Exogenous testosterone enhances cortisol and affective responses to social-evaluative stress in dominant men

The effect of physical exercise during competitions and in simulated conditions on hormonal-neurophysiological relationships in kickboxers

K1-format kickboxing is a widely followed combat sport that requires intense physical exercise. However, research into the body's response to this type of combat is sparse. This study aims to assess the alterations in hormone levels and brain activity in elite kickboxers following an actual K1 bout and compare these changes with those observed in a control group engaged in a simulated fight exercise with a punchbag. The study included 100 male professional kickboxers, randomly divided into two groups: an experimental group (K1 fight) and a control group (simulated fight with a punchbag). Blood samples were obtained before and after exercise to evaluate testosterone (T) and cortisol concentrations (C). Concurrently, brain activity was recorded using quantitative electroencephalography (QEEG). After the activity in the experimental group mean testosterone level slightly, non-significantly decreased from 13.7 nmol/l to 12.4 nmol/l, while mean cortisol significantly (p < 0.001) increased from 313 to 570 nmol/l. In the control group after the exertion against a punchbag mean cortisol significantly (p < 0.001) increased from 334 to 452 nmol/l and testosterone increased non-significantly, from 15.1 to 16.3 nmol/l. In both groups, the testosterone/cortisol ratio (T/C ratio) showed significantly lower levels after the intervention (p < 0.001 and p < 0.032) in the experimental and control group respectively. The comparison of groups after exercise revealed significantly higher cortisol levels (experimental group x = 570 nmol/l; control group x = 452 nmol/l) and a significantly lower T/C ratio (experimental group x = 2.7; control group x = 3.9), (p = 0.001) in the experimental group. Significantly higher brain activity was found in selected leads after a bout (experimental group). Furthermore, in the experimental group, significant associations of weak to moderate strength were found between hormone fluctuations and selected areas of brain activity (p < 0.05). K1-format kickboxing induces a stress response, evident in the sharp changes in cortisol and testosterone levels. A notable observation was the inverse direction of changes in both hormones. Brain activity analysis indicated the potential influence of raised cortisol concentrations on specific brain areas. This study augments our understanding of the physiological responses during K1 kickboxing bouts and may inform the future evolution of this sport.

Salivary testosterone and cortisol response in acute stress modulated by seven sessions of mindfulness meditation in young males

Stress is an established risk factor for negative health outcomes. Salivary cortisol and testosterone concentrations increase in response to acute psychosocial stress. It's crucial to reduce stress for health and well-being through evidence-based interventions. Body-mind interventions such as meditation and Tai Chi have shown reduced cortisol levels but mixed results in testosterone concentration after stress. To address this research gap, we conducted a pilot randomized controlled trial to examine the modulating effects of a short-term (seven 20-minute sessions) mindfulness meditation on testosterone and cortisol in response to acute stress. Using one form of mindfulness meditation - Integrative Body-Mind Training (IBMT) and an active control-relaxation training (RT), we assessed salivary cortisol and testosterone concentrations at three stages of stress intervention - rest, stress, and an additional 20-min IBMT or RT practice. We found increased cortisol and testosterone concentrations after acute stress in both groups, but testosterone rise was not associated with cortisol rise. Moreover, an additional practice immediately after stress produced higher testosterone concentrations in the IBMT group than the RT group, whereas cortisol concentration increased in the RT group than in the IBMT group at the same time point. These findings indicate that brief mindfulness intervention modulates a dual-hormone profile of testosterone and cortisol in response to acute stress presumably via the co-regulation of hypothalamus-pituitary-adrenal and hypothalamus-pituitary-testicular axes.

Testosterone administration enhances the expectation and perception of painful and non-painful somatosensory stimuli

