Investigating Hope and Expectations in Open-Label Placebos

Pain Clinical Trial

— I-HELP  

Official title:

Hope and Expectations as Components of Open-Label Placebos: An Experimental Study Investigating Pain

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03517644
• Other study ID #: 2017-58v
• Status: Completed
• Phase: N/A
• Start date: February 10, 2018
• Est. completion date: August 21, 2018

Study information

• Verified date: August 2018
• Source: Philipps University Marburg Medical Center
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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..

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 100
• Est. completion date: August 21, 2018
• Est. primary completion date: June 30, 2018
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 80 Years

Eligibility

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

Related Conditions & MeSH terms

• Pain

Intervention

Other:
• DP
Participants are informed that they are about to receive an effective analgesic cream. They are instructed to apply the cream using a cotton pad.
• OLP Hope
Participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. Therefore, participants are supposed to evaluate the subjective probability for a positive effect of the cream as rather low. However, using verbal instructions, the investigator aims to induce hope among the participants that the cream could have a positive effect for them because this placebo cream did have a positive among some former participants who were similar to the current participant. The emphasis of this similarity (regarding age and sex) aims to induce a feeling of connectedness to previous participants who reported positive effects of the placebo cream.
• OLP Expectation
Participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. However, participants are told that placebos have been shown to contribute substantially to clinical outcomes such as pain intensity/unpleasantness. This positive effect of placebos is reasoned by explaining learning mechanisms such as classical conditioning. We anticipated that after hearing this instruction, participants would consider it to be likely that the placebo has a positive effect for them.
• Placebo cream
The participants receive an inert placebo cream (standard basic cream with oil of thyme produced by a local pharmacy).
• Heat pain
Participant receive heat pain stimuli using the suprathreshold method of the Thermo Sensory Analyser (TSA-II), a commonly used device to study pain sensation and analgesic effects.

Locations

Country	Name	City	State
Germany	Philipps-University of Marburg	Marburg	Hessen

Sponsors (1)

Lead Sponsor	Collaborator
Philipps University Marburg Medical Center

Country where clinical trial is conducted

Germany, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Change in pain intensity scale	Change in subjective pain intensity assessed using a visual analogue scale (ranging from 0 to 100, with higher values reflecting more pain intensity)	Baseline and 45 minutes
Secondary	Change in pain unpleasantness scale	Change in subjective pain unpleasantness assessed using a visual analogue scale (ranging from 0 to 100, with higher values reflecting more pain unpleasantness)	Baseline and 45 minutes
Secondary	Change in physiological heat pain threshold	Change in the individual heat pain threshold (the point when the stimulus changes from being warm to being painful)	Baseline and 45 minutes
Secondary	Change in physiological heat pain tolerance	Change in the individual heat pain tolerance (the point when participants cannot stand the heat pain stimulus any longer)	Baseline and 45 minutes