Acute Stress Effects on Statistical Learning and Episodic Memory.

Stress is widely considered to negatively impact hippocampal function, thus impairing episodic memory. However, the hippocampus is not merely the seat of episodic memory. Rather, it also (via distinct circuitry) supports statistical learning. On the basis of rodent work suggesting that stress may impair the hippocampal pathway involved in episodic memory while sparing or enhancing the pathway involved in statistical learning, we developed a behavioral experiment to investigate the effects of acute stress on both episodic memory and statistical learning in humans. Participants were randomly assigned to one of three conditions: stress (socially evaluated cold pressor) immediately before learning, stress ∼15 min before learning, or no stress. In the learning task, participants viewed a series of trial-unique scenes (allowing for episodic encoding of each image) in which certain scene categories reliably followed one another (allowing for statistical learning of associations between paired categories). Memory was assessed 24 hr later to isolate stress effects on encoding/learning rather than retrieval. We found modest support for our hypothesis that acute stress can amplify statistical learning: Only participants stressed ∼15 min in advance exhibited reliable evidence of learning across multiple measures. Furthermore, stress-induced cortisol levels predicted statistical learning retention 24 hr later. In contrast, episodic memory did not differ by stress condition, although we did find preliminary evidence that acute stress promoted memory for statistically predictable information and attenuated competition between statistical and episodic encoding. Together, these findings provide initial insights into how stress may differentially modulate learning processes within the hippocampus.

Cold pressor stress effects on cardiac repolarization.

The cold pressor test (CPT) elicits strong cardiovascular reactions via activation of the sympathetic nervous system (SNS), yielding subsequent increases in heart rate (HR) and blood pressure (BP). However, little is known on how exposure to the CPT affects cardiac ventricular repolarization. Twenty-eight healthy males underwent both a bilateral feet CPT and a warm water (WW) control condition on two separate days, one week apart. During pre-stress baseline and stress induction cardiovascular signals (ECG lead II, Finometer BP) were monitored continuously. Salivary cortisol and subjective stress ratings were assessed intermittently. Corrected QT (QTc) interval length and T-wave amplitude (TWA) were assessed for each heartbeat and subsequently aggregated individually over baseline and stress phases, respectively. CPT increases QTc interval length and elevates the TWA. Stress-induced changes in cardiac repolarization are only in part and weakly correlated with cardiovascular and cortisol stress-reactivity. Besides its already well-established effects on cardiovascular, endocrine, and subjective responses, CPT also impacts on cardiac repolarization by elongation of QTc interval length and elevation of TWA. CPT effects on cardiac repolarization share little variance with the other indices of stress reactivity, suggesting a potentially incremental value of this parameter for understanding psychobiological adaptation to acute CPT stress.

The impact of virtual reality scenes on stress response characteristics of individuals with different personality traits.

Virtual reality based physical stress (VRPS) paradigms could eliminate the influence of social factors on participants, and it may be a desirable tool to explore the impact of personality traits on stress levels. In this study, we attempt to explore the effects of VRPS on stress response among individuals with different personality traits. Forty male participants with an average age of 22.79 ± 0.41 years were divided into two groups based on Harm Avoidance (HA) scores of Tridimensional Personality Questionnaire (TPQ), referred to as the Low-HA group and the High-HA group. The stress levels of the participants were assessed using salivary α-amylase (sAA) activity and heart rate variability (HRV) indices pre- and post-stress. The influence of personality traits on stress response among different groups was analyzed. VRPS significantly affected the sAA activity and HRV indicators of both groups. During and after stress, there were significant differences in sAA activity and HRV indicators between the two groups. The sAA levels and HRV indices of the Low-HA group were lower than those of the High-HA group. Furthermore, sAA levels and HRV indices were correlated with the scores of TPQ. VRPS scenarios elicit different stress responses on individuals with different harm avoidance personality traits. Stress evaluation based on VR scenarios presents potential in personality trait assessments, particularly for distinguishing between individuals with low and high HA tendencies.

