Counterconditioning as treatment for pain

Treatment opportunities for persistent physical symptoms, such as chronic pain, are currently limited. It is suggested that nocebo effects (i.e. adverse outcomes not attributable to an active treatment, putatively mediated by negative expectations) can negatively influence symptom progression. With procedures of counterconditioning, combined with verbal suggestions, previously learned associations (causing negative expectations) between different stimuli can be reversed. Therefore, counterconditioning could provide an innovative method for reducing physical symptoms. ln the current study, the feasibility of using counterconditioning methods as a novel treatment method for reducing pain symptoms will be examined in a clinical population of fibromyalgia patients.

The primary objective of the current pilot study is to investigate the feasibility of a 6-week counterconditioning treatment method aimed to reduce pain in patients with fibromyalgia. This will be assessed by looking at the drop-out rate; by measuring participant's satisfaction with the intervention; by examining what, according to the participants, is causing the possible increase and reduction of experimentally evoked pressure pain in the test phase of (counter)conditioning (e.g., the TENS device, the placebo or nocebo effect); by examining the amount of experimentally-evoked pressure pain reported during the test phase of counterconditioning, whether this reduces over time, as well as the speed of this reduction.

Additionally, we will explore whether an induced nocebo effect in the intervention group can be successfully reduced (or even reversed) by comparing the change in the conditioned nocebo effect from the test phase of conditioning (session 1) to the counterconditioned nocebo effect from the test phase of counterconditioning (session 6 + 3- and 6-month follow-up) in the intervention group and the control group. We will also explore whether these effects generalize to clinical pain symptoms. Last, we will explore whether there is a relationship between individual characteristics, such as pain catastrophizing and participants' expectations about the intervention, and the changes due to counterconditioning.

9 lab sessions (intake session, 6-week intervention, 3-and 6-month follow-up). Each lab session lasts approximately 45 minutes, with the exception of the intake session and the first session, which last 30 minutes and two hours, respectively. The homework exercises will take approximately 10 minutes per day.

Counterconditioning methods will be used for desensitization of pain symptoms in the intervention group. Participants in the intervention group will participate in a conditioning procedure once during session 1, in order to ensure that a specific association with the primary symptom of pain is established that can be counterconditioned.

During conditioning and counterconditioning, the learning phase consists of 20 pressure stimuli, which are either moderately painful (nocebo conditioning) or non-painful (counterconditioning) during the experimental trials and slightly painful during control trials. In the control group, all stimuli will be given in a randomized order. The test phase for all groups consists of 6 trials with slightly painful pressure stimuli presented in both experimental and control trials.
ln sessions 2-6, only the (sham) counterconditioning procedure will be repeated, meaning only non-painful and slightly painful stimuli will be used.

Participants in both groups are asked to rate their levels of pain after every pressure stimulus on an NRS, which will later be used to calculate the individual reduction of the nocebo effect.

Participants will be given homework exercises to strengthen the intervention and promote generalization of symptom desensitization to everyday life.