Steven J. Stanton

Salivary testosterone, cortisol, and progesterone: Two-week stability, interhormone correlations, and effects of time of day, menstrual cycle, and oral contraceptive use on steroid hormone levels ☆

With salivary assessment of steroid hormones increasing, more work is needed to address fundamental properties of steroid hormone levels in humans. Using a test-retest design and radioimmunoassay assessment of salivary steroids, we tested the reliability of testosterone, cortisol, and progesterone levels across two weeks, as well as the effects of oral contraceptives, menstrual cycle phase, and time of day on steroid hormone levels. Testosterone and cortisol were found to be highly reliable in both sexes. Progesterone was found to be reliable after collapsing across sex. Oral contraceptive use was associated with lower levels of testosterone, but did not affect cortisol. Contrary to expectations, oral contraceptives also did not affect progesterone. Menstrual cycle was found to affect levels of progesterone, but not testosterone or cortisol. Time of day had an effect on cortisol, on progesterone only at one testing time, and no effect on testosterone. We explored the interhormone correlations among testosterone, progesterone, and cortisol. All three hormones were positively correlated with one another in men. In women, progesterone was positively correlated with testosterone and cortisol, but testosterone and cortisol were uncorrelated.

Testosterone is positively associated with risk taking in the Iowa Gambling Task

The association between testosterone and economic risk is not well-understood and is understudied. The present study aimed to further characterize what if any relationship testosterone has with risky economic decisions. To do so, 154 participants (78 men) completed the Iowa Gambling Task (IGT) (Bechara et al., 1994) and also provided saliva samples, which were assayed for endogenous testosterone levels using radioimmunoassay. High-levels of endogenous testosterone were associated with choosing less frequently from advantageous IGT decks of cards, indicating greater risk taking. The data showed that the effects of testosterone on IGT performance were similar for men and women. High-testosterone women and high-testosterone men made riskier choices than their low-testosterone counterparts of the same sex, and this effect was pronounced in women. Thus, high levels of testosterone are associated with willingness to incur greater risk in both sexes.

Psychological and Neural Mechanisms of Trait Mindfulness in Reducing Depression Vulnerability

Mindfulness-based interventions are effective for reducing depressive symptoms. However, the psychological and neural mechanisms are unclear. This study examined which facets of trait mindfulness offer protection against negative bias and rumination, which are key risk factors for depression. Nineteen male volunteers completed a 2-day functional magnetic resonance imaging study. One day utilized a stress-induction task and the other day utilized a mindful breathing task. An emotional inhibition task was used to measure neural and behavioral changes related to state negative bias, defined by poorer performance in inhibiting negative relative to neutral stimuli. Associations among trait mindfulness [measured by the Five Facet Mindfulness Questionnaire (FFMQ)], trait rumination, and negative bias were examined. Non-reactivity scores on the FFMQ correlated negatively with rumination and negative bias following the stress induction. Non-reactivity was inversely correlated with insula activation during inhibition to negative stimuli after the mindful breathing task. Our results suggest non-reactivity to inner experience is the key facet of mindfulness that protects individuals from psychological risk for depression. Based on these results, mindfulness could reduce vulnerability to depression in at least two ways: (i) by buffering against trait rumination and negative bias and (ii) by reducing automatic emotional responding via the insula.

Low- and High-Testosterone Individuals Exhibit Decreased Aversion to Economic Risk

Testosterone is positively associated with risk-taking behavior in social domains (e.g., crime, physical aggression). However, the scant research linking testosterone to economic risk preferences presents inconsistent findings. We examined the relationship between endogenous testosterone and individuals’ economic preferences (i.e., risk preference, ambiguity preference, and loss aversion) in a large sample (N = 298) of men and women. We found that endogenous testosterone levels have a significant U-shaped association with individuals’ risk and ambiguity preferences, but not loss aversion. Specifically, individuals with low or high levels of testosterone (more than 1.5 SD from the mean for their gender) were risk and ambiguity neutral, whereas individuals with intermediate levels of testosterone were risk and ambiguity averse. This relationship was highly similar in men and women. In contrast to received wisdom regarding testosterone and risk, the present data provide the first robust evidence for a nonlinear association between economic preferences and levels of endogenous testosterone.

Endogenous testosterone levels are associated with amygdala and ventromedial prefrontal cortex responses to anger faces in men but not women

Testosterone moderates behavioral and physiological responses to the emotion anger. However, little is known about the effects of testosterone in the human brain in the context of the perception of anger. We used fMRI to measure BOLD responses to anger faces in the amygdala and ventromedial prefrontal cortex (vmPFC) as a function of endogenous testosterone levels in 24 participants (10 men). In one task, participants passively viewed anger faces and neutral faces and in another task, participants engaged in an oddball task while viewing anger and neutral faces. Mens, but not womens, amygdala BOLD response to anger faces was negatively correlated with their endogenous testosterone levels in both tasks. Mens, but not womens, vmPFC BOLD response to anger faces was positively correlated with their endogenous testosterone levels in the passive-viewing task. In men, amygdala and vmPFC BOLD responses to anger faces were negatively associated. Our results extend past research by documenting associations between endogenous testosterone levels and BOLD responses to anger faces in the amygdala and vmPFC in men, and our results also support research that documents negative associations between amygdala and vmPFC activity.