The influence of testosterone on pain perception remains inconsistent in the literature. This randomized, placebo-controlled, double-blind, crossover study investigated the effect of testosterone administration on perception and expectation of electrocutaneous stimulus. Thirty healthy male participants received a single dose of testosterone in one session and a placebo in the other session. For each session, they completed a pain-rating task in which a predictability cue was inserted before a painful or non-painful electocutaneous stimulus delivery, while neural activity was simultaneously recorded by a 64-channel electroencephalographic (EEG) system. Expected and perceived pain ratings, as well as event-related potentials (ERPs) to electocutaneous stimuli and prestimulus EEG oscillatory activities while expecting upcoming electocutaneous stimuli were comprehensively compared between testosterone and placebo sessions. Compared with the placebo session, participants in the testosterone session reported greater pain rating and exhibited greater amplitude of N1 component on ERPs when perceiving both painful and non-painful electrocutaneous stimuli. Mediation analysis revealed that testosterone enhanced the pain-intensity ratings via the N1 response to the electrocutaneous stimulus. Upon viewing the predictability cues after testosterone administration, expected pain intensity increased and spontaneous low-frequency α-oscillation power in the frontal region decreased. These results provide evidence that testosterone enhanced perception and expectation of somatosensory events, and that this was a general effect rather than pain-specific. A plausible explanation for these findings is that testosterone acts to increase vigilance and sustained attention levels, as evidenced by the decreased α-oscillation power. Thus, our findings support a causal role for testosterone in heightening the biological salience of incoming somatosensory information.

No Compelling Evidence that Self-Reported Personality Traits Explain Basal Testosterone and Cortisol’s Associations with Status-Relevant Behavior

Objective

A goal of behavioral neuroendocrinology is to understand how basal hormone levels relate to behavior. Studies of human participants sometimes measure self-reported personality traits, in addition to or instead of direct behavioral observation. Although personality traits often predict their respective behaviors, whether personality explains hormone-behavior relationships remains unclear.

Methods

We obtained data from eight previous studies (total N = 985) that examined baseline testosterone and cortisol as predictors of status-relevant behavior (competitiveness, dominance, risk-taking, aggression, affiliation, and social status). We tested whether the previously reported hormone-behavior relationships are mediated by self-reported personality traits (e.g., trait dominance, prestige, extraversion). As a secondary research question, we also tested whether trait dominance moderated the testosterone-behavior relationships.

Results

As expected, self-reported personality traits often predicted status-relevant behaviors, but there was little evidence that traits also correlated with basal testosterone or the testosterone × cortisol interaction. Across all eight studies, personality traits did not significantly mediate hormone-behavior relationships. Indeed, the effect sizes of the hormone-behavior relationships were robust to the inclusion of personality traits as covariates. Further, we did not find strong or consistent evidence that trait dominance moderates the testosterone-behavior association.

Conclusion

Results suggest that basal testosterone and cortisol predict status-related behavior independent of self-reported personality. We discuss how these results may have broader implications for the physiological mechanisms by which testosterone and cortisol influence behavior, a process that could be unconscious and automatic. We also discuss alternative explanations, limitations, and future directions.

Sex and Time: Important Variables for Understanding the Impact of Constant Darkness on Behavior, Brain, and Physiology

The circadian clock can coordinate, regulate and predict physiology and behavior in response to the standard light-dark (LD: 12 h light and 12 h dark) cycle. If we alter the LD cycle by exposing mice to constant darkness (DD: 00 h light and 24 h dark), it can perturb behavior, the brain, and associated physiological parameters. The length of DD exposure and the sex of experimental animals are crucial variables that could alter the impact of DD on the brain, behavior, and physiology, which have not yet been explored. We exposed mice to DD for three and five weeks and studied their impact on (1) behavior, (2) hormones, (3) the prefrontal cortex, and (4) metabolites in male and female mice. We also studied the effect of three weeks of standard light-dark cycle restoration after five weeks of DD on the parameters mentioned above. We found that DD exposure was associated with anxiety-like behavior, increased corticosterone and pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β), downregulated neurotrophins (BDNF and NGF), and altered metabolites profile in a duration of DD exposure and sex-dependent manner. Females showed a more robust adaptation than males under DD exposure. Three weeks of restoration was adequate to establish homeostasis in both sexes. To the best of our knowledge, this study is the first of its kind to look at how DD exposure impacts physiology and behavior as a function of sex- and time. These findings would have translational value and may help in establishing sex-specific interventions for addressing DD-related psychological issues.