Unique and interactive effects of threat and deprivation on latent trait cortisol among emerging adults.

Though considerable work supports the Dimensional Model of Adversity and Psychopathology, prior research has not tested whether the dimensions-threat (e.g., abuse) and deprivation (e.g., neglect)-are uniquely related to salivary trait indicators of hypothalamic pituitary adrenal (HPA) axis activity. We examined the unique and interactive effects of threat and deprivation on latent trait cortisol (LTC)-and whether these effects were modified by co-occurring adversities. Emerging adults (n = 90; Mage = 19.36 years; 99.88% cisgender women) provided salivary cortisol samples four times a day (waking, 30 min and 45 min postwaking, bedtime) over three 3-day measurement waves over 13 weeks. Contextual life stress interviews assessed early adversity. Though the effects varied according to the conceptualization of early adversity, overall, threat-but not deprivation, nor other co-occurring adversities-was uniquely associated with the across-wave LTC. Specifically, the incidence and frequency of threat were each negatively related to the across-wave LTC. Threat severity was also associated with the across-wave LTC, but only among those with no deprivation. Finally, the effects of threat were modified by other co-occurring adversities. Findings suggest that threat has unique implications for individual differences in HPA axis activity among emerging adults, and that co-occurring adversities modify such effects.

Analysis of the Effect of Exams on Perceived Stress and Temporomandibular Joint Status in Physiotherapy Students: A Pilot Study.

Background and Objectives: Temporomandibular disorders or dysfunction (TMDs) encompass a range of complex conditions that impact the temporomandibular joint (TMJ), chewing muscles, teeth, and/or their supporting tissues. Stress is one of the most associated factors studied as a TMD predictor. The aim is to figure out the influence of stress on TMJ status and salivary cortisol in university students during and before exams. Materials and Methods: The study was non-experimental, employing a longitudinal, analytical, observational cohort design. The study population consisted of students enrolled in the physiotherapy degree program at the Alfonso X El Sabio University (Madrid, Spain). Data were collected during two distinct academic periods: the first period was characterized by low academic stress and no exams, and the second period coincided with the high academic stress of final course exams. The collected results included sociodemographic data, assessment of TMJ status (Fonseca Index), evaluation of muscle evaluation (masseter, upper trapezius, and sternocleidomastoid) using a MOXY Monitor (muscle oxygenation) and Neurotrac® (surface EMG, sEMG), assessment of perceived stress (PSS-14), and measurement of salivary cortisol (enzyme immunoassay with Elisa). The statistical analysis was conducted with a confidence level of 95% (p ≤ 0.05) and asymptotic or bilateral significance. Results: 70 students were analyzed during two different measurement periods. According to the Fonseca Index, initially, 37.14% of the analyzed students showed mild TMDs, 17.14% moderate TMDs, and 45.72% showed no TMDs. In general terms, stress increased with age and is related to female sex, maximum mouth opening decreased with age, oxygen saturation decreased with age and academic stress, and myoglobin concentration was related to age. Furthermore, muscle contraction decreased during higher academic stress and increased with age. For women, age was a risk factor for suffering from TMDs, and stress worsened the transition from having TMDs to having no TMDs in both sexes. Conclusions: Academic stress influences TMJ status and muscle outcomes such as oxygen saturation, myoglobin concentration, and muscle contraction, although more research is needed.

Prenatal serotonin reuptake inhibitor antidepressant exposure, SLC6A4 genetic variations, and cortisol activity in 6-year-old children of depressed mothers: A cohort study.

