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Knezevic NN, Sic A, Worobey S, Knezevic E. Justice for Placebo: Placebo Effect in Clinical Trials and Everyday Practice. MEDICINES (BASEL, SWITZERLAND) 2025; 12:5. [PMID: 40137049 PMCID: PMC11944128 DOI: 10.3390/medicines12010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2024] [Revised: 01/21/2025] [Accepted: 02/20/2025] [Indexed: 03/27/2025]
Abstract
The placebo effect has been widely documented across various medical conditions, demonstrating its ability to influence both subjective and objective outcomes. Placebo responses can significantly improve symptoms in these different conditions, such as pain, Parkinson's disease, depression, anxiety, and addiction. Psychological mechanisms, particularly the power of patient expectations, appear to play a central role, with neurobiological evidence supporting the activation of dopamine, endogenous opioids, and endocannabinoids in response to placebo interventions. Studies have demonstrated that placebo injections and more complex procedures, including sham surgeries, can produce therapeutic effects comparable to real treatments, particularly in pain management and neurological disorders. Moreover, placebo responses could be amplified when patients are aware of receiving treatment, as shown by research on open-label placebos and open versus hidden medical treatments. The effectiveness of 0.9% sodium chloride solution as a placebo in clinical trials is debated, with some studies indicating its potential to induce clinical improvements, though it may not be an ideal control in inflammatory pain conditions. Advances in neuroimaging have revealed that placebo treatments trigger tangible biological processes in the brain and body and are supported by psychological and physiological mechanisms that interact, suggesting real biological processes are involved in the observed effects. Overall, the growing understanding of placebo mechanisms suggests that incorporating placebo-based strategies, with patient awareness and appropriate ethical considerations, may offer significant potential for improving patient outcomes, particularly in chronic pain, mental health, and neurological conditions.
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Affiliation(s)
- Nebojsa Nick Knezevic
- Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, IL 60657, USA; (A.S.); (S.W.); (E.K.)
- Department of Anesthesiology, University of Illinois, Chicago, IL 60612, USA
- Department of Surgery, University of Illinois, Chicago, IL 60612, USA
| | - Aleksandar Sic
- Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, IL 60657, USA; (A.S.); (S.W.); (E.K.)
- Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
| | - Samantha Worobey
- Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, IL 60657, USA; (A.S.); (S.W.); (E.K.)
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA
| | - Emilija Knezevic
- Department of Anesthesiology, Advocate Illinois Masonic Medical Center, Chicago, IL 60657, USA; (A.S.); (S.W.); (E.K.)
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Wish ED, Billing AS, Massey E, Cole T, Greenblatt A, Weintraub E, Dohlman P, Belcher A. On the Value of Measuring Recent Drug Use by Self-Reports and Urinalysis in Clinical Trials. Subst Use Misuse 2024; 59:2112-2115. [PMID: 39267267 DOI: 10.1080/10826084.2024.2401341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/17/2024]
Abstract
Background: Valid measurement of drug use in patients enrolled in clinical trials that treat substance use disorder is vital to determine the trial's outcome. Self-reports are often used but their validity has been studied with mixed results. Urinalysis may sometimes be employed as an alternative or supplement to self-reports. Objectives: This study examined how estimating drug use by either method would affect the results from a randomized clinical trial conducted in a methadone treatment program. At the initial Baseline interview and four follow-up interviews, participants were asked about their drug use history and provided a urine specimen for drug testing. Results: In most cases, the urinalyses detected more drugs than the patients had reported using. A major exception was heroin, whose use was an eligibility criterion for enrollment in the study and methadone treatment. Conclusions: The patients' self-reports would have led us to conclude that the use of heroin and fentanyl had declined from the initial Baseline interview to the final follow-up interview, while the urinalysis results indicated no change in exposure to heroin and an increase in exposure to fentanyl. Clinical trials would be well served to employ the use of biological tests in addition to self-reports to measure recent drug use and to accurately estimate the efficacy of the experimental protocols and patients' exposure to drugs.
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Affiliation(s)
- Eric D Wish
- CESAR: Center for Substance Use, Addiction & Health Research, University of Maryland, College Park, Maryland, USA
| | - Amy S Billing
- CESAR: Center for Substance Use, Addiction & Health Research, University of Maryland, College Park, Maryland, USA
| | - Ebonie Massey
- CESAR: Center for Substance Use, Addiction & Health Research, University of Maryland, College Park, Maryland, USA
| | - Thomas Cole
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Aaron Greenblatt
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Eric Weintraub
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Priya Dohlman
- CESAR: Center for Substance Use, Addiction & Health Research, University of Maryland, College Park, Maryland, USA
| | - Annabelle Belcher
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Schaefer M, Kühnel A, Enge S. Open-label placebos reduce weight in obesity: a randomized controlled trial. Sci Rep 2024; 14:21311. [PMID: 39266589 PMCID: PMC11392943 DOI: 10.1038/s41598-024-69866-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 08/09/2024] [Indexed: 09/14/2024] Open
Abstract
Obesity is a major public health problem worldwide. Different approaches are known to face this problem, for example, dieting, surgery, or drug interventions. It has also been shown that placebos may help to reduce weight and hunger feelings, but the use of placebos is linked to problems with respect to the patient-healthcare-provider relationship. However, recent studies demonstrated that even placebos without deception (open-label placebos) affect symptoms such as pain, anxiety, or emotional distress. Here we aimed to examine whether an open-label placebo may help to lose weight in obesity. Our study included fifty-seven overweight and obese patients who aimed to lose weight using a combination of diet and sports. Patients were randomly divided into two groups. Participants in the open-label placebo group received two placebos each day. A treatment-as-usual group received no pills. Primary outcome included changes of body weight. Secondary outcomes were change of eating behavior and self-management abilities. After 4 weeks we found that participants in the open-label placebo condition lost more weight than the treatment-as-usual group. Furthermore, OLP treatment affected eating behavior. No effects for self-management abilities were found. Although further research is necessary, open-label placebos might help individuals to lose weight.