The causal effect of testosterone on men's competitive behavior is moderated by basal cortisol and cues to an opponent's status: Evidence for a context-dependent dual-hormone hypothesis

Testosterone has been theorized to direct status-seeking behaviors, including competitive behavior. However, most human studies to date have adopted correlational designs, and findings across studies are inconsistent. This experiment (n = 115) pharmacologically manipulated men's testosterone levels prior to a mixed-gender math competition and examined basal cortisol (a hormone implicated in stress and social avoidance) and context cues related to an opponent's perceived status (an opponent's gender or a win/loss in a prior competition) as factors that may moderate testosterone's impact on competitive behavior. We test and find support for the hypothesis that testosterone given to low-cortisol men evokes status-seeking behavior, whereas testosterone given to high-cortisol men evokes status-loss avoidance. In the initial rounds of competition, testosterone's influence on competitive decisions depended on basal cortisol and opponent gender. After providing opponent-specific win-lose feedback, testosterone's influence on decisions to reenter competitions depended on basal cortisol and this objective cue to status, not gender. Compared to placebo, men given exogenous testosterone who were low in basal cortisol showed an increased tendency to compete against male and high-status opponents relative to female and low-status opponents (status-seeking). Men given exogenous testosterone who were high in basal cortisol showed the opposite pattern-an increased tendency to compete against female and low-status opponents relative to male and high-status opponents (status-loss avoidance). These results provide support for a context-dependent dual-hormone hypothesis: Testosterone flexibly directs men's competitive behavior contingent on basal cortisol levels and cues that signal an opponent's status. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Two Routes to Status, One Route to Health: Trait Dominance and Prestige Differentially Associate with Self-reported Stress and Health in Two US University Populations

Objective

Social status has been extensively linked to stress and health outcomes. However, two routes by which status can be earned - dominance and prestige - may not uniformly relate to lower stress and better health because of inherent behavioral and stress-exposure differences in these two routes.

Methods

In one exploratory and two preregistered studies, participants (total N = 978) self-reported their trait dominance and prestige and self-reported several stress and health outcomes.

Results

The meta-effects evident across the three studies indicate that higher trait dominance was associated with worse outcomes - higher stress, poorer physical and mental health, poorer behavioral health, poorer life satisfaction, higher negative affect (range of absolute values of non-zero correlations, |r| = [0.074, 0.315], ps < 0.021) - and higher trait prestige was associated with better outcomes - lower stress, better physical and mental health, better behavioral health, better life satisfaction, higher positive and lower negative mood (|r| = [0.134, 0.478], ps < 0.001). These effects remained evident (with few exceptions) after controlling for socioeconomic status, other status-relevant traits, or self-enhancing motives; associations with behavior relevant to the COVID19 pandemic generally were not robust.

Conclusions

This work indicates that evolved traits related to the preferred route by which status is earned likely impact self-reported stress and health outcomes. Future research is necessary to examine physiological and other objective indicators of stress and health in more diverse populations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40750-022-00199-3.

Social reputation influences on liking and willingness-to-pay for artworks: A multimethod design investigating choice behavior along with physiological measures and motivational factors

Art, as a prestigious cultural commodity, concerns aesthetic and monetary values, personal tastes, and social reputation in various social contexts—all of which are reflected in choices concerning our liking, or in other contexts, our actual willingness-to-pay for artworks. But, how do these different aspects interact in regard to the concept of social reputation and our private versus social selves, which appear to be essentially intervening, and potentially conflicting, factors driving choice? In our study, we investigated liking and willingness-to-pay choices using—in art research—a novel, forced-choice paradigm. Participants (N = 123) made choices from artwork-triplets presented with opposing artistic quality and monetary value-labeling, thereby creating ambiguous choice situations. Choices were made in either private or in social/public contexts, in which participants were made to believe that either art-pricing or art-making experts were watching their selections. A multi-method design with eye-tracking, neuroendocrinology (testosterone, cortisol), and motivational factors complemented the behavioral choice analysis. Results showed that artworks, of which participants were told were of high artistic value were more often liked and those of high monetary-value received more willingness-to-pay choices. However, while willingness-to-pay was significantly affected by the presumed observation of art-pricing experts, liking selections did not differ between private/public contexts. Liking choices, compared to willingness-to-pay, were also better predicted by eye movement patterns. Whereas, hormone levels had a stronger relation with monetary aspects (willingness-to-pay/ art-pricing expert). This was further confirmed by motivational factors representative for reputation seeking behavior. Our study points to an unexplored terrain highlighting the linkage of social reputation mechanisms and its impact on choice behavior with a ubiquitous commodity, art.