Prenatal exposure to maternal depression and serotonin reuptake inhibitor (SRI) antidepressants both affect the development of the hypothalamic-pituitary-adrenal (HPA) system, possibly via the neurotransmitter serotonin (5HT). In a community cohort, we investigated the impact of two factors that shape prenatal 5HT signaling (prenatal SRI [pSRI] exposure and child SLC6A4 genotype) on HPA activity at age 6 years. Generalized estimating equation (GEE) models were used to study associations between cortisol reactivity, pSRI exposure, and child SLC6A4 genotype, controlling for maternal depression, child age, and sex (48 pSRI exposed, 74 nonexposed). Salivary cortisol levels were obtained at five time points during a laboratory stress challenge: arrival at the laboratory, following two sequential developmental assessments, and then 20 and 40 min following the onset of a stress-inducing cognitive/social task. Cortisol decreased from arrival across both developmental assessments, and then increased across both time points following the stress challenge in both groups. pSRI-exposed children had lower cortisol levels across all time points. In a separate GEE model, we observed a lower cortisol stress response among children with LG /S alleles compared with children with La/La alleles, and this was particularly evident among children of mothers reporting greater third trimester depressed mood. Our findings suggest that pSRI exposure and a genetic factor associated with modulating 5HT signaling shaped HPA reactivity to a laboratory stress challenge at school age.

Stress system dysfunction revealed by integrating reactivity of stress pathways to psychological stress in lean and overweight/obese men.

Although the patterns of response within the sympathoadrenal medullary (SAM) system and hypothalamo-pituitary adrenal (HPA) axis are interesting and important in their own accord, the overall response to acute psychological stress involves reactivity of both pathways. We tested the hypothesis that consideration of the integrated response of these pathways may reveal dysregulation of the stress systems, which is not evident when considering either system alone. Age-matched lean and overweight/obese men were subjected to a Trier Social Stress Test and reactivity of the SAM system (salivary α-amylase, systolic blood pressure, diastolic blood pressure, and heart rate) and the HPA axis (salivary cortisol) were measured. Relative reactivity of SAM system and HPA axis was calculated as the ratio between the measures from each pathway. Although analysis of reactivity of individual stress pathways showed no evidence of dysfunction in overweight/obese compared with lean men, analysis of HPA/SAM reactivity revealed significantly lower cortisol over systolic blood pressure (CoSBP) and cortisol over diastolic blood pressure (CoDBP) reactivity in overweight/obese compared with lean men. Other measures of HPA/SAM reactivity and all measures of SAM/HPA reactivity were unaltered in overweight/obese compared with lean men. These findings suggest that the cortisol response per unit of blood pressure response is blunted in men with elevated adiposity. Furthermore, these findings support a notion of a coordinated overall approach to activation of the stress pathways with the degree of activation in one pathway being related to the degree of activation in the other.

Psychophysiological Stress Markers During Preseason Among Elite Female Soccer Players.

ABSTRACT: Botelho, R, Abad, CCC, Spadari, RC, Winckler, C, Garcia, MC, and Guerra, RLF. Psychophysiological stress markers during preseason among elite female soccer players. J Strength Cond Res 36(6): 1648-1654, 2022-This study aimed to investigate changes and correlations between mood states and various physiological stress markers after a 7-week preseason period among elite female soccer players. Twenty-four elite female soccer players participated in this study (26.4 ± 3.7 years). Their internal training load, mood states, day and evening salivary testosterone and cortisol concentrations, blood creatine kinase concentration (CK), and heart rate variability (HRV) were assessed during the first week of preseason (PRE), and again 7 weeks after a systematic training period (END). After the preseason, there were significant increases in subject negative mood scales (p ≤ 0.03; Effect Size [ES] > 0.60), total mood scores (p = 0.01; QI = 100/0/0; ES = 1.32), day and evening testosterone and cortisol concentrations (p ≤ 0.03; ES > 0.54), and CK concentrations (p = 0.01; QI = 100/0/0; ES = 1.54). Correlations were found between cortisol and tension (r = 0.53 and 0.60; p ≤ 0.02), cortisol and confusion (r = 0.75; p = 0.01), and cortisol and the LF/HF index of HRV (r = -0.52; p = 0.04). Mood states (except vigor), salivary testosterone, and cortisol concentrations, as well as CK, showed significant changes after a 7-week systematic training system. The cortisol was the factor most highly related to various mood states (including tension and confusion), and with the HRV indices. Coaches and researchers can use these data to design, monitor, and control soccer training programs, in particular throughout the preseason period.

