Simulating a medical expertise: a robust novel stress induction paradigm in chronic pain patients
Maladaptive stress responses may exacerbate chronic widespread pain (CWP) and deserve further investigations. Yet, existing paradigms lack relevance for individuals with this condition. Hence, we developed the Social Benefits Stress Test (SBST), adapted from the Trier Social Stress Test. Instead of a job interview, the patients task is to justify their inability to work in front of a simulated medical expert in social insurances. Forty women with a type of CWP: hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorders were included. After a 30-min baseline, they had 5 minutes to justify their inability to work, followed by an arithmetic task. After a recovery period, patients were fully debriefed. The psychophysiological stress response was captured using self-reported stress ratings, salivary cortisol and -amylase, and continuous physiological monitoring including heart rate variability (HRV). Compared to baseline, the analysis revealed a significant and transient increase in stress ratings during the stress task associated with a peak in salivary biomarkers concentrations. Physiological stress response was reported through HRV during the task with significant increase in heart rate, decrease in high frequency power (HF), increase in low frequency power (LF) and in LF/HF ratio. Stress ratings positively correlated with changes in salivary biomarkers and LF/HF ratio. The results validate the SBST as a relevant experimental model of social stress in CWP patients as it induced a reproducible moderate stress response across subjective and physiological measures. The SBST opens up for important new studies on the relationship between stress and maintenance of chronic pain.