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Blythe JS, Thomaidou MA, Peerdeman KJ, van Laarhoven AI, van Schothorst MM, Veldhuijzen DS, Evers AW. Placebo effects on cutaneous pain and itch: a systematic review and meta-analysis of experimental results and methodology. Pain 2023; 164:1181-1199. [PMID: 36718994 PMCID: PMC10184563 DOI: 10.1097/j.pain.0000000000002820] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 09/14/2022] [Accepted: 10/20/2022] [Indexed: 02/01/2023]
Abstract
ABSTRACT Placebo effects, positive treatment outcomes that go beyond treatment processes, can alter sensations through learning mechanisms. Understanding how methodological factors contribute to the magnitude of placebo effects will help define the mechanisms by which these effects occur. We conducted a systematic review and meta-analysis of experimental placebo studies in cutaneous pain and itch in healthy samples, focused on how differences in methodology contribute to the resulting placebo effect magnitude. We conducted meta-analyses by learning mechanism and sensation, namely, for classical conditioning with verbal suggestion, verbal suggestion alone, and observational learning, separately for pain and itch. We conducted subgroup analyses and meta-regression on the type of sensory stimuli, placebo treatment, number of acquisition and evocation trials, differences in calibrated intensities for placebo and control stimuli during acquisition, age, and sex. We replicated findings showing that a combination of classical conditioning with verbal suggestion induced larger placebo effects on pain ( k = 68, g = 0 . 59) than verbal suggestion alone ( k = 39, g = 0.38) and found a smaller effect for itch with verbal suggestion alone ( k = 7, g = 0.14). Using sham electrodes as placebo treatments corresponded with larger placebo effects on pain than when topical gels were used. Other methodological and demographic factors did not significantly affect placebo magnitudes. Placebo effects on pain and itch reliably occur in experimental settings with varied methods, and conditioning with verbal suggestion produced the strongest effects. Although methods may shape the placebo effect to some extent, these effects appear robust overall, and their underlying learning mechanisms may be harnessed for applications outside the laboratory.
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Affiliation(s)
- Joseph S. Blythe
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Mia A. Thomaidou
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Kaya J. Peerdeman
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Antoinette I.M. van Laarhoven
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
- Department of Psychiatry, Leiden University Medical Centre, Leiden, the Netherlands
| | | | - Dieuwke S. Veldhuijzen
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
| | - Andrea W.M. Evers
- Health, Medical and Neuropsychology Unit, Leiden University, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden, the Netherlands
- Medical Delta Healthy Society, Leiden University, Technical University Delft, and Erasmus University Rotterdam, Rotterdam, the Netherlands
- Department of Psychiatry, Leiden University Medical Centre, Leiden, the Netherlands
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Tu Y, Zhang L, Kong J. Placebo and nocebo effects: from observation to harnessing and clinical application. Transl Psychiatry 2022; 12:524. [PMID: 36564374 PMCID: PMC9789123 DOI: 10.1038/s41398-022-02293-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 12/25/2022] Open
Abstract
Placebo and nocebo effects are salubrious benefits and negative outcomes attributable to non-specific symbolic components. Leveraging advanced experimental and analytical approaches, recent studies have elucidated complicated neural mechanisms that may serve as a solid basis for harnessing the powerful self-healing and self-harming capacities and applying these findings to improve medical practice and minimize the unintended exacerbation of symptoms in medical practice. We review advances in employing psychosocial, pharmacological, and neuromodulation approaches to modulate/harness placebo and nocebo effects. While these approaches show promising potential, translating these research findings into clinical settings still requires careful methodological, technical, and ethical considerations.
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Affiliation(s)
- Yiheng Tu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China. .,Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
| | - Libo Zhang
- grid.9227.e0000000119573309CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China ,grid.410726.60000 0004 1797 8419Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Jian Kong
- grid.32224.350000 0004 0386 9924Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA USA
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Benson S, Theysohn N, Kleine-Borgmann J, Rebernik L, Icenhour A, Elsenbruch S. Positive Treatment Expectations Shape Perceived Medication Efficacy in a Translational Placebo Paradigm for the Gut-Brain Axis. Front Psychiatry 2022; 13:824468. [PMID: 35401247 PMCID: PMC8987023 DOI: 10.3389/fpsyt.2022.824468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
Placebo research has established the pivotal role of treatment expectations in shaping symptom experience and patient-reported treatment outcomes. Perceived treatment efficacy constitutes a relevant yet understudied aspect, especially in the context of the gut-brain axis with visceral pain as key symptom. Using a clinically relevant experimental model of visceral pain, we elucidated effects of pre-treatment expectations on post-treatment perceived treatment efficacy as an indicator of treatment satisfaction in a translational placebo intervention. We implemented positive suggestions regarding intravenous treatment with a spasmolytic drug (in reality saline), herein applied in combination with two series of individually calibrated rectal distensions in healthy volunteers. The first series used distension pressures inducing pain (pain phase). In the second series, pressures were surreptitiously reduced, modeling pain relief (pain relief phase). Using visual analog scales (VAS), expected and perceived treatment efficacy were assessed, along with perceived pain intensity. Manipulation checks supported that the induction of positive pre-treatment expectations and the modeling of pain relief were successful. Generalized Linear Models (GLM) were implemented to assess the role of inter-individual variability in positive pre-treatment expectations in perceived treatment efficacy and pain perception. GLM indicated no association between pre-treatment expectations and perceived treatment efficacy or perceived pain for the pain phase. For the relief phase, pre-treatment expectations (p = 0.024) as well as efficacy ratings assessed after the preceding pain phase (p < 0.001) were significantly associated with treatment efficacy assessed after the relief phase, together explaining 54% of the variance in perceived treatment efficacy. The association between pre-treatment expectations and perceived pain approached significance (p = 0.057) in the relief phase. Our data from an experimental translational placebo intervention in visceral pain support that reported post-treatment medication efficacy is shaped by pre-treatment expectations. The observation that individuals with higher positive expectations reported less pain and higher treatment satisfaction after pain relief may provide first evidence that perceived symptom improvement may facilitate treatment satisfaction. The immediate experience of symptoms within a given psychosocial treatment context may dynamically change perceptions about treatment, with implications for treatment satisfaction, compliance and adherence of patients with conditions of the gut-brain axis.