How to alleviate the agony of providing negative feedback: Emotion regulation strategies affect hormonal stress responses to a managerial task.

Providing negative feedback can be demanding, as it typically requires dealing with multiple negative emotions. The first aim of this study was to transfer this work-related task to a new laboratory protocol and to investigate short-term hormonal changes among feedback providers. The second aim was to test if such hormonal stress responses can be attenuated through a priori instructions on how to regulate emotions. Each of 150 participants (51% women) provided eight saliva samples before, during, and after anticipating and conducting a negative feedback conversation with a professional actor who displayed negative emotional reactions. Participants were divided into four conditions regarding the way they were instructed to regulate their emotions: expressive suppression (keeping a neutral expression); cognitive reappraisal (staying task-oriented and emotionally distanced); affect utilization (moving towards and using emotions); or control condition. By means of three-phase spline growth models, latent growth factors during baseline, stress response, and recovery were specified. Providing negative feedback was followed by significant temporary testosterone decreases as well as cortisol increases. Testosterone (but not cortisol) responses were attenuated when feedback providers had been instructed to either follow a cognitive reappraisal or affect utilization strategy. This study provides evidence that a typical managerial task, that is, having to provide negative feedback, is a testosterone- and cortisol-relevant experience. Down-regulation of an individual's emotional involvement through reappraisal, as well as the newly introduced technique of moving towards and making use of the interaction partner's emotions (affect utilization), revealed consequences in terms of attenuating the testosterone response to stress.

Individual resting-state frontocingular functional connectivity predicts the intermittent theta burst stimulation response to stress in healthy female volunteers.

Intermittent theta burst stimulation (iTBS) delivered to the dorsolateral prefrontal cortex (DLPFC) has been investigated as a promising treatment for stress and stress-related mental disorders such as major depression, yet large individual differences in responsiveness demand further exploration and optimization of its effectiveness. Clinical research suggests that resting-state functional connectivity (rsFC) between the DLPFC and the anterior cingulate cortex (ACC) can predict iTBS treatment response in depression. The present study aimed to investigate whether rsFC between the left DLPFC and ACC subregions could predict the degree to which the stress system is affected by iTBS. After assessment of baseline resting-state fMRI data, 34 healthy female participants performed the Trier Social Stress Test on two separate days, each followed by active or sham iTBS over the left DLPFC. To evaluate iTBS effects on the stress-system, salivary cortisol was measured throughout the procedure. Our results showed that a stronger negative correlation between the left DLPFC and the caudal ACC was linked to a larger attenuation of stress-system sensitivity during active, but not during sham iTBS. In conclusion, based on individual rsFC between left DLPFC and caudal ACC, iTBS could be optimized to more effectively attenuate deregulation of the stress system.

Psychosocial stress reactivity habituates following acute physiological stress.

Acute and chronic stress are important factors in the development of mental disorders. Reliable measurement of stress reactivity is therefore pivotal. Critically, experimental induction of stress often involves multiple "hits" and it is an open question whether individual differences in responses to an earlier stressor lead to habituation, sensitization, or simple additive effects on following events. Here, we investigated the effect of the individual cortisol response to intravenous catheter placement (IVP) on subsequent neural, psychological, endocrine, and autonomous stress reactivity. We used an established psychosocial stress paradigm to measure the acute stress response (Stress) and recovery (PostStress) in 65 participants. Higher IVP-induced cortisol responses were associated with lower pulse rate increases during stress recovery (b = -4.8 bpm, p = .0008) and lower increases in negative affect after the task (b = -4.2, p = .040). While the cortisol response to IVP was not associated with subsequent specific stress-induced neural activation patterns, the similarity of brain responses Pre- and PostStress was higher IVP-cortisol responders (t[64] = 2.35, p = .022) indicating faster recovery. In conclusion, preparatory stress induced by IVP reduced reactivity in a subsequent stress task by modulating the latency of stress recovery. Thus, an individually stronger preceding release of cortisol may attenuate a second physiological response and perceived stress suggesting that relative changes, not absolute levels are crucial for stress attribution. Our study highlights that considering the entire trajectory of stress induction during an experiment is important to develop reliable individual biomarkers.

