexual identity modulates endocrine stress responses and stress responses habituation in healthy heterosexual and gay men. We also explored the associations between perceived sexual minority stigma and cortisol response to stress in the latter group.

METHODS

Gay (N = 49) and heterosexual (N = 40) men, aged 24.4 years, were confronted twice with the Trier Social Stress Test and provided 5 salivary cortisol samples for each of the two testing sessions. A multilevel mixed-effects approach was used to model the cortisol curve throughout the two-day procedure. Habituation to repeated stress was conceptualized as the decrease in the total cortisol levels as well as the change in the cortisol curvilinearity between the first and the second testing session.

RESULTS

Gay participants were characterized by significantly higher cortisol levels throughout both laboratory visits. Their cortisol levels were also predicted by perceived rejection from family due to minority sexual identity, and stigma-related vicarious trauma. Although neither group showed habituation defined as the decrease in cortisol level, the shape of the cortisol curve changed between both visits only in the heterosexual participants.

CONCLUSIONS

Increased cortisol levels observed in gay men are predicted by minority stressors. Combined with non-habituation, the upregulation of the HPA axis may constitute a physiological pathway linking stigma to adverse health outcomes.

Naturalistic Stress Hormone Levels Drive Cumulative Epigenomic Changes along the Cellular Lifespan

Environmental stress is ubiquitous in modern societies and can exert a profound and cumulative impact on cell function and health phenotypes. This impact is thought to be in large part mediated by the action of glucocorticoid stress hormones, primarily cortisol in humans. While the underlying molecular mechanisms are unclear, epigenetics-the chemical changes that regulate genomic function without altering the genetic code-has emerged as a key link between environmental exposures and phenotypic outcomes. The present study assessed genome-wide DNA (CpG) methylation, one of the key epigenetic mechanisms, at three timepoints during prolonged (51-day) exposure of cultured human fibroblasts to naturalistic cortisol levels, which can be reached in human tissues during in vivo stress. The findings support a spatiotemporal model of profound and widespread stress hormone-driven methylomic changes that emerge at selected CpG sites, are more likely to spread to nearby located CpGs, and quantitatively accrue at open sea, glucocorticoid receptor binding, and chromatin-accessible sites. Taken together, these findings provide novel insights into how prolonged stress may impact the epigenome, with potentially important implications for stress-related phenotypes.

Genetic and environmental influences on cortisol reactivity to a psychosocial stressor in adolescents and young adults

Individuals vary in their response to psychological and physiological stressors, and this reactivity can be captured using measures of cortisol. Previous research suggests cortisol reactivity is under some degree of genetic control; however, the measures used have varied widely. This study (N = 524) examined potential differences in heritability across varying cortisol metrics of stress reactivity following the Trier Social Stress Test (TSST) and whether these measures are genetically or environmentally interrelated. Participants included twins aged 15-20 years (56% female). Cortisol reactivity to the TSST was assessed via serial salivary cortisol samples collected pre- and post-TSST. Modest to moderate heritability estimates (12% [95CI: 1-36%] - 45% [95CI: 16-69%]) were observed across measures purported to capture stress reactivity (peak, area under the curve [AUC], baseline-to-peak change). Findings also demonstrate both shared and unique genetic and environmental influences between baseline cortisol and cortisol reactivity. Minimal to no additional genetic innovations above and beyond the contributions of peak cortisol were found for other measures of cortisol reactivity such as AUC. This study is one of the largest twin-based samples to examine the heritability of cortisol reactivity, and results suggest that simpler measures of cortisol reactivity demonstrate higher heritability compared to more complex measurements.

The Impact of Chronic Stress and Eating Concern on Acylated Ghrelin Following Acute Psychological Stress in Healthy Men

Stress, mood, and eating behavior play an important role in appetite and weight regulation. In particular, ghrelin, as the only known orexigenic hormone, has been suggested to be an influential mediator in food intake responses to stress. The exact role of ghrelin in the hypothalamic–pituitary–adrenal axis is still unknown and further challenged by the psychological aspects of stress and eating behavior. This study aimed to assess the effect of chronic stress and subjective concern about eating on acute stress-induced changes in acylated ghrelin. In a 2-day study, sixteen healthy male participants were confronted with a stressful situation as well as a control situation. Additional measurements of heart rate, subjective hunger ratings, and subjective mood ratings were made to assess successful acute stress induction. The linear mixed model approach revealed a significant effect of acute stress on acylated ghrelin for a study-day*chronic-stress interaction (p < 0.001). Concern about eating did not affect acylated ghrelin levels after acute stress exposure. The significant interaction showed that lower chronic stress exposure was associated with a stronger acylated ghrelin response after acute stress exposure versus control condition. At the same time, participants with higher chronic stress exposure showed a blunted acylated ghrelin response after acute stress exposure compared to the control situation. Our findings indicate that chronic stress exposure can influence acylated ghrelin response after acute stress encounters, possibly affecting subsequent food intake and explaining the often diverse outcome in measurements of acute stress responses.

