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Mitsikostas DD, Blease C, Carlino E, Colloca L, Geers AL, Howick J, Evers AWM, Flaten MA, Kelley JM, Kirsch I, Klinger R, MaassenVanDenBrink A, Moerman DE, Sfikakis PP, Vase L, Wager TD, Benedetti F. European Headache Federation recommendations for placebo and nocebo terminology. J Headache Pain 2020; 21:117. [PMID: 32977761 PMCID: PMC7519524 DOI: 10.1186/s10194-020-01178-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 08/26/2020] [Indexed: 12/31/2022] Open
Abstract
Background and aim Despite recent publications, practitioners remain unfamiliar with the current terminology related to the placebo and nocebo phenomena observed in clinical trials and practice, nor with the factors that modulate them. To cover the gap, the European Headache Federation appointed a panel of experts to clarify the terms associated with the use of placebo in clinical trials. Methods The working group identified relevant questions and agreed upon recommendations. Because no data were required to answer the questions, the GRADE approach was not applicable, and thus only expert opinion was provided according to an amended Delphi method. The initial 12 topics for discussion were revised in the opinion of the majority of the panelists, and after a total of 6 rounds of negotiations, the final agreement is presented. Results/recommendations Two primary and mechanism-based recommendations are provided for the results of clinical trials: [1] to distinguish the placebo or nocebo response from the placebo or nocebo effect; and [2] for any favorable outcome observed after placebo administration, the term “placebo response” should be used, and for any unfavorable outcome recorded after placebo administration, the term “nocebo response” should be used (12 out of 17 panelists agreed, 70.6% agreement). The placebo or nocebo responses are attributed to a set of factors including those that are related to the medical condition (e.g. natural history, random comorbidities, etc.), along with idiosyncratic ones, in which the placebo or nocebo effects are attributed to idiosyncratic, or nonspecific mechanisms, exclusively (e.g. expectation, conditioning, observational learning etc.). To help investigators and practitioners, the panel summarized a list of environmental factors and idiosyncratic dynamics modulating placebo and nocebo effects. Some of them are modifiable, and investigators or physicians need to know about them in order to modify these factors appropriately to improve treatment. One secondary recommendation addresses the use of the terms “placebo” and “nocebo” (“placebos” and “nocebos” in plural), which refer to the triggers of the placebo/nocebo effects or responses, respectively, and which are inert agents or interventions that should not be confused with the placebo/nocebo responses or effects themselves (all panelists agreed, 100% agreement). Conclusion The working group recommends distinguishing the term response from effect to describe health changes from before to after placebo application and to distinguish the terms placebo(s) or nocebo(s) from the health consequences that they cause (placebo/nocebo responses or effects).
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Affiliation(s)
- Dimos D Mitsikostas
- 1st Neurology Department, Aeginiton Hospital, Medical School, National and Kapodistrian University of Athens, 72-72 Vas. Sofia's Avenue, 11528, Athens, Greece.
| | - Charlotte Blease
- General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Elisa Carlino
- Physiology and Neuroscience, University of Turin Medical School, Turin, Italy
| | - Luana Colloca
- Departments of Pain Translational Symptoms Science and Anaesthesiology, School of Nursing and Medicine, University of Maryland Baltimore, Baltimore, MD, USA
| | - Andrew L Geers
- Department of Psychology, University of Toledo, Toledo, OH, USA
| | - Jeremy Howick
- Faculty of Philosophy, University of Oxford, Oxford, UK
| | - Andrea W M Evers
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Leiden University, Leiden, The Netherlands
| | - Magne A Flaten
- Department of Psychology, Norwegian University of Science and Technology, Trondheim, Norway
| | - John M Kelley
- Beth Israel Deaconess Medical Center, Program in Placebo Studies, Boston, MA, USA
| | - Irving Kirsch
- Beth Israel Deaconess Medical Center, Program in Placebo Studies, Boston, MA, USA
| | - Regine Klinger
- Department of Anesthesiology University Medical Center Hamburg-Eppendorf, Center for Anesthesiology and Intensive Care Medicine, Hamburg, Germany
| | | | | | - Petros P Sfikakis
- 1st Department of Propedeutic and Internal Medicine, National and Kapodistrian University Medical School, Athens, Greece
| | - Lene Vase
- Department of Psychology and Behavioural Sciences, Aarhus University, Aarhus, Denmark
| | - Tor D Wager
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, USA
| | - Fabrizio Benedetti
- Physiology and Neuroscience, University of Turin Medical School, Turin, Italy
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Palermo S, Giovannelli F, Bartoli M, Amanzio M. Are Patients With Schizophrenia Spectrum Disorders More Prone to Manifest Nocebo-Like-Effects? A Meta-Analysis of Adverse Events in Placebo Groups of Double-Blind Antipsychotic Trials. Front Pharmacol 2019; 10:502. [PMID: 31156432 PMCID: PMC6533921 DOI: 10.3389/fphar.2019.00502] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/23/2019] [Indexed: 12/12/2022] Open
Abstract
Background: Antipsychotic clinical trials use to present adverse events (AEs) for the drug under evaluation to treat schizophrenia. Interestingly, patients who receive the placebo during antipsychotic trials often report several AEs, but little is known about the essence of these negative effects in patients with schizophrenia spectrum disorders (SCD). In the present meta-analysis, we evaluated the relationship between the level of psychiatric symptomatology expressed as Positive and Negative Syndrome Scale (PANSS) scores and the rates of AEs reported in the placebo arms of double-blind clinical trials, for commonly prescribed atypical antipsychotic medications. Methods: We selected 58 clinical trials describing AEs in SCD placebo groups, which compared atypical antipsychotic medications with placebo. A total of 6,301 placebo-treated patients were considered. AE profiles of the class were clusterized using MedDRA classification and analysed using a meta-regression approach. Results: In the placebo arms the proportions of patients with any AE was 66.3% (95% CI: 62.7–69.8%). The proportion of withdrawal of patients treated with placebo because of AEs was 7.2% (95% CI: 5.9–8.4%). Interestingly, the AEs in the placebo arms corresponded to those of the antipsychotic-atypical-medication-class against which the placebo was compared. Namely, using meta-regression analysis we found an association between the level of psychiatric symptomatology measured with PANSS scores and higher AEs reported as nervous system (p = 0.020) and gastrintestinal disorders (p = 0.004). Moreover, the level of a higher psychiatric symptomatology expressed with PANSS scores was also related with higher AEs associated with psychiatric symptoms (p = 0.017). Conclusion: These findings emphasise that the AEs in placebo arms of clinical trials of antipsychotic medications were substantial. Importantly, a higher level of psychiatric symptomatology makes SCD patients more prone to express AEs, thus contributing to possible drop-outs and to a lower adherence to treatments. These results are consistent with the expectation theory of placebo and nocebo effects.
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Affiliation(s)
- Sara Palermo
- Department of Psychology, University of Turin, Turin, Italy.,European Innovation Partnership on Active and Healthy Ageing, Brussels, Belgium
| | - Fabio Giovannelli
- Section of Psychology, Department of Neuroscience, Psychology, Drug Research, Child Health, University of Florence, Florence, Italy
| | | | - Martina Amanzio
- Department of Psychology, University of Turin, Turin, Italy.,European Innovation Partnership on Active and Healthy Ageing, Brussels, Belgium
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