Emotionality vs. Other Biobehavioural Traits: A Look at Neurochemical Biomarkers for Their Differentiation

This review highlights the differential contributions of multiple neurochemical systems to temperament traits related and those that are unrelated to emotionality, even though these systems have a significant overlap. The difference in neurochemical biomarkers of these traits is analysed from the perspective of the neurochemical model, Functional Ensemble of Temperament (FET) that uses multi-marker and constructivism principles. Special attention is given to a differential contribution of hypothalamic-pituitary hormones and opioid neuropeptides implicated in both emotional and non-emotional regulation. The review highlights the role of the mu-opioid receptor system in dispositional emotional valence and the role of the kappa-opioid system in dispositional perceptual and behavioural alertness. These opioid receptor (OR) systems, microbiota and cytokines are produced in three neuroanatomically distinct complexes in the brain and the body, which all together integrate dispositional emotionality. In contrast, hormones could be seen as neurochemical biomarkers of non-emotional aspects of behavioural regulation related to the construction of behaviour in fast-changing and current situations. As examples of the role of hormones, the review summarised their contribution to temperament traits of Sensation Seeking (SS) and Empathy (EMP), which FET considers as non-emotionality traits related to behavioural orientation. SS is presented here as based on (higher) testosterone (fluctuating), adrenaline and (low) cortisol systems, and EMP, as based on (higher) oxytocin, reciprocally coupled with vasopressin and (lower) testosterone. Due to the involvement of gonadal hormones, there are sex and age differences in these traits that could be explained by evolutionary theory. There are, therefore, specific neurochemical biomarkers differentiating (OR-based) dispositional emotionality and (hormones-based) body's regulation in fast-changing events. Here we propose to consider dispositional emotionality associated with OR systems as emotionality in a true sense, whereas to consider hormonal ensembles regulating SS and EMP as systems of behavioural orientation and not emotionality.

The gonadal response to social stress and its relationship to cortisol

The cortisol response to social evaluative stress has been well characterized. However, data regarding changes in gonadal hormones after stress are still scarce and inconsistent. The majority of studies have focused on testosterone reactivity to stress in men, while estradiol responses or gonadal stress responses in women have hardly been investigated. Furthermore, it has not been evaluated whether sex hormone reactivity to stress differs between men and women and the relationship between cortisol and gonadal reactivity to stress is still unclear. To address these questions, we re-analyzed saliva samples collected from 37 men and 30 women in their luteal cycle phase before and repeatedly after social-evaluative stress. Both, testosterone and estradiol levels were assessed. In both men and women, testosterone was significantly reduced after stress. Testosterone levels were at their lowest after 20 minutes, but did not return to baseline until 35 minutes after stress. Across the whole sample, estradiol was significantly increased after stress with two separate peaks after 15 and 30 minutes. Follow-up analyses revealed that 41 participants actually responded with a decrease in estradiol levels to stress, with lowest levels after 20 min, while the remaining participants responded with an increase in estradiol levels. These gonadal stress responses appear to be largely independent of the cortisol response to stress. These results demonstrate that the endocrinological stress response is not restricted to the HPA axis and stress responsivity of gonadal hormones is not simply driven by cortisol. Accordingly, the stress responsivity of gonadal hormones and their association to psychological variables is an additional avenue to explore in both men and women.

Children's hair cortisol and hair testosterone concentrations in response to environmental changes: from summer holidays to school

Elevated hair cortisol concentrations in children have been linked to several stress-related conditions, including school-related demands. However, little is known about changes in hair testosterone in children. The present study investigated changes in hair cortisol and hair testosterone concentrations in the time course of four months - from summer holidays until mid of autumn of the following school year - in 60, 10-12-year-old (11.31 ± 0.63) school children (29 girls). Children's mental health was assessed by the strengths and difficulties questionnaire (SDQ) and related to hair cortisol and hair testosterone levels. Body mass index, waist-to-height ratio, and parental education were evaluated as potential confounders. In girls, the expected increase of hair cortisol concentrations was observed during school as compared to summer holidays, partly accounted for by peer- and emotional problems and the increase of HTC. In boys, hair cortisol and testosterone concentrations were significantly higher. Hair cortisol increased only slightly, while hair testosterone decreased significantly during school. The findings suggest a reciprocal influence of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axis, differentially affecting girls' and boys' hormone production in response to environmental changes.

