Components of Placebo Effects in Sadness
Condition: Dysphoric Mood
Study type: Interventional

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.
    

Intervention name(s): OLP scientifically-objective; OLP personally-affective; DP scientifically-objective; DP personally-affective
Intervention type(s): Other; Other; Other; Other
Intervention description(s): 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.; 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.; 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.; 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.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Participants are assigned to one of five experimental groups in parallel for the duration of the study
Masking: Single (Investigator)
Primary purpose: Treatment