Interaction between three stress-related gene polymorphisms and food addiction increases the risk to develop obesity in a sample of Mexican people attending a nutrition clinic

Chronic stress exposure impacts negatively in individuals leading to food addiction, overweight or obesity. Stress-genes and their translation products are responsible for the responses of humans to adverse environments. Alterations in stress-genes expression or protein function may induce behaviors as compulsive eating of high-energy containing food, which decreases stress-induced negative feelings. However, chronic stress is not assessed in Mexican population. We analyzed here the association between polymorphisms of CRH, CRHR2 and glucocorticoids (GR, NR3C1) receptor genes with food addiction and obesity and overweight in Mexican patients of a Nutrition Clinic. We recruited 508 individuals of both genders, who accepted to participate in the study at their first visit to the clinic, obtaining their fat mass percentage and a blood sample for the genetic analysis. Participants answered the Yale's food addiction scale and were subjected to a Trier social test, as an acute stressful stimulus. Pre and post-test saliva samples were obtained to evaluate cortisol levels and adrenal axis' response to the acute stress. The 63% of participants classified as stressed (S); 6.5% of normal-weight individuals showed food-addiction, whereas 63% of participants with food-addiction were also stressed. The fat mass percentage was greater in stress-addiction than in stressed non-addiction participants. The best interaction model for obesity development risk comprehended the presence of polymorphisms of the three genes that in combination with food addiction increased the risk for developing obesity 2.8-4-fold. Thus, frequent stress exposure favors food-addiction, which along with genetic susceptibility seems to add up to Mexican obesity/overweight rates.

Hyper- and hypo-cortisol functioning in post-institutionalized adolescents: The role of severity of neglect and context

Understanding the developmental timing of stress exposure may help inform mechanisms underlying how stress "gets under the skin" and influences the stress response system, including the HPA axis and its end-product cortisol. Early adversity may be particularly detrimental; however, it is difficult to disentangle the timing of adversity from its cumulative burden because there is typically high continuity between early and later adversity. Moreover, context and the different stressors inherent in various contexts may interact with stress exposure to influence psychophysiological functioning. To address this issue, we examined adolescents who had been reared in institutions and suffered neglect or social deprivation ranging from approximately six months to several years of life prior to adoption into U.S. homes. We focused on the stress hormone cortisol because it can reflect continued regulatory problems in youth, even years after youth transition to typical homes. We examined cortisol morning levels and diurnal rhythms across multiple contexts (home, school, lab) on 5 separate days in 41 post-institutionalized youth and 78 comparison youth. Employing hierarchical linear modeling, we found that when assessed in the lab, post-institutionalized (PI) youth displayed lower morning cortisol levels and flatter diurnal slopes than the control youth. Yet at home, PI youth displayed higher morning cortisol levels than the control youth. In addition to group effects, we also examined severity of early adversity and found that PI kids who had endured the most severe early adversity displayed lower home cortisol levels than controls. No significant predictors of diurnal cortisol on school days were identified. These data fit with the notion that the HPA axis is impacted by early adversity, even years after adoption, and with emerging theories that postulate that stress physiology calibrates within youth to help them adapt to their context. In the case of severe early adversity, the cost of such adaptation may not be desirable. It also highlights the important role of context when assessing HPA axis activity, particularly in post-institutionalized youth.

Exhaustion and dependency: a habituation–sensitization perspective on the duality of habit in social media use

Purpose

The current work builds on the dual process theory of habituation and sensitization to empirically investigate theory-based mechanisms through which social media use habit influences continued social media use intentions in the context of problematic social media use (SMU).

Design/methodology/approach

We build on the dual process theory of habituation and sensitization and test our model with structural equation modeling technique applied to survey-based data collected from 337 social media users.

Findings

Findings suggest that SMU Habit may increase user's perceived Habituation and directly reduce user's experienced SMU related Exhaustion. Furthermore, Habituation and SMU related Exhaustion are negatively associated in a nonlinear fashion. Also, SMU Habit may promote higher level of SMU Dependency through Sensitization. Increased level of SMU Dependency is associated with increased level of SMU related Exhaustion. Thus, SMU Habit simultaneously shapes two opposing forces driving continued use decisions.

Practical implications

The current work can serve as a basis for developing effective interventions especially given the increase in problematic uses of IS fostered by the development of technology use habits.

Originality/value

Although separate strands of research independently examined the role of “pull” forces such as SMU dependency and the role of “push” forces such as SMU related Exhaustion in influencing users' inclination toward future SMU, a unified theoretical framework considering the triad of SMU Habit, “pull” and “push” forces together is yet to be offered. Deploying Habituation–Sensitization theory will shed new light on dual mechanisms through which habit drives continued use decisions in SMU context. Thus, the current work can serve as a basis for developing effective interventions given the increase in problematic uses of IS.

Dynamics and determinants of cortisol and alpha-amylase responses to repeated stressors in recent interpersonal trauma survivors

BACKGROUND

Alterations in major stress response systems are present during the immediate aftermath of trauma and may play a role in determining risk for developing posttraumatic stress disorder (PTSD). However, the dynamics and determinants of stress responses during this acute recovery phase, and their relevance for longitudinal clinical course and prognosis, have yet to be fully examined. The objectives of the present study were to characterize stress response and habituation patterns to repeated social stressors in women who recently experienced interpersonal trauma and to determine the extent to which these stress responses were associated with PTSD during prospective follow-up.