Neural responses to social evaluative threat in the absence of negative investigator feedback and provoked performance failures.

Functional neuroimaging of social stress induction has considerably furthered our understanding of the neural risk architecture of stress-related mental disorders. However, broad application of existing neuroimaging stress paradigms is challenging, among others due to the relatively high intensity of the employed stressors, which limits applications in patients and longitudinal study designs. Here, we introduce a less intense neuroimaging stress paradigm in which subjects anticipate, prepare, and give speeches under simulated social evaluation without harsh investigator feedback or provoked performance failures (IMaging Paradigm for Evaluative Social Stress, IMPRESS). We show that IMPRESS significantly increases perceived arousal as well as adrenergic (heart rate, pupil diameter, and blood pressure) and hormonal (cortisol) responses. Amygdala and perigenual anterior cingulate cortex (pACC), two key regions of the emotion and stress regulatory circuitry, are significantly engaged by IMPRESS. We further report associations of amygdala and pACC responses with measures of adrenergic arousal (heart rate, pupil diameter) and social environmental risk factors (adverse childhood experiences, urban living). Our data indicate that IMPRESS induces benchmark psychological and endocrinological responses to social evaluative stress, taps into core neural circuits related to stress processing and mental health risk, and is promising for application in mental illness and in longitudinal study designs.

Brain-derived neurotropic factor and cortisol levels negatively predict working memory performance in healthy males.

There is now significant literature suggesting that increasing brain-derived neurotropic factor (BDNF) signalling may improve memory-related disorders such as Alzheimer's disease. However, the effects of BDNF on short-term and working memory are not clear and existing evidence is inconsistent. Here we measured plasma BDNF and salivary cortisol levels, as well as working memory, on an N-Back task before and after mixed psychosocial/physiological stress induction in healthy males (N = 29). Stress induction was associated with higher circulating cortisol, but not BDNF levels. Higher cortisol and BDNF levels were significantly associated with poorer accuracy before and after stress induction. There was also a significant interaction, such that higher BDNF was associated with a buffering effect on the negative association between high cortisol and working memory. Future studies should replicate this data in larger samples, with emphasis on cortisol/BDNF interactions in determining working memory performance.

Subjective social status and stress responsivity in late adolescence.

Subjective social status (SSS) reflects one's perception of one's standing within society. SSS has been linked with health outcomes, over and above socioeconomic status, and is thought to influence health in part by shaping stress responsivity. To test this, the present study examined the links between SSS and psychological, hypothalamic-pituitary-adrenal (HPA) axis, and cardiovascular responsivity in a sample of 87 ethnically diverse late adolescents (Mage = 18.39 years). Participants rated their family's SSS while either in high school (n = 50) or 1 year afterward (n = 37). Participants completed the Trier Social Stress Task (TSST) and reported their fear during baseline and after task completion, provided six saliva samples throughout the task, and had their heart rate monitored continuously throughout the task. Multilevel models, with time points nested within participants, were conducted to assess reactivity and recovery for each outcome. Results indicated that lower SSS was associated with greater fear reactivity and faster rates of HPA axis reactivity and recovery to baseline. Regarding cardiovascular responses, no differences were observed with respect to heart rate. Lower SSS predicted increased respiratory sinus arrhythmia during the stress task only among participants who rated their SSS while in high school; no association was observed for those who rated SSS after high school. Results suggest that perceptions of one's family's standing in society can shape responses to stress and potentially broader health.HighlightsSubjective social status (SSS) was linked with differences in stress responsivity. Specifically, lower SSS was associated with greater increases in fear following an acute stressor and faster rates of cortisol reactivity and recovery. Adolescents with lower SSS in high school showed less cardiovascular reactivity and recovery with respect to respiratory sinus arrhythmia, a marker of parasympathetic nervous system activity.

