Neural and cortisol responses to acute psychosocial stress in work-related burnout: The Regensburg Burnout Project

BACKGROUND

While several attempts have been made to elucidate the pathophysiology of burnout, neural stress responses have not yet been investigated. Therefore, the aim of this study was to examine salivary cortisol and - for the first time - neural responses to acute psychosocial stress within a strictly specified sample consisting of individuals suffering from burnout (BO group) and a healthy comparison group (HC group).

METHODS

After a multi-stage recruitment procedure based on burnout symptomatology and pathogenesis, 55 individuals suffering from burnout (25 women) and 61 individuals serving as HC group (31 women) out of an initial sample of 1022 volunteers were exposed to acute psychosocial stress during functional magnetic resonance imaging (fMRI) applying ScanSTRESS.

RESULTS

No differences were found between the BO and the HC group with respect to cortisol and mean neural stress responses. However, an exploratory comparison of neural stress responses of the first and second run of ScanSTRESS (exposure-time effect) revealed group-specific response patterns in one cluster peaking in the left dorsal anterior cingulate cortex (dACC). While the neural activation of the HC group was higher in the first compared to the second run of ScanSTRESS (i.e., decreasing activation), this pattern was reversed in the BO group (i.e., increasing activation).

CONCLUSIONS

Our analysis mainly did not provide evidence for altered acute cortisol and mean neural stress responses in burnout. However, the BO group was characterized by a limited capacity to show decreasing activation over stress exposure-time and exhibited instead increasing activation. Importantly, this group difference manifested in the left dACC which is both involved in neural stress processing and affected in individuals suffering from burnout. Given the present results, it seems promising to further examining temporal dynamics of neural stress responses in (sub-) clinical conditions such as burnout.

Association of polygenic scores for depression and neuroticism with perceived stress in daily life during a long-lasting stress period

Genetic factors contribute significantly to interindividual differences in the susceptibility to stress-related disorders. As stress can also be conceptualized as environmental exposure, controlled gene-environment interaction (GxE) studies with an in-depth phenotyping may help to unravel mechanisms underlying the interplay between genetic factors and stress. In a prospective-longitudinal quasi-experimental study, we investigated whether polygenic scores (PGS) for depression (DEP-PGS) and neuroticism (NEU-PGS), respectively, were associated with responses to chronic stress in daily life. We examined law students (n = 432) over 13 months. Participants in the stress group experienced a long-lasting stress phase, namely the preparation for the first state examination for law students. The control group consisted of law students without particular stress exposure. In the present manuscript, we analyzed perceived stress levels assessed at high frequency and in an ecologically valid manner by ambulatory assessments as well as depression symptoms and two parameters of the cortisol awakening response. The latter was only assessed in a subsample (n = 196). No associations between the DEP-PGS and stress-related variables were found. However, for the NEU-PGS we found a significant GxE effect. Only in individuals experiencing academic stress a higher PGS for neuroticism predicted stronger increases of perceived stress levels until the exam. At baseline, a higher NEU-PGS was associated with higher perceived stress levels in both groups. Despite the small sample size, we provide preliminary evidence that the genetic disposition for neuroticism is associated with stress level increases in daily life during a long-lasting stress period.

Neural responses to acute stress predict chronic stress perception in daily life over 13 months

The importance of amygdala, hippocampus, and medial prefrontal cortex (mPFC) for the integration of neural, endocrine, and affective stress processing was shown in healthy participants and patients with stress-related disorders. The present manuscript which reports on one study-arm of the LawSTRESS project, aimed at investigating the predictive value of acute stress responses in these regions for biopsychological consequences of chronic stress in daily life. The LawSTRESS project examined law students either in preparation for their first state examination (stress group [SG]) or in the mid-phase of their study program (control group [CG]) over 13 months. Ambulatory assessments comprising perceived stress measurements and the cortisol awakening response (CAR) were administered on six sampling points (t1 = - 1 year, t2 = - 3 months, t3 = - 1 week, t4 = exam, t5 =  + 1 week, t6 =  + 1 month). In a subsample of 124 participants (SG: 61; CG: 63), ScanSTRESS was applied at baseline. In the SG but not in the CG, amygdala, hippocampus, and (post-hoc analyzed) right mPFC activation changes during ScanSTRESS were significantly associated with the trajectory of perceived stress but not with the CAR. Consistent with our finding in the total LawSTRESS sample, a significant increase in perceived stress and a blunted CAR over time could be detected in the SG only. Our findings suggest that more pronounced activation decreases of amygdala, hippocampus, and mPFC in response to acute psychosocial stress at baseline were related to a more pronounced increase of stress in daily life over the following year.

Associations between cortisol stress responses and limbic volume and thickness in young adults: An exploratory study

The investigation of the relationship between neural measures of limbic structures and hypothalamic pituitary adrenal axis responses to acute stress exposure in healthy young adults has so far focused in particular on task-based and resting state functional connectivity studies. Thus, the present study examined the association between limbic volume and thickness measures and acute cortisol responses to the psychosocial stress paradigm ScanSTRESS. Using Permutation Analysis of Linear Models controlling for sex, age and total brain volume, the associations between (sex-specific) cortisol increases and human connectome project style anatomical variables of limbic structures (i.e. volume and thickness) were investigated in 66 healthy and young (18-33 years) subjects (35 men, 31 women taking oral contraceptives). In addition, exploratory (sex-specific) bivariate correlations between cortisol increases and structural measures were conducted. The present data provide interesting new insights into the involvement of striato-limbic structures in psychosocial stress processing, suggesting that acute cortisol stress responses are also associated with mere structural measures of the human brain. Thus, our preliminary findings suggest that not only situation- and context-dependent reactions of the limbic system (i.e. blood oxygenation level-dependent reactions) are related to acute (sex-specific) cortisol stress responses but also basal and somewhat more constant structural measures. Our study hereby paves the way for further analyses in this context and highlights the relevance of the topic.

Investigation of cross-sectional and longitudinal associations between work-related burnout and hair cortisol: The Regensburg Burnout Project

BACKGROUND

Burnout is characterized by feelings of exhaustion, depersonalization as well as reduced personal accomplishment and is linked to various negative health effects. Previous studies on biological correlates of burnout have focused on the hypothalamic-pituitary-adrenal (HPA) axis. However, especially studies on hair cortisol concentrations (HCC) were often based on cross-sectional data and yielded inconsistent results, probably due to the heterogeneity of the selected samples. Accordingly, the aim of the present study was to investigate cross-sectional as well as longitudinal associations between burnout and HCC within a sample consisting of a strictly specified group of individuals suffering from burnout (BO group) and a healthy comparison group (HC group).

METHODS

After a multi-stage recruitment procedure based on burnout symptoms and pathogenesis, eligible subjects (out of an initial sample of 1022 volunteers) were assigned either to a BO (n = 55) or HC group (n = 59), as described in detail in Bärtl et al. (2022). Burnout symptoms as well as HCC (1 cm hair samples) were measured repeatedly at two sampling time points t1 (n = 114) and t2 (n = 100) with an interval of M = 7.20 months (SD = 1.16) between assessments.

RESULTS

In the total study sample, no cross-sectional associations between burnout and HCC were found either at t1 or at t2. When the analysis was restricted to the BO group, HCC was positively related to burnout symptomatology at t1 but not t2. In the longitudinal analysis, burnout symptoms at t1 were significant negative predictors of HCC at t2. However, the change in HCC from t1 to t2 was not associated with the change in burnout symptoms.

CONCLUSIONS

In the present study, we investigated the association between HCC and burnout in a strictly defined sample of subjects suffering from burnout and healthy controls. Our findings mainly do not support our hypotheses. At least, the positive association between HCC and burnout symptoms only within the BO group supports the idea that HPA axis alterations in burnout might only become apparent once a certain threshold of burnout symptomatology has been exceeded, while the longitudinal data provide some empirical evidence for the potential long-term development of hypocortisolism in burnout. However, respective results remain relatively inconclusive.

