Dodo bird verdict: Verbal modeling, counterconditioning, and operant conditioning are effective in nocebo hyperalgesia attenuation

Nocebo hyperalgesia, the increased pain following inert interventions, is frequently observed in clinical practice. The limited research has focused on methods of attenuating this effect. The current study investigates whether nocebo hyperalgesia can be reduced through counterconditioning, verbal modeling, and operant conditioning. Healthy volunteers (N=168) were randomly allocated to three experimental and two control groups. In the experimental groups, nocebo hyperalgesia was induced via classical conditioning by applying high-intensity pain stimuli with a placebo and low-intensity pain stimuli without a placebo. In the control groups, sham conditioning was implemented (the relation between pain intensity and placebo was non-contingent). Nocebo hyperalgesia was then attenuated by 1) counterconditioning (low-intensity pain stimuli with a placebo, and high-intensity pain stimuli without a placebo); 2) verbal modeling (moderate pain stimuli with and without a placebo, with pain ratings provided by others suggesting less pain with placebo); 3) operant conditioning (moderate pain stimuli with and without a placebo, and participants were rewarded when experiencing less pain with placebo). In one control group, sham conditioning was continued; the other group received no manipulation. Classical conditioning induced nocebo hyperalgesia. All three learning procedures effectively attenuated the nocebo effect with no difference in their effectiveness. Expectancies changed similarly to pain ratings. The induction of nocebo hyperalgesia was fully mediated by expectancies. The current study demonstrates that nocebo hyperalgesia can be attenuated by verbal modeling, counterconditioning, and operant conditioning. Our findings suggest that healthcare workers may have flexibility in selecting nocebo-attenuating procedures when considering the treatment context or patient preferences.