Unpredictable pain timings lead to greater pain when people are highly intolerant of uncertainty

Abstract

Abstract : Background and purpose: Many psychological factors are known to influence pain perception. Amongthem, intolerance of uncertainty (IU) may play a key modulating role in situations where uncertaintyprevails, especially uncertainty regarding the timing of painful events. The objective of this study was toexplore the impact of individual differences in IU on pain perception during predictable and unpredictablestimulation timings. We hypothesized that people with high IU, as opposed to those with low IU, wouldperceive more pain when the timing of painful stimulations cannot be predicted, as compared to whenthey can.Methods: Twenty (20) healthy adults, aged between 18 and 35 years old, were recruited. Painful sensa-tions were provoked using transcutaneous electrical stimulations of the right sural nerve. By measuringIU (Intolerance of Uncertainty Scale) and subjective pain (verbal numerical rating scale), it was possibleto test the relationship between IU and pain perception, by simulating predictable and unpredictablepainful experiences. This was done through cued shock interval (CSI) blocks, with either variable timingor fixed timings (long or short time frame). Self-administered questionnaires were also used to measurepain hypervigilance, pain catastrophizing, state anxiety, and trait anxiety.Results: Pearson correlations confirmed the presence of an association (r = 0.63) between IU and thechange in pain intensity provoked by unpredictable stimulation timings. Importantly, this associationwas significant only for stimulations provided at long CSIs, indicating that higher IU scores predictedhigher pain intensity scores when stimulation timings became unpredictable, and when the cued delaywas long. No association was found between pain scores and other psychological variables.Conclusions: Our results show that IU moderately correlates to the change in pain intensity provokedby unpredictable stimulation timings. High IU scores were associated with a worsening of the subjectivepain experience, especially during long delays in an unpredictable situation. These observations suggestthat IU could be considered as a psychological variable that is able to influence pain perception in certainsituations.Implications: Assessing and addressing IU could be an added value in pain-related therapy, especially in chronic pain.