Gay men's stress response to a general and a specific social stressor

Gay men show altered psychobiological stress responses and exhibit a higher prevalence of mental disorders than their heterosexual counterparts. Both of these findings are likely due to gay-specific discrimination. Since it has not yet been determined whether gay-specific stress is more noxious than general stress, we tested whether gay men react more strongly to gay-specific socially stressful stimuli than to general socially stressful stimuli. N = 33 self-identified gay men (mean = 26.12 years of age, SD = 5.89), 63.6% of whom were in a relationship with a man, participated in an experimental within-group study, in which they were exposed to the Trier Social Stress Test (TSST) as well as a gay-specific TSST in a randomized order. Salivary cortisol and testosterone were assessed at five time points during the laboratory tests and perceived stress was assessed at four time points. According to psychobiological and perceived stress indices, the participants reacted similarly to a gay-specific and general social stressor. There were no significant differences in the outcomes, either when looking at pre-post-test differences or when comparing the overall stress responses. Given that the response to a gay-specific social stressor was equally pronounced as the one to a general social stressor, programs aiming to decrease minority stress but overlooking general stress are likely to yield only partial improvements in gay men's mental health. Instead, we suggest helping gay men cope with both forms of stress through building social support, assertiveness, and mindfulness skills, as well as decreasing emotional dysregulation.

Consideration of sex as a biological variable in the translation of pharmacotherapy for stress-associated drug seeking

Stress is a frequent precipitant of relapse to drug use. Pharmacotherapies targeting a diverse array of neural systems have been assayed for efficacy in attenuating stress-induced drug-seeking in both rodents and in humans, but none have shown enough evidence of utility to warrant routine use in the clinic. We posit that a critical barrier in effective translation is inattention to sex as a biological variable at all phases of the research process. In this review, we detail the neurobiological systems implicated in stress-induced relapse to cocaine, opioids, methamphetamine, and cannabis, as well as the pharmacotherapies that have been used to target these systems in rodent models, the human laboratory, and in clinical trials. In each of these areas we additionally describe the potential influences of biological sex on outcomes, and how inattention to fundamental sex differences can lead to biases during drug development that contribute to the limited success of large clinical trials. Based on these observations, we determine that of the pharmacotherapies discussed only α₂-adrenergic receptor agonists and oxytocin have a body of research with sufficient consideration of biological sex to warrant further clinical evaluation. Pharmacotherapies that target β-adrenergic receptors, other neuroactive peptides, the hypothalamic-pituitary-adrenal axis, neuroactive steroids, and the endogenous opioid and cannabinoid systems require further assessment in females at the preclinical and human laboratory levels before progression to clinical trials can be recommended.

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.

Beyond the challenge hypothesis: The emergence of the dual-hormone hypothesis and recommendations for future research

The challenge hypothesis makes specific predictions about the association between testosterone and status-seeking behaviors, but the findings linking testosterone to these behaviors are often inconsistent. The dual-hormone hypothesis was developed to help explain these inconsistencies. Specifically, according to this hypothesis, testosterone's association with status-seeking behavior depends on levels of cortisol. Here, we (1) describe the dual-hormone hypothesis in relation to the challenge hypothesis; (2) review recent studies that tested the dual-hormone hypothesis as well as meta-scientific evidence of heterogeneous dual-hormone findings across studies; (3) discuss potential explanations for this heterogeneity, including methodological considerations, contextual factors, and individual differences; and (4) provide recommendations for new work aimed at testing and extending the dual-hormone hypothesis.

The effects of testosterone on the physiological response to social and somatic stressors

Higher testosterone levels in males have previously been linked to decreased stress reactivity, but in other cases, testosterone has been reported to increase the stress response. We addressed these inconsistencies in a placebo-controlled single-dose testosterone administration study, in which 120 male participants were randomly assigned to undergo a cold-pressor test (CPT, a non-social somatic stressor), a socially evaluated cold-pressor test (SECPT, a social-somatic stressor), or a lukewarm water test (LWT, a non-stressful control condition). Throughout the experiment, blood pressure and interbeat intervals were measured continuously, and saliva samples for hormonal analyses were taken repeatedly at predefined time points. When comparing the groups treated with placebo, the SECPT elicited a larger increase in the systolic blood pressure than CPT, in agreement with previous studies. However, testosterone administration altered this pattern. Compared to placebo, testosterone increased systolic blood pressure during the CPT, whereas the opposite effect was found during the SECPT. Cortisol reactivity was not affected by testosterone administration. The CAG repeat polymorphism of the androgen receptor gene was unrelated to the effects of testosterone on the stress response, but it was correlated with blood pressure across the whole sample. Our findings demonstrate that testosterone's effects on the stress response are dependent on the social context. Testosterone's ability to flexibly influence the response to stressors may be an important mechanism through which the hormone promotes adaptive behavior. Our results are also in line with research showing that testosterone decreases social anxiety and suggest it may help to modulate the effects of stress in socially challenging situations.

