Components of Placebo Effects in Sadness

Study Overview
=================
Brief Summary
-----------------
Research has shown that placebo effects contribute substantially to clinical outcomes. Recent evidence suggests that placebos remain effective even if they are openly described as placebos (so-called Open-Label Placebos). In this study, the investigators examine components of open-label placebos and traditional deceptive placebos in an experimental study investigating sadness.

Detailed Description
-----------------
A growing body of research has indicated that placebos contribute substantially to clinical outcomes. Yet, the implementation of deceptive placebos in clinical practice is incompatible with key principles of openness and patient autonomy. However, recent research suggests that placebos remain effective even if they openly described as placebos (so-called Open-Label Placebos (OLP)), hence questioning the necessity of deception in clinical trials. However, comparisons between OLP and deceptive placebos (DP) with regard to their particular mechanisms are lacking. Therefore, the current study aims to identify components of OLP and DP. For this purpose, experimentally induced sadness is examined using a standardized paradigm which has previously been developed by our working group. In particular, healthy volunteers are informed that a new application method for a well-known antidepressant would be tested. Sadness is assessed before and after receiving a nasal spray. Two experimental groups (DP groups) are informed that they would receive an antidepressant nasal spray, another two experimental groups (OLP groups) are informed that they would receive a placebo. In fact, all nasal sprays are active placebos inducing prickling nasal sensations (sesame oil with 0.014% capsaicin). In addition to the factor Transparency (DP vs. OLP), the instruction is experimentally varied, with which the substance is administered (scientifically-objective vs. personally-affective), resulting in a 2x2 design. Further, there is an additional fifth group receiving no intervention. The primary outcome is self-rated sadness after taking the nasal spray.

Official Title
-----------------
Components of Placebo Effects in Sadness (COPES): An Experimental Study Comparing Deceptive and Non-deceptive Placebos

Conditions
-----------------
Dysphoric Mood

Intervention / Treatment
-----------------
* Other: OLP scientifically-objective
* Other: OLP personally-affective
* Other: DP scientifically-objective
* Other: DP personally-affective


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: age between 18 and 40 years no mental disorder or physical disease sufficient German language knowledge Exclusion Criteria: intake of psychopharmacological drugs intake of illegal drugs in the last two weeks consumption of alcohol in the last twelve hours allergy to capsaicin or sesame

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants are assigned to one of five experimental groups in parallel for the duration of the study
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: OLP scientifically-objective<br>Participants are informed that they are about to take a placebo. The rationale for the effectivity of placebos is explained in a scientifically-objective manner. | Other: OLP scientifically-objective<br>* Participants are informed that they are about to take a placebo. The rationale for the effectivity of placebos is explained in a scientifically-objective manner.<br>|
| Experimental: OLP personally-affective<br>Participants are informed that they are about to take a placebo. The rationale for the effectivity of placebos is explained in a personally-affective manner. | Other: OLP personally-affective<br>* Participants are informed that they are about to take a placebo. The rationale for the effectivity of placebos is explained in a personally-affective manner.<br>|
| Experimental: DP scientifically-objective<br>Participants are informed that they are about to take an effective antidepressant. The rationale for the effectivity of the antidepressant is explained in a scientifically-objective manner. | Other: DP scientifically-objective<br>* Participants are informed that they are about to take an effective antidepressant. The rationale for the effectivity of the antidepressant is explained in a scientifically-objective manner.<br>|
| Experimental: DP personally-affective<br>Participants are informed that they are about to take an effective antidepressant. The rationale for the effectivity of the antidepressant is explained in a personally-affective manner. | Other: DP personally-affective<br>* Participants are informed that they are about to take an effective antidepressant. The rationale for the effectivity of the antidepressant is explained in a personally-affective manner.<br>|
| No Intervention: Control group<br>This group does not take the nasal spray. | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Positive and Negative Affect Schedule (PANAS) | Change of self-rated sadness | Baseline and 45 minutes |