Evaluation and update of the expert consensus guidelines for the assessment of the cortisol awakening response (CAR)

The cortisol awakening response (CAR) is frequently assessed in psychobiological (stress) research. Obtaining reliable CAR data, however, requires careful attention to methodological detail. To promote best practice, expert consensus guidelines on the assessment of the CAR were published (Stalder et al., 2016, PNEC). However, it is unclear whether these highly cited guidelines have resulted in actual methodological improvements. To explore this, the PNEC editorial board invited the present authors to conduct a critical evaluation and update of current CAR methodology, which is reported here. (i) A quantitative evaluation of methodological quality of CAR research published in PNEC before and after the guidelines (2013-2015 vs. 2018-2020) was conducted. Disappointingly, results reveal little improvement in the implementation of central recommendations (especially objective time verification) in recent research. (ii) To enable an update of guidelines, evidence on recent developments in CAR assessment is reviewed, which mostly confirms the accuracy of the majority of the original guidelines. Moreover, recent technological advances, particularly regarding methods for the verification of awakening and sampling times, have emerged and may help to reduce costs in future research. (iii) To aid researchers and increase accessibility, an updated and streamlined version of the CAR consensus guidelines is presented. (iv) Finally, the response of the PNEC editorial board to the present results is described: potential authors of future CAR research to be published in PNEC will be required to submit a methodological checklist (based on the current guidelines) alongside their article. This will increase transparency and enable reviewers to readily assess the quality of the respective CAR data. Combined, it is hoped that these steps will assist researchers and reviewers in assuring higher quality CAR assessments in future research, thus yielding more reliable and reproducible results and helping to further advance this field of study.

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

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

Daily life stress and the cortisol awakening response over a 13-months stress period - Findings from the LawSTRESS project

The LawSTRESS project is a controlled prospective-longitudinal study on psychological, endocrine, central nervous and genetic predictors of responses to long-lasting academic stress in a homogenous cohort. In this first project report, we focused on the association between daily life stress and the cortisol awakening response (CAR). The CAR, a distinct cortisol rise in the first 30-45 min after morning awakening, is a well-established marker of cortisol regulation in psychoneuroendocrinology. Law students from Bavarian universities (total n = 452) have been studied over a 13-months period at six sampling points starting 12 months prior exam. The stress group (SG) consisted of students experiencing a long-lasting and significant stress period, namely the preparation for the first state examination for law students. Law students assigned to the control group (CG) were studied over an equally long period without particular and sustained stress exposure. To investigate stress related alterations in the CAR, we examined a subsample of the LawSTRESS project consisting of 204 students with 97 participants from the SG (69.1% female, mean age = 22.84 ± 1.82) and 107 from the CG (78.5% female, mean age = 20.95 ± 1.93). At each sampling point, saliva samples for cortisol assessment were collected immediately upon awakening and 30 as well as 45 min later. Perceived stress in daily life was measured by repeated ambulatory assessments (about 100 queries over six sampling points). The time course of perceived stress levels in the two groups differed significantly, with the SG showing an increase in perceived stress until the exam and a decrease thereafter. Stress levels in the CG were relatively stable. The CAR was not significantly different between groups at baseline. However, a blunted CAR in the SG compared to the baseline measure and to the CG developed over the measurement timepoints and reached significance during the exam. Remarkably, this effect was neither associated with the increase in perceived stress nor with anxiety and depression symptoms, test anxiety and chronic stress at baseline. The present study successfully assessed multidimensional stress trajectories over 13 months and it documented the significant burden, law students preparing for the first state examination are exposed to. This period was related to a blunted CAR with presumed physiological consequences (e.g., on energy metabolism and immune function). Mean psychological stress levels as well as the CAR returned to baseline levels after the exam, suggesting a fast recovery in the majority of the participants.

Sustained threat and phasic fear in the laboratory and cognitive-emotional processes of anxiety in everyday life - An ambulatory assessment study

Fear is a phasic state of apprehension to an imminent threat, whereas anxiety is a more sustained state of expecting a potential threat leading to tension and worry. The NPU-threat test is a laboratory startle paradigm allowing a reliable and valid assessment of both, fear- and anxiety-potentiated reactions. It is suggested to differentiate between anxiety disorders, but little is known on associations with everyday life experiences of cognitive-emotional processes regarding anxiety in non-clinical samples. In the present project, the NPU-threat test was applied in three studies with (1) unselected healthy individuals, (2) participants with extreme manifestations of trait anxiety (low vs. high) and (3) individuals preparing for a high-stakes exam. Self-reported states of emotionality and worry were assessed during a four-day ambulatory assessment (AA). Overall, NPU-threat test measures did not significantly differ between studies, while the AA dependent measures were sufficiently sensitive to capture differences between groups. However, there was no significant association between psychophysiological measures of the NPU-threat test and AA state measures across participants. In participants recruited for low vs. high trait anxiety we found an association with AA worry and emotionality, but no interaction with potentiated startle. The present findings do not support the idea of a link between our laboratory biomarker and adaptive regulation of cognitive-emotional states in everyday life in healthy individuals. We speculate that an association between laboratory physiological measures and everyday experience of anxious states may be detectable in clinical samples.

Externalizing behavior in healthy young adults is associated with lower cortisol responses to acute stress and altered neural activation in the dorsal striatum

The externalizing spectrum is characterized by disinhibition, impulsivity, antisocial-aggressive behavior as well as substance (mis)use. Studies in forensic samples and mentally impaired children suggested that higher rates of externalization are linked to lower cortisol stress responses and altered affect-related neural activation. In this fMRI-study, we investigated whether externalizing behavior in healthy participants is likewise associated with altered cortisol responses and neural activity to stress. Following a quasi-experimental approach, we tested healthy participants (N = 61, 31 males) from the higher versus lower range of the non-clinical variation in externalization (31 participants with high externalization) as assessed by the subscales disinhibition and meanness of the Triarchic-Psychopathy-Measure. All participants were exposed to ScanSTRESS, a standardized psychosocial stress paradigm for scanner environments. In both groups, ScanSTRESS induced a significant rise in cortisol levels with the high externalization group showing significantly lower cortisol responses to stress than the low externalization group. This was mainly driven by males. Further, individual increases in cortisol predicted neural response differences between externalization groups, indicating more activation in the dorsal striatum in low externalization. This was primarily driven by females. In contrast, post-hoc analysis showed that hypothalamic-pituitary-adrenal axis hyporeactivity in males was associated with prefrontal and hippocampal activation. Our data substantiate that individuals from the general population high on externalization, show reduced cortisol stress responses. Furthermore, dorsal striatum activity as part of the mesolimbic system, known to be sensitive to environmental adversity, seems to play a role in externalization-specific cortisol stress responses. Beyond that, a modulating influence of gender was disclosed.

Everyday moral decision-making after acute stress exposure: do social closeness and timing matter?

There is increasing empirical evidence that social distance and timing affect prosocial behavior after acute stress exposure. The present study focused on everyday moral decision-making after acute psychosocial stress and how it is influenced by effects of social closeness and timing. We exposed 40 young healthy men to the Trier Social Stress Test (TSST, n = 20) or its non-stressful placebo version (PTSST, n = 20). Moral decision-making was assessed early (+10 until +30 min) and late (+75 until +95 min) after (P)TSST exposure by the Everyday Moral Conflict Situations (EMCS) Scale. The EMCS Scale requests altruistic versus egoistic responses to everyday moral conflict situations with varying closeness of target persons. Results revealed significantly higher total percentages of altruistic decisions in the stress than in the control condition and for scenarios involving socially close (e.g., mother) versus socially distant (e.g., stranger) protagonists, while the main effect of timing was nonsignificant. Only secondary analyses showed increased altruistic decision-making after acute stress exposure toward socially close but not toward distant protagonists at the early but not at the late point of measurement. Moreover, psychological stress responses and personality traits were significantly associated with EMCS scores. Positive correlations between cortisol levels and altruistic decision-making were descriptively observable, but did not reach statistical significance. In sum, our findings suggest increased altruistic decision-making toward socially close compared to socially distant protagonists and provide further evidence that acute stress influences decision-making in everyday moral conflict scenarios in a prosocial manner.Lay summaryIn order to investigate the effects of acute stress on everyday moral decision-making, 40 young healthy men were exposed to moderate psychosocial stress by the use of the Trier Social Stress Test (TSST) or its non-stressful placebo version and then completed a hypothetical everyday moral decision-making paradigm. Our findings provide evidence that acute stress exposure influences decision-making in everyday moral conflict situations in a prosocial manner. Furthermore, participants decided more altruistically in scenarios involving socially close (e.g., mother) versus socially distant (e.g., stranger) protagonists.

