Open and closed label nocebo and placebo

Completed

Conditions: Itch, expectations
Jeuk, verwachtingen

Registration Number: NL-OMON25317

Lead Sponsor: eiden University

Brief Summary: n/a

Detailed Description: Not available

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 92

Inclusion Criteria

1. Between 18 and 35 years old.

2. Good understanding of written and spoken Dutch.

Exclusion Criteria

1. Refusal to provide written informed consent.

2. Severe somatic or psychological morbidity (e.g. heart and lung diseases or DSM-IV psychiatric disorders) that would adversely affect participant’s safety or that might interfere with the study protocol.

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
The primary study outcome is the difference in self-reported itch rating during a short-term validated histamine test (histamine iontophoresis) between the combined open- and closed-label positive verbal suggestion group and the combined open- and closed-label negative verbal suggestion group.

Secondary Outcome Measures

Name	Time	Method
Secondary analyses will be conducted to examine the difference in self-reported itch between the negative and positive verbal suggestion groups separately for the open-label condition, and the closed-label condition. Negative and positive VS groups will additionally be compared on secondary outcome measures (e.g. self-reported skin condition). These analyses will be conducted for the open-label VS and closed-label VS groups combined as well as separately. In addition, the possible influence of psychological parameters on outcomes will be explored.