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Affiliation(s)
- Sven Benson
- Institute for Medical Education, Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.,Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Nina Theysohn
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Julian Kleine-Borgmann
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Laura Rebernik
- Institute of Medical Psychology and Behavioral Immunobiology, Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Adriane Icenhour
- Department of Medical Psychology and Medical Sociology, Ruhr University Bochum, Bochum, Germany
| | - Sigrid Elsenbruch
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.,Department of Medical Psychology and Medical Sociology, Ruhr University Bochum, Bochum, Germany
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Muthulingam JA, Hansen TM, Olesen SS, Drewes AM, Frøkjaer JB. Two-Week Cervical Vagus Nerve Stimulation in Chronic Pancreatitis Patients Induces Functional Connectivity Changes of Limbic Structures. Neuromodulation 2021; 25:471-478. [PMID: 35396075 DOI: 10.1111/ner.13482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 05/05/2021] [Accepted: 05/24/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Noninvasive vagus nerve stimulation (nVNS) has not only shown antinociceptive effects, but also demonstrated anti-inflammatory and antidepressant effects. These effects could be beneficial in chronic pancreatitis (CP) patients suffering from chronic abdominal pain, even though the underlying central mechanisms remain unclear. The aim was to investigate the effect of cervical nVNS in patients with painful CP on brain functional connectivity and cerebral metabolites. MATERIALS AND METHODS In a randomized double-blind, sham-controlled crossover trial, we used resting-state functional magnetic resonance imaging to investigate functional connectivity changes of limbic structures (seed-based analysis) after two weeks cervical nVNS treatment (GammaCore) as compared with two weeks sham treatment. Similarly, magnetic resonance spectroscopy was performed in the anterior cingulate cortex (ACC) with assessment of glutamate/creatine (Glu/cre) and N-acetylaspartate/creatine (NAA/cre). RESULTS Sixteen CP patients (mean age 56.6 ± 9.4 years) completed the trial. nVNS induced reduced functional connectivity compared to sham treatment between 1) bilateral thalamus and bilateral superior frontal gyrus, 2) ACC and putamen, and 3) posterior cingulate cortex and right thalamus (all p < 0.05). No changes were observed in Glu/cre (p = 0.96) and NAA/cre (p = 0.43) levels between the nVNS and sham treatments. CONCLUSION In our population of CP patients, cervical nVNS compared with sham treatment induced reduced functional connectivity of limbic structures, as also observed in other patient groups. The findings are relevant, since we have previously demonstrated an effect on pain scores in CP patients for both nVNS and sham treatment. Our results elucidate the effects in the central nervous system following nVNS treatment of CP patients, pointing at potential beneficial effects in this patient group.
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Affiliation(s)
- Janusiya Anajan Muthulingam
- Mech-Sense, Department of Radiology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Tine Maria Hansen
- Mech-Sense, Department of Radiology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Søren Schou Olesen
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.,Centre for Pancreatic Diseases, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Asbjørn Mohr Drewes
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.,Centre for Pancreatic Diseases, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Jens Brøndum Frøkjaer
- Mech-Sense, Department of Radiology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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Lee IS, Jung WM, Lee YS, Wallraven C, Chae Y. Operant and classical learning principles underlying mind-body interaction in pain modulation: a pilot fMRI study. Sci Rep 2021; 11:1663. [PMID: 33462278 PMCID: PMC7813884 DOI: 10.1038/s41598-021-81134-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 01/04/2021] [Indexed: 11/09/2022] Open
Abstract
The operant conditioning has been less studied than the classical conditioning as a mechanism of placebo-like effect, and two distinct learning mechanisms have never been compared to each other in terms of their neural activities. Twenty-one participants completed cue-learning based pain rating tasks while their brain responses were measured using functional magnetic resonance imaging. After choosing (instrumental) or viewing (classical) one of three predictive cues (low- and high-pain cues with different level of certainty), they received painful stimuli according to the selected cues. Participants completed the same task during the test session, except that they received only a high pain stimulus regardless of the selected cues to identify the effects of two learning paradigms. While receiving a high pain stimulation, low-pain cue significantly reduced pain ratings compared to high-pain cue, and the overall ratings were significantly lower under operant than under classical conditioning. Operant behavior activated the temporoparietal junction significantly more than the passive behavior did, and neural activity in the primary somatosensory cortex was significantly reduced during pain in instrumental as compared with classical conditioning trials. The results suggest that pain modulation can be induced by classical and operant conditioning, and mechanisms of attention and context change are involved in instrumental learning.
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Affiliation(s)
- In-Seon Lee
- Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Won-Mo Jung
- Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Ye-Seul Lee
- Department of Anatomy and Acupoint, College of Korean Medicine, Gachon University, Seongnam, Republic of Korea
| | - Christian Wallraven
- Department of Artificial Intelligence, Department of Brain Cognitive Engineering, Korea University, Seoul, Republic of Korea
| | - Younbyoung Chae
- Acupuncture and Meridian Science Research Center, College of Korean Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
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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: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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