METHOD

This longitudinal study examined salivary cortisol and alpha-amylase and heart rate (HR) responses to repeated stressors in 98 young women (ages 18-30). Participants included women who had experienced an incident of interpersonal trauma (i.e., physical and/or sexual assault) in the three months prior to their baseline assessment (n = 58) and a comparison group of healthy, non-traumatized women (n = 40). Women completed the Trier Social Stress Test (TSST), clinical interviews to evaluate posttraumatic stress symptom severity at the baseline assessment and again at 1-, 3-, and 6-month follow-ups.

RESULTS

Multilevel models revealed a pattern of robust initial cortisol TSST responses and habituation across successive TSSTs; alpha-amylase and HR responses showed no evidence of habituation across TSSTs. Among interpersonal trauma survivors, current PTSD status was associated with more pronounced cortisol responses to the first TSST. Survivors exhibited similarly blunted cortisol responses across follow-up TSSTs regardless of PTSD status, suggesting habituation of cortisol responses among survivors who developed PTSD. PTSD re-experiencing symptoms were uniquely associated with blunting of cortisol TSST responses.

CONCLUSION

Findings suggest that PTSD as a diagnostic entity is meaningfully associated with cortisol responses to repeated social stressors. Social-evaluative threat is a salient form of danger for interpersonal trauma survivors. Identifying the determinants of cortisol (non)habituation to repeated social-evaluative threat among interpersonal trauma survivors could inform the development of early interventions for PTSD.

Prolonged Glucocorticoid Exposure Does Not Accelerate Telomere Shortening in Cultured Human Fibroblasts

Psychosocial stress, especially when chronic or excessive, can increase disease risk and accelerate biological aging. Although the underlying mechanisms are unclear, in vivo studies have associated exposure to stress and glucocorticoid stress hormones with shorter telomere length. However, the extent to which prolonged glucocorticoid exposure can shorten telomeres in controlled experimental settings remains unknown. Using a well-characterized cell line of human fibroblasts that undergo gradual telomere shortening during serial passaging in culture, we show that prolonged exposure (up to 51 days) to either naturalistic levels of the human endogenous glucocorticoid cortisol or the more potent synthetic glucocorticoid dexamethasone is not sufficient to accelerate telomere shortening. While our findings await extension in other cell types and biological contexts, they indicate that the in vivo association of psychosocial stress with telomere shortening is unlikely to be mediated by a direct and universal glucocorticoid effect on telomere length.

Ex vivo LPS-stimulated cytokine production is associated with cortisol curves in response to acute psychosocial stress

BACKGROUND

Empirical and theoretical evidence suggest that because of the co-evolution of the endocrine and immune response systems, different types of stressors may lead to similar levels of physiological activation. The present analyses examined associations between two physiological stress responses: the cortisol response to an acute laboratory stressor and ex vivo lipopolysaccharide (LPS) stimulated inflammatory cytokine production.

METHODS

Healthy middle-aged adults (N = 65) completed testing at two appointments, two weeks apart. Blood was collected at each appointment to measure circulating inflammatory cytokine levels and stimulated inflammatory cytokine production after 4 and 24 hours of incubation with LPS. A cumulative standardized composite measure of inflammation was calculated using the cytokines interleukin-6 (IL-6), interleukin-1β (IL-1β), and interferon-γ (IFN-γ). At visit two, after the blood draw, participants completed the Trier Social Stress Test (TSST); saliva samples were collected before and after to generate cortisol response curves (area under the curve with respect to ground [AUC_G] and increase/decrease [AUC_I]).

RESULTS

AUC_G was significantly associated with stimulated cytokine production at visit 2 after both 4 hours (B = 6.89; p = 0.007) and 24 hours (B = 7.50; p = 0.005) of incubation, controlling for age, sex, and BMI. AUC_I was also significantly associated with stimulated cytokine production at visit 2 after 4 hours (B = 6.28; p = 0.004) and 24 hours (B = 6.16; p = 0.007) of incubation, controlling for age, sex, and BMI. Stimulated inflammatory cytokine production was strongly correlated across the two visits (2 weeks apart) after 4 hours of incubation (r = 0.80, p < 0.001) and after 24 hours (r = 0.80, p < 0.001). Within each visit, stimulated cytokine production after 4 hours was significantly correlated with stimulated inflammation at 24 hours (r = 0.93-0.94, p < 0.05) CONCLUSIONS: These results suggest that LPS-stimulated inflammatory cytokine production and the cortisol response to the TSST contain comparable information about acute human physiological stress responses. Moreover, measurement of stimulated cytokines was highly stable across a two-week time period whether measured after 4 or 24 hours of incubation with LPS.

Corroborative evidence for an association between initial hypothalamic-pituitary-adrenocortical axis reactivity and subsequent habituation in humans

BACKGROUND

The extant literature predicts that initial hypothalamic-pituitary-adrenocortical (HPA) axis response magnitude and subsequent habituation are associated with health, such that both heightened stress reactivity and non-habituation to repeated stressors are associated with disease. Yet, despite evidence for an association between initial HPA axis reactivity and subsequent habituation, the extant literature often considers health implications of these stress response patterns independently or make interpretations based on an initial response alone. This may be because past tests of the association between reactivity and habituation were subject to statistical bias (e.g., regression to the mean), and no prior work has examined the association between initial cortisol reactivity and subsequent habituation using analytic strategies capable of estimating the unbiased relationship between initial value (i.e., reactivity) and subsequent change (i.e., habituation). Accordingly, the present investigation drew from two previously published studies to test the association between initial HPA axis reactivity and subsequent habituation using analytic strategies capable of estimating the relationship between initial reactivity and subsequent habituation with minimal bias.

