Clinical trial NCT03507959: Components of Placebo Effects in Sadness
Official title: Components of Placebo Effects in Sadness (COPES): An Experimental Study Comparing Deceptive and Non-deceptive Placebos
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Dysphoric Mood
Lead sponsor: Philipps University Marburg
Sponsor class: OTHER
First posted: 2018-04-25
Enrollment: 159
Sex: ALL
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Participants are assigned to one of five experimental groups in parallel for the duration of the study
Primary purpose: TREATMENT

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.

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

Primary outcomes:
measure: Change in Positive and Negative Affect Schedule (PANAS)
timeFrame: Baseline and 45 minutes
Secondary outcomes:
Other outcomes:
Locations:
city: Marburg
country: Germany
facility: Philipps-University of Marburg
state: Hessen
Study officials:
affiliation: Philipps University Marburg
name: Tobias Kube, PhD
role: PRINCIPAL_INVESTIGATOR
References: