Do Emotions and Pain Combined Affect Mechanical Pain Thresholds and Other Pain-related Variables in Individuals with Chronic Pain?

Overview

The purpose of this study is to investigate if different emotional states could influence mechanical pain thresholds and other pain - related variables such as pain tolerance, pain intensity and pain - related negative affect in individuals with chronic pain.

Detailed description

Participants with chronic pain will be randomized into 4 different groups watching different short video-clips (2.20 min), while at the same time experience short-lasting, experimentally induced pain. The negative emotions group will watch an uncomfortable short video containing violence and blood, the positive emotions group will watch a video containing a stand-up comedy show, the neutral emotions group will watch a video about how to paint a house, and the control group will just wait for 2.20 min, without any instructions about what to think about. Pressure pain thresholds, pain tolerance, pain intensity and pain-related negative affect will be measured with an algometer before and after the video-clip combined with experimental pain interventions.

Interventions

• Other Emotional intervention
  Emotional intervention Description: The participant will watch a short video-clip with negative emotional content while simultaneously experience experimentally induced pain.
• Other Emotional intervention
  Description: The participant will watch a short video-clip with positive emotional content while simultaneously experience experimentally induced pain.
• Other Emotional intervention
  Description: The participant will watch a short video-clip with neutral emotional content while simultaneously experience experimentally induced pain.

Primary outcome measures

• Pressure pain thresholds [Time frame: Day 1: baseline PPTs are measured, intervention 2.20 min follows and intervention PPTs are measured directly after the intervention. Recruitment for single appointments for each participant will take place for 4 months.]

Secondary outcome measures (3)

• Pain tolerance (time in seconds the left hand is immersed in cold water 1 degree C). [Time frame: Day 1: During a single session (30 min), the participant will keep their hand immersed in cold water for as long as possible while watching a video. This time will be measured in seconds.]
• Pain intensity on the NRS [Time frame: Day 1: Pain intensity will be estimated at single session appointments (30 min) on the NRS (Numerical Rating Scale) after the intervention. Participants will be successively recruited for single session appointments for 4 months.]
• Pain-related negative affect on the NRS-A [Time frame: Day 1: Pain intensity will be estimated at single session appointments (30 min) on the NRS-A (Numerical Rating Scale-Anxiety) after the intervention. Participants will be successively recruited for single session appointments for 4 months.]

Eligibility criteria

Inclusion criteria

• Above 18 years of age
• Fluent in Swedish
• Persistent chronic pain with duration > 6 months

Exclusion criteria

\- Known neurological disease

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Basic science

Study locations

Center list to be confirmed — check the primary protocol.

Identifiers

NCT: NCT06851208 · 2024-07781-01 ethic approval

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