METHODS

We examined salivary cortisol and plasma ACTH responses to three repeated social-evaluative stressors (Study 1) and salivary cortisol responses to two repeated social-evaluative stressors (Study 2).

RESULTS

As predicted, results indicated a negative relationship (Pearson's r ranging from -0.27 to -0.91) where initial HPA axis reactivity was associated with subsequent habituation across both studies, even when using estimation procedures capable of producing an unbiased estimate of this relationship.

CONCLUSIONS

Results support the claim that initial HPA axis reactivity to acute stress is associated with subsequent habituation, such that initially high reactors are likely to habituate, whereas initially blunted reactors are likely to sensitize. In view of these results, hypothesized long-term health implications of acute cortisol reactivity and habituation patterns should be considered in tandem.

Literature review and methodological considerations for understanding circulating risk biomarkers following trauma exposure

Exposure to traumatic events is common. While many individuals recover following trauma exposure, a substantial subset develop adverse posttraumatic neuropsychiatric sequelae (APNS) such as posttraumatic stress, major depression, and regional or widespread chronic musculoskeletal pain. APNS cause substantial burden to the individual and to society, causing functional impairment and physical disability, risk for suicide, lost workdays, and increased health care costs. Contemporary treatment is limited by an inability to identify individuals at high risk of APNS in the immediate aftermath of trauma, and an inability to identify optimal treatments for individual patients. Our purpose is to provide a comprehensive review describing candidate blood-based biomarkers that may help to identify those at high risk of APNS and/or guide individual intervention decision-making. Such blood-based biomarkers include circulating biological factors such as hormones, proteins, immune molecules, neuropeptides, neurotransmitters, mRNA, and noncoding RNA expression signatures, while we do not review genetic and epigenetic biomarkers due to other recent reviews of this topic. The current state of the literature on circulating risk biomarkers of APNS is summarized, and key considerations and challenges for their discovery and translation are discussed. We also describe the AURORA study, a specific example of current scientific efforts to identify such circulating risk biomarkers and the largest study to date focused on identifying risk and prognostic factors in the aftermath of trauma exposure.

Evaluation of the Effectiveness of One- and Multi-Session Exposure-Based Treatments in Reducing Biological and Psychological Responses to Rat Phobia Among Students

BACKGROUND

Animal phobia is one of the most common forms of specific phobias. This anxiety disorder challenges the medical student working with animal models. Regarding this, the present study was conducted to investigate the effectiveness of one- and multi-session cognitive exposure-based treatments in students with rat phobia.

METHODS

For the purpose of the study, a total of 40 female students with rat phobia were allocated into two groups of one- and multi-session cognitive exposure-based treatments. The data were collected using psychological measures, including state anxiety, rat phobia, and disgust questionnaires, which were completed in three stages, including the baseline, pre-treatment, and post-treatment. The gene expression levels of pro-inflammatory cytokines (ie, interleukin-1 [IL-1], nuclear factor-kappaB [NF-κB], and tumor necrosis factor-alpha [TNFα]) associated with acute stress, as well as the serum levels of IL-6 and cortisol, were determined using reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) methods. This study was registered at the Iranian Registry of Clinical Trials (IRCT20171123037602N1).

RESULTS

According to the results, both treatments yielded a significant reduction in almost all psychological measures and biological variables, except for IL-6. Rat phobia was the only variable that showed a statistically greater reduction in the multi-session treatment group. Furthermore, rat phobia and disgust reduction were maintained in both groups to the same extent during follow-up.

CONCLUSION

The findings of the present study were indicative of the incidence of habituation in psychological and biological factors following exposure therapy. Both one- and multi-session treatments reduced the factors associated with rat phobia almost to the same degree. As a result of the high levels of disgust, anxiety-related biological factors remained high in four students despite observing a significant reduction in their fear. This led to passive avoidance in this group. The OST enabled the students to handle rats in less than half a day. Accordingly, it could be applied as a half-day workshop for students in medical universities to avoid the incidence of associated anxiety-related disorders in this group.

Focusing attention on biological markers of acute stressor intensity: Empirical evidence and limitations

ARMARIO, A, J. Labad and R. Nadal. Focusing attention on biological markers of acute stressor intensity: empirical evidence and limitations. NEUROSCIENCE AND BIOBEHAVIORAL REVIEWS. The availability of biological markers that objectively quantify stress is a highly relevant issue. However, experimental evidence suggests that most physiological changes elicited by emotional stressors do not reflect their intensity and are not useful for this purpose. Thus, we review experimental evidence in animals and humans about the putative validity of neuroendocrine and sympathetic/parasympathetic variables to measure stress. Plasma levels of some hormones (e.g. ACTH, glucocorticoids, prolactin and catecholamines) have been found to reflect, at least under certain conditions, the intensity of emotional stressors in animals and probably in humans. However, the temporal resolution of hormone changes is insufficient to reflect the very dynamic psychological processes taking place while experiencing stressors. Cardiovascular parameters (e.g. heart rate and blood pressure) have much better temporal resolution but their validity as markers of stressor intensity either in animals or humans is problematic. Skin conductance and pupil dilation appear to be promising. Additional and more systematic studies are needed to demonstrate the actual validity of stress-induced physiological changes to quantify stress.

