Minderung physiologischer Reaktivität auf psychosozialen Stress durch Taiji-Training - wer profitiert besonders? Eine Untersuchung moderierender Effekte von selbstberichteter dispositioneller psychologischer Stressreaktivität und Achtsamkeit.

Theoretical background and objectives: Stress reducing effects of Taiji practice have been repeatedly reported. The aim of the present study was to investigate which persons benefit the most from Taiji practice in terms of reduced physiological stress reactivity. Methods: We conducted a secondary data analysis of a randomized controlled Taiji trial that significantly lowered stress reactivity of salivary cortisol and alpha-amylase in a Taiji group (n = 26) compared to a control group (n = 23). By using hierarchical regression analyses potential moderating influences of self-reported trait-mindfulness and trait values of general psychological stress reactivity on stress protective effects of a three months Taiji training were examined. Moderator variables were assessed at the beginning of the study using the Freiburg-Mindfulness-Inventory and the Perceived- Stress-Reactivity-Scale. Results: The interaction effect "study group x mindfulness" was significant for stress reactivity of salivary alpha-amylase (p = 0.050). Participants in the Taiji group with higher trait-mindfulness showed a lower salivary alpha-amylase stress reactivity, while in the control group higher trait-mindfulness was associated with higher alpha-amylase stress reactivity. In the control group (p = 0.042) but not in the Taiji group (p = 0.69) salivary cortisol stress reactivity was significantly increased in persons with higher trait-mindfulness scores. We could not find moderating effects of general psychological stress reactivity. Conclusion: Our results suggest that without intervention higher trait-mindfulness is associated with increased physiological stress reactivity. Persons with higher trait-mindfulness seem to benefit the most from practicing Taiji in terms of reduced sympathetic stress reactivity.

Social support and oxytocin interact to suppress cortisol and subjective responses to psychosocial stress

BACKGROUND The presence of social support has been associated with decreased stress responsiveness. Recent animal studies suggest that the neuropeptide oxytocin is implicated both in prosocial behavior and in the central nervous control of neuroendocrine responses to stress. This study was designed to determine the effects of social support and oxytocin on cortisol, mood, and anxiety responses to psychosocial stress in humans. METHODS In a placebo-controlled, double-blind study, 37 healthy men were exposed to the Trier Social Stress Test. All participants were randomly assigned to receive intranasal oxytocin (24 IU) or placebo 50 min before stress, and either social support from their best friend during the preparation period or no social support. RESULTS Salivary free cortisol levels were suppressed by social support in response to stress. Comparisons of pre- and poststress anxiety levels revealed an anxiolytic effect of oxytocin. More importantly, the combination of oxytocin and social support exhibited the lowest cortisol concentrations as well as increased calmness and decreased anxiety during stress. CONCLUSIONS Oxytocin seems to enhance the buffering effect of social support on stress responsiveness. These results concur with data from animal research suggesting an important role of oxytocin as an underlying biological mechanism for stress-protective effects of positive social interactions.

Being optimally aroused matters: Effects of a weak stress manipulation on children’s executive functions are moderated by temperament and age

We tested a core assumption of the bidirectional model of executive function (EF) (Blair & Ursache, 2011) indicating that EF is dependent on arousal. From a bottom-up perspective the performance on EF tasks is assumed to be curvilinearly related to arousal, with very high or low levels of arousal impairing EF. N = 107 4-and 6-year-olds’ performance on EF tasks was explored as a function of a weak stress manipulation aiming to raise children’s emotional arousal. EF (Stroop, Flanker, Go/no-go, and Backwards Color Recall) was assessed and stress was induced in half of the children by imposing a mild social evaluative threat. Furthermore, children’s temperament was assessed as a potential moderator. We found that stress effects on children’s EF performance were moderated by age and temperament: 4-year-olds with high Inhibitory Control and high Attentional Focusing were negatively affected by the stressor. However, it is unclear whether these effects were mediated by self-reported arousal. Our findings disconfirmed the hypotheses that adverse effects of the stressor are particularly high in children high on emotional reactivity aspects of temperament and low on self-regulatory aspects of temperament. Further, 6-year-olds did not show any stress effects. Results will be discussed within the framework of the Yerkes-Dodson law and with regard to stress manipulations in children.

The implicit affiliation motive moderates cortisol responses to acute psychosocial stress in high school students

It has been previously shown that the implicit affiliation motive – the need to establish and maintain friendly relationships with others – leads to chronic health benefits. The underlying assumption for the present research was that the implicit affiliation motive also moderates the salivary cortisol response to acute psychological stress when some aspects of social evaluation and uncontrollability are involved. By contrast we did not expect similar effects in response to exercise as a physical stressor. Fifty-nine high school students aged M = 14.8 years were randomly assigned to a psychosocial stress (publishing the results of an intelligence test performed), a physical stress (exercise intensity of 65–75% of HRmax), and a control condition (normal school lesson) each lasting 15 min. Participants’ affiliation motives were assessed using the Operant Motive Test and salivary cortisol samples were taken pre and post stressor. We found that the strength of the affiliation motive negatively predicted cortisol reactions to acute psychosocial but not to physical stress when compared to a control group. The results suggest that the affiliation motive buffers the effect of acute psychosocial stress on the HPA axis.