Sex-Specific Interaction Between Cortisol and Striato-Limbic Responses to Psychosocial Stress

Although women and men differ in psychological and endocrine stress responses as well as in the prevalence rates of stress-related disorders, knowledge on sex differences regarding stress regulation in the brain is scarce. Therefore, we performed an in-depth analysis of data from 67 healthy participants (31 women, taking oral contraceptives), who were exposed to the ScanSTRESS paradigm in a functional magnetic resonance imaging study. Changes in cortisol, affect, heart rate and neural activation in response to psychosocial stress were examined in women and men as well as potential sex-specific interactions between stress response domains. Stress exposure led to significant cortisol increases, with men exhibiting higher levels than women. Depending on sex, cortisol elevations were differently associated with stress-related responses in striato-limbic structures: higher increases were associated with activations in men but with deactivations in women. Regarding affect or heart rate responses, no sex differences emerged. Although women and men differ in their overall stress reactivity, our findings do not support the idea of distinct neural networks as the base of this difference. Instead, we found differential stress reactions for women and men in identical structures. We propose considering quantitative predictors such as sex-specific cortisol increases when exploring neural response differences of women and men.

A graph neural network framework for causal inference in brain networks

A central question in neuroscience is how self-organizing dynamic interactions in the brain emerge on their relatively static structural backbone. Due to the complexity of spatial and temporal dependencies between different brain areas, fully comprehending the interplay between structure and function is still challenging and an area of intense research. In this paper we present a graph neural network (GNN) framework, to describe functional interactions based on the structural anatomical layout. A GNN allows us to process graph-structured spatio-temporal signals, providing a possibility to combine structural information derived from diffusion tensor imaging (DTI) with temporal neural activity profiles, like that observed in functional magnetic resonance imaging (fMRI). Moreover, dynamic interactions between different brain regions discovered by this data-driven approach can provide a multi-modal measure of causal connectivity strength. We assess the proposed model's accuracy by evaluating its capabilities to replicate empirically observed neural activation profiles, and compare the performance to those of a vector auto regression (VAR), like that typically used in Granger causality. We show that GNNs are able to capture long-term dependencies in data and also computationally scale up to the analysis of large-scale networks. Finally we confirm that features learned by a GNN can generalize across MRI scanner types and acquisition protocols, by demonstrating that the performance on small datasets can be improved by pre-training the GNN on data from an earlier study. We conclude that the proposed multi-modal GNN framework can provide a novel perspective on the structure-function relationship in the brain. Accordingly this approach appears to be promising for the characterization of the information flow in brain networks.

Effects of gender and personality on everyday moral decision-making after acute stress exposure

Exposure to acute psychosocial stress has been shown to affect moral decision-making, though little is known about potential gender differences or effects of personality. In two within-subjects design studies, 179 healthy men and women (N = 99 in Study 1, N = 80 in Study 2) were exposed to the Trier Social Stress Test (TSST) and a non-stress control condition (resting period) on two testing days in random order. After stress/resting, moral decision-making was assessed by the Everyday Moral Conflict Situations (EMCS) Scale (Singer et al., 2019), which requests altruistic versus egoistic responses to everyday moral conflict scenarios with varying closeness of target persons. We investigated effects of acute stress, social closeness, participants' gender, and the a priori selected personality traits agreeableness, empathy, and social desirability on everyday moral decision-making. Despite high statistical power, we could neither confirm the hypothesized effects of acute stress nor social closeness on EMCS scores in both samples. However, our data revealed a prosocial impact of acute stress on everyday moral decisions rather in females than males as well as effects of agreeableness and social desirability. Salivary alpha-amylase (sAA) levels in Study 1 and cortisol levels in females in Study 2 were significantly correlated with higher EMCS scores after acute stress exposure. Additionally, lower anticipatory subjective stress responses were associated with more altruistic decisions. Moreover, we found positive relationships between hypothetical moral decision-making and real prosocial behavior (opportunity for a charitable donation). In sum, due to methodological differences compared to previous between-subjects design studies, it might not be justified to rule out effects of acute stress on everyday moral decision-making based on the current within-subjects results. Nevertheless, the present data suggest that specific personality traits like agreeableness might have a stronger impact on everyday moral decision-making than short term-exposure to acute stress.

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.

Simultaneous quantification of steroid hormones and endocannabinoids (ECs) in human hair using an automated supported liquid extraction (SLE) and LC-MS/MS - Insights into EC baseline values and correlation to steroid concentrations

Endogenous steroid hormones and endocannabinoids (ECs) are important regulators in the stress response of the human body. For the measurement of chronic stress, hair analysis has been established as method of choice for long-term and retrospective determination of endogenous stress markers. A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of five steroid hormones (cortisone, cortisol, androstenedione, testosterone, progesterone) and four endocannabinoids (anandamide, palmitoylethanolamide, 2-arachidonylglycerol, oleoylethanolamide) in hair was developed and validated. The hair samples were extracted with methanol and cleaned up with a fully automated supported liquid extraction (SLE) before analysis. Special attention was paid to the difficulties accompanying the quantification of endogenous analytes in hair. Five different strategies for endogenous compound quantification in hair (surrogate analyte, standard addition, background correction, stripped matrix and solvent calibration) were tested and compared. As a result, the approach of the surrogate analyte was used for the quantification of steroid hormones whereas background correction was used for endocannabinoids. The measurement of 58 samples from healthy young adults allowed insights into endocannabinoid ranges in hair and the correlation to steroid hormones. No significant differences in steroid and EC concentration levels of male and female in hair were found, except for testosterone (p < 0.001) and androstenedione (p < 0.0001). Cortisol to cortisone and testosterone to androstenedione concentrations were significantly and positively correlated. There were significant intercorrelations between endocannabinoids.

Effect of sugar administration on cortisol responses to acute psychosocial stress

Sugar administration prior acute psychosocial stress exposure was shown to enhance subsequent salivary cortisol responses. However, this finding is based on studies that have administered high doses of glucose to male subjects after long fasting periods. Therefore, in the present study, we investigated the effect of different sugar-containing drinks on acute cortisol stress responses under experimental conditions that are commonplace in stress research and our sample included females and males. Our primary aim was to derive feasible recommendations for a standardized sugar administration in future studies. Of the 103 healthy young participants (49 females, 54 males), 72 were confronted with the Trier Social Stress Test after being randomly assigned to one of three sugar conditions (200 ml of grape juice, a 75 g glucose or a 75 g maltodextrin drink); 31 subjects served as control sample and were exposed to the TSST without sugar administration. Cortisol stress responses were significantly enhanced in the grape juice as well as the glucose group as compared to the control group. Post hoc analysis revealed that this effect seemed to be more pronounced in males than in females. We did not find a significant effect of maltodextrin. Cortisol responder rates in all three experimental groups were higher than in the control group. Our results suggest that, at least in males, the administration of 200 ml of grape juice is sufficient to facilitate HPA axis reactivity and to minimize confounding effects due to interindividual differences in energy availability while being exposed to a laboratory stress paradigm. The unexpected gender-specific effect is of potential relevance and should be scrutinized in future studies.

