Pain-related Fear as a Facilitator of Nocebo Hyperalgesia

Nocebo hyperalgesia is characterized by adverse pain outcomes, induced by patients' expectations. In the lab, nocebo effects are commonly studied via classical conditioning, a method that employs pairings of neutral cues/treatments with different pain intensities to install differential pain-related expectations. In such conditioning experiments, participants are typically taught that a (sham) treatment exaggerates their pain, by surreptitiously administering high intensity (e.g. pain) stimuli in combination with this treatment. Verbal suggestions are also often used to inform participants of the supposed adverse effects of such treatments. In nocebo studies, higher pain levels and suggestions that are of more threatening nature may induce fear, thereby adding a crucial element to the experimental manipulation. Since nocebo effects are hypothesized to arise in clinical settings due to a combination of several psychological and cognitive mechanisms, it is important to study the role that factors such as higher pain levels, conditioned pain-related fear, or more threatening verbal suggestions may play in the formation of nocebo hyperalgesia. To date, no studies have focused on the fear-inducing effect that different pain intensities or verbal threat suggestions may have and how this fear, in turn, may strengthen the acquisition of nocebo effects. This study aims to investigate whether higher pain intensity or higher pain-related fear induced via threatening suggestions facilitate the acquisition and hinder subsequent extinction of nocebo hyperalgesia. This study will be conducted at Leiden University.