Teamwork reduces physiological stress in junior surgeons

Objective: The quality of teamwork depends not only on communication skills but also on team familiarity and hierarchical structures. The aim of the present study is to evaluate the physiological impact of close teamwork between senior and junior surgeons performing elective open abdominal surgery for six months in stable teams. Methods: Physiological measurements of the main and junior surgeons were taken in a total of 40 procedures. Cumulative stress was assessed by the mea- surements of urine catecholamines (Adrenaline, Noradrenaline, Dopamine, Metanephrine, Normetanephrine). Heart rate variability was measured to assess temporal aspects of stress. The procedures were observed by a trained team of work psychologists. Direct observations of distractors, team inter- actions and communication were performed. Specific questionnaires were filled by members of the surgical team that include surgeons, nurses and anesthetists. Results: In junior surgeons, physiological stress is reduced over a period of close collaboration. Case-related communication is not stressful. However, tension within the surgical team is associated with increased levels of cat- echolamine in the urine of the senior surgeon. The difficulty of the oper- ation impacts on heart-rate variability of the junior but not of the senior surgeon. Conclusion: Junior surgeons may require months of teamwork within one stable team in order to reduce levels of physiological stress. Senior surgeons are more resistant to stressful clinical situations compared to junior surgeons but are vulnerable to tension within the surgical team.

Social Stress at Work and Change in Women's Body Weight

Social stressors at work (such as conflict or animosities) imply disrespect or a lack of appreciation and thus a threat to self. Stress induced by this offence to self might result, over time, in a change in body weight. The current study investigated the impact of changing working conditions--specifically social stressors, demands, and control at work--on women's change in weighted Body-Mass-Index over the course of a year. Fifty-seven women in their first year of occupational life participated at baseline and thirty-eight at follow-up. Working conditions were assessed by self-reports and observer-ratings. Body-Mass-Index at baseline and change in Body-Mass-Index one year later were regressed on self-reported social stressors as well as observed work stressors, observed job control, and their interaction. Seen individually, social stressors at work predicted Body-Mass-Index. Moreover, increase in social stressors and decrease of job control during the first year of occupational life predicted increase in Body-Mass-Index. Work redesign that reduces social stressors at work and increases job control could help to prevent obesity epidemic.

Stress-induced cortisol secretion impairs detection performance in x-ray baggage screening for hidden weapons by screening novices

Aviation security strongly depends on screeners' performance in the detection of threat objects in x-ray images of passenger bags. We examined for the first time the effects of stress and stress-induced cortisol increases on detection performance of hidden weapons in an x-ray baggage screening task. We randomly assigned 48 participants either to a stress or a nonstress group. The stress group was exposed to a standardized psychosocial stress test (TSST). Before and after stress/nonstress, participants had to detect threat objects in a computer-based object recognition test (X-ray ORT). We repeatedly measured salivary cortisol and X-ray ORT performance before and after stress/nonstress. Cortisol increases in reaction to psychosocial stress induction but not to nonstress independently impaired x-ray detection performance. Our results suggest that stress-induced cortisol increases at peak reactivity impair x-ray screening performance.

Effects of dark chocolate consumption on the prothrombotic response to acute psychosocial stress in healthy men

Flavanoid-rich dark chocolate consumption benefits cardiovascular health, but underlying mechanisms are elusive. We investigated the acute effect of dark chocolate on the reactivity of prothrombotic measures to psychosocial stress. Healthy men aged 20-50 years (mean ± SD: 35.7 ± 8.8) were assigned to a single serving of either 50 g of flavonoid-rich dark chocolate (n=31) or 50 g of optically identical flavonoid-free placebo chocolate (n=34). Two hours after chocolate consumption, both groups underwent an acute standardised psychosocial stress task combining public speaking and mental arithmetic. We determined plasma levels of four stress-responsive prothrombotic measures (i. e., fibrinogen, clotting factor VIII activity, von Willebrand Factor antigen, fibrin D-dimer) prior to chocolate consumption, immediately before and after stress, and at 10 minutes and 20 minutes after stress cessation. We also measured the flavonoid epicatechin, and the catecholamines epinephrine and norepinephrine in plasma. The dark chocolate group showed a significantly attenuated stress reactivity of the hypercoagulability marker D-dimer (F=3.87, p=0.017) relative to the placebo chocolate group. Moreover, the blunted D-dimer stress reactivity related to higher plasma levels of the flavonoid epicatechin assessed before stress (F=3.32, p = 0.031) but not to stress-induced changes in catecholamines (p's=0.35). There were no significant group differences in the other coagulation measures (p's≥0.87). Adjustments for covariates did not alter these findings. In conclusion, our findings indicate that a single consumption of flavonoid-rich dark chocolate blunted the acute prothrombotic response to psychosocial stress, thereby perhaps mitigating the risk of acute coronary syndromes triggered by emotional stress.