Optimizing the Efficacy of Progressive Muscle Relaxation Using Placebo Mechanisms in an Guided and Unguided Online-intervention

Study Overview
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Brief Summary
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This study aims to determine whether a brief video aiming to optimize expectations regarding the effectiveness of progressive muscle relaxation (PMR) can enhance the efficacy of a PMR compared to a neutral video control group in an online intervention. Another aim is to assess whether this effect will be moderated by the degree of human support (guided or unguided intervention).

Detailed Description
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This study aims to determine whether a brief video aiming to optimize expectations regarding the effectiveness of progressive muscle relaxation (PMR) can enhance the efficacy of a PMR session compared to a neutral video control group in an online intervention. Another aim is to assess whether this effect will be moderated by the degree of human support (guided or unguided intervention). After the baseline assessment, participants are randomized to one of 4 possible intervention groups: i) watching a video aiming to optimize participants' expectations before undergoing a single PMR session without personal support of the experimenter (unguided), ii) watching a video aiming to optimize participants' expectations before undergoing a single PMR session with the personal support of the experimenter (guided), iii) watching a neutral video (not aiming to optimize participants' expectations) before undergoing a single PMR session without personal support of the experimenter (unguided), or iv) watching a neutral video (not aiming to optimize participants' expectations) before undergoing a single PMR session with the personal support of the experimenter (guided). In a pre-posttest design, the subjective stress levels of the participants in the for groups will be analyzed.

Official Title
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Optimizing the Efficacy of Progressive Muscle Relaxation Using Placebo Mechanisms in an Guided and Unguided Online-intervention

Conditions
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Healthy Participants

Intervention / Treatment
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* Behavioral: Video optimizing expectations before PMR (unguided) + Progressive Muscle Relaxation (PMR)
* Behavioral: Video optimizing expectations before PMR (guided) + Progressive Muscle Relaxation (PMR)
* Behavioral: Neutral video before PMR (unguided) + Progressive Muscle Relaxation (PMR)
* Behavioral: Neutral video before PMR (guided)+ Progressive Muscle Relaxation (PMR)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy participants fluency in the German language to provide informed consent Exclusion Criteria: muscle disease, muscle cramps, acute psychosis, acute trauma responses, or another chronic somatic illness Mental disorder

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Video optimizing expectations before PMR (unguided)<br>watching a video aiming to optimize participants' expectations before undergoing a single PMR session without personal support of the experimenter (unguided) | Behavioral: Video optimizing expectations before PMR (unguided) + Progressive Muscle Relaxation (PMR)<br>* Participants watch a video aiming to optimize participants' expectations before undergoing a single PMR session without personal support of the experimenter (unguided). The PMR session involves learning to monitor tension in each specific muscle group in the body by deliberately inducing tension in each group. This tension is then released, with attention paid to the contrast between tension and relaxation.<br>|
| Experimental: Video optimizing expectations before PMR (guided)<br>watching a video aiming to optimize participants' expectations before undergoing a single PMR session with the personal support of the experimenter (guided) | Behavioral: Video optimizing expectations before PMR (guided) + Progressive Muscle Relaxation (PMR)<br>* Participants watch a video aiming to optimize participants' expectations before undergoing a single PMR session with the personal support of the experimenter (guided). The PMR session involves learning to monitor tension in each specific muscle group in the body by deliberately inducing tension in each group. This tension is then released, with attention paid to the contrast between tension and relaxation.<br>|
| Active Comparator: Neutral video before PMR (unguided)<br>watching a neutral video (not aiming to optimize participants' expectations) before undergoing a single PMR session without personal support of the experimenter (unguided), | Behavioral: Neutral video before PMR (unguided) + Progressive Muscle Relaxation (PMR)<br>* Participants watch a neutral video (not aiming to optimize participants' expectations) before undergoing a single PMR session without personal support of the experimenter (unguided). The PMR session involves learning to monitor tension in each specific muscle group in the body by deliberately inducing tension in each group. This tension is then released, with attention paid to the contrast between tension and relaxation.<br>|
| Active Comparator: Neutral video before PMR (guided)<br>watching a neutral video (not aiming to optimize participants' expectations) before undergoing a single PMR session with the personal support of the experimenter (guided) | Behavioral: Neutral video before PMR (guided)+ Progressive Muscle Relaxation (PMR)<br>* Participants watch a neutral video (not aiming to optimize participants' expectations) before undergoing a single PMR session with the personal support of the experimenter (guided).The PMR session involves learning to monitor tension in each specific muscle group in the body by deliberately inducing tension in each group. This tension is then released, with attention paid to the contrast between tension and relaxation.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in perceived stress | Participants are asked to rate how stressed they feel at the moment at two time points (baseline and after the PMR intervention) on a questionnaire (VAS: item ranges from 0 (not stressed at all) - 100 (very stressed). Change scores are calculated (post- minus pre-scores). More negative change scores are better since it indicates a stronger stress reduction (maximum reduction: -100). Higher positive change scores are worse since this indicates an increase in perceived stress (maximum increase: +100). Range of change scores: -100 - +100). | Change from pre (baseline) to post scores (30 minutes later) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in positive affect | Participants are asked to rate adjectives regarding their current mood (positive and negative) at two time points (baseline and after the PMR intervention) on a questionnaire. Change scores are calculated (post- minus pre-scores). Instrument: Positive and Negative Affect Scale (PANAS) by Watson, Clark, and Tellegen (1988) is a self-report questionnaire that consists of two 10-item scales to measure both positive and negative affect. Each item is rated on a 5-point scale of 1 (not at all) to 5 (very much). Range for sum score of positive/negative affect: 10-50. For positive affect higher scores are better; for negative affect lower scores are better. | Change from pre (baseline) to post scores (30 minutes later) |