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Jacob C, Olliges E, Haile A, Hoffmann V, Jacobi B, Steinkopf L, Lanz M, Wittmann M, Tschöp MH, Meissner K. Placebo effects on nausea and motion sickness are resistant to experimentally-induced stress. Sci Rep 2023; 13:9908. [PMID: 37336972 DOI: 10.1038/s41598-023-36296-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 05/31/2023] [Indexed: 06/21/2023] Open
Abstract
Nausea often occurs in stressful situations, such as chemotherapy or surgery. Clinically relevant placebo effects in nausea have been demonstrated, but it remains unclear whether stress has an impact on these effects. The aim of this experimental study was to investigate the interplay between acute stress and placebo effects in nausea. 80 healthy female volunteers susceptible to motion sickness were randomly assigned to either the Maastricht Acute Stress Test or a non-stress control condition, and to either placebo treatment or no treatment. Nausea was induced by a virtual vection drum and behavioral, psychophysiological as well as humoral parameters were repeatedly assessed. Manipulation checks confirmed increased cortisol levels and negative emotions in the stressed groups. In the non-stressed groups, the placebo intervention improved nausea, symptoms of motion sickness, and gastric myoelectrical activity (normo-to-tachy (NTT) ratio). In the stressed groups, the beneficial effects of the placebo intervention on nausea and motion sickness remained unchanged, whereas no improvement of the gastric NTT ratio was observed. Results suggest that placebo effects on symptoms of nausea and motion sickness are resistant to experimentally-induced stress. Stress most likely interfered with the validity of the gastric NTT ratio to measure nausea and thus the gastric placebo effect.
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Affiliation(s)
- Carmen Jacob
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336, Munich, Germany
- Wessex Neurological Centre, University Hospital Southampton and Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK
| | - Elisabeth Olliges
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336, Munich, Germany
- Department of Psychosomatic Medicine and Psychotherapy, Klinik Barmelweid AG, 5017, Barmelweid, Switzerland
- Division of Health Promotion, Coburg University of Applied Sciences and Arts, Friedrich-Streib-Str. 2, 96450, Coburg, Germany
| | - Anja Haile
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336, Munich, Germany
| | - Verena Hoffmann
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336, Munich, Germany
| | - Benjamin Jacobi
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336, Munich, Germany
- Department of Psychiatry, University of Connecticut Health Center, H1010, Farmington, CT, 06030-1410, USA
| | - Leander Steinkopf
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336, Munich, Germany
| | - Marina Lanz
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336, Munich, Germany
| | - Marc Wittmann
- Institute for Frontier Areas of Psychology and Mental Health, 79098, Freiburg, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, 85764, Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, 81675, Munich, Germany
| | - Karin Meissner
- Institute of Medical Psychology, Medical Faculty, LMU Munich, 80336, Munich, Germany.
- Division of Health Promotion, Coburg University of Applied Sciences and Arts, Friedrich-Streib-Str. 2, 96450, Coburg, Germany.
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Skvortsova A, Cohen Rodrigues T, de Buisonjé D, Kowatsch T, Santhanam P, Veldhuijzen DS, van Middendorp H, Evers A. Increasing the Effectiveness of a Physical Activity Smartphone Intervention With Positive Suggestions: Randomized Controlled Trial. J Med Internet Res 2022; 24:e32130. [PMID: 35230245 PMCID: PMC8924786 DOI: 10.2196/32130] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/29/2021] [Accepted: 12/07/2021] [Indexed: 01/19/2023] Open
Abstract
Background eHealth interventions have the potential to increase the physical activity of users. However, their effectiveness varies, and they often have only short-term effects. A possible way of enhancing their effectiveness is to increase the positive outcome expectations of users by giving them positive suggestions regarding the effectiveness of the intervention. It has been shown that when individuals have positive expectations regarding various types of interventions, they tend to benefit from these interventions more. Objective The main objective of this web-based study is to investigate whether positive suggestions can change the expectations of participants regarding the effectiveness of a smartphone physical activity intervention and subsequently enhance the number of steps the participants take during the intervention. In addition, we study whether suggestions affect perceived app effectiveness, engagement with the app, self-reported vitality, and fatigue of the participants. Methods This study involved a 21-day fully automated physical activity intervention aimed at helping participants to walk more steps. The intervention was delivered via a smartphone-based app that delivered specific tasks to participants (eg, setting activity goals or looking for social support) and recorded their daily step count. Participants were randomized to either a positive suggestions group (69/133, 51.9%) or a control group (64/133, 48.1%). Positive suggestions emphasizing the effectiveness of the