Increasing Deactivation of Limbic Structures Over Psychosocial Stress Exposure Time

BACKGROUND

Understanding the interplay between central nervous system and hypothalamic-pituitary-adrenal axis responses to stress in humans is assumed to be essential to contribute to the central question of stress research, namely how stress can increase disease risk. Therefore, the present study used a neuroimaging stress paradigm to investigate the interplay of 3 stress response domains. Furthermore, we asked if the brain's stress response changes over exposure time.

METHODS

In a functional magnetic resonance imaging study, changes in brain activation, cortisol levels, affect, and heart rate in response to an improved ScanSTRESS protocol were assessed in 67 young, healthy participants (31 females).

RESULTS

Stress exposure led to significant increases in cortisol levels, heart rate, and negative affect ratings as well as to activations and deactivations in (pre)limbic regions. When cortisol increase was used as a covariate, stronger responses in the hippocampus, amygdala, medial prefrontal cortex, and cingulate gyrus were observed. Responses within the same regions predicted negative affect ratings. Remarkably, an increasing deactivation over the two ScanSTRESS runs was found, again, in the same structures. A reanalysis of an independent sample confirmed this finding.

CONCLUSIONS

For the first time, reactions in a cluster of (pre)limbic structures was consistently found to be associated with changes in cortisol and negative affect. The same neural structures showed increasing deactivations over stress exposure time. We speculate that investigating possible associations between exposure-time effects in neural stress responses and stress-related interindividual differences (e.g., chronic stress) might be a promising new avenue in stress research.

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.

Decision-making in everyday moral conflict situations: Development and validation of a new measure

In everyday life, we are often confronted with morally conflicting social interaction situations. Therefore, the main objective of the present set of studies was the development and validation of a new measure to assess decision-making in everyday moral conflict situations. All vignettes required a decision between an altruistic versus an egoistic behavioral response alternative. In three independent surveys (N = 200), we developed a 40-items measure with preferable mean rates of altruistic decisions (Study 1), clear representation of altruistic and egoistic response classes (Study 2), unambiguousness of social closeness classifications (socially close vs. socially distant protagonists; Studies 1 and 2), and high similarity to reality ratings (Studies 1 and 2). Additionally, we developed two parallelized item sets for future use in within-subjects design studies and investigated the measurement properties of our new scale (Studies 1 and 3). Results of Rasch model analyses and classical test theory fit indices showed unidimensionality and confirmed the appropriateness of the fragmentation into two parallelized item sets. Notably, in our data, there were neither effects of social closeness nor gender on the percentage of altruistic decisions. In sum, we propose the Everyday Moral Conflict Situations (EMCS) Scale as a promising new measurement tool that may facilitate further research in different research areas due to its broad applicability.

Hair Cortisol in Twins: Heritability and Genetic Overlap with Psychological Variables and Stress-System Genes

Hair cortisol concentration (HCC) is a promising measure of long-term hypothalamus-pituitary-adrenal (HPA) axis activity. Previous research has suggested an association between HCC and psychological variables, and initial studies of inter-individual variance in HCC have implicated genetic factors. However, whether HCC and psychological variables share genetic risk factors remains unclear. The aims of the present twin study were to: (i) assess the heritability of HCC; (ii) estimate the phenotypic and genetic correlation between HPA axis activity and the psychological variables perceived stress, depressive symptoms, and neuroticism; using formal genetic twin models and molecular genetic methods, i.e. polygenic risk scores (PRS). HCC was measured in 671 adolescents and young adults. These included 115 monozygotic and 183 dizygotic twin-pairs. For 432 subjects PRS scores for plasma cortisol, major depression, and neuroticism were calculated using data from large genome wide association studies. The twin model revealed a heritability for HCC of 72%. No significant phenotypic or genetic correlation was found between HCC and the three psychological variables of interest. PRS did not explain variance in HCC. The present data suggest that HCC is highly heritable. However, the data do not support a strong biological link between HCC and any of the investigated psychological variables.

Acute psychosocial stress and everyday moral decision-making in young healthy men: The impact of cortisol

In everyday life, moral decisions must frequently be made under acute stress. Although there is increasing evidence that both stress and cortisol affect moral judgment and behavior as well as decision-making in various domains unrelated to morality, surprisingly few attempts have been made to explore the effects of stress on everyday moral decision-making. Therefore, in the present study, we exposed 50 young healthy men to the Trier Social Stress Test (TSST) or its non-stressful placebo version (PTSST). We investigated the impact of acute stress exposure and stress-related cortisol levels on decision-making, decision certainty, and emotions in 28 everyday moral conflict situations with altruistic versus egoistic response alternatives. Results showed that the TSST-exposed group made more altruistic decisions than the non-stress control group, while groups did not differ in decision certainty and emotion ratings. Moreover, in correlational as well as regression analyses, additionally controlling for confounding variables, we observed significant positive associations between cortisol levels and altruistic decision-making. Further analyses revealed that altruistic decisions came along with significantly higher decision certainty and significantly more positive emotion ratings than egoistic decisions. Notably, our data also raise the idea that the personality trait agreeableness plays an important role in everyday moral decision-making. In sum, our findings provide initial evidence that both acute stress exposure and cortisol levels have prosocial effects on everyday moral decision-making in young healthy men.

Sex-Dependent Association of Perigenual Anterior Cingulate Cortex Volume and Migration Background, an Environmental Risk Factor for Schizophrenia

Migration status is one of the best-established risk factors for schizophrenia. An increase in risk is observed in both first- and second-generation immigrants, with a varying magnitude depending on the ethnic background of the individuals. The underlying mechanisms for the increased risk are only recently coming into focus. A causal role for social stress has been widely proposed, and recent work indicated altered neural stress processing in the perigenual anterior cingulate cortex (pACC) in migrants. Since previous work shows that social stress may lead to enduring changes in the gray matter volume of vulnerable brain regions, we investigated the impact of migration background on brain structure. We studied healthy young adults (N = 124), native Germans and second-generation migrants, using whole-brain structural magnetic resonance imaging. Groups were matched for a broad range of sociodemographic characteristics including age, gender, urban exposure, and education. We found a significant group by sex interaction effect in pACC gray matter volume, which was reduced in males with migration background only. This mirrors previous findings in urban upbringing, another risk factor for schizophrenia. Our results provide convergent evidence for an impact of environmental risk factors linked to schizophrenia on gray matter volume and extend prior data by highlighting the possibility that the pACC structure may be particularly sensitive to the convergent risk factors linked to schizophrenia.

Sex-specific association between functional neuropeptide S receptor gene (NPSR1) variants and cortisol and central stress responses

The brain neuropeptide S (NPS) system has recently generated substantial interest and may be of major relevance for central stress regulation. The NPS receptor (NPSR1) is highly expressed in the limbic system, exogenous NPS exerts pronounced anxiolytic and fear-attenuating effects in rodents and extensive close crosstalk between the NPS system and the hypothalamic-pituitary-adrenal (HPA) axis has been demonstrated. In humans, associations between NPSR1 variants and anxiety and panic disorder, as well as amygdala responsiveness to fear- relevant faces and prefrontal cortex activity in a fear conditioning paradigm have been reported. Moreover, a NPSR1 sequence variant was found to be associated with cortisol stress responses in males. Here, we performed a haplotype-based analysis covering three functional NPSR1 single nucleotide polymorphisms in the promoter (rs2530547), in exon 3 (rs324981) and exon 6 (rs727162) in 277 healthy subjects who were exposed to the Trier Social Stress Test (TSST). A significant sex-specific association with salivary cortisol responses to acute psychosocial stress was detected for the common TTC haplotype 2 (frequency of about 20%). In an additional study using an imaging genetics approach, 65 healthy subjects were exposed to a stress paradigm for scanner environments (“ScanSTRESS”). We found a significant and, again, sex-specific interaction between rs324981 (whose minor T-allele is harbored by haplotype 2) and the neural stress response in a cluster close to the parahippocampal gyrus (whole brain corrected). Moreover, as in the TSST sample, NPSR1 variation was associated with salivary cortisol responses (on a trend level) in a sex-specific way. In summary, our preliminary findings in two independent cohorts exposed to different stress paradigms suggest that the NPS system significantly influences acute stress responses and that sequence variation in NPSR1 may contribute to sex differences in stress regulation.