Moving 2 Mindful (M2M) study protocol: testing a mindfulness group plus ecological momentary intervention to decrease stress and anxiety in adolescents from high-conflict homes with a mixed-method longitudinal design

INTRODUCTION

Interparental conflict exposure places adolescents at risk for problems with stress and anxiety; existing prevention/intervention strategies focus on reducing interparental conflict. Mindfulness-based programmes may be a promising treatment strategy for this population, but studies have not yet tested whether they are effective in this high-conflict context. In addition, evidence suggests that extensions to traditional treatments, such as delivering components in daily life that are tailored to moments of need, can increase treatment efficacy, particularly when combined with in-person treatments and particularly for adolescents. However, there are no such extensions to mindfulness interventions available. The Moving 2 Mindful study aims to (1) develop an ecological momentary intervention (EMI) supplement to Learning to BREATHE (L2B), an evidence-based mindfulness intervention for adolescents; (2) refine the EMI programme and determine the best delivery plan; (3) examine the feasibility and acceptability of L2B Plus (L2B plus the developed supplement) and (4) examine the potential for L2B Plus to reduce stress and anxiety for adolescents from high-conflict homes.

METHODS AND ANALYSIS

The Moving 2 Mindful study proposes a mixed-methods approach to developing and refining a multimethod adaptive supplement to L2B. Feasibility, acceptability and potential effectiveness will be tested in a sample of 38 families, who will be randomly assigned to receive L2B Plus or an active health and wellness control condition and followed until 3 months postintervention. A range of psychosocial and physiological factors will be assessed at multiple time points. This study is registered with clinicaltrials.gov (ID NCT03869749; pre-results).

ETHICS AND DISSEMINATION

The Institutional Review Board at Colorado State University has approved this study. Findings will be disseminated in scientific journals and conferences, whether they are positive, negative or inconclusive.

Repeated stress leads to enhanced cortisol stress response in child social anxiety disorder but this effect can be prevented with CBT

Social anxiety disorder (SAD) is associated with continual social stress in everyday life. Two physiological components of stress are the hypothalamus-pituitary-adrenal axis, as captured by cortisol reactivity, and the autonomous nervous system, as captured by salivary alpha amylase (sAA) reactivity. In children with SAD, initial evidence points to dysregulated physiological stress reactivity for both systems. Furthermore, hardly any studies have assessed stress reactivity twice, including exploring possible changes after cognitive behavioral therapy (CBT). Children with SAD (n = 65; aged 9-13 years) and healthy controls (HCs, n = 55) participated in a social stress task (Trier Social Stress Test for Children, TSST-C), which was repeated with children with SAD after either 12 sessions of CBT or a waiting period to explore possible habituation or sensitization effects. Before treatment, children in the SAD and HC groups did not differ in their cortisol stress reactivity toward the TSST-C but did differ in their sAA response with a more pronounced response in the SAD group. After treatment, children with SAD in the waitlist group differed from children with SAD in the CBT group by showing stronger cortisol reactivity and a higher responder rate, indicative of a possible sensitization to stress. No difference was found for sAA. Future research should compare children with SAD and HC children concerning the effect of repeated stress on sensitization.

Symposium review: Scientific assessment of affective states in dairy cattle

Affective states, which refer to feelings or emotions, are a key component of animal welfare, but these are also difficult to assess. Drawing upon a body of theoretical and applied work, we critically review the scientific literature on the assessment of affective states in animals, drawing examples where possible from research on dairy cattle, and highlighting the strengths and weaknesses of scientific methods used to assess affective states in animals. We adopt the "valence/arousal" framework, describing affect as a 2-dimensional space (with valence referring to whether an experience is positive or negative, and arousal referring to the intensity of the experience). We conclude that spontaneous physiological and behavioral responses typically reflect arousal, whereas learned responses can be valuable when investigating valence. We also conclude that the assessment of affective states can be furthered using mood assessments and that the use of drug treatments with known emotional effects in humans can be helpful in the assessment of specific affective states in animals.

Stress and inflammation - The need to address the gap in the transition between acute and chronic stress effects

Stress responses help us navigate our environment and respond appropriately to threats. Stress systems communicate threats to the entire organism, and as such, also stimulate inflammatory mechanisms. This modulation might serve protective functions in the short term, but sustained low-grade inflammation has severe long-term health consequences. While we have reached a reasonable level of understanding of acute, as well as chronic stress effects on inflammatory mechanisms, there is a significant gap in our understanding of the transitional phase between acute and chronic stress. The purpose of this review is to first summarize current knowledge of our understanding of acute stress effects on inflammation, as well as of chronic stress effects on inflammation, and to then analyze the state of knowledge about the transitional phase between acute and chronic stress. Research discussed here shows that we are beginning to understand the early phase of repeated acute stress, but lack information on longer term exposure to repeated acute stress experiences. More research is needed to bridge this important gap und our conceptualization and understanding of the stress and health relationship.

