Nocebo hyperalgesia is the phenomenon in which negative pain expectations lead to augmented pain experiences. Studies have shown that psychosocial factors might influence nocebo hyperalgesia and...Show moreNocebo hyperalgesia is the phenomenon in which negative pain expectations lead to augmented pain experiences. Studies have shown that psychosocial factors might influence nocebo hyperalgesia and facilitate nocebo responses in clinical settings, thus worsening pain. This study aimed to identify whether social stress, fear of pain and pain catastrophizing influence the magnitude of nocebo hyperalgesia. Higher nocebo hyperalgesic responses were anticipated. Additionally, the potential mediating role of subjective stress was explored. Twenty-five healthy male and female participants were recruited and randomly assigned to the experimental (social stress) and control (no-stress) conditions, which underwent the Trier Social Stress Test (TSST) and a friendly version of it (friendly-TSST), correspondingly. Fear of pain and pain catastrophizing were measured with the Fear of Pain Questionnaire-III and the Pain Catastrophizing Scale. Subjective stress was measured on a 0-10 Numeric Rating Scale. A sham electrical stimulation device was applied to induce nocebo along with negative verbal suggestions of pain worsening. Thermal pain stimuli were paired with ON (nocebo trial) and OFF (control trial) visual signs during the acquisition and testing blocks of nocebo conditioning. The first nocebo and control trials of the testing block were compared to estimate the extent of nocebo hyperalgesia. One-way ANOVA, simple linear regression and mediation analysis with the method of bootstrapping were applied (P < 0.05). The one-way ANOVA was non-significant between the social stress and no-stress conditions (P = 0.74). Regression results were non-significant for fear of pain (B = - 0.38, P = 0.11) and pain catastrophizing (B = - 0.30, P = 0.22). Mediation analysis for subjective stress revealed a non significant indirect effect of - 0.009 (95% BCa CI [-1.10, 0.68]). Our study suggests that social stress does not appear to increase the magnitude of nocebo hyperalgesia and that fear of pain and pain catastrophizing might not predict higher nocebo hyperalgesic responses. In addition, subjective stress may not mediate the relationship between social stress and nocebo hyperalgesia. In conclusion, as social stress, fear of pain, pain catastrophizing and subjective stress can co-occur in clinical practices, future research could examine their potential cumulative effect on nocebo hyperalgesia.Show less
Pain is a common complaint that can interfere with daily life severely. Expectations play a crucial role in pain perception. It has been found that fear of pain interacts with these expectations....Show morePain is a common complaint that can interfere with daily life severely. Expectations play a crucial role in pain perception. It has been found that fear of pain interacts with these expectations. Research investigating the influence of fear of pain on pain perception is sparse. The aim of the present study is to investigate whether increased pain sensitivity can be induced by conditioning and verbal suggestion of negative expectations. Moreover, the study investigated if fear of pain could predict increased sensitivity to pain. Data of 27 healthy young adults (22 females) was used in this study. Participants received induction of negative expectations regarding electrical pain. Fear of pain was measured prior to the induction of electrical pain by using the minor pain subscale of the Fear of Pain Questionnaire III. Pain was electrically induced and measured by numerical pain rating scales. The participants were randomized into an experimental (induction of negative expectations) or a control group (expectations not manipulated). The results show that the experimental group scored higher on increased sensitivity to pain than the control group. Therefore, it can be concluded that an increased sensitivity to pain can be induced by a negative expectation learning procedure. This effect is strong and can have a strong negative effect on treatment outcomes. Furthermore, it has been found that fear of pain cannot predict nocebo hyperalgesia. This may relate to the healthy sample. It is important to investigate the relation of expectations, increased pain sensitivity and fear of pain. Doing so optimizes treatment and therefore prevents patients with chronic pain to experience increased pain.Show less