Perceived stress and hair cortisol: Differences in bipolar disorder and schizophrenia

INTRODUCTION

Bipolar disorder (BD) and schizophrenia (SCZ) are psychiatric disorders with shared and distinct clinical and genetic features. In both disorders, stress increases the risk for onset or relapse and dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis has been reported. The latter is frequently investigated by measuring changes in the hormonal end product of the HPA axis, i.e., the glucocorticoid cortisol, whose concentration exhibits diurnal variation. The analysis of hair cortisol concentration (HCC) is a new method, which allows assessment of cumulative cortisol secretion over the preceding three months.

AIMS

To explore whether perceived stress and HCC: (i) differ between BD patients, SCZ patients, and controls; (ii) change over disease course; and iii) are associated with an increased genetic risk for BD or SCZ.

METHODS

159 SCZ patients, 61 BD patients and 82 controls were included. Assessment included psychopathology, perceived stress, and HCC. Inpatients with an acute episode (38 BD and 77 SCZ) were assessed shortly after admission to hospital and at 3 and 6 months follow-up. Outpatients in remission and controls were assessed at one time point only. Polygenic risk scores for BD and SCZ were calculated based on results of the Psychiatric Genomic Consortium.

RESULTS

(i) Perceived stress was higher in BD and SCZ patients compared to controls (p<0.02), and was lower in outpatients in remission compared to inpatients on admission. HCC was higher in BD patients compared to SCZ patients and controls (p<0.02), and higher in inpatients on admission than in outpatients in remission (p=0.0012). In BD patients (r=0.29; p=0.033) and SCZ patients (r=0.20; p=0.024) manic symptoms were correlated with HCC. (ii) In both BD and SCZ inpatients, perceived stress decreased over the 6 month study period (p=0.048), while HCC did not change significantly over the 6 month study period. (iii) In controls, but not in the patient groups, the genetic risk score for BD was associated with HCC (r=0.28, p=0.023).

CONCLUSIONS

While our results are consistent with previous reports of increased perceived stress in BD and SCZ, they suggest differential involvement of the HPA axis in the two disorders. The genetic study supports this latter finding, and suggests that this effect is present below the threshold of manifest disorder.

Assessment of the cortisol awakening response: Expert consensus guidelines

The cortisol awakening response (CAR), the marked increase in cortisol secretion over the first 30-45 min after morning awakening, has been related to a wide range of psychosocial, physical and mental health parameters, making it a key variable for psychoneuroendocrinological research. The CAR is typically assessed from self-collection of saliva samples within the domestic setting. While this confers ecological validity, it lacks direct researcher oversight which can be problematic as the validity of CAR measurement critically relies on participants closely following a timed sampling schedule, beginning with the moment of awakening. Researchers assessing the CAR thus need to take important steps to maximize and monitor saliva sampling accuracy as well as consider a range of other relevant methodological factors. To promote best practice of future research in this field, the International Society of Psychoneuroendocrinology initiated an expert panel charged with (i) summarizing relevant evidence and collective experience on methodological factors affecting CAR assessment and (ii) formulating clear consensus guidelines for future research. The present report summarizes the results of this undertaking. Consensus guidelines are presented on central aspects of CAR assessment, including objective control of sampling accuracy/adherence, participant instructions, covariate accounting, sampling protocols, quantification strategies as well as reporting and interpreting of CAR data. Meeting these methodological standards in future research will create more powerful research designs, thus yielding more reliable and reproducible results and helping to further advance understanding in this evolving field of research.

Brain structure correlates of urban upbringing, an environmental risk factor for schizophrenia

Urban upbringing has consistently been associated with schizophrenia, but which specific environmental exposures are reflected by this epidemiological observation and how they impact the developing brain to increase risk is largely unknown. On the basis of prior observations of abnormal functional brain processing of social stress in urban-born humans and preclinical evidence for enduring structural brain effects of early social stress, we investigated a possible morphological correlate of urban upbringing in human brain. In a sample of 110 healthy subjects studied with voxel-based morphometry, we detected a strong inverse correlation between early-life urbanicity and gray matter (GM) volume in the right dorsolateral prefrontal cortex (DLPFC, Brodmann area 9). Furthermore, we detected a negative correlation of early-life urbanicity and GM volumes in the perigenual anterior cingulate cortex (pACC) in men only. Previous work has linked volume reductions in the DLPFC to the exposure to psychosocial stress, including stressful experiences in early life. Besides, anatomical and functional alterations of this region have been identified in schizophrenic patients and high-risk populations. Previous data linking functional hyperactivation of pACC during social stress to urban upbringing suggest that the present interaction effect in brain structure might contribute to an increased risk for schizophrenia in males brought up in cities. Taken together, our results suggest a neural mechanism by which early-life urbanicity could impact brain architecture to increase the risk for schizophrenia.

Effect of grain size and microporosity on the in vivo behaviour of β-tricalcium phosphate scaffolds

Defining the most adequate architecture of a bone substitute scaffold is a topic that has received much attention over the last 40 years. However, contradictory results exist on the effect of grain size and microporosity. Therefore, the aim of this study was to determine the effect of these two factors on the in vivo behaviour of β-tricalcium phosphate (β-TCP) scaffolds. For that purpose, β-TCP scaffolds were produced with roughly the same macropore size (≈ 150 μm), and porosity (≈ 80 %), but two levels of microporosity (low: 10 % / high: ≈ 25 %) and grain size (small: 1.3 μm /large: ≈ 3.3 μm). The sample architecture was characterised extensively using materialography, Hg porosimetry, micro-computed tomography (μCT), and nitrogen adsorption. The scaffolds were implanted for 2, 4 and 8 weeks in a cylindrical 5-wall cancellous bone defect in sheep. The histological, histomorphometrical and μCT analysis of the samples revealed that all four scaffold types were almost completely resorbed within 8 weeks and replaced by new bone. Despite the three-fold difference in microporosity and grain size, very few biological differences were observed. The only significant effect at p < 0.01 was a slightly faster resorption rate and soft tissue formation between 4 and 8 weeks of implantation when microporosity was increased. Past and present results suggest that the biological response of this particular defect is not very sensitive towards physico-chemical differences of resorbable bone graft substitutes. As bone formed not only in the macropores but also in the micropores, a closer study at the microscopic and localised effects is necessary.

24 h urinary free cortisol in large-scale epidemiological studies: short-term and long-term stability and sources of variability

BACKGROUND

Function of the hypothalamus-pituitary-adrenal (HPA) axis has been associated with several somatic and psychiatric health problems. The amount of free cortisol excreted in the urine during 24h (24-h UFC) has often been used as a proxy for HPA-axis function. Reference values for 24-h UFC and their stability in the short and long term, as well as sources of variability, are largely lacking.

METHODS

This study was performed in a general population cohort. Participants collected 24-h UFC on two consecutive days (T1), and repeated this collection approximately 2 years later (T2). Cortisol in urine was measured using LC-MS/MS. Height and weight were measured at the research facilities; glomerular filtration rate was estimated using creatinine clearance. Psychological distress (General Health Questionnaire), smoking, alcohol use and exercise were measured by means of questionnaires.