HPA axis responses to psychological challenge linking stress and disease: What do we know on sources of intra- and interindividual variability?

Stress is an ubiquitous phenomenon with significant impact on human physiology when it lasts too long, when it is too intense, or when it hits vulnerable individuals. Examining the mechanisms linking stress exposure with health and disease is an important endeavor in psychoneuroendocrine research. Empirical evidence so far revealed large intra- as well as inter-individual variability in hypothalamic-pituitary-adrenal (HPA) axis responses to acute psychosocial stress, showing that the HPA axis is a highly adaptive system. Thus, the characterization of intra- und inter-individual patterns of HPA axis reactivity is of high scientific interest and forms the basis on which mechanistic links between stress response (dys)regulation and health impairments can be examined. To date, basic knowledge has been, and still is, accumulated on demographic, biological (including genetic and epigenetic) factors, lifestyle behavioral variables, consumption of substances and medication, psychological and personality factors, as well as on methodological aspects. Besides this, there is also very recent progress in respect to the development of laboratory stress paradigms that can be applied in virtual reality or inside an MRI-scanner. In sum, the present review updates our current knowledge on moderating and intervening factors as sources of intra- und inter-individual variability in human cortisol stress responses and offers recommendations for future research designs.

Endocrine and psychological stress response in simulated doctor-patient interactions in medical education

BACKGROUND

Training of doctor-patient interactions by means of patient actors is considered a useful didactic tool in medical education. However, though students report it as being highly stressful little systematic research has verified this notion.

AIMS

To assess the endocrine and psychological stress responses of students in the doctor vs. the observer role in simulated doctor-patient interactions.

METHODS

Salivary cortisol and anxiety was assessed in N = 86 participants of a mandatory course on doctor-patient interactions on three consecutive days. During two of these days they were in the observer role and gave feedback to another student and on one of these days they were in the doctor role and were being given feedback. Saliva was sampled at 4 points in time per day: prior to interaction (T1); after watching the video of the interaction (T2); after feedback (T3); after observation of another interaction (T4). Assessments on observer days took place at the respective time points and at the same time of the day. 3-way mixed ANOVAs were computed with the factors "day of data sampling" (F1); "day with doctor role" (F2); "measurement time"(F3).

RESULTS

Significant two-way interactions F1 × F2 and three-way interactions F1 × F2 × F3 were observed both for cortisol and for anxiety (all p < .001). Neither cortisol nor anxiety were related to task severity. Anxiety at T1 correlated with cortisol increase from T1 to T2 (r = .266; p = .013).

DISCUSSION

Results confirm that playing the doctor role in a simulated doctor-patient interaction represents a significant stressor in medical students. Effect sizes considerably exceed those observed in laboratory stress. This brings about new questions regarding moderating factors, effects of repetitions and relationship to medical performance. The ecological validity of this stressor can also make it a useful tool in basic endocrine research.

Cognitive behavioral therapy, mindfulness, and cortisol habituation: A randomized controlled trial

BACKGROUND

Hypothalamic-pituitary-adrenocortical (HPA) axis dysregulation is associated with disease and may be indexed by poor cortisol habituation (i.e., a failure to show decreased responding with repeated stressor exposure). Thus, stress management training that can enhance HPA axis habituation may benefit health. To date, the effects of Mindfulness Based Stress Reduction (MBSR) and Cognitive Behavioral Therapy (CBT) interventions on HPA axis habituation remain untested. To test the effects of MBSR and CBT on HPA axis habituation, the present study used a parallel arm randomized controlled trial.

METHODS

Healthy adults reporting moderate-to-high stress (n = 138) were randomly assigned to a 6-week MBSR intervention, a 6-week CBT intervention, or Waitlist control group. Post-intervention, participants completed a social-evaluative performance stressor during each of two laboratory visits scheduled 48-h apart. Salivary cortisol was collected pre-stressor, and 25, 35, and 60 min post-stressor onset during each visit. Final analyses included 86 participants who completed procedures up to the first laboratory visit.

RESULTS

Relative to the control condition, both MBSR and CBT groups showed greater cortisol habituation. The MBSR group exhibited marginally greater habituation than the Waitlist group in cortisol samples corresponding to the recovery time points (35 and 60 min post-stressor onset). In contrast, the CBT group showed greater habituation than the Waitlist across all sampling timepoints collected (pre-stressor, 25, 35, and 60 min post-stressor onset). Yet, the CBT group also demonstrated elevated pre-stressor cortisol during the first visit.

CONCLUSIONS

Results suggest that MBSR and CBT interventions promote greater HPA axis habituation relative to no training, but do not reduce overall cortisol output (i.e., across both visits). Observed differences between CBT and MBSR training in relation to cortisol habituation are discussed.