Testosterone administration in human social neuroendocrinology: Past, present, and future

Over the past 20 years, social neuroendocrinology researchers have developed pharmacological challenge paradigms to assess the extent to which testosterone plays a causal role in human psychological and behavioural processes. The current paper provides a brief summary of this research and offers recommendations for future research examining the neuroendocrine mechanisms underlying human behaviour.

Salivary Cortisol, Subjective Stress and Quality of Sleep Among Female Healthcare Professionals

Background

Stress is globally recognised as a risk factor impacting workers’ health and workplace safety. Women healthcare professionals are at risk for considerable stress given the demanding nature of their jobs and current working conditions. This study assessed levels of stress among women healthcare professionals using measures of their cortisol levels, subjective stress and quality of sleep.

Participants and Methods

This study used a cross-sectional design. Data were collected from 335 apparently healthy adult women healthcare professionals working in the United Arab Emirates. Participants provided morning and bedtime saliva samples for analysis of their cortisol levels. The Perceived Stress Scale, Stress Symptoms Scale, Brief Coping Scale and Pittsburgh Sleep Quality Index were used to assess perceived stress level, symptoms of stress, stress-coping strategies and sleep quality, respectively.

Results

In total, 121 (36.15%) women had impaired morning cortisol levels (below the normal range of 0.094–1.551 µg/dL) and 48 (14.3%) had impaired bedtime cortisol levels (above 0.359 µg/dL). Around 57% of women reported moderate levels of perceived stress, with the most frequently reported stress symptoms being heart rate and back/neck pain. Poor sleep quality was reported by around 60% of participating women. No significant association was found between cortisol and psychosocial measurements of stress or sleep quality. However, night shift and longer shift duration (more than 8 hrs) were significantly associated with impaired morning and bedtime cortisol levels (P ≥ 0.05). Impaired cortisol levels were strongly dependent on using adaptive coping strategies such as active coping, acceptance and seeking emotional support (P ≥ 0.05).

Conclusion

Evaluating cortisol levels and subjective stress could help to identify groups with impaired response to stress and elevated cortisol levels. Our findings support the need to examine shift work patterns and stress coping strategies in women healthcare professionals to promote their health and productivity and maintain workplace safety.

Neuroendocrine and cardiovascular responses to shifting status

We review recent work on human neuroendocrine and cardiovascular responses to stable and unstable status. We describe experiments examining inter-personal and inter-group contexts, involving both experimentally created as well as naturalistic (gender, SES) status differences. Across studies the pattern of results is clear: Stable status differences are stressful for those low in status, which is evident from increased cortisol and a cardiovascular response-pattern indicative of threat (low cardiac output, high vascular resistance); however, when status differences are unstable the same effects are found among those high in status, while those low in status show challenge (low vascular resistance, high cardiac output). Potential status-loss also leads to increased testosterone. We discuss implications and suggestions for further research.

Testosterone, cortisol, and status-striving personality features: A review and empirical evaluation of the Dual Hormone hypothesis

Decades of research in behavioral endocrinology has implicated the gonadal hormone testosterone in the regulation of mating effort, often expressed in primates in the form of aggressive and/or status-striving behavior. Based on the idea that neuroendocrine axes influence each other, recent work among humans has proposed that links between testosterone and indices of status-striving are rendered conditional by the effects of glucocorticoids. The Dual Hormone hypothesis is one particular instance of this argument, predicting that cortisol blocks the effects of testosterone on dominance, aggression, and risk-taking in humans. Support for the Dual Hormone hypothesis is wide-ranging, but considerations of theoretical ambiguity, null findings, and low statistical power pose problems for interpreting the published literature. Here, we contribute to the development of the Dual Hormone hypothesis by (1) critically reviewing the extant literature-including p-curve analyses of published findings; and, (2) "opening the file drawer" and examining relationships between testosterone, cortisol, and status-striving personality features in seven previously published studies from our laboratories (total N = 718; median N per feature = 318) that examined unrelated predictions. Results from p-curve suggest that published studies have only 16% power to detect effects, while our own data show no robust interactions between testosterone and cortisol in predicting status-striving personality features. We discuss the implications of these results for the Dual Hormone hypothesis, limitations of our analyses, and the development of future research.