RESULTS

24-h UFC stability on a day-to-day basis was 0.69 (T1, N=1192) and 0.72 (T2, N=963) (both p<0.001). Long-term stability as indicated by correlation between 2-day averages of T1 and T2 was 0.60 (N=972, p<0.001). Multivariable linear regression analysis revealed that 24-h UFC was predicted by urine volume (standardized beta 0.282 (T1, N=1556) and 0.276 (T2, N=1244); both p<0.001) and glomerular filtration rate (standardized beta 0.137 (T1) and 0.179 (T2); both p<0.001), while also sex explained a small part (standardized beta for female sex -0.057 (T1) and -0.080 (T2); both p<0.05).

CONCLUSION

24-h UFC is moderately stable both in the short and the long term. The effects of urine volume and glomerular filtration rate on 24-h UFC are much stronger than those of sex.

A functional variant in the neuropeptide S receptor 1 gene moderates the influence of urban upbringing on stress processing in the amygdala

We have previously shown that urban upbringing and city living were associated with stress-induced activity in the amygdala and the perigenual anterior cingulate cortex (pACC). This finding might link the epidemiological risk factor "urbanicity" to neurobiological mechanisms of psychiatric disorders. However, given the heritability of stress-related phenotypes, it appears likely that genetic factors can modulate the effect of urbanicity on social stress processing. In the present exploratory study, we investigated if a functional sequence variation in the neuropeptide S receptor gene (NPSR1 rs324981) is associated with brain activation patterns under acute psychosocial stress and if it modulates the link between urbanicity and central stress processing. In animals, neuropeptide S has strong anxiolytic effects and it induces hypothalamus-pituitary-adrenal (HPA) axis activation. In humans, rs324981 was found to be associated with anxiety and stress-related phenotypes. Forty-two subjects were exposed to a psychosocial stress task for scanner environments (ScanSTRESS). While no main effect of rs324981 on amygdala and pACC activity was detected, we found a distinct interaction between rs324981 and urban upbringing modulating right amygdala responses. Moreover, right amygdala responses were significantly higher in subjects who also showed a salivary cortisol response to the stress exposure. The present finding of a gene × environment interaction further supports the view that the brain NPS system is involved in central stress regulation. This study provides first evidence for the assumption that a NPSR1 variant modulates brain activation under stress, interacting with the environmental risk factor urban upbringing.

Neuroimaging evidence for a role of neural social stress processing in ethnic minority-associated environmental risk

IMPORTANCE

Relative risk for the brain disorder schizophrenia is more than doubled in ethnic minorities, an effect that is evident across countries and linked to socially relevant cues such as skin color, making ethnic minority status a well-established social environmental risk factor. Pathoepidemiological models propose a role for chronic social stress and perceived discrimination for mental health risk in ethnic minorities, but the neurobiology is unexplored.

OBJECTIVE

To study neural social stress processing, using functional magnetic resonance imaging, and associations with perceived discrimination in ethnic minority individuals.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional design in a university setting using 3 validated paradigms to challenge neural social stress processing and, to probe for specificity, emotional and cognitive brain functions. Healthy participants included those with German lineage (n = 40) and those of ethnic minority (n = 40) from different ethnic backgrounds matched for sociodemographic, psychological, and task performance characteristics. Control comparisons examined stress processing with matched ethnic background of investigators (23 Turkish vs 23 German participants) and basic emotional and cognitive tasks (24 Turkish vs 24 German participants).

MAIN OUTCOMES AND MEASURES

Blood oxygenation level-dependent response, functional connectivity, and psychological and physiological measures.

RESULTS

There were significant increases in heart rate (P < .001), subjective emotional response (self-related emotions, P < .001; subjective anxiety, P = .006), and salivary cortisol level (P = .004) during functional magnetic resonance imaging stress induction. Ethnic minority individuals had significantly higher perceived chronic stress levels (P = .02) as well as increased activation (family-wise error-corrected [FWE] P = .005, region of interest corrected) and increased functional connectivity (PFWE = .01, region of interest corrected) of perigenual anterior cingulate cortex (ACC). The effects were specific to stress and not explained by a social distance effect. Ethnic minority individuals had significant correlations between perceived group discrimination and activation in perigenual ACC (PFWE = .001, region of interest corrected) and ventral striatum (PFWE = .02, whole brain corrected) and mediation of the relationship between perceived discrimination and perigenual ACC-dorsal ACC connectivity by chronic stress (P < .05).

CONCLUSIONS AND RELEVANCE

Epidemiologists proposed a causal role of social-evaluative stress, but the neural processes that could mediate this susceptibility effect were unknown. Our data demonstrate the potential of investigating associations from epidemiology with neuroimaging, suggest brain effects of social marginalization, and highlight a neural system in which environmental and genetic risk factors for mental illness may converge.

Sexual dysfunction during treatment with serotonergic and noradrenergic antidepressants: clinical description and the role of the 5-HTTLPR

OBJECTIVES

Sexual dysfunction (SD) is a frequently reported side-effect of antidepressant treatment, particularly of selective serotonin reuptake inhibitors (SSRIs). In the multicentre clinical and pharmacogenetic GENDEP study (Genome-based Therapeutic Drugs for Depression), the effect of the serotonin transporter gene promoter polymorphism 5-HTTLPR on sexual function was investigated during treatment with escitalopram (SSRI) and nortriptyline (tricyclic antidepressant).

METHODS

A total of 494 subjects with an episode of DSM-IV major depression were randomly assigned to treatment with escitalopram or nortriptyline. Over 12 weeks, depressive symptoms and SD were measured weekly with the Montgomery-Asberg Depression Rating Scale, the Antidepressant Side-Effect Checklist, the UKU Side Effect Rating Scale, and the Sexual Functioning Questionnaire.

RESULTS

The incidence of reported SD after 12 weeks of treatment was relatively low, and did not differ significantly between antidepressants (14.9% escitalopram, 19.7% nortriptyline). There was no significant interaction between the 5-HTTLPR and antidepressant on SD. Improvement in depressive symptoms and younger age were both associated with lower SD. The effect of age on SD may have been moderated by the 5-HTTLPR.

CONCLUSIONS

In GENDEP, rates of reported SD during treatment were lower than those described in previous reports. There was no apparent effect of the 5-HTTLPR on the observed decline in SD.

Glucocorticoid receptor gene, low-grade inflammation, and heart failure: the Heart and Soul study

CONTEXT

A common haplotype of the glucocorticoid receptor (GR) gene has been associated with increased susceptibility to coronary heart disease (CHD). Whether this haplotype predisposes to heart failure (HF) is unknown.

OBJECTIVE

The objective of the study was to determine whether GR haplotype 3 is associated with HF and whether this association is explained by low-grade inflammation (C-reactive protein).

DESIGN

In a prospective cohort study, participants were genotyped for common GR gene polymorphisms (ER22/23EK, BclI C/G, N363S, 9beta A/G). Haplotype analyses were conducted.

SETTING

The study was conducted at one university medical center, two Veterans Affairs medical centers, and nine public health clinics.

PATIENTS

Patients included 526 white outpatients with stable CHD.

MAIN OUTCOME MEASURES

Echocardiographic evidence of ventricular dysfunction, self-reported heart failure, and subsequent hospitalization for heart failure were measured.

RESULTS

After adjusting for age, sex, smoking, and body mass index, participants with two copies of haplotype 3 were more likely than those with 0 or 1 copy to report heart failure [hazard ratio (HR) 4.15, 95% confidence interval (CI) 1.5-11.3, P < 0.01], have systolic dysfunction (left ventricular ejection fraction <50%) (HR 3.0, 95% CI 0.9-9.9, P = 0.07), and be hospitalized for HF during a mean follow-up of 6 yr (HR 3.0, 95% CI 1.3-7.0, P = 0.01). These associations were attenuated after adjustment for higher C-reactive protein levels in patients with two copies of haplotype 3.

CONCLUSIONS

We found that the GR gene haplotype 3 was associated with prevalent HF, systolic dysfunction, and subsequent HF hospitalization in patients with CHD. This association was partly mediated by low-grade inflammation.

