Stress can have a significant impact on the daily lives of individuals and can increase vulnerability to a number of medical conditions. This study aims to estimate the ratio of male to female participants in acute social stress research in healthy individuals. We examined original research articles published over the last 20 years. Each article was screened to determine the total number of female and male participants. We extracted data from 124 articles involving a total of 9539 participants. A total of 4221 (44.2%) participants were female, 5056 (53.0%) were male and 262 (2.7%) were unreported. Articles incorporating only females were significantly underrepresented compared to articles incorporating only males. Forty articles (63.5%) which presented data from both females and males, failed to analyse and interpret the results by sex, a significant methodological limitation. In conclusion, in the literature published over the last 20 years, female participants are significantly underrepresented. In the studies where females are represented, severe methodological limitations are apparent. Researchers should be conscious of sexual dimorphism, menstrual phase and use of hormonal contraception, which may impact the interpretation of their results.

Introduction: By virtue of the nature of their work, emergency medicine physicians and residents experience high cognitive load and stress, which are known to affect physician performance and patient outcomes. However, the contribution of cognitive load has not previously been measured during the clinical work of emergency physicians. The objectives of this study were to measure cognitive load and stress in emergency physicians and residents during clinical work, evaluate the relative contribution of multiple factors on cognitive load, and to determine the effect of experience on these results. Methods: This observational study was conducted at an academic Canadian Urgent Care Centre from July to August 2018. Emergency medicine residents and staff physicians completed a survey while on shift to evaluate measures of cognitive load and acute stress. Patient acuity and the number of active patients for each physician, hours worked and patients in the waiting room were recorded. Correlational analyses and multivariable linear regression were performed to evaluate the effect of each predictor on measures of overall cognitive load. Results: A total of 131 questionnaires were completed by 42 physicians (87 questionnaires from 26 staff physicians and 44 questionnaires from 16 residents). Results showed that staff physicians carried a significantly higher patient load compared to residents (p < 0.001). There were no differences in mean overall cognitive load (p = 0.25), acute stress (p = 0.17) or measured subcomponents of cognitive load between the two groups. Perceived case difficulty and acute stress were strong predictors of overall cognitive load, while level of distraction did not correlate with the other outcomes. The number of patients in the waiting room predicted acute stress in staff physicians, while the number of higher acuity patients was a significant predictor in residents. Conclusion: Measures of overall cognitive load and acute stress were strongly correlated in the clinical setting. Different factors affect cognitive load and acute stress in staff physicians compared to residents. Appreciating these differences may help medical educators understand the cognitive challenges faced by learners in a clinical context, and aid in the design of cognitive and educational strategies to help mitigate these challenges and reduce stress.

Clinical depression is accompanied by changes in sleep patterning, which is controlled in a circadian fashion. It is thus desirable that animal models of depression mirror such diurnally-specific state alterations, along with other behavioral and physiological changes. We previously found several changes in behavior indicative of a depression-like phenotype in offspring of rats subjected to repeated, variable prenatal stress (PNS), including increased locomotor activity during specific periods of the circadian cycle. We, therefore, investigated whether PNS rats also exhibit alterations in sleep/wakefulness behavior around the change from light-to-dark phase. Control and PNS Sprague–Dawley rats were implanted with electrodes for continuous monitoring of electroencephalic activity used to determine behavioral state. The distribution of slow-wave sleep (SWS), rapid eye movement sleep (REMS) and wakefulness was compared for periods before and after lights were turned off, between baseline conditions and after exposure to an acute stressor. Both REMS and SWS amounts were increased in PNS rats relative to control animals in the beginning of the dark phase. REMS changes were due to an increase in REMS bout number, rather than in bout duration. During this circadian time period, we did not find any sex differences in the state changes. These results indicate that PNS affects baseline sleep patterning in both male and female rats around active-phase onset.

