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Components of Placebo Effects in Sadness

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

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03507959
Acronym
COPES
Enrollment
159
Registered
2018-04-25
Start date
2018-03-15
Completion date
2020-01-31
Last updated
2020-12-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Dysphoric Mood

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.

Interventions

OTHEROLP scientifically-objective

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.

OTHEROLP personally-affective

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.

OTHERDP scientifically-objective

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.

OTHERDP personally-affective

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.

Sponsors

Philipps University Marburg
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Investigator)

Masking description

With regard to the four treatment groups, the investigator is not aware which experimental condition participants were allocated to. Regarding the control group, masking is not feasible.

Intervention model description

Participants are assigned to one of five experimental groups in parallel for the duration of the study

Eligibility

Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes

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

Design outcomes

Primary

MeasureTime frameDescription
Change in Positive and Negative Affect Schedule (PANAS)Baseline and 45 minutesChange of self-rated sadness

Countries

Germany

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026