Effects of Micro-Interventions on Stress Reactivity

Study Overview
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Brief Summary
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This study aims to investigate the effects of short, psychological interventions on bio-psychological stress responses after an acute stressor. The efficacy of two different approaches (expectation-bases vs. acceptance-based) will be compared to a control-group.

Official Title
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The Effects of Brief, Psychological Interventions (Micro-Interventions) on the Individual Stress Reactivity

Conditions
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Psychological Stress, Physiological Stress

Intervention / Treatment
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* Behavioral: Expectation
* Behavioral: Acceptance


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: fluent in German language Exclusion Criteria: chronic disease mental disease the evening before the day of the experiment until end of the experiment (the next day): caffeine, alcohol, intensive physical exercise, chewing gum acute hay fever current intake of psychotropic medication current intake of orale contraceptives visual impairments heart conditions (self and close relatives)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Expectation<br>Participants are asked to think of three strength which have helped them in prior stressful events. They then have to think of ways how these strength may help them in future stressful situations, i.e. a test in this experiment. | Behavioral: Expectation<br>* writing task<br>|
| Experimental: Acceptance<br>Participants listen to an audio-instruction on cognitive defusion. They shall observe the thoughts and feelings of stress and, with the help of the instruction, distance themselves from it. | Behavioral: Acceptance<br>* listening<br>|
| No Intervention: Control<br>Participants wait for the stress-test to start. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Subjective Stress Ratings | VAS (visual analogue scale) | at baseline, before the intervention, after the intervention; during the stressor, after the stressor; in total 45 minutes | 
| Change in Cortisol Levels | saliva sample | at baseline (min. -37), after the intervention (min. -19), after the stressor (min. 0), recovery 1 (min. +15), recovery 2 (min. +30); in total 67 minutes | 
| Changes in Heart-Rate-Variability (HRV) | electrocardiogram | during baseline (duration 10 minutes), during the stressor (duration 20 minutes), during recovery (duration 10 minutes); in total 40 minutes | 
| Changes in Affect | VAS (visual analogue scale) | at baseline, after the stressor; in total 45 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Self-Efficacy | questionnaire (self-efficacy scale; Schwarzer & Jerusalem, 1999) | at baseline, after the recovery-phase; in total 55 minutes | 
| Positivity | questionnaire (positivity scale; Caprara et al., 2012, König, 2012) | at baseline, after the recovery-phase; in total 55 minutes |