Therapeutic Strategies During Exposure to Pain in an Experimental Design

Study Overview
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Brief Summary
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The goal of the present study is to compare different therapeutic strategies (according to habituation model vs. according to the inhibitory learning approach) during exposure to thermal pain in an experimental design.

Detailed Description
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Exposure therapy is effective for the treatment of individuals with chronic pain and high levels of fear-avoidance. Nevertheless, mechanisms of change for exposure treatment are not sufficiently investigated. According to the habituation model, the activation of a fear structure leads to a habituation of the initial physical response. Therefore, the therapeutic recommendation is to focus on the reduction of fear during exposure sessions. According to the inhibitory learning approach, however, exposure experiences compete with the original US-CS fear association. Therefore, the therapist should maximize the violation of negative expectancies. The present study intends to compare both strategies during the exposure to pain in an experimental design.

Official Title
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Exposure Works, But How? Testing Different Therapeutic Strategies During Exposure to Pain in an Experimental Design

Conditions
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Pain, Acute

Intervention / Treatment
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* Behavioral: Exposure therapy (according to habituation approach)
* Behavioral: Exposure therapy (according to inhibitory learning approach)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: female gender sufficient knowledge of German language Exclusion Criteria: chronic and acute pain conditions Raynaud's disease high blood pressure neuropathy, coronary diseases diabetes, current alcohol drug or pain-medication (last 24hours)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: participants are assigned to one of three experimental groups in parallel for the duration of the study
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Habituation<br>The habituation instruction focuses on changes of the initial physical fear-responses during exposure sessions. It is explained that the level of anxiety will gradually decrease, or habituate, each time someone faces a feared situation. Participants are then instructed to observe their own level of fear during the three practice trials with the thermode. Together with the experimenter, participants have to indicate their level of arousal on an 11-point scale (0= neutral, 10 = very high) in-between and after the three practice trials. After the practice trial, participants are instructed to reconsider their own development of physical responses. Participants are encouraged to remember the development of their level of arousal during the test trail with the thermode. | Behavioral: Exposure therapy (according to habituation approach)<br>* Exposure instruction focuses on fear reduction during exposure sessions<br>|
| Experimental: Expectation Violation<br>The expectation violation instruction focuses on the verification of negative expectancies during exposures sessions. It is explained that exposure exercises help to create own experiences which allow to directly test negative predicted outcomes. Together with the experimenter, participants are then encouraged to formulate concrete concerns in regard to the practice trail with the thermode. Before the practice trails, participants have to indicate the likelihood of their concerns on an 11-point scale (0= not likely, 10 = very likely). After the practice trails, participants are instructed to evaluate their own concerns by some guided questions (e.g. What did you learn?). Participants are encouraged to keep their own experience in mind during the test trail with the thermode. | Behavioral: Exposure therapy (according to inhibitory learning approach)<br>* Exposure instruction focuses on expectation violation during exposure sessions<br>|
| No Intervention: Control<br>Participants in the control group are not provided with information about exposure therapy. Instead, participants listen to a newspaper article which reports on the daily work in a botanical garden. Together with the experimenter, participants are then asked to name the most interesting aspect in the article. Before the practice trails, participants have to rate how likely it is that they would further inform themselves about botanical gardens on an 11-point scale (0= not likely, 10 = very likely). After the practice trails, participants are provided with some further questions about the newspaper article (e.g. Did you find the newspaper article interesting?). This cognitive exercise does not cover any pain-related topics and, therefore, does not serve as a distraction instruction. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain tolerance | Determined by the temperature at which the participant stopped the heat stimulus | 5 minutes prior and 5 minutes after three exposure practice trials | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain intensity | Measured on an 11-point scale (0 = no pain; 10 = worst imaginable pain) | 5 minutes prior and 5 minutes after three exposure practice trials | 
| Pain quality | Measured on an 11-points scale (0 = bearable; 10 = unbearable) | 5 minutes prior and 5 minutes after three exposure practice trials | 
| Pain Catastrophizing Scale (PCS) | Pain catastrophizing thoughts (e.g. I worry all the time about whether the pain will end.) | 1-week prior and 10 minutes after three exposure practice trials | 
| Pain Anxiety Symptom Scale (PASS) | Pain-related anxiety (e.g. I worry when I am in pain.) | 1-week prior and 10 minutes after three exposure practice trials | 
| Pain Processing (Fragebogen zur Erfassung der Schmerzverarbeitung, FESV) | Cognitive pain coping strategies (e.g. When I am in pain, I know several possibilities how to handle them.) | 1-week prior and 10 minutes after three exposure practice trials | 
| Psychophysiological activation | e.g. skin conductance responses, heart rate | throughout the experiment (5 minutes prior, during and 10 minutes after three exposure practice trails |