Higher trait reappraisal predicts stronger HPA axis habituation to repeated stress

Undergoing stress can be advantageous when it leads to adaptation and growth; however, failure of the hypothalamic-pituitary-adrenal (HPA) axis to habituate (i.e., nonhabituation) involves continuing to become highly activated in response to repeated exposure of the same stimulus and is considered maladaptive. Although 50-75% of individuals assessed in a laboratory exhibit adaptive habituation to repeated stress, variability in habituation suggests psychological processes used in response to stress may play a role, such as emotion regulation (ER). Nonetheless, no research to date has investigated whether ER strategies affect HPA axis habituation. We investigated whether tendency to use two ER strategies, reappraisal and suppression, influenced HPA axis habituation among 84 healthy young adults (60.7% female; M_age = 24.8 years, SD = 6.0) exposed to a standardized experimental stress paradigm on two consecutive days. HPA axis stress responses were assessed using salivary cortisol concentrations. We also examined whether non-manipulated state ER strategies (i.e., those used by the participant during and following the stressor on the first day) modulated HPA axis habituation over and above trait-use in a subsample (N = 60). Trait, but not state, reappraisal was associated with stronger HPA axis habituation. Neither trait nor state suppression were significantly associated with HPA axis habituation. These findings expand our current understanding of how ER can affect stress-related health outcomes and suggest habitual reappraisal plays an important role in adaption of the HPA axis to stress.

Acute Stress Assessment From Excess Cortisol Secretion: Fundamentals and Perspectives

Our paper aims to redefine the concept of stress in the context of maintaining allostasis; the term has been reserved for situations that concomitantly involve established physiological and psychological stress components. In particular, we analyze how novelty, unpredictability, threat to the ego, and low sense of control challenge allostasis. The concept of stress is then related to a state of difficulty in maintaining allostasis, rather than referring to the overall body response to the situation. This state of difficulty may be observed either in planning the strategy to deal with the situation, evaluating consequent target trajectories for the actuators, the catabolic mediators and the activators, or regulation of the biological systems through these trajectories. Catabolic mediator excesses are proposed as scaling the level of difficulty in maintaining allostasis. The excess proportion of cortisol load (EPCL) is consequently proposed to scale the stress level. A first proof-of-concept of this indicator is realized using the Physiostress dataset, by asserting that it is, as predicted from its theoretical basis, more in phase with the stress level expected from the nature of the task and participant-reported stress compared to common indicators based on the cortisol response magnitude itself.

Biopsychosocial approach to understanding resilience: Stress habituation and where to intervene

BACKGROUND

Resilience in the face of adversity is a human experience that leads to better health, both mentally and physically. We briefly review its historical origins rooted in ecological biology and its adoption into health care. Resilience is the common response to adversity or potential traumatic events. Individual differences in emotion regulation and coping skills as well as social capital and one's physical environment influence a person's ability to achieve resilience.

PROPOSED MECHANISM

One potential biopsychosocial measure of resilience includes stress habituation to repeated stress as demonstrated in the laboratory, possibly providing a tool to observe mastery of resilience training in the clinic. Evidence-based interventions at the individual and small group level (eg, family, classroom) have successfully shown development of resilient behaviours and improved mental and physical health outcomes. However, the role of social context and public policy clearly influence an individual's ability to be resilient.

CONCLUSIONS

Despite the current limited evidence of the effectiveness of resilience building interventions, clinicians, researchers, and other health care professions have an obligation to become advocates for laws and policies that support the most vulnerable, and least resilient, in our society to attain resilience for their health. This salutary effect will enable them to become socially as well as economically productive members of the community at large. It is not possible to remove stress or adversity from life, but we can influence the development of regulatory flexibility and decrease the sociocultural factors linked to the nonresilient experience, thus mitigating adversity's long-term effects on health.

Effects of milk-based phospholipids on cognitive performance and subjective responses to psychosocial stress: A randomized, double-blind, placebo-controlled trial in high-perfectionist men

OBJECTIVES

The aim of this study was to examine the stress-buffering potential of phospholipid (PL) intake on cognitive performance and neuroendocrine and psychological responses under conditions of psychosocial stress in a high-stress vulnerable (perfectionist) sample.

METHODS

Fifty-four high-perfectionist men consumed a 6-wk daily intake of a bovine milk-derived PL (2.7 g/d) or placebo drink in a randomized, double-blind, placebo-controlled, parallel groups design. Working memory, executive control function, and acute physiological/subjective responses to an acute psychosocial stressor were examined before and after the 6-wk PL or placebo intake.

RESULTS

PL intake improved post-stress reaction time performance on an attention-switching task (P = 0.01). No significant attenuation of the salivary cortisol stress response was shown. PL intake significantly increased mid-stress induction energetic arousal (P = 0.03). A non-significant reduction in anticipatory subjective stress was reported after PL intake (P = 0.06). Systolic and diastolic blood pressures (P<0.04 and P = 0.01, respectively) were significantly augmented in the PL condition.

CONCLUSIONS

Dietary intake of bovine milk PLs conferred cognitive performance benefit under conditions of psychosocial stress but failed to moderate cortisol response. Moderation of subjective response to stress exposure may have underpinned this performance protection.

