Skip to main content
OpenTrials
Completed

NCT Number: NCT03517644

Investigating Hope and Expectations in Open-Label Placebos

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..

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Pain Neurologic Manifestations Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Philipps-University of Marburg

Marburg, Hesse, 35037, Germany

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

DP

Other

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

Other

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

Other

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

Other

The participants receive an inert placebo cream (standard basic cream with oil of thyme produced by a local pharmacy).

Heat pain

Other

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.

Primary outcomes

  1. 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

  1. Change in pain unpleasantness scale

    Time frame: Baseline and 45 minutes

    Change in subjective pain unpleasantness assessed using a visual analogue scale (ranging from 0 to 100, with higher values reflecting more pain unpleasantness)

  2. Change in physiological heat pain threshold

    Time frame: Baseline and 45 minutes

    Change in the individual heat pain threshold (the point when the stimulus changes from being warm to being painful)

  3. Change in physiological heat pain tolerance

    Time frame: Baseline and 45 minutes

    Change in the individual heat pain tolerance (the point when participants cannot stand the heat pain stimulus any longer)

Sponsors and collaborators

Lead sponsor

Philipps University Marburg

Other

Registry information

Official study title

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

Acronym: I-HELP

Important dates

Study start
2018
Primary completion
2018
Study completion
2018
First posted
May 7, 2018
Registry last updated
Aug 23, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.