Association between a serotonin transporter length polymorphism and primary insomnia

STUDY OBJECTIVE

To test the hypothesis that a 44-base-pair insertion/deletion polymorphism in the 5' regulatory region of the serotonin transporter gene (5-HTTLPR) is associated with primary insomnia.

DESIGN

Association study.

SETTING

Sleep laboratory at the Central Institute of Mental Health, Mannheim, Germany.

PATIENTS

157 patients with primary insomnia and 827 healthy controls.

INTERVENTIONS

N/A.

MEASUREMENT AND RESULTS

We found the short (s-) allele of the 5-HTTLPR to be significantly more frequent in patients suffering from insomnia than in control individuals (47.1% vs. 39.9%: OR = 1.34).

CONCLUSIONS

This finding contributes to the understanding of the pathophysiology of primary insomnia and suggests a biological basis between the prevalent comorbidity of primary insomnia and other psychiatric disorders.

Working memory performance is associated with common glucocorticoid receptor gene polymorphisms

Cortisol has a modulatory influence on cognitive functions in humans. Both impairing and enhancing effects of cortisol administration have been shown for hippocampus-dependent declarative memory, and impairing effects have been shown for prefrontal-cortex-dependent working memory function. Given the high density of glucocorticoid (GC) receptors in the prefrontal cortex, we investigated whether common polymorphisms of the GC receptor (GR) gene (ER22/23EK, N363S, BclI, 9 beta A3669G) modulate the influence of cortisol administration on working memory. Working memory performance was investigated in 169 subjects on 10 mg hydrocortisone (cortisol) and placebo using an item recognition task. No impairing effect of hydrocortisone treatment became evident. However, a sex x genotype interaction on general working memory performance was revealed (p = 0.02). While female heterozygous carriers of the 9 beta G allele displayed faster reaction times than the other genotype groups, 9 beta G heterozygous men were relatively slower. Heritability estimates for memory are roughly 50%, indicating that common genetic polymorphisms have an important impact on cognitive performance. Our results suggest that variants of the GR gene might explain some of the variance attributable to genetic factors. Furthermore, it can be speculated that they modulate the individual vulnerability for memory impairments related to stress-related psychiatric disorders.

Human models in acute and chronic stress: assessing determinants of individual hypothalamus-pituitary-adrenal axis activity and reactivity

Stress is one of the most significant health problems in modern societies and the 21st century. This explains a pressing need for investigations into the biological pathways linking stress and health. Besides the locus coeruleus-noradrenaline/autonomic (sympathetic) nervous system ( Chrousos and Gold 1992 ), the hypothalamus-pituitary-adrenal (HPA) axis is the major physiological stress response system in the body. Since alterations in HPA axis regulation under basal conditions and in response to acute stress appear to be a close correlate or even a determining factor of the onset of different diseases or disease progression ( Holsboer 1989 ; Chrousos and Gold 1992 ; Tsigos and Chrousos 1994, 2002 ; Stratakis and Chrousos 1995 ; McEwen 1998 ; Heim et al. 2000a ; Raison and Miller 2003 ), the characterization of an individual's HPA axis activity as well as reactivity pattern to psychosocial stress appears to be of major interest. It is obvious that such a research agenda substantially depends on the availability of appropriate measures. However, since the HPA axis is a highly adaptive system which is characterized by marked inter- and intraindividual variability ( Mason 1968 ; Hellhammer et al. 2009 ), the development of such markers of HPA axis regulation in humans was-and still is-a rather challenging task. In this brief review, we focus on findings on two HPA axis measures, namely the cortisol-awakening response (CAR) to assess HPA axis basal activity and the Trier social stress test (TSST) to investigate HPA axis stress reactivity.

Prenatal psychosocial stress exposure is associated with subsequent working memory performance in young women

The aim of the present study was to examine the association between prenatal psychosocial stress exposure and subsequent prefrontal cortex-dependent working memory performance in human adults. Working memory performance was assessed using an item-recognition task under 10 mg hydrocortisone (cortisol) and placebo conditions in a sample of 32 healthy young women (mean age = 25 +/- 4.34 years) whose mothers experienced a major negative life event during their pregnancy (Prenatal Stress, PS group), and in a comparison group of 27 healthy young women (mean age = 24 +/- 3.4 years). The two groups did not differ in the placebo condition, however, subjects in the PS group showed longer reaction times after hydrocortisone administration compared with subjects in the comparison group (p = .02). These findings provide support for an association between prenatal stress exposure and the potential modulatory effect of cortisol on working memory performance in young adults, which may reflect compromised development of the prefrontal cortex in prenatal life.

Glucocorticoid receptor gene and depression in patients with coronary heart disease: the Heart and Soul Study-2009 Curt Richter Award Winner

Alterations of glucocorticoid receptor sensitivity have been associated with depression. Thus, variation in the glucocorticoid receptor gene that determines glucocorticoid sensitivity may influence risk for depression. In a cross-sectional genetic association study of 526 white outpatients with chronic coronary heart disease, we examined whether haplotypes of the glucocorticoid receptor gene (NR3C1) are associated with depression. Participants were genotyped for four common glucocorticoid receptor gene polymorphisms (ER22/23EK, BclI C/G, N363S, and 9beta A/G) and haplotype analyses were conducted. Depression was assessed by an interview (Computerized Diagnostic Interview Schedule). Of the 526 participants, 355 (67.5%) were non-carriers, 153 (29.1%) had one copy, and 17 (3.2%) had 2 copies of the haplotype 3 allele, which includes the minor allele of the 9beta A/G polymorphism and which has been associated with reduced glucocorticoid sensitivity. The prevalence of depression ranged from 24.4% in the non-carriers to 34.4% in heterozygotes to 52.9% in participants homozygous for the haplotype 3 allele (p<0.01). In logistic regression analyses, carriers of one haplotype 3 allele had an odds ratio of 1.64 (95% CI 1.1-2.5, p=0.02) for depression, while the odds ratio of homozygous haplotype 3 carriers was 3.52 (95% CI 1.3-9.4, p=0.01). These associations persisted after adjusting for potentially confounding variables. A common GR haplotype was associated with depression in a gene-dosage dependent manner and might be a vulnerability factor for depression.

Sex-specific association between the 5-HTT gene-linked polymorphic region and basal cortisol secretion

OBJECTIVE

A key regulator of serotonergic neurotransmission is the serotonin transporter (5-HTT) and a common 5HTT gene promoter polymorphism, termed 5HTTLPR, is associated with phenotypes related to anxiety and depression. Furthermore, the serotonergic system influences hypothalamus-pituitary-adrenal (HPA) axis activity, which, in turn, is related to psychiatric diseases.

METHODS

To explore the association between the 5-HTTLPR and HPA axis regulation we performed a detailed endophenotyping in 216 healthy subjects (all 126 females used oral contraceptives).

RESULTS

While ACTH and cortisol responses to an established psychosocial stress paradigm (Trier Social Stress Test) were not found to be related to the 5-HTTLPR, we observed a significant and sex-specific association with the cortisol awakening response, which is a reliable marker of basal cortisol secretion, and with ACTH levels after dexamethasone administration. The supplementary inclusion of a 5-HTT A/G polymorphism (rs25531) in the analyses did not substantially modify our results.

CONCLUSION

These findings support the view that the 5-HTTLPR is associated with a major neuroendocrine stress system. It could be speculated that the sex-specific nature of this association contributes to the distinct gender differences in the vulnerability for depression.