Transcendental meditation and hypothalamic-pituitary-adrenal axis functioning: a pilot, randomized controlled trial with young adults.

Transcendental meditation (TM) is effective in alleviating stress and anxiety and promoting well-being. While the underlying biological mechanisms of TM are not yet fully explored, the hypothalamic-pituitary-adrenal (HPA) axis represents an index providing important clues embodying the stress system cascade. In this pilot study, young adults were randomly assigned to TM training followed by 8 weeks of meditation practice or a wait-list control condition. TM was conducted over 8 weeks. Thirty-four young adult participants were randomized; 27 participants completed the HPA outcome assessments (41% male). To assess HPA axis functioning, salivary samples to assess cortisol awakening response (CAR) that were collected in the morning, both at baseline and at week-4. Salivary cortisol in the context of a social stressor using the Trier Social Stress Test (TSST) was collected at week-8. The results indicate that participants who were randomly assigned to TM had lower awakening salivary cortisol levels and a greater drop in CAR from baseline to week-4 than the control group. There were no significant differences in HPA axis functioning in the context of the TSST. Primary limitations of this randomized controlled trial were the small sample size, the use of a wait-list as opposed to an active control, and the limited scope of HPA axis assessments. The results of this pilot study provide tentative evidence that TM may impact biological stress system functioning and suggests that this may be a worthwhile avenue to continue to examine. It will also be useful to extend these findings to a broader array of meditative and mindful practices, particularly for those who are experiencing more distress.

Cortisol response to stress: The role of expectancy and anticipatory stress regulation.

An exacerbated physiological response to stress is associated with the development of stress-related disorders (e.g., depression and anxiety disorders). Recently, it has been proposed that individuals with high expectancies of being able to deal with stressful situations will activate regulatory mechanisms during the anticipation of the stressful event that would improve stress regulation. To test this hypothesis, 52 women in young adulthood (M = 21.06; SD = 2.58) anticipated and performed a laboratory-based stress task after receiving positive or negative bogus feedback on their abilities to deal with stressful events. Heart rate variability and salivary cortisol were assessed throughout the experimental protocol. Participants receiving positive bogus feedback (i.e., High Expectancy group) showed a more positive anticipatory cognitive stress appraisal (i.e., they anticipated the stress task as less threatening/challenging, and they perceived that they were more able to deal with it), and they showed a lower cortisol response to stress. Moreover, a more positive anticipatory cognitive stress appraisal was associated with better anticipatory stress regulation (indexed as less decrease in heart rate variability), leading to a lower cortisol response. Our results indicate that people with positive expectancy initiate mechanisms of anticipatory stress regulation that enhance the regulation of the physiological stress response. Expectancy and anticipatory stress regulation may be key mechanisms in the development and treatment of stress-related disorders.

Neuroendocrine coordination and youth behavior problems: A review of studies assessing sympathetic nervous system and hypothalamic-pituitary adrenal axis activity using salivary alpha amylase and salivary cortisol.

Externalizing and internalizing behavior problems can have deleterious psychosocial consequences for youth. Both sympathetic nervous system (SNS) and hypothalamic-pituitary adrenal (HPA) axis activity and reactivity may contribute to behavior problems but have largely been studied separately, with inconsistent findings. Because the SNS and HPA axis interact to carry out physiological processes (e.g., responding to stressors), considering SNS and HPA axis activity jointly may elucidate disparate findings. This review discusses studies that simultaneously assessed SNS and HPA axis (re)activity and youth behavior problems using measures of salivary alpha amylase (sAA) and salivary cortisol. Multiple patterns of SNS and HPA axis coordination were associated with problem behaviors, especially when considering individual differences and youth's psychosocial context. Importantly, many study findings may be artifacts of widespread methodological differences. The reviewed studies lay the foundation for future research on neuroendocrine coordination as a contributing factor to youth problem behaviors and some recommendations for future research are discussed.

