Can nocebo effects on itch be modified by a positive expectation induction?

Can nocebo effects on itch be modified by a positive expectation induction? - Can nocebo effects on itch be modified?

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

NL-OMON

Registry ID

NL-OMON40445

Enrollment

Registered

2014-02-26

Start date

2014-09-10

Completion date

Unknown

Last updated

2024-04-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Itch pruritus

Interventions

None listed

Eligibility

Age

18 Years to 99 Years

Inclusion criteria

Inclusion criteria: Healthy human volunteers, 18 - 35 year old, fluent in Dutch language

Exclusion criteria

Exclusion criteria: Severe morbidity (e.g., multiple sclerosis, diabetes mellitus, heart or lung diseases), psychiatric disorders (e.g., depression), use of pacemaker, color-blindness, diagnose of histamine hypersensitivity, and chronic itch or pain complaints.

Design outcomes

Primary

Measure	Time frame
The main study endpoint is the difference in the levels of itch (VAS scores) evoked by the electrical stimuli associated with the conditioned cues versus the neutral cues in the testing phase of part II of the experiment. It is investigated whether nocebo effects (negative expectation effects) can be modified by a positive expectation induction by conditioning and verbal suggestion (low-itch expectation induction) (group 1), resulting in lower itch VAS scores than a repeated negative expectation induction (high-itch expectation induction) (group 2), or a neutral procedure (neutral expectation induction) (group 3).	—

Measure

Time frame

The main study endpoint is the difference in the levels of itch (VAS scores) evoked by the electrical stimuli associated with the conditioned cues versus the neutral cues in the testing phase of part II of the experiment. It is investigated whether nocebo effects (negative expectation effects) can be modified by a positive expectation induction by conditioning and verbal suggestion (low-itch expectation induction) (group 1), resulting in lower itch VAS scores than a repeated negative expectation induction (high-itch expectation induction) (group 2), or a neutral procedure (neutral expectation induction) (group 3).

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Secondary

Measure	Time frame
The secondary study endpoints of the present experiment are: a) the itch related expectancy effects on scratching behavior; b) the itch related expectancy effects regarding itch evoked by histamine iontophoresis; c) the role of individual characteristics (e.g., optimism) on (the modifiability) of expectancy effects; and d) the role of 5-HTTLPR genotype and other genetic variants on (the modifiability) of expectancy effects.	—

Measure

Time frame

The secondary study endpoints of the present experiment are: a) the itch related expectancy effects on scratching behavior; b) the itch related expectancy effects regarding itch evoked by histamine iontophoresis; c) the role of individual characteristics (e.g., optimism) on (the modifiability) of expectancy effects; and d) the role of 5-HTTLPR genotype and other genetic variants on (the modifiability) of expectancy effects.

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Countries

Netherlands

Outcome results