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Back to Basics - Effects, Narratives and Routes of Administration of Open-label Placebo

Not Applicable
Completed
Conditions
Pain
Expectancy
Placebo Effect
Interventions
Other: deceptive placebo
Other: open-label placebo
Registration Number
NCT02578420
Lead Sponsor
University Hospital, Basel, Switzerland
Brief Summary

To date, very little is known about the mechanisms of open-label placebo treatment and there is a lack in highly controlled experimental designs. Therefore, the planned project will test well-established explanatory models of (deceptive) placebo, i.e., (1) expectancy, (2) meaning response, in an open-label placebo design, investigating their influence on placebo analgesia.

Detailed Description

The current project will consist of one experimental study and one qualitative study:

1. the effects of open-label, and deceptive placebo administration on placebo analgesia will be directly compared when both groups have a comparable expectancy-inducing scientific rationale;

2. subjective meaning models will be assessed by comparing subjective narratives of the placebo effect in open-label and deceptive placebo groups in a nested qualitative study.

The experimental study will be a randomized experiment with healthy subjects (N=120), and pain will be induced using a standardized heat pain paradigm (Medoc, Ramatishai, Israel; thermo-sensory analyzer (TSA)-II). Effects of the experimental conditions will be assessed both objectively (i.e. heat pain threshold and tolerance) and subjectively (i.e. subjective pain ratings, pain intensity and unpleasantness). Furthermore, investigators will randomly select 30 participants to take part in a nested qualitative study in order to qualitatively assess the meaning response by comparing subjective narratives of the placebo effect in the open-label and deceptive placebo groups, as well as in the control group.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
160
Inclusion Criteria
  • Healthy male and female adults aged 18-65
  • Healthy by self-report statement, thus no known current or chronic somatic diseases or psychiatric disorders
  • Right-handedness (Oldfield, 1971),
  • Willing to participate in study
Exclusion Criteria
  • Medicine or Psychology Students
  • Any acute or chronic disease (chronic pain, hypertension, heart disease, renal disease, liver disease, diabetes) as well as skin pathologies, neuropathies or nerve entrapment symptoms, sensory abnormalities affecting the tactile or thermal modality
  • Current medications (psychoactive medication, narcotics, intake of analgesics) or being currently in psychological or psychiatric treatment
  • Insufficient German language skills to understand the instructions
  • Previous participation in studies using pain assessment (threshold and tolerance) with Peltier Devices
  • Daily consumption of more than three alcoholic standard beverages per day (a standard alcoholic beverage is defined as either 3dl beer or 1 dl wine or 2cl spirits)
  • Current or regular drug consumption (THC, cocaine, heroin, etc.)

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
deceptive placebodeceptive placeboParticipants (N=40) will have the information that they are receiving an analgesic cream ("Antidolor, containing "Lidocain"), while in fact they will receive an inert cream, only. Antidolor will be described as an analgesic cream.
control groupopen-label placeboParticipants (N=40) will have the information that they are receiving an inert control cream.
open-label placeboopen-label placeboParticipants (N=40) will have the information that they are receiving an inert cream (i.e. "placebo"). Placebo will be described as an inert or inactive cream, with no medication in it. Additionally, participants will be told that "placebo has been shown in rigorous clinical testing to produce significant mind-body self-healing processes." The placebo administration will be combined with the following scientific rationale/verbal suggestion: (a) placebos are effective analgesics, (b) classical conditioning as a possible mechanism of this effect, (c) compliance is important for outcome and (d) positive expectations increase placebo effects, but are not necessary.
Primary Outcome Measures
NameTimeMethod
subjective intensity and unpleasantness ratings of heat pain tolerance2 hours

Visual Analogue Scale (VAS)

objective heat pain tolerance2 hours

Temperatures

Secondary Outcome Measures
NameTimeMethod
objective heat pain threshold2 hours

Temperatures

Desire for Relief Scale (DRS)2 hours
subjective intensity and unpleasantness ratings of heat pain threshold2 hours

Visual Analogue Scale (VAS)

multidimensional sensitivities questionnaire (Mehrdimensionaler Befindlichkeitsfragebogen (MDBF))2 hours
NEO five-factor inventory (NEO-FFI)2 hours
Credibility and Effectiveness of the placebo analgesia expectation; adapted Version of the Context Model Questionnaire; Kontextmodellfragebogen (KMF)2 hours
Revised Life Orientation Test (LOT-R)2 hours
questionnaire on competence and locus of control (Fragebogen zu Kompetenz- und Kontrollüberzeugungen (FKK))2 hours
Expectancy of Relief Scale (ERS; Erwartungsfragebogen)2 hours
Anxiety and Depression Scale (HADS-D)2 hours
Beliefs in holistic health and holistic treatments; Complementary and Alternative Medicine Beliefs Intentory (CAMBI)2 hours
sociodemographic questionnaire (Soziodemographischer Fragebogen (SDD))2 hours

Trial Locations

Locations (1)

University of Basel

🇨🇭

Basel, Switzerland

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