The effect of HF-rTMS over the left DLPFC on stress regulation as measured by cortisol and heart rate variability.

The prefrontal cortex, and especially the Dorsolateral Prefrontal Cortex (DLPFC), plays an inhibitory role in the regulation of the Hypothalamic-Pituitary-Adrenal (HPA) axis under stressful situations. Moreover, recent evidence suggests that a sustained DLPFC activation is associated with adaptive stress regulation in anticipation of a stressful event, leading to a reduced stress-induced amygdala response, and facilitating the confrontation with the stressor. However, studies using experimental manipulation of the activity of the DLPFC before a stressor are scarce, and more research is needed to understand the specific role of this brain area in the stress-induced physiological response. This pre-registered study investigated the effect on stress regulation of a single excitatory high frequency (versus sham) repetitive transcranial magnetic stimulation (HF-rTMS) session over the left DLPFC applied before the Trier Social Stress Test in 75 healthy young women (M = 21.05, SD = 2.60). Heart rate variability (HRV) and salivary cortisol were assessed throughout the experimental protocol. The active HF-rTMS and the sham group showed a similar cognitive appraisal of the stress task. No differences in HRV were observed during both the anticipation and the actual confrontation with the stress task and therefore, our results did not reflect DLPFC-related adaptive anticipatory adjustments. Importantly, participants in the active HF-rTMS group showed a lower cortisol response to stress. The effect of left prefrontal HF-rTMS on the stress system provides further critical experimental evidence for the inhibitory role played by the DLPFC in the regulation of the HPA axis.

Use of the birth control pill affects stress reactivity and brain structure and function.

Millions of women worldwide use oral contraceptives (i.e., birth control pill; OCs), often starting during puberty/adolescence; however, it is unknown how OC use during this critical period of development affects the brain, especially with regard to emotional working memory. Here, we examined stress reactivity, and brain structure and function in OC users using the Trier Social Stress Test and structural and functional magnetic resonance imaging (MRI). Our results show that OC use during puberty/adolescence gives rise to a blunted stress response and alters brain activation during working memory processing. OC use, in general, is also linked to increased prefrontal brain activation during working memory processing for negatively arousing stimuli. OC use is also related to significant structural changes in brain regions implicated in memory and emotional processing. Together, these findings highlight that OC use induces changes to brain structure and function and alters stress reactivity. These findings may provide a mechanistic insight for the increased vulnerability to mood-related mental illness in women after OC use.

Neuroendocrine responses to a psychosocial stress test for larger groups of participants: comparison of two test exposures.

Objective. Individual stress tests characterized by social evaluative threat and uncontrollability are known to elicit strong neuroendocrine responses. We tested whether a psychosocial stressor submitted to a larger group of participants (up to 60) may elicit comparable stress responses.Methods. A total of 59 adult subjects (33 women, 26 men) participated in the study, whereas 24 of them suffered from allergy and 35 were healthy. The stress test consisted of a distraction stress task followed by a speech task, in which the participants were randomly subjected to questions related to a topic that they had to prepare as well as arithmetic questions in front of their peers and a committee that responded in standardized and non-supporting manner. State and trait anxiety inventory (STAI) for anxiety state was administrated before and after the test and salivary samples taking. The test was repeated after five months.Results. The results showed that the shared psychosocial stress application in a larger group of subjects was prosperous. The larger group test (LGST) resulted in an enhanced subjectively experienced stress and an intensive sympathetic nervous system activation, reflected by elevated salivary alpha-amylase activity and the heart rate. The cortisol increment after exposure to the stress test was not significant. Repeated exposure to the test failed to reproduce the original stress responses with exception of the heart rate rise.Conclusions. In a larger group of subjects, the psychosocial stress test did elicit stress responses similar to the individual stress tests. Our data indicate that the above-mentioned stress test is apparently not an appropriate approach for the repeated use.