intervention were implemented in a web-based flyer sent to the participants before the intervention. Suggestions were repeated on days 8 and 15 of the intervention via the app. Results Participants significantly increased their daily step count from baseline compared with 21 days of the intervention (t107=−8.62; P<.001) regardless of the suggestions. Participants in the positive suggestions group had more positive expectations regarding the app (B=−1.61, SE 0.47; P<.001) and higher expected engagement with the app (B=3.80, SE 0.63; P<.001) than the participants in the control group. No effects of suggestions on the step count (B=−22.05, SE 334.90; P=.95), perceived effectiveness of the app (B=0.78, SE 0.69; P=.26), engagement with the app (B=0.78, SE 0.75; P=.29), and vitality (B=0.01, SE 0.11; P=.95) were found. Positive suggestions decreased the fatigue of the participants during the 3 weeks of the intervention (B=0.11, SE 0.02; P<.001). Conclusions Although the suggestions did not affect the number of daily steps, they increased the positive expectations of the participants and decreased their fatigue. These results indicate that adding positive suggestions to eHealth physical activity interventions might be a promising way of influencing subjective but not objective outcomes of interventions. Future research should focus on finding ways of strengthening the suggestions, as they have the potential to boost the effectiveness of eHealth interventions. Trial Registration Open Science Framework 10.17605/OSF.IO/CWJES; https://osf.io/cwjes
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Affiliation(s)
- Aleksandrina Skvortsova
- Department of Psychology, McGill University, Montreal, QC, Canada.,Health, Medical and Neuropsychology, Faculty of Social and Behavioural Sciences, Leiden, Netherlands
| | - Talia Cohen Rodrigues
- Health, Medical and Neuropsychology, Faculty of Social and Behavioural Sciences, Leiden, Netherlands
| | - David de Buisonjé
- Health, Medical and Neuropsychology, Faculty of Social and Behavioural Sciences, Leiden, Netherlands
| | - Tobias Kowatsch
- Centre for Digital Health Interventions, Department of Management, Technology, and Economics, ETH Zurich, Zurich, Switzerland.,Centre for Digital Health Interventions, Institute of Technology Management, University of St.Gallen, St.Gallen, Switzerland
| | - Prabhakaran Santhanam
- Centre for Digital Health Interventions, Department of Management, Technology, and Economics, ETH Zurich, Zurich, Switzerland
| | - Dieuwke S Veldhuijzen
- Health, Medical and Neuropsychology, Faculty of Social and Behavioural Sciences, Leiden, Netherlands
| | - Henriët van Middendorp
- Health, Medical and Neuropsychology, Faculty of Social and Behavioural Sciences, Leiden, Netherlands
| | - Andrea Evers
- Health, Medical and Neuropsychology, Faculty of Social and Behavioural Sciences, Leiden, Netherlands.,Department of Psychiatry, Leiden University Medical Center, Leiden, Netherlands.,Medical Delta, Leiden University, Technical University Delft and Erasmus University, Leiden, Delft, Rotterdam, Netherlands
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3
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'Measuring up': A comparison of two response expectancy assessment formats completed by men treated with radiotherapy for prostate cancer. J Psychosom Res 2020; 132:109979. [PMID: 32146249 DOI: 10.1016/j.jpsychores.2020.109979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 02/25/2020] [Accepted: 02/27/2020] [Indexed: 02/01/2023]
Abstract
OBJECTIVE Response expectancies of cancer treatment toxicities are often, but not always, associated with subsequent experiences. A recent meta-analysis indicated that response expectancies, measured using different assessment formats, reveal different effect sizes, potentially explaining mixed outcomes. Utilizing a clinical sample, we compared 5-point assessments and visual analogue scales, as measures of response expectancies for the incidence and severity of subsequent toxicities. METHODS Four weeks pre-radiotherapy, 45 men with prostate cancer rated their response expectancies of the same 18 toxicities on 5-point assessments and visual analogue scales, presented in random order. Descriptors anchored each end of visual analogue scales and every point of 5-point assessments was labelled, including an 'unsure' midpoint. Toxicities were subsequently assessed 2-weeks into radiotherapy on 100-point visual analogue scales. RESULTS Across all toxicities, 17.5-62.8% of patients selected 'unsure' on 5-point assessments. No response expectancies were reported on 5-point assessments for 'blood in stools' or 'rectal urgency' yet 54.8%-64.3% of patients indicated response expectancies for these toxicities on visual analogue scales. Visual analogue scales and 5-point scales demonstrated small-to-moderate associations (r = 0.30-0.58) as measures of response expectancy incidence, but mostly large associations when visual analogue scales captured severity (r = 0.43-0.76). Response expectancies measured with visual analogue scales predicted more toxicities to a moderate degree or greater (68.8%) than 5-point assessments (37.5%). CONCLUSION This novel investigation demonstrated an 'unsure' midpoint is often selected, potentially reducing the sensitivity of 5-point assessments. Based on their associations, and outcomes, these assessment formats should be considered independent in response expectancy research of cancer treatment toxicities.