TESTOSTERONE AND SPORT: CURRENT PERSPECTIVES

Testosterone and other anabolic-androgenic steroids enhance athletic performance in men and women. As a result, exogenous androgen is banned from most competitive sports. However, due to variability in endogenous secretion, and similarities with exogenous testosterone, it has been challenging to establish allowable limits for testosterone in competition. Endogenous androgen production is dynamically regulated by both exercise and winning in competition. Furthermore, testosterone may promote athletic performance, not only through its long-term anabolic actions, but also through rapid effects on behavior. In women, excess production of endogenous testosterone due to inborn disorders of sexual development (DSD) may convey a competitive advantage. For many years, female competitors have been subject to tests of sexual genotype and phenotype known as gender verification. Although gender verification has not identified any normal man competing as a woman, this process has identified women athletes with DSD. As understanding of DSD has expanded in recent years, women with DSD are increasingly able to continue athletic competition.

Endogenous estradiol levels are associated with attachment avoidance and implicit intimacy motivation.

Estradiol has been linked with attachment and caregiving processes in humans and other mammals; however, relations between estradiol and personality constructs relevant to intimate relationships have not yet been explored. In the present sample of 100 adult participants (52 men, 48 women), we examined endogenous estradiol levels in relation to two personality constructs that predict comfort with and desire for close, intimate relationships-attachment style and implicit intimacy motivation. In both men and women, estradiol levels were predicted by an interaction between a dimension of attachment style-attachment avoidance-and implicit intimacy motivation. Specifically, the highest estradiol levels were observed among participants whose explicit traits support the expression of their implicit motives, that is, those characterized by both low avoidance and high intimacy motivation. Our findings provide novel evidence that endogenous estradiol levels are associated with relationship-relevant personality constructs in theoretically meaningful ways. These findings also highlight the importance of considering interactions between implicit and explicit personality constructs in the study of the biological bases of personality.

The essential implications of gender in human behavioral endocrinology studies.

Carney et al. (2010) recently published a study in which they examined the effect of assuming “high- and low-power” body postures on changes in testosterone levels in men and women. To do so, they randomly assigned participants to two groups (high-power and low-power), and then placed them in two successive 1-min poses appropriate for their group. They reported that “high-power” poses produced testosterone increases in participants and “low-power” poses produced testosterone decrements, while collapsing over gender in their analyses. This study tested an important hypothesis regarding the effects of dominance posturing on endocrine changes that may be critical precursors to dominance competition, in which dominance posturing could lead to pre-competition changes in testosterone that influence the impending dominance competition (Mazur, 1985; Salvador et al., 2003; Gleason et al., 2009; Edwards and Kurlander, 2010). While Carney et al. (2010) asked an important research question, there are a number of methodological and analytical factors regarding gender and testosterone that must be considered in greater detail before their data can be fully understood and used to motivate future research.

Loss of sustained activity in the ventromedial prefrontal cortex in response to repeated stress in individuals with early-life emotional abuse: implications for depression vulnerability.

Repeated psychosocial stress in early-life has significant impact on both behavior and neural function which, together, increase vulnerability to depression. However, neural mechanisms related to repeated stress remain unclear. We hypothesize that early-life stress may result in a reduced capacity for cognitive control in response to a repeated stressor, particularly in individuals who developed maladaptive emotional processing strategies, namely trait rumination. Individuals who encountered early-life stress but have adaptive emotional processing, namely trait mindfulness, may demonstrate an opposite pattern. Using a mental arithmetic task to induce mild stress and a mindful breathing task to induce a mindful state, we tested this hypothesis by examining blood perfusion changes over time in healthy young men. We found that subjects with early-life stress, particularly emotional abuse, failed to sustain neural activation in the orbitofrontal and ventromedial prefrontal cortex (vmPFC) over time. Given that the vmPFC is known to regulate amygdala activity during emotional processing, we subsequently compared the perfusion in the vmPFC and the amygdala in depression-vulnerable (having early-life stress and high in rumination) and resilient (having early-life stress and high in mindfulness) subjects. We found that depression-vulnerable subjects had increased amygdala perfusion and reduced vmPFC perfusion during the later runs than that during the earlier stressful task runs. In contrast, depression-resilient individuals showed the reverse pattern. Our results indicate that the vmPFC of depression-vulnerable subjects may have a limited capacity to inhibit amygdala activation to repeated stress over time, whereas the vmPFC in resilient individuals may adapt to stress quickly. This pilot study warrants future investigation to clarify the stress-related neural activity pattern dynamically to identify depression vulnerability at an individual level.