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Archivos Argentinos de Pediatria Dec 2020
Topics: Ethics, Medical; Humans; Placebo Effect
PubMed: 33231040
DOI: 10.5546/aap.2020.eng.370 -
Drugs of Today (Barcelona, Spain : 1998) Jul 2019The placebo effect is a phenomenon of great scientific interest that affects the response in both inactive and active treatments. It is broadly understood as the product... (Review)
Review
The placebo effect is a phenomenon of great scientific interest that affects the response in both inactive and active treatments. It is broadly understood as the product of a central integration of positive expectations, reward learning and continuous conditioning inducing physiological changes in the brain. The placebo effect is accepted as a phenomenon which can be harnessed in clinical practice. It has emerged that there is not a single neurobiological mechanism involved in placebo responses, but many depending on the underlying disease. Molecular neuroimaging techniques with positron emission tomography and selective radiotracers have been significant in the understanding of the neurobiological systems involved in the placebo effect. The aim of this review was to summarize the key findings relating to the neurobiology behind the placebo effect.
Topics: Brain; Humans; Neurobiology; Placebo Effect; Positron-Emission Tomography
PubMed: 31347615
DOI: 10.1358/dot.2019.55.7.3010575 -
Handbook of Experimental Pharmacology 2019In this review, we explored different ways of controlling the placebo effects in clinical trials and described various factors that may increase/decrease the placebo... (Review)
Review
In this review, we explored different ways of controlling the placebo effects in clinical trials and described various factors that may increase/decrease the placebo effect in randomized placebo-controlled trials. These factors can be subdivided into four groups, and while not all factors are effective in every study and under all clinical conditions, they show on the whole that - even under the ideal condition of drug therapy, where blinded placebo provision is much easier and warranted than in, e.g., psychotherapy - many factors need to be controlled to ascertain that the goal of the clinical trials, fair assessment of superiority of the drug over placebo in placebo-controlled trials and fair assessment of non-inferiority of the drug compared to another drug in comparator trials, is reached. Ignorance towards the placebo effect, which was common in the past, is no longer acceptable; instead, it should be the goal of all therapeutic trials to minimize the placebo effect in clinical trials, while utilizing and maximizing it in clinical routine.
Topics: Placebo Effect; Placebos; Randomized Controlled Trials as Topic
PubMed: 31463606
DOI: 10.1007/164_2019_269 -
The New England Journal of Medicine Feb 2020
Review
Topics: Conditioning, Psychological; Humans; Hyperalgesia; Nervous System Physiological Phenomena; Nocebo Effect; Placebo Effect
PubMed: 32023375
DOI: 10.1056/NEJMra1907805 -
Trials Jul 2021Contextual effects (i.e., placebo response) refer to all health changes resulting from administering an apparently inactive treatment. In a randomized clinical trial... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Contextual effects (i.e., placebo response) refer to all health changes resulting from administering an apparently inactive treatment. In a randomized clinical trial (RCT), the overall treatment effect (i.e., the post-treatment effect in the intervention group) can be regarded as the true effect of the intervention plus the impact of contextual effects. This meta-research was conducted to examine the average proportion of the overall treatment effect attributable to contextual effects in RCTs across clinical conditions and treatments and explore whether it varies with trial contextual factors.
METHODS
Data was extracted from trials included in the main meta-analysis from the latest update of the Cochrane review on "Placebo interventions for all clinical conditions" (searched from 1966 to March 2008). Only RCTs reported in English having an experimental intervention group, a placebo comparator group, and a no-treatment control group were eligible.
RESULTS
In total, 186 trials (16,655 patients) were included. On average, 54% (0.54, 95%CI 0.46 to 0.64) of the overall treatment effect was attributable to contextual effects. The contextual effects were higher for trials with blinded outcome assessor and concealed allocation. The contextual effects appeared to increase proportional to the placebo effect, lower mean age, and proportion of females.
CONCLUSION
Approximately half of the overall treatment effect in RCTs seems attributable to contextual effects rather than to the specific effect of treatments. As the study did not include all important contextual factors (e.g., patient-provider interaction), the true proportion of contextual effects could differ from the study's results. However, contextual effects should be considered when assessing treatment effects in clinical practice.
TRIAL REGISTRATION
PROSPERO CRD42019130257 . Registered on April 19, 2019.
Topics: Female; Humans; Placebo Effect; Randomized Controlled Trials as Topic
PubMed: 34311793
DOI: 10.1186/s13063-021-05454-8 -
Manual Therapy Aug 2016Placebo and nocebo represent complex and distinct psychoneurobiological phenomena in which behavioural and neurophysiological modifications occur together with the... (Review)
Review
INTRODUCTION
Placebo and nocebo represent complex and distinct psychoneurobiological phenomena in which behavioural and neurophysiological modifications occur together with the application of a treatment. Despite a better understanding of this topic in the medical field, little is known about their role in physiotherapy.
PURPOSE
The aim of this review is: a) to elucidate the neurobiology behind placebo and nocebo effects, b) to describe the role of the contextual factors as modulators of the clinical outcomes in rehabilitation and c) to provide clinical and research guidelines on their uses.
