Components of Placebo Effects in Sadness
Components of Placebo Effects in Sadness
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.
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.
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