Association between changes in heart rate variability during the anticipation of a stressful situation and the stress-induced cortisol response

Vagal activity - reflecting the activation of stress regulatory mechanisms and prefrontal cortex activation - is thought to play an inhibitory role in the regulation of the hypothalamus-pituitary-adrenal axis. However, most studies investigating the association between stress-induced changes in heart rate variability (HRV, an index of cardiac vagal tone) and cortisol have shown a non-significant relationship. It has been proposed that physiological changes observed during anticipation of a stressor allow individuals to make behavioral, cognitive, and physiological adjustments that are necessary to deal with the upcoming actual stressor. In this study, in a large sample of 171 healthy adults (96 men and 75 women; mean age = 29.98, SD = 11.07), we investigated whether the cortisol response to a laboratory-based stress task was related to anticipation-induced or stress task-induced changes in HRV. As expected, regression analyses showed that a larger decrease in HRV during the anticipation of a stress task was related to higher stress task-induced cortisol increase, but not cortisol recovery. In line with prior research, the stress task-induced change in HRV was not significantly related to cortisol increase or recovery. Our results show for the first time that anticipatory HRV (reflecting differences in stress regulation and prefrontal activity before the encounter with the stressor) is important to understand the stress-induced cortisol increase.

Developmental differences in stress responding after repeated underwater trauma exposures in rats

Adolescence is a distinct developmental period characterized by behavioral and physiological maturation. Rapid ongoing changes during neurodevelopment in particular present potential opportunities for stress to have lasting effects on longitudinal outcomes of behavioral and neuroendocrine function. While adult stress effects on outcomes during adulthood have been characterized, little is known about the lasting effects of adolescent repeated stressor exposure on outcomes during adolescence. We have previously reported different stress responses in adolescent rats relative to adult rats, including a blunted fear response outcome in adulthood in rats stressed during adolescence. The present study characterized the ontogeny of behavioral and neuroendocrine responses to eight underwater trauma (UWT) exposures in rats over a two week poststress time period during adolescence (P34) or adulthood (P83) relative to age-matched control groups that underwent eight swimming episodes without UWT. Repeated UWT exposures starting in adolescence, but not adulthood, resulted in adverse behavioral responses on the elevated plus maze 1 day post-stress. Corticosterone responses did not differ between UWT-exposed and controls for either age group at 1 day or at 7 days poststress, although there was an effect of age on corticosterone levels. We conclude that repeated UWT stress events have a lasting, negative behavioral effect on adolescent rats that is not observed in adult rats after the two-week exposure window. These results suggest that neurophysiological mechanisms underlying recovery from a repeated stressor are immature in adolescence relative to adulthood in rats.

Constitutive differences in glucocorticoid responsiveness to stress are related to variation in aggression and anxiety-related behaviors

Glucocorticoids coordinate responses that enable an individual to cope with stressful challenges and, additionally, mediate adaptation following cessation of a stressor. There are important individual differences in the magnitude of glucocorticoid responsiveness to stressors. However, whether individual differences in glucocorticoid responsiveness to stress are linked to different behavioral strategies in coping with social and non-social challenges is not easily studied, owing to the lack of appropriate animal models. To address this, we generated three lines of Wistar rats selectively bred for the magnitude of their glucocorticoid responses following exposure to a variety of stressors over three consecutive days at juvenility. Here, we present findings following observations of a high level of variation in glucocorticoid responsiveness to stress in outbred Wistar rats, and the strong response to selection for this trait over a few generations. When challenged with different stressful challenges, rats from the three lines differed in their coping behaviors. Strikingly, the line with high glucocorticoid responsiveness to stress displayed enhanced aggression and anxiety-like behaviors. In addition, these rats also showed alterations in the expression of genes within both central and peripheral nodes of the hypothalamic-pituitary-adrenal (HPA) axis and enhanced reactivity to acute stress exposure. Together, these findings strongly link differences in glucocorticoid responsiveness to stress with marked differences in coping styles. The developed rat lines are thus a promising model with which to examine the relationship between variation in reactivity of the HPA axis and stress-related pathophysiology and could be employed to assess the therapeutic potential of treatments modulating stress habituation to ameliorate psychopathology.

The anticipatory stress response to sport competition; a systematic review with meta-analysis of cortisol reactivity

Objective

Athletes anticipating sport competition regularly experience distinct emotional and physiological responses as a result of the expected psychosocial and physical stress. Specifically, cortisol, an indicator of hypothalamic-pituitary-adrenal axis activation, prepares the athlete for the psychological and physiological demands of competition. The objective of this meta-analysis is to analyse the magnitude of the anticipatory cortisol response in athletes preparing to participate in sport competition and to examine the influence of gender, level of competition and data collection time.

Design

Systematic review with meta-analysis.

Data sources

Four electronic databases were searched to March 2017: PubMed, PsycINFO, SPORTDiscus and Scopus.

Eligibility criteria for selecting studies

(1) Athletes participating in real sport competition;(2) salivary cortisol concentration collected before competition in addition to baseline sample(s);(3) original research article published in English language.

Results

Data from 25 studies provided 27 effect sizes. A significant anticipatory cortisol response of g=0.85, p<0.001 was identified. Males had a stronger trend for greater cortisol reactivity (g=1.07) than females (g=0.56, p=0.07). Females and athletes competing at international level did not demonstrate a significant anticipatory stress response. There were no significant differences between level of competition, type of sport or time of competition. Meta-regression indicated that the anticipatory cortisol response is greater when assessed closer to the start of competition (Q=6.85, p=0.009).

Summary/conclusion

The anticipatory cortisol response before sport competition reflects moderate cortisol reactivity that prepares athletes optimally for the demands of sport competition via the influence on cognitive processes and attentional control. However, both female athletes and international competitors did not demonstrate a significant anticipatory cortisol response, possibly due to differences in appraisal of the stress of sport competition.