Placebo Impacts Sleep and Pain Modulation in Chronic Pain

Description

This is a longitudinal parallel randomized clinical trial with TMD participants randomly assigned to either 1) the open-label placebo (OLP) + expectations management group, 2) OLP only, and 3) the standard of care group. To examine how baseline chronic pain and sleep patterns could have impacted the effects of OLP, we will deep-phenotype participants based on their sleep profiles and fluctuations in their chronic pain characteristics via a 2-day phenotyping phase. Following the 2-day phenotyping phase, participants will enter a 45-day intervention phase. The nature of the participation will be voluntary. Namely, participants can withdraw during trial from the study without any consequences.

Phenotyping phase (2-day) The phenotyping phase includes an in-person visit and a 2-day at-home monitoring period. During the in-person visit, after signing the informed consent form with the trained staff, participants will complete a heat pain sensitivity test using a 30mmx30mm Advanced Thermal Stimulator (ATS) via the Medoc Pathway system (Medoc Advanced Medical Systems, Medoc Ltd., Israel). Painful and non-painful stimuli will be delivered to the ventral forearm of the non-dominant hand.

After the in-person visit, participants will enter a 2-day daily monitoring period, where their daily pain expectations, pain experience fluctuations, and sleep diaries will be assessed in real time and in their natural environment using the Ecological Momentary Assessment (EMA) method. Sleep profiles will be assessed using polysomnography to obtain natural sleep architectures, including the duration of different sleep stages, sleep efficiency, breathing, and body movement during sleep.

Free-choice OLP intervention Immediately following the phenotyping phase, participants will return to the laboratory before entering the 45-day intervention phase. Participants will be randomized to either 1. OLP+expectations management, 2. OLP alone, and 3. Standard of care groups. Participants in the two OLP groups will receive a bottle of 45 OLP pills. According to the free-choice paradigm, participants in the OLP group are allowed to choose whether to take the pills each day during the intervention. This paradigm maximizes participant benefit because it provides the option of “not” taking the placebo pills. Participants in the wait-list group will not receive OLP pills until the end of the 45-day monitoring period.