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Aichner S, Haile A, Hoffmann V, Olliges E, Tschöp MH, Meissner K. The Role of Tactile Stimulation for Expectation, Perceived Treatment Assignment and the Placebo Effect in an Experimental Nausea Paradigm. Front Neurosci 2019; 13:1212. [PMID: 31798402 PMCID: PMC6863803 DOI: 10.3389/fnins.2019.01212] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 10/28/2019] [Indexed: 12/25/2022] Open
Abstract
Introduction Tactile stimulation during a placebo treatment could enhance its credibility and thereby boost positive treatment expectations and the placebo effect. This experimental study aimed to investigate the interplay between tactile stimulation, expectation, and treatment credibility for the placebo effect in nausea. Methods Ninety healthy participants were exposed to a 20-min vection stimulus on two separate days and were randomly allocated to one of three groups on the second day after the baseline period: Placebo transcutaneous electrical nerve stimulation (TENS) with tactile stimulation (n = 30), placebo TENS without tactile stimulation (n = 30), or no intervention (n = 30). Placebo TENS was performed for 20 min at a dummy acupuncture point on both forearms. Expected and perceived nausea severity and further symptoms of motion sickness were assessed at baseline and during the evaluation period. At the end of the experiment, participants in the placebo groups guessed whether they had received active or placebo treatment. Results Expected nausea decreased significantly more in the placebo groups as compared to the no treatment control group (interaction day × group, F = 6.60, p = 0.003, partial η2 = 0.20), with equal reductions in the two placebo groups (p = 1.0). Reduced expectation went along with a significant placebo effect on nausea (interaction day × group, F = 22.2, p < 0.001, partial η2 = 0.35) with no difference between the two placebo groups (p = 1.0). Twenty-three out of 29 participants in the tactile placebo group (79%) but only 14 out of 30 participants (47%) in the non-tactile placebo group believed that they had received the active intervention (p = 0.015). Bang’s blinding index (BI) indicated random guessing in the non-tactile placebo group (BI = 0; 95% CI, −0.35 to 0.35) and non-random guessing in the direction of an “opposite guess” in the tactile placebo group (BI = −0.52; 95% CI, −0.81 to −0.22). Conclusion Tactile stimulation during placebo TENS did not further enhance positive treatment expectations and the placebo effect in nausea but increased the credibility of the intervention. Further trials should investigate the interaction between perceived treatment assignment, expectation, and the placebo effect during the course of a trial.
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Affiliation(s)
- Simone Aichner
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Anja Haile
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Verena Hoffmann
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Munich, Germany
| | - Elisabeth Olliges
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Munich, Germany.,Division of Health Promotion, Coburg University of Applied Sciences, Coburg, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, Munich, Germany.,German Center for Diabetes Research (DZD), Munich, Germany.,Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Karin Meissner
- Institute of Medical Psychology, Faculty of Medicine, LMU Munich, Munich, Germany.,Division of Health Promotion, Coburg University of Applied Sciences, Coburg, Germany
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Understanding Acupoint Sensitization: A Narrative Review on Phenomena, Potential Mechanism, and Clinical Application. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2019; 2019:6064358. [PMID: 31485246 PMCID: PMC6710800 DOI: 10.1155/2019/6064358] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 07/09/2019] [Accepted: 07/15/2019] [Indexed: 01/08/2023]
Abstract
As part of traditional Chinese medicine, acupoints are considered a dynamic functional area, which can reflect the internal condition of the body. When the body is suffering from disease or injury, corresponding acupoints are believed to be activated and manifest in several sensitized forms, including expansion of the receptive field, pain sensitization, and heat sensitization. Such phenomena are believed to gradually disappear concomitantly with recovery from the disease. Acupoint states are therefore changeable according to health status, a phenomenon known as acupoint sensitization. This review aims to provide an overview of acupoint sensitization based on existing research results and determine priorities for future research. Systematic literature retrieval was conducted in Medline, Embase, Cochrane Library, CINAHL, and AMED from inception to 18 July 2018. Current evidence from research findings to date indicate that acupoint sensitization is based on neurogenic inflammation and that stimulation of sensitized acupoints presents a potential trend of generating a better clinical effect when compared with stimulation of unsensitized points.
