Hope and Expectations as Components of Open-Label Placebos: An Experimental Study Investigating Pain
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Enrollment
- 100
- Locations
- 2
- Primary Endpoint
- Change in pain intensity scale
Study Overview
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 hope and expectations as components of open-label placebos in an experimental study investigating pain..
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, research identifying the specific mechanisms underlying OLP is lacking. Therefore, the current study aims to examine hope and expectations as components of OLP in pain.
For this purpose, experimentally induced heat pain is examined. First, all participants receive heat pain stimuli and evaluate them. Next, participants are randomly assigned to one of four groups: (1) a traditional deceptive placebo (DP) group, which is told that they receive an effective analgesic cream, (2) an OLP group inducing hope among the participants that the placebo cream could help them tolerating painful stimuli (OLP hope), (3) and OLP group raising the expectation that the placebo cream will help participants tolerating heat pain (OLP expectation), (4) a control group receiving no cream. Finally, participants receive and evaluate heat pain again.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Single (Participant)
Masking Description
Using a cover story, participants are instructed to think that there are three experimental groups: a treatment condition, a placebo condition, and a control condition. Therefore, participants from the open-label groups do know that they receive a placebo, but do not know which specific mechanism is being addressed in their condition.
Eligibility Criteria
- Ages
- 18 Years to 80 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •sufficient German language knowledge
- •at least 18 years old
Exclusion Criteria
- •current mental disorder
- •current medical disease
- •studying psychology or medicine
- •pregnancy or breastfeeding period
- •intake of drugs
- •severely visually impaired
Arms & Interventions
Deceptive Placebo (DP)
After pretreatment heat pain assessment, participants are informed that they are about to receive an effective analgesic cream. In fact, they receive a placebo cream. Next, the posttreatment pain assessment is conducted.
Intervention: DP (Other)
Deceptive Placebo (DP)
After pretreatment heat pain assessment, participants are informed that they are about to receive an effective analgesic cream. In fact, they receive a placebo cream. Next, the posttreatment pain assessment is conducted.
Intervention: Placebo cream (Other)
Deceptive Placebo (DP)
After pretreatment heat pain assessment, participants are informed that they are about to receive an effective analgesic cream. In fact, they receive a placebo cream. Next, the posttreatment pain assessment is conducted.
Intervention: Heat pain (Other)
OLP with Hope (OLP Hope)
After pretreatment heat pain assessment, participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. However, using verbal instructions, the investigator aims to induce hope among the participants that the cream could have a positive effect. Next, the posttreatment pain assessment is conducted.
Intervention: OLP Hope (Other)
OLP with Hope (OLP Hope)
After pretreatment heat pain assessment, participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. However, using verbal instructions, the investigator aims to induce hope among the participants that the cream could have a positive effect. Next, the posttreatment pain assessment is conducted.
Intervention: Placebo cream (Other)
OLP with Hope (OLP Hope)
After pretreatment heat pain assessment, participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. However, using verbal instructions, the investigator aims to induce hope among the participants that the cream could have a positive effect. Next, the posttreatment pain assessment is conducted.
Intervention: Heat pain (Other)
OLP with Expectations (OLP Expectation)
After pretreatment heat pain assessment, participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. However, using verbal instructions, the investigator aims to raise expectations among the participants that the cream will have a positive effect. Next, the posttreatment pain assessment is conducted.
Intervention: OLP Expectation (Other)
OLP with Expectations (OLP Expectation)
After pretreatment heat pain assessment, participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. However, using verbal instructions, the investigator aims to raise expectations among the participants that the cream will have a positive effect. Next, the posttreatment pain assessment is conducted.
Intervention: Placebo cream (Other)
OLP with Expectations (OLP Expectation)
After pretreatment heat pain assessment, participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. However, using verbal instructions, the investigator aims to raise expectations among the participants that the cream will have a positive effect. Next, the posttreatment pain assessment is conducted.
Intervention: Heat pain (Other)
Control
After pretreatment heat pain assessment, this group does not receive an intervention targeting pain sensation prior to the posttreatment pain assessment.
Intervention: Heat pain (Other)
Outcomes
Primary Outcomes
Change in pain intensity scale
Time Frame: Baseline and 45 minutes
Change in subjective pain intensity assessed using a visual analogue scale (ranging from 0 to 100, with higher values reflecting more pain intensity)
Secondary Outcomes
- Change in pain unpleasantness scale(Baseline and 45 minutes)
- Change in physiological heat pain threshold(Baseline and 45 minutes)
- Change in physiological heat pain tolerance(Baseline and 45 minutes)