Acute stress and decision making (DM) interact in life – although little is known about the role of ambiguity and risk in this interaction. The aim of this study is to clarify the effect of acute stress on DM under various conditions. Thirty-one young healthy men were randomly distributed into two groups: experimental and control. DM processes were evaluated before and after an experimental session. For the experimental group, the session consisted of an acute stress battery; and the protocol was similar for the control group but the instructions were designed to minimize acute stress. Cardiovascular variables were continuously recorded 30 minutes before the DM tasks and during the experimental session. Cortisol, glucose, mood responses, and personality factors were also assessed. Acute stress was found to enhance disadvantageous decisions under ambiguous conditions (F(1, 29) = 4.16, p = .05, η2p = .13), and this was mainly explained by the stress induced cortisol response (26.1% of variance, F(1, 30) = 11.59, p = .002). While there were no significant effects under risky conditions, inhibition responses differed between groups (F(1, 29) = 4.21, p = .05, η2p = .13) and these differences were explained by cardiovascular and psychological responses (39.1% of variance, F(3, 30) = 7.42, p < .001). Results suggest that DM tasks could compete with cognitive resources after acute stress and could have implications for intervention in acute stress effects on DM in contexts such as addiction or eating disorders.

Caring for an offspring diagnosed with a psychological chronic disorder is used in research as a model of chronic stress. Indeed, it is usually associated with disturbances in the salivary cortisol (Csal) levels of the caregiver. An imbalance between salivary testosterone (Tsal) and Csal levels is a marker of proneness to social aggression. Given this, we aimed to establish whether the salivary testosterone/cortisol (Tsal/Csal) ratio response to acute stress could be employed as a marker of proneness to anger in informal caregivers of offspring with autism spectrum (ASD). Tsal/Csal ratio and anger responses to a set of different cognitive tasks as well as anger trait and expression were compared in these informal caregivers and controls. Caregivers, particularly those of offspring with ASD, had higher Tsal/Csal ratios than controls in response to acute stress, concretely after the stress in the case of fathers (p = .05) and before stress when analyzing mothers (p = .05). Moreover, ASD fathers and mothers obtained higher magnitude of the T/C ratio response to stress (p = .03 and p =.04, respectively), anger state (p = .02 and p = .02, respectively) and expression scores (p = .05 and p = .05, respectively) than controls. Finally, high Tsal/Csal ratio levels and response to stress were significantly associated with high anger feelings increases (p < .01 and p < .001, respectively), trait (p < .001 and p > .05, respectively) and expression (p < .05 and p > .05, respectively) in caregivers.

The aims of this study were, first, to evaluate eye temperature (ET) with infrared thermography and heart rate (HR) to measure stress in horses during show jumping competitions and their relationship with competition results, and second, to evaluate the influence of different extrinsic and intrinsic factors of the horse on the stress measurements analysed. One hundred and seventy-three Spanish Sport Horses were analysed for ET and HR, and these measurements were taken 3 h before the competition, just after and 3 h after it. Two interval measurements were also assessed for each parameter. Positive significant correlations were found between ET and HR, measured before (r=0.23), just after competition (r=0.28) and for the later interval (r=0.26), whereas negative correlations with competition results were found only for ET when measured just after competing (r=−0.25). Two intrinsic factors (genetic line and age) and no extrinsic factors showed significant differences for ET, whereas one intrinsic factor (age) and two extrinsic factors (journey duration and number of training hours) showed significant differences for HR. The marginal means showed significantly higher ET values for the Anglo-Arab genetic line and for 5-year-old animals. HR values were significantly higher for 4-year-old animals, for horses which had travelled 4 to 6 h and for horses that had 3 to 6 h of daily training. This study suggests that, although ET and HR seemed to share a similar physiological basis, the factors that most influenced each parameter were different. Finally, ET seems to be a suitable tool for assessing stress during show jumping competitions in horses.

Psychological stress is a common feature of modern day societies, and contributes to the global burden of disease. It was proposed by Henry over 20 years ago that the salt intake of a society reflects the level of stress, and that stress, through its effect on increasing salt intake, is an important factor in the development of hypertension. This review evaluates the evidence from animal and human studies to determine if stress does induce a salt appetite and increase salt consumption in human subjects. Findings from animal studies suggest that stress may drive salt intake, with evidence for a potential mechanism via the sympatho-adrenal medullary system and/or the hypothalamo–pituitary–adrenal axis. In contrast, in the few laboratory studies conducted in human subjects, none has found that acute stress affects salt intake. However, one study demonstrated that life stress (chronic stress) was associated with increased consumption of snack foods, which included, but not specifically, highly salty snacks. Studies investigating the influence of chronic stress on eating behaviours are required, including consumption of salty foods. From the available evidence, we can conclude that in free-living, Na-replete individuals, consuming Na in excess of physiological requirements, stress is unlikely to be a major contributor to salt intake.