Moderators of nocebo effects in controlled experiments: A multi-level meta-analysis

Stein MV, Heller M, Hughes N, Marr D, Brake B, Chapman S, James Rubin G, Terhune DB (2025)

Publication Type: Journal article, Review article

Publication year: 2025

Journal

Neuroscience and Biobehavioral Reviews Elsevier

Book Volume: 172

Article Number: 106042

DOI: 10.1016/j.neubiorev.2025.106042

Abstract

Nocebo effects are a heterogenous phenomenon in which contextual cues trigger or exacerbate symptoms independently of active interventions. Suggestion, conditioning, and social observation are widely recognised as hallmark methods for inducing nocebo effects, but the extent to which nocebo effects are differentially influenced by suggestion type (e.g., direct or indirect suggestion) and mode of administration (e.g., verbal, textual, visual, etc.) across symptom domains remains unknown. We conducted a pre-registered meta-analysis (PROSPERO registration number CRD42023402097) to quantitatively synthesize available research on the factors that moderate effects in controlled nocebo experiments. Of 8469 search results, 105 experiments comprising 5017 participants and 391 effect sizes were analyzed. A multi-level meta-analysis revealed an overall moderate effect size for nocebo effects, g=0.50, [0.39, 0.62]. The magnitude of symptom expectancy effects was a significant moderator of nocebo effects. Verbal suggestion and social observation yielded moderate and comparable nocebo effects whereas technological devices, sham stimulation, and conditioning were independently associated with the induction of large nocebo effects. Greater specificity in the reporting of nocebo induction methods is required to elucidate the efficacy of different types of suggestions in inducing nocebo effects.

Authors with CRIS profile

Danielle Marr Juniorprofessur für Wahrnehmungspsychologie

Involved external institutions

King’s College London GB United Kingdom (GB) University College London (UCL) GB United Kingdom (GB) Leiden University NL Netherlands (NL)

How to cite

APA:

Stein, M.V., Heller, M., Hughes, N., Marr, D., Brake, B., Chapman, S.,... Terhune, D.B. (2025). Moderators of nocebo effects in controlled experiments: A multi-level meta-analysis. Neuroscience and Biobehavioral Reviews, 172. https://doi.org/10.1016/j.neubiorev.2025.106042

MLA:

Stein, Madeline V., et al. "Moderators of nocebo effects in controlled experiments: A multi-level meta-analysis." Neuroscience and Biobehavioral Reviews 172 (2025).

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