Research into the effects of optimism on pain and brain activity

JRCT ID: jRCT1022240036

Registered date:15/11/2024

Basic Information

• Recruitment status: Pending
• Health condition(s) or Problem(s) studied: Healthy adults (no particular disease)
• Date of first enrollment: 15/11/2024
• Target sample size: 160
• Study type: Interventional

Intervention(s)

1. Optimism intervention group: participants were presented with highly likely positive events, such as "enjoying a delicious dinner with a close friend," and highly unlikely negative events, such as "being arrested for murder." Participants were asked to answer whether or not the event was likely to happen to them in the future.
2. Control group: participants were presented with similar stimulus phrases and asked to judge whether the phrases contained adjectives.

Outcome(s)

• Primary Outcome: Pain intensity (capsaicin-induced): VAS visual analogue scale score

Secondary Outcome

Task 1: Behavioral experiment on the effect of optimism induction on experimental pain
1. Optimism scale (LOT-R optimism)
2. Pain catastrophizing scale (Pain Catastrophizing Scale (PCS) Pain catastrophizing scale)
3. Personality trait scale (Big Five scale Japanese abbreviated version)

Task 2: fMRI experiment on the effect of optimism on experimental pain and brain activity
1. Optimism scale (LOT-R optimism)
2. Changes in brain activity (by fMRI scan)
3. Pain catastrophizing scale (Pain Catastrophizing Scale (PCS) Pain catastrophizing scale)
Personality trait scale (Big Five scale Japanese abbreviated version)

Key inclusion & exclusion criteria

• Age minimum: > 18age old
• Age maximum: < 40age old
• Gender: Both

Include criteria

1.Age: 18-40 years old (when registering)
2.Right-handed
3.Any gender
4.Individuals who have given written consent to participate in the study

Exclude criteria

Task 1: Behavioral Experiment on the Effects of Optimism Induction on Experimental Pain 1. Individuals experiencing pain from injury or other causes at the time of recruitment.
2. Individuals with allergies to capsaicin.
3. Individuals who are pregnant or may be pregnant.
4. Individuals using analgesics or drugs affecting the central nervous system.
5. Individuals with neurological or psychiatric disorders (including a history of these).
6. Individuals with skin disorders (such as atopic dermatitis) that may cause inflammation or irritation from capsaicin cream application.Task 2: fMRI Experiment on the Effects of Optimism Induction on Experimental Pain and Brain Activity 1. Individuals experiencing pain from injury or other causes at the time of recruitment.
2. Individuals with allergies to capsaicin.
3. Individuals who are pregnant or may be pregnant.
4. Individuals using analgesics or drugs affecting the central nervous system.
5. Individuals with neurological or psychiatric disorders (including a history of these).
6. Individuals who meet MRI contraindications (to be confirmed using the MRI pre-screening checklist).
7. Individuals with a tendency toward claustrophobia.
8. Individuals who participated in Task 1: Behavioral Experiment on the Effects of Optimism Induction on Experimental Pain.
9. Individuals with skin disorders (such as atopic dermatitis) that may cause inflammation or irritation from capsaicin cream application.

Related Information

• Primary Sponsor: SUGIURA Motoaki
• Secondary ID(s): Nil known