Cortisol awakening response in healthy children and children with ADHD: impact of comorbid disorders and psychosocial risk factors

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common child psychiatric disorders. Previous studies have reported a blunted cortisol response to challenging situations and a decreased cortisol awakening response (CAR) in children with ADHD. As ADHD often is comorbid with oppositional defiant disorder (ODD), conduct disorder (CD), or anxiety disorder (AnxD), and changes in hypothalamic-pituitary-adrenal (HPA) axis activity have also been reported for these disorders, the present study aimed to compare the CAR in children with ADHD with and without comorbid disorders. Data on the CAR were obtained in 128 children with ADHD (aged 6-13 years) and in 96 control children (aged 6-12 years). Children with ADHD+ODD showed an attenuated CAR (area under the curve, AUC) compared to children with ADHD without ODD/CD and control children. Findings point towards either disinhibition or pervasive underarousal in children with ADHD+ODD, and seem to be specific for children with ADHD+ODD, as the attenuated CAR-AUC was not observed in children with ADHD without comorbid disorders or children with ADHD+CD or ADHD+AnxD. In addition, current adverse parenting conditions, family conflicts, and acute life events were associated with mean increase in CAR, emphasizing the role of psychosocial risk factors in mediating HPA axis activity in children with ADHD.

Characterization of a glucocorticoid receptor gene (GR, NR3C1) promoter polymorphism reveals functionality and extends a haplotype with putative clinical relevance

Hyperactivity of the hypothalamus-pituitary-adrenal (HPA) axis has been associated with the etiology of major depression. One of the factors underlying altered glucocorticoid signaling might be variability of the glucocorticoid receptor gene (GR, NR3C1). GR polymorphisms have been associated with variability in glucocorticoid sensitivity and endocrine responses to psychosocial stress. Furthermore, a common GR SNP (rs10482605), located in the promoter region, has been associated with major depression. We performed functional characterization of this SNP in vitro using a reporter gene assay under different stimulation conditions. Furthermore, we genotyped 219 subjects previously genotyped for four common GR SNPs to further characterize GR haplotype structure. The minor C allele of the rs10482605 SNP showed reduced transcriptional activity under unstimulated conditions and under different stimulation conditions in two brain derived cell lines. Linkage analyses revealed that the rs10482605 SNP is in high linkage disequilibrium with a A/G SNP in exon 9beta (rs6198), associated with relative glucocorticoid resistance and increased GRbeta mRNA stability. We provide evidence that two functional GR SNPs in linkage disequilibrium are responsible for both regulation of GR expression and mRNA stability. This newly characterized haplotype could increase the risk for the development of stress related disorders, including major depression.

Salivary cortisol as a biomarker in stress research

Salivary cortisol is frequently used as a biomarker of psychological stress. However, psychobiological mechanisms, which trigger the hypothalamus-pituitary-adrenal axis (HPAA) can only indirectly be assessed by salivary cortisol measures. The different instances that control HPAA reactivity (hippocampus, hypothalamus, pituitary, adrenals) and their respective modulators, receptors, or binding proteins, may all affect salivary cortisol measures. Thus, a linear relationship with measures of plasma ACTH and cortisol in blood or urine does not necessarily exist. This is particularly true under response conditions. The present paper addresses several psychological and biological variables, which may account for such dissociations, and aims to help researchers to rate the validity and psychobiological significance of salivary cortisol as an HPAA biomarker of stress in their experiments.

Prenatal exposure to maternal psychosocial stress and HPA axis regulation in young adults

Epidemiological studies have reported associations between measures of size and weight at birth and disease risk in later life. Alteration in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis in response to prenatal stress has been proposed as one underlying mechanism. The present study investigated in humans the association of prenatal psychosocial stress exposure with subsequent HPA axis regulation in adult life, with a focus on measures of response to challenge and feedback sensitivity. Healthy young adults whose mothers experienced severe stress during their pregnancy in form of major negative life events (e.g. death of someone close; prenatal stress (PS) group, n=31) and an age-matched comparison group (CG, n=30) underwent the Trier Social Stress Test (TSST) and a 1 microg ACTH(1-24) stimulation test. In addition, a diurnal cortisol profile was assessed. ACTH concentrations following a standardized behavioural challenge paradigm (TSST) were marginally significantly higher in PS subjects than in CG subjects (p=.06). Pre-TSST adrenocortical (cortisol) levels were lower (p=.007), whereas the increase in cortisol in response to the TSST was higher (p=.03) in PS subjects compared to CG subjects. Cortisol concentrations following a pharmacological stimulation test simulating pituitary activity (ACTH(1-24) test) were significantly lower in PS than in CG subjects (p=.006). No differences emerged between the two groups in basal diurnal cortisol levels. This study provides first evidence in humans of an association between prenatal psychosocial stress exposure and subsequent alterations in the regulation of the HPA axis.

Influence of prenatal psychosocial stress on cytokine production in adult women

The aim of the present study was to determine the association between prenatal stress and immune function in human adults. Peripheral blood mononuclear cells (PBMCs) from 34 healthy young women whose mothers experienced major negative life events during their pregnancy (Prenatal Stress, PS group, mean age 25, SD +/- 4.34 years), and from a female comparison group (n = 28, CG, mean age 24 +/- 3.40 years), were stimulated with phytohemagglutinin (PHA), and subsequent cytokine production was measured. A bias for T-helper 2 (Th2) cytokine production due to an overproduction of IL-4 relative to IFN-gamma after PHA stimulation was observed in PS subjects. In addition, IL-6 and IL-10 were also significantly elevated. To the best of our knowledge, this study is the first to suggest a direct association between prenatal stress exposure and alterations in immune parameters in adult women.

Why do we respond so differently? Reviewing determinants of human salivary cortisol responses to challenge

Stress and stress-related health impairments are major problems in human life and elucidating the biological pathways linking stress and disease is of substantial importance. However, the identification of mechanisms underlying a dysregulation of major components of the stress response system is, particularly in humans, a very challenging task. Salivary cortisol responses to diverse acute challenge paradigms show large intra- and interindividual variability. In order to uncover mechanisms mediating stress-related disorders and to potentially develop new therapeutic strategies, an extensive phenotyping of HPA axis stress responses is essential. Such a research agenda depends on substantial knowledge of moderating and intervening variables that affect cortisol responses to different stressors and stimuli. The aim of this report is, therefore, to provide a comprehensive summary of important determinants of, in particular, human salivary cortisol responses to different kinds of laboratory stimuli including acute psychosocial stress as well as pharmacological provocation procedures. This overview demonstrates the role of age and gender, endogenous and exogenous sex steroid levels, pregnancy, lactation and breast-feeding, smoking, coffee and alcohol consumption as well as dietary energy supply in salivary cortisol responses to acute stress. Furthermore, it briefly summarizes current knowledge of the role of genetic factors and methodological issues in terms of habituation to repeated psychosocial stress exposures and time of testing as well as psychological factors, that have been shown to be associated with salivary cortisol responses like early life experiences, social factors, psychological interventions, personality as well as acute subjective-psychological stress responses and finally states of chronic stress and psychopathology.

Prenatal psychosocial stress exposure is associated with insulin resistance in young adults

OBJECTIVE

The objective of the study was to examine the association in humans between maternal psychosocial stress exposure during pregnancy and measures of glucose-insulin metabolism in the adult offspring.

STUDY DESIGN

Healthy young adults whose mothers experienced major stressful life events during their pregnancy (n = 36, prenatal stress, PS group, mean age 25 +/- 5.14 [SD] years) and a comparison group (n = 22, CG, mean age 24 +/- 3.7 [SD] years) underwent an oral glucose tolerance test.

RESULTS

Glucose levels were not significantly different across the groups; however, prenatally stressed subjects showed significantly elevated 2-hour insulin (P = .01) and C-peptide levels (P = .03). These differences were independent of other major risk factors for insulin resistance, including birth phenotype (birthweight, length of gestation), a family history of diabetes, gestational diabetes, body mass index, proinflammatory state, and smoking.

CONCLUSION

Higher insulin responses reflect relative insulin resistance in these prenatally stressed young adults. This study is the first to provide evidence for a link in humans between prenatal psychosocial stress exposure and alterations in glucose-insulin metabolic function.