IMPLICATIONS
The physiotherapist's features, the patient's features, the patient-physiotherapist relationship, the characteristics of the treatment and the overall healthcare setting are all contextual factors influencing clinical outcomes. Since every physiotherapy treatment determines a specific and a contextual effect, physiotherapists should manage the contextual factors as a boosting element of any manual therapy to improve placebo effects and avoid detrimental nocebo effects.
Topics: Humans; Musculoskeletal Diseases; Musculoskeletal Manipulations; Nocebo Effect; Pain Management; Physical Therapy Modalities; Placebo Effect; Treatment Outcome
PubMed: 27133031
DOI: 10.1016/j.math.2016.04.006 -
Musculoskeletal Science & Practice Dec 2022While the placebo effect is increasingly recognised as a contributor to treatment effects in clinical practice, the nocebo and other undesirable effects are less well... (Review)
Review
INTRODUCTION
While the placebo effect is increasingly recognised as a contributor to treatment effects in clinical practice, the nocebo and other undesirable effects are less well explored and likely underestimated. In the chiropractic, osteopathy and physiotherapy professions, some aspects of historical models of care may arguably increase the risk of nocebo effects.
PURPOSE
In this masterclass article, clinicians, researchers, and educators are invited to reflect on such possibilities, in an attempt to stimulate research and raise awareness for the mitigation of such undesirable effects.
IMPLICATIONS
This masterclass briefly introduces the nocebo effect and its underlying mechanisms. It then traces the historical development of chiropractic, osteopathy, and physiotherapy, arguing that there was and continues to be an excessive focus on the patient's body. Next, aspects of clinical practice, including communication, the therapeutic relationship, clinical rituals, and the wider social and economic context of practice are examined for their potential to generate nocebo and other undesirable effects. To aid reflection, a model to reflect on clinical practice and individual professions through the 'prism' of nocebo and other undesirable effects is introduced and illustrated. Finally, steps are proposed for how researchers, educators, and practitioners can maximise positive and minimise negative clinical context.
Topics: Humans; Nocebo Effect; Placebo Effect; Physical Therapy Modalities; Communication
PubMed: 36368170
DOI: 10.1016/j.msksp.2022.102677 -
Psychotherapy and Psychosomatics 2018Placebo and nocebo effects occur in clinical or laboratory medical contexts after administration of an inert treatment or as part of active treatments and are due to...
BACKGROUND
Placebo and nocebo effects occur in clinical or laboratory medical contexts after administration of an inert treatment or as part of active treatments and are due to psychobiological mechanisms such as expectancies of the patient. Placebo and nocebo studies have evolved from predominantly methodological research into a far-reaching interdisciplinary field that is unravelling the neurobiological, behavioural and clinical underpinnings of these phenomena in a broad variety of medical conditions. As a consequence, there is an increasing demand from health professionals to develop expert recommendations about evidence-based and ethical use of placebo and nocebo effects for clinical practice.
METHODS
A survey and interdisciplinary expert meeting by invitation was organized as part of the 1st Society for Interdisciplinary Placebo Studies (SIPS) conference in 2017. Twenty-nine internationally recognized placebo researchers participated.
RESULTS
There was consensus that maximizing placebo effects and minimizing nocebo effects should lead to better treatment outcomes with fewer side effects. Experts particularly agreed on the importance of informing patients about placebo and nocebo effects and training health professionals in patient-clinician communication to maximize placebo and minimize nocebo effects.
CONCLUSIONS
The current paper forms a first step towards developing evidence-based and ethical recommendations about the implications of placebo and nocebo research for medical practice, based on the current state of evidence and the consensus of experts. Future research might focus on how to implement these recommendations, including how to optimize conditions for educating patients about placebo and nocebo effects and providing training for the implementation in clinical practice.
Topics: Consensus; Drug-Related Side Effects and Adverse Reactions; Evidence-Based Practice; Humans; Nocebo Effect; Physician-Patient Relations; Placebo Effect
PubMed: 29895014
DOI: 10.1159/000490354 -
International Review of Neurobiology 2018
Topics: Animals; Biomedical Research; Humans; Placebo Effect; Placebos
PubMed: 29681338
DOI: 10.1016/S0074-7742(18)30027-8 -
Annual Review of Pharmacology and... Jan 2024Adverse nocebo responses can cause harm to patients and interfere with treatment adherence and effects in both clinic practice and clinical trials. Nocebo responses... (Review)
Review
Adverse nocebo responses can cause harm to patients and interfere with treatment adherence and effects in both clinic practice and clinical trials. Nocebo responses refer to negative outcomes to active medical treatments in clinical trials or practice that cannot be explained by the treatment's pharmacologic effects. Negative expectancies and nocebo effects are less known than placebo responses. Nocebo effects can be triggered by verbal suggestions, prior negative experiences, observation of others experiencing negative outcomes, and other contextual and environmental factors. As research advances over the years, mechanistic knowledge is accumulating on the neurobiological mechanisms of nocebo effects. This review summarizes studies on different facets of nocebo effects and responses and discusses clinical implications, ethical considerations, and future directions.
Topics: Humans; Nocebo Effect; Placebo Effect
PubMed: 37585661
DOI: 10.1146/annurev-pharmtox-022723-112425