Effect of exogenous testosterone on cooperation depends on personality and time pressure

The social heuristic hypothesis posits that human cooperation is an intuitive response that is expressed especially under conditions of time-constraint. Conversely, it proposes that for individuals given an opportunity for reflection, cooperation is more likely to be curtailed by an optimizing process calibrated to maximize individual benefit in a given situation. Notably, the steroid hormone testosterone has also been implicated in intuitive decision-making, including both prosocial and anti-social behaviors, with effects strongest in men with particular dispositional characteristics. This raises the possibility that increased testosterone may augment the effects predicted by the social heuristic hypothesis, particularly among men higher in specific dispositional characteristics (dominance, impulsivity, independent self-construal: high risk for testosterone-induced antisocial behavior). Here, in a testosterone administration study with a relatively large sample of men (N = 400), we test this possibility in a double-blind, placebo-controlled paradigm, with men randomly assigned to play a one-shot public goods game either under time-pressure (forced intuition) or with a time delay (forced reflection). Results revealed that within the placebo group, time-pressure (versus forced delay) increased cooperation among low risk men, but decreased cooperation among high risk men. Testosterone further moderated this pattern by abolishing the time-pressure effect in low risk men and-in high risk men-reversing the effect by selectively reducing offers (compared to placebo) under forced delay. This is the first evidence that testosterone and personality can interact with time-pressure and delay to predict human cooperation.

Human social neuroendocrinology: Review of the rapid effects of testosterone

Contribution to Special Issue on Fast effects of steroids. It is well documented that testosterone concentrations change rapidly within reproductively relevant contexts (e.g., competition, mate-seeking). It has been argued that such rapid changes in testosterone may serve to adaptively fine-tune ongoing and/or future social behaviour according to one's social environment. In this paper, we review human correlational and experimental evidence suggesting that testosterone fluctuates rapidly in response to competition and mate-seeking cues, and that such acute changes may serve to modulate ongoing and/or future social behaviours (e.g., risk-taking, competitiveness, mate-seeking, and aggression). Some methodological details, which limit interpretation of some of this human work, are also discussed. We conclude with a new integrative model of testosterone secretion and behaviour, the Fitness Model of Testosterone Dynamics. Although we focus primarily on human aggression in this review, we also highlight research on risk-taking, competitiveness, and mate-seeking behaviour.

Role of HPA and the HPG Axis Interaction in Testosterone-Mediated Learned Helpless Behavior

Affective disorders show sex-specific differences in prevalence, symptoms, and complications. One hypothesis for this discrepancy is the interaction between the hypothalamic-pituitary-adrenal (HPA) axis and hypothalamic-pituitary-gonadal (HPG) axis. The present study investigates the influence of androgen on the behavioral phenotype and explores how it interacts with HPA axis genes. Gonadectomized (GDX) and GDX rats treated with testosterone propionate (T) were tested for learned helplessness (LH) behavior and compared with tested controls (TC). Prefrontal cortex was used for analyses of HPG- axis-related genes (androgen receptor, (Ar); estrogen receptor-β (Er-β)) and HPA axis-related genes (corticotropin-releasing hormone, (Crh); glucocorticoid receptor, (Nr3c1); corticotropin-releasing hormone receptor 1, (Crhr1); corticotropin-releasing hormone receptor 2, (Crhr2); FK506 binding protein 5, (Fkbp5)). Promoter-specific CpG methylation in the Crh gene was determined by bisulfite sequencing. Chromatin immunoprecipitation (ChIP) assay was used for determining ER-β binding on the proximal promoter region of Crh gene. Serum testosterone levels confirmed a testosterone-depleted GDX group, a group with supraphysiological levels of testosterone (T) and another group with physiological levels of testosterone (control (C)). Unlike GDX rats, T group exhibited significantly higher LH score when compared with any other group. Crh and Fkbp5 genes were significantly upregulated in GDX group compared with controls, whereas Er-β showed a significant downregulation in the same group. Methylation analysis showed no significant differences in-between groups. ChIP assay was unable to determine a significant change in ER-β binding but revealed a notable contrast in Crh promoter occupancy between T and GDX groups. Altogether, the present study reveals an increased susceptibility to depression-like behavior due to chronic supraphysiological level of androgen via HPA axis inhibition.