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Wolters F, Peerdeman KJ, Evers AW. Placebo and Nocebo Effects Across Symptoms: From Pain to Fatigue, Dyspnea, Nausea, and Itch. Front Psychiatry 2019; 10:470. [PMID: 31312148 PMCID: PMC6614509 DOI: 10.3389/fpsyt.2019.00470] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/13/2019] [Indexed: 01/06/2023] Open
Abstract
Placebo and nocebo effects are, respectively, the helpful and harmful treatment effects that do not arise from active treatment components. These effects have thus far been researched most often in pain. It is not yet clear to what extent these findings from pain can be generalized to other somatic symptoms. This review investigates placebo and nocebo effects in four other highly prevalent symptoms: dyspnea, fatigue, nausea, and itch. The role of learning mechanisms (verbal suggestions, conditioning) in placebo and nocebo effects on various outcomes (self-reported, behavioral, and physiological) of these different somatic symptoms is explored. A search of experimental studies indicated that, as in pain, the combination of verbal suggestion and conditioning is generally more effective than suggestion alone for evoking placebo and nocebo effects. However, conditioning appears more and verbal suggestions less relevant in symptoms other than pain, with the exception of placebo effects on fatigue and nocebo effects on itch. Physiological measures, such as heart rate, lung function, or gastric activity, are rarely affected even when self-reported symptoms are. Neurobiological correlates are rarely investigated, and few commonalities appear across symptoms. Expectations generally predict placebo and nocebo effects for dyspnea and itch but seem less involved in fatigue and nausea. Individual characteristics do not consistently predict placebo or nocebo effects across symptoms or studies. In sum, many conclusions deriving from placebo and nocebo pain studies do appear to apply to other somatic symptoms, but a number of important differences exist. Understanding what type of learning mechanisms for which symptom are most likely to trigger placebo and nocebo effects is crucial for generalizing knowledge for research and therapies across symptoms and can help clinicians to optimize placebo effects in practice.
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Affiliation(s)
- Fabian Wolters
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, Netherlands
- Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands
| | - Kaya J. Peerdeman
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, Netherlands
- Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands
| | - Andrea W.M. Evers
- Health, Medical and Neuropsychology Unit, Institute of Psychology, Faculty of Social and Behavioral Sciences, Leiden University, Leiden, Netherlands
- Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands
- Department of Psychiatry, Leiden University Medical Center, Leiden, Netherlands
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Casteleijn D, Steel A, Bowman D, Lauche R, Wardle J. A naturalistic study of herbal medicine for self-reported depression and/or anxiety a protocol. Integr Med Res 2019; 8:123-128. [PMID: 31193603 PMCID: PMC6536771 DOI: 10.1016/j.imr.2019.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/15/2019] [Accepted: 04/17/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Mental health conditions including anxiety and depression account for around 8% of the global disease burden. Anxiety and depression often coexist and impose a high individual and social burden. Patients with mental and behavioural conditions may be at increased risk of co-morbidities and are often high health-care utilisers. Herbal medicine is estimated to be used by up to 80% of the worlds population, and by 22% of Australian women seeking care for depression. The holistic and tailored treatment approach offered by practitioners of herbal medicine is difficult to capture in randomised controlled trials and as such there is a paucity of research demonstrating the outcomes of real-life practice. This project aims to address this gap with a whole practice, observational model. METHODS/DESIGN The study will employ a naturalistic observational design. Two-hundred patient participants will be recruited to be treated by 15 clinician participants from different naturopathic clinics. The observed changes in anxiety and depression symptoms of patients will be documented across three consultations using validated patient-reported outcome measures (SF-36, DASS-21, GHQ-28 and POMS-2). CONCLUSION Clinical studies investigating the efficacy of individualised herbal medicine treatment as prescribed by a naturopath are rare. Our study attempts to fill this gap with a longitudinal observation of individualised care as practiced by naturopaths in Australia; to offer valuable insights into the effectiveness of individualised herbal medicine practice and provide contextualisation of data currently focused on individual herbal medicines in specific conditions.Trial Registration: Australian and New Zealand Clinical Trials Registry: ACTRN12616000010493.
