Human Studies

In most experimental studies in which verbal suggestion and classical conditioning are implemented together to induce placebo effects, the former precedes the latter. In naturally occurring situations, however, the information concerning pain does not always precede but often follows the pain experience. Moreover, this information is not always congruent with experience. This study investigates whether the chronology of verbal suggestion and conditioning, as well as their congruence, affects placebo hypoalgesia and nocebo hyperalgesia. The effects induced in 15 groups were compared. The participants in 8 experimental groups were presented with verbal suggestions that were either congruent or incongruent with classical conditioning. The verbal suggestions were provided either before or after conditioning. In 2 other experimental groups, placebo conditioning or nocebo conditioning was implemented without any verbal suggestion; in 2 groups, verbal suggestion of hypoalgesia or hyperalgesia without conditioning was applied. The control groups without any suggestions or conditioning were also included. Placebo hypoalgesia induced by congruent procedures was significantly stronger when the suggestion of hypoalgesia preceded rather than followed conditioning. The order of the congruent procedures did not affect the magnitude of nocebo hyperalgesia. In the groups in which incongruent procedures were implemented, placebo hypoalgesia or nocebo hyperalgesia was in line with the direction of the last-used procedure, regardless of whether it was conditioning or verbal suggestion. The results show that not the type of the procedure (verbal suggestion or conditioning), but the direction of the last-used procedure shapes pain-related expectancies and determines placebo effects.

Spinal fusion surgery is associated with severe acute postsurgical pain and high rates of chronic postsurgical pain in adolescents. Psychological distress, sleep disturbance, and low pain self-efficacy predict higher acute pain and likelihood of developing chronic postsurgical pain. Interventions targeting baseline psychosocial risk factors have potential to interrupt a negative trajectory of continued pain and poor health-related quality of life (HRQL) over time but have not yet been developed and evaluated. This randomized controlled trial will test effectiveness of a digital peri-operative cognitive-behavioral intervention (SurgeryPal) vs. education-control delivered to adolescents and their parents to improve acute and chronic pain and health outcomes in adolescents undergoing spine surgery.

There is a lack of knowledge on coping with pain and sub-group specific pain-coping profiles among older home care receivers with chronic pain. To describe pain-coping strategies, identify subgroups based on cognitive and behavioral pain-coping strategies and pain-related psychological impairment and to compare these groups with regard to socio-demographic, medical, pharmacological and psychological characteristics.