Nocebo hyperalgesia and pain progression: prediction, acquisition, and recovery

Abstract

Nocebo effects are adverse treatment outcomes that cannot be attributed to active treatment components. A common example is the experiencing of side effects after reading the side effect description on a medication leaflet. Nocebo hyperalgesia, i.e., increased pain sensitivity due to nocebo effects, can be acquired via learning in both healthy and clinical populations, and has a large social and economic impact on healthcare. In the current dissertation, we investigated the experimental learning mechanisms behind the acquisition and recovery of nocebo hyperalgesia in healthy individuals and in patients with fibromyalgia, and the potential differences between groups. Additionally, we investigated the predictors of nocebo hyperalgesia acquisition and recovery to identify individuals who are more susceptible to these effects. Lastly, we stepped outside of the lab-settings and in an electronic diary study, examined the role of (experimentally-induced) nocebo hyperalgesia in daily pain progression of patients with fibromyalgia. The current dissertation offers insights for better understanding the expectancy and learning mechanisms behind nocebo hyperalgesia in individuals with and without chronic pain. These can be useful for the future design of personalised learning-based interventions for targeting nocebo effects on pain.