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Affiliation(s)
| | - Amie Steel
- University of Technology Sydney, Sydney, Australia
| | - Diana Bowman
- University of Technology Sydney, Sydney, Australia
| | - Romy Lauche
- Klinik für Integrative Medizin und Naturheilkunde, Sozialstiftung Bamberg, Bamberg, Germany
| | - Jon Wardle
- University of Technology Sydney, Sydney, Australia
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Koch A, Cascorbi I, Westhofen M, Dafotakis M, Klapa S, Peter Kuhtz-Buschbeck J. The Neurophysiology and Treatment of Motion Sickness. DEUTSCHES ARZTEBLATT INTERNATIONAL 2018; 115:687-696. [PMID: 30406755 PMCID: PMC6241144 DOI: 10.3238/arztebl.2018.0687] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 03/28/2018] [Accepted: 08/09/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Seasickness and travel sickness are classic types of motion illness. Modern simulation systems and virtual reality representations can also induce comparable symptoms. Such manifestations can be alleviated or prevented by various measures. METHODS This review is based on pertinent publications retrieved by a PubMed search, with special attention to clinical trials and review articles. RESULTS Individuals vary in their susceptibility to autonomic symptoms, ranging from fatigue to massive vomiting, induced by passive movement at relatively low frequencies (0.2 to 0.4 Hz) in situations without any visual reference to the horizontal plane. Younger persons and women are considered more susceptible, and twin studies have revealed a genetic component as well. The various types of motion sickness are adequately explained by the intersensory conflict model, incorporating the vestibular, visual, and proprioceptive systems and extended to include consideration of postural instability and asymmetry of the otolith organs. Scopolamine and H1-antihistamines, such as dimenhydrinate and cinnarizine, can be used as pharmacotherapy. The symptoms can also be alleviated by habituation through long exposure or by the diminution of vestibular stimuli. CONCLUSION The various types of motion sickness can be treated with general measures to lessen the intersensory conflict, behavioral changes, and drugs.
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Affiliation(s)
- Andreas Koch
- Naval Institute of Maritime Medicine, Kronshagen, Institute of Experimental Medicine, Section Maritime Medicine Christian-Albrechts-Universität, Kiel
| | - Ingolf Cascorbi
- Institute of Experimental and Clinical Pharmacology, University Hospital Schleswig-Holstein, Campus Kiel
| | - Martin Westhofen
- Clinic for Otorhinolaryngology and Plastic Surgery of the Head and Throat, RWTH Aachen
| | | | - Sebastian Klapa
- Naval Institute of Maritime Medicine, Kronshagen, Institute of Experimental Medicine, Section Maritime Medicine Christian-Albrechts-Universität, Kiel
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Meissner K, Linde K. Are Blue Pills Better Than Green? How Treatment Features Modulate Placebo Effects. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2018; 139:357-378. [PMID: 30146054 DOI: 10.1016/bs.irn.2018.07.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Treatment-related expectations are important predictors for placebo effects in various medical conditions. They are formed by verbal and nonverbal cues during the administration of treatments, such as verbal suggestions, conscious and unconscious associations with previous treatments, characteristics of patients and health-care providers as well as perceptual characteristics of the treatment. This review provides an overview of studies that aimed to elucidate the impact of treatment characteristics on expectations and placebo effects. Results show that high price, brand label, the use of invasive placebos and high placebo dose increase the expectations toward the beneficial effect of a placebo treatment, which in turn boost the placebo effect. Neuroimaging studies provide first insights into the neurobiological mechanisms underlying these differential placebo effects.
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Affiliation(s)
- Karin Meissner
- Division of Integrative Health Promotion, Coburg University of Applied Sciences, Coburg, Germany.
| | - Klaus Linde
- Institute of General Practice, Technical University of Munich, München, Germany
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Novel designs and paradigms to study the placebo response in gastroenterology. Curr Opin Pharmacol 2017; 37:72-79. [PMID: 29102743 DOI: 10.1016/j.coph.2017.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 10/04/2017] [Accepted: 10/06/2017] [Indexed: 12/18/2022]
Abstract
The investigation of the placebo and the nocebo effect and their mechanisms has a rather short history of less than 20 years, especially in gastroenterology, and only the last 5 years have resulted in substantial improvement of understanding. Placebo refers to symptom improvement following a treatment, nocebo to the opposite, symptom worsening. Among the factors driving this progress are traditional psychological models derived from learning (conditioning) theory bridging into clinical science, new animal models to investigate the pharmacology of placebo analgesia, and novel study designs to overcome limitations of traditional randomized and placebo-controlled study designs in drug testing. These are explored here for their implementation and application in gastroenterology, with a focus on visceral pain and nausea.
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