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Affiliation(s)
- Michael Schaefer
- MSB Medical School Berlin, Rüdesheimer Str. 50, 14197, Berlin, Germany.
| | - Anja Kühnel
- MSB Medical School Berlin, Rüdesheimer Str. 50, 14197, Berlin, Germany
| | - Sören Enge
- MSB Medical School Berlin, Rüdesheimer Str. 50, 14197, Berlin, Germany
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Wessels J, Klinger R, Benson S, Brenner T, Elsenbruch S, Aulenkamp JL. Preoperative Anxiolysis and Treatment Expectation (PATE Trial): open-label placebo treatment to reduce preoperative anxiety in female patients undergoing gynecological laparoscopic surgery - study protocol for a bicentric, prospective, randomized-controlled trial. Front Psychiatry 2024; 15:1396562. [PMID: 39045553 PMCID: PMC11265268 DOI: 10.3389/fpsyt.2024.1396562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 06/14/2024] [Indexed: 07/25/2024] Open
Abstract
One of the most common concerns of patients undergoing surgery is preoperative anxiety, with a prevalence of up to 48%. The effects of preoperative anxiety continue beyond the preoperative period and are associated with more severe postoperative pain and poorer treatment outcomes. Treatment options for preoperative anxiety are often limited as sedatives cause side effects and their efficacy remains controversial. Placebo research has shown that optimization of positive treatment expectations, as can be achieved through placebo administration and education, has clinically relevant effects on preoperative anxiety, pain and treatment outcomes. As the administration of masked placebos raises ethical questions, clinical studies have increasingly focused on the use of open, non-deceptive placebo administration (open-label placebo, OLP). The use of OLPs to reduce preoperative anxiety and modify clinically relevant postoperative outcomes has not yet been investigated. This bicentric, prospective, randomized-controlled clinical trial (PATE Trial; German Registry for Clinical Studies DRKS00033221), an associated project of the Collaborative Research Center (CRC) 289 "Treatment Expectation", aims to alleviate preoperative anxiety by optimizing positive treatment expectations facilitated by OLP. Furthermore, this study examines a potential enhancement of these effects through aspects of observational learning, operationalized by a positive expectation-enhancing video. In addition, patient's perspective on the self-efficacy and appropriateness of OLPs prior to surgery will be assessed. To achieve these objectives, female patients will be randomized into three groups before undergoing gynecological laparoscopic surgery. One group receives the OLP with a positive rationale conveyed by a study physician. A second group receives the same intervention, OLP administration and rationale provided by a physician, and additionally watches a video on OLP presenting a satisfied patient. A third group receives standard treatment as usual (TAU). Outcome measures will be effects on preoperative anxiety and postoperative experience, particularly visceral and somatic postoperative pain. As the non-deceptive administration of placebos; when indicated; may yield positive outcomes without side effects, and as current treatment of preoperative anxiety is limited, evidence from clinical placebo research has the potential to improve outcomes and patient experience in the surgical setting.
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Affiliation(s)
- Johannes Wessels
- Department of Anesthesiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Regine Klinger
- Department of Anesthesiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Sven Benson
- Institute for Medical Education, Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Thorsten Brenner
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Sigrid Elsenbruch
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University Duisburg-Essen, Essen, Germany
- Department of Medical Psychology and Medical Sociology, Ruhr University Bochum, Bochum, Germany
| | - Jana L. Aulenkamp
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Essen, University Duisburg-Essen, Essen, Germany
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University Duisburg-Essen, Essen, Germany
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Caliskan EB, Bingel U, Kunkel A. Translating knowledge on placebo and nocebo effects into clinical practice. Pain Rep 2024; 9:e1142. [PMID: 38533458 PMCID: PMC10965200 DOI: 10.1097/pr9.0000000000001142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 12/18/2023] [Indexed: 03/28/2024] Open
Abstract
Introduction Positive and negative treatment expectations are powerful modulators of health and treatment outcomes. A substantial part of treatment success is due to contextual factors modulating patient's expectations towards a treatment. Consequently, treatment expectations should be a target of therapeutic interventions themselves. Objectives This article highlights the neurobiological underpinnings of treatment expectations as well as strategies to modulate contextual factors to optimize treatment outcomes in daily clinical settings. Methods This clinical update aligns with the 2022 IASP Global Year Translating Pain Knowledge into Practice and selectively reviews the best available evidence and practice. Results The effects of treatment expectations, also known as placebo and nocebo effects, are observed in various clinical conditions and physiological systems. However, most of our knowledge comes from the field of pain, where expectation effects substantially contribute to overall analgesic treatment outcomes. Experimental placebo analgesia paradigms provide the best illustration of how analgesic effects can be attributed not only to a pharmacological or specific treatment, but instead are the result of the expectation towards the treatment. The impact of expectations on treatment outcome is highly variable between individuals, and the identification of factors predicting an individual's response has proven to be challenging. Further research is required to provide personalized treatment strategies for the daily clinical practice. Conclusion Patient's previous experiences and expectations are powerful modulators of treatment efficacy, tolerability, and adherence. By providing a comprehensive overview of recent advances in this field, this review offers valuable insights for clinicians and researchers seeking to improve patient-clinician interaction.
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Affiliation(s)
- Elif Buse Caliskan
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Ulrike Bingel
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Angelika Kunkel
- Department of Neurology, Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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