Assessing the Repeatability of a Psychological Stress Test

To establish the efficacy and repeatability of a suitable psychological stress test. The Mannheim Multicomponent Stress Test (MMST) is a validated laboratory stress test that combines cognitive, emotional, acoustic and motivational stress components. Despite the test increasing self-reported levels of stress, meaningful changes in saliva cortisol are typically observed in only half of all participants. In addition, the MMST is susceptible to habituation of the cortisol response upon repeated exposures, limiting its current usefulness for repeated measures. Given the multicomponent nature of the MMST, there is potential for components of the test to be manipulated to overcome these limitations i.e., increase the magnitude of the saliva cortisol response and mitigate against habituation effects. In addition, a supplementary topic of interest is to what extent cortisol responses to acute laboratory stress tests, like the MMST, relate to the well described rise in morning cortisol ~30 minutes after awakening. This may be of clinical relevance given that blunted cortisol response upon awakening and in response to acute psychological stress tests have been associated with poor health outcomes. The primary objective of the current study is to investigate if the MMST elicits a meaningful increase in saliva cortisol. The secondary objective is to investigate the efficacy of mitigation strategies to overcome habituation to the MMST. A supplementary objective is to to investigate the relationship between the saliva cortisol response upon awakening and the saliva cortisol response to the MMST.

The investigators propose a parallel experimental trial examining physiological and psychological responses to a socio-evaluative stress task (The Mannheim Multicomponent Stress Test; MMST) under laboratory conditions. Participants will be tested on three occasions in a randomised order, with each trial separated by 7 days. On two occasions, participants will be complete a socially evaluated math-based serial addition task whilst simultaneously viewing a series of positive and negative images and in the presence of white noise (duration ~ 5 minutes). On the other occasion, participants will rest quietly and will be exposed to a short film and some images that are not designed to induce anxiety or stress for the same duration as the stress test in the stress induction room. The non-stress control condition, will occur either 1-week preceding or 1-week following both MMST trials, thereby controlling for order effects influencing baseline physiological and psychological outcome measures.

Saliva samples will be identified by participant identification number only. Technicians assessing levels of biological measures in these samples will be blind to condition.

The format of the MMST will remain the same; however, the white noise, images and math task will be modified to mitigate habituation effects.

Questionnaire comprised of a 10-point rating scale from 0 to 9 (0 - no subjective stress experience at all; 9 - extreme experience of subjective stress experience.

Questionnaire used to determine the extent to which participants felt the MMST was difficult, challenging, and upsetting. Using a 7-pt scale (1 = not at all; 7 = extremely) participants rate their level of nervousness during the laboratory task. Participants will also rate the level of effort they put into the task on a scale ranging from 1 (didn't try at all) to 7 (tried as hard as I could), which will be used as a manipulation check.

Questionnaire used to determine the extent of rumination about an induced stressful situation. Using a 7-pt scale (1= not at all, 7 = all the time), participants indicate the extent to which they; thought about the test (stress test and control) after having completed it, criticised themselves about not performing well, thought about other past experiences of being evaluated, thought about the anxiety they felt during the task.

A biomarker for Hypothalamic Pituitary Adrenal activity; a naturally occurring increase in cortisol upon waking, assessed by ELISA.

Assessing upon awakening, and every 15 minutes for the first 45 minutes after awakening (i.e. +15, +30, +45, +60 minutes after awakening)

Inclusion Criteria: Participants who… have read and signed the study informed consent are healthy, recreationally active men and women aged 18-35 years test negative for coronavirus (COVID-19) are willing to provide saliva samples throughout and complete the MMST through the duration of the study are using monophasic birth control (women only) Exclusion Criteria: Participants who… have a recent history or are a current smoker are currently taking prescription/Over-the-counter medication consume ≥ 91 units of alcohol per month have a clinically diagnosed history of cardiovascular and/or metabolic disease including diabetes and abnormal blood pressure are pregnant have a recent or ongoing viral or bacterial illness in past 4 weeks test positive for coronavirus (COVID-19) have a clinically diagnosed psychiatric disorder have a clinically diagnosed sleeping disorder have a clinically diagnosed gambling addiction BMI ≥ 30 kg/m2 - calculated in the online health screening questionnaire report unusually high levels of recent or ongoing life stress over the last month; as assessed by the perceived stress scale (PSS) i.e. rating ≥ 13 indicates high perception of recent and ongoing life stress Endurance trained or engage in ≥3.5 hours of physical activity a week