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Experimental and Clinical... Aug 2000This review outlines the development and use of placebo cigarettes in smoking research. Research on effects of smoking has been disadvantaged by the lack of an adequate... (Review)
Review
This review outlines the development and use of placebo cigarettes in smoking research. Research on effects of smoking has been disadvantaged by the lack of an adequate placebo condition. Recently, tobacco-based denicotinized cigarettes have been used in smoking research to distinguish effects of smoking due to the delivery of nicotine, other components of tobacco smoke, and the sensory process of smoking. Placebo cigarettes do not increase heart rate and blood pressure or produce electroencephalogram changes ordinarily associated with nicotine. However, placebo cigarettes reduce subjective measures of tobacco craving, desire to smoke, and tobacco withdrawal. These findings indicate that the effects of cigarette smoking are dependent on the delivery of nicotine, tar, other compounds of tobacco smoke, and the sensory stimuli. The next generation of research may begin to investigate the mechanisms that modulate these placebo effects.
Topics: Behavior; Humans; Placebos; Plants, Toxic; Smoking; Nicotiana
PubMed: 10975620
DOI: 10.1037//1064-1297.8.3.326 -
JAMA May 1994To estimate the importance and implications of placebo effects in pain treatment and research from the existing literature, with emphasis on their magnitude and... (Review)
Review
OBJECTIVE
To estimate the importance and implications of placebo effects in pain treatment and research from the existing literature, with emphasis on their magnitude and duration, the conditions influencing them, and proposed explanations.
DATA SOURCES
English-language articles and books identified through MEDLINE (1980 through 1993) and PsycLIT (1967 through 1993) database searching, bibliography review, and expert consultation.
STUDY SELECTION
Articles were included if they pertained to the review objectives.
RESULTS
Placebo response rates vary greatly and are frequently much higher than the often-cited one third. Placebos have time-effect curves, and peak, cumulative, and carryover effects similar to those of active medications. As with medication, surgery can produce substantial placebo effects, and this possibility is commonly overlooked in case series reports on back surgery. Individuals are not consistent in their placebo responses, and a placebo-responder personality has not been identified. Models advanced to explain placebo effects emphasize the role of anxiety, expectations, and learning.
CONCLUSIONS
Placebo effects influence patient outcomes after any treatment, including surgery, that the clinician and patient believe is effective. Placebo effects plus disease natural history and regression to the mean can result in high rates of good outcomes, which may be misattributed to specific treatment effects. The true causes of improvements in pain after treatment remain unknown in the absence of independently evaluated randomized controlled trials.
Topics: Dose-Response Relationship, Drug; Humans; Models, Psychological; Pain Management; Physician-Patient Relations; Placebo Effect; Placebos; Practice Patterns, Physicians'; Research Design; Surgical Procedures, Operative
PubMed: 7880221
DOI: No ID Found -
JAMA Internal Medicine Nov 2013When analyzing results of randomized clinical trials, the treatment with the greatest specific effect compared with its placebo control is considered to be the most... (Meta-Analysis)
Meta-Analysis Review
IMPORTANCE
When analyzing results of randomized clinical trials, the treatment with the greatest specific effect compared with its placebo control is considered to be the most effective one. Although systematic variations of improvements in placebo control groups would have important implications for the interpretation of placebo-controlled trials, the knowledge base on the subject is weak.
OBJECTIVE
To investigate whether different types of placebo treatments are associated with different responses using the studies of migraine prophylaxis for this analysis.
DESIGN, SETTING, AND PARTICIPANTS
We searched relevant sources through February 2012 and contacted the authors to identify randomized clinical trials on the prophylaxis of migraine with an observation period of at least 8 weeks after randomization that compared an experimental treatment with a placebo control group. We calculated pooled random-effects estimates according to the type of placebo for the proportions of treatment response. We performed meta-regression analyses to identify sources of heterogeneity. In a network meta-analysis, direct and indirect comparisons within and across trials were combined. Additional analyses were performed for continuous outcomes.
EXPOSURE
Active migraine treatment and the placebo control conditions.
MAIN OUTCOMES AND MEASURES
Proportion of treatment responders, defined as having an attack frequency reduction of at least 50%. Other available outcomes in order of preference included a reduction of 50% or greater in migraine days, the number of headache days, or headache score or a significant improvement as assessed by the patients or their physicians.
RESULTS
Of the 102 eligible trials, 23 could not be included in the meta-analyses owing to insufficient data. Sham acupuncture (proportion of responders, 0.38 [95% CI, 0.30-0.47]) and sham surgery (0.58 [0.37-0.77]) were associated with a more pronounced reduction of migraine frequency than oral pharmacological placebos (0.22 [0.17-0.28]) and were the only significant predictors of response in placebo groups in multivariable analyses (P = .005 and P = .001, respectively). Network meta-analysis confirmed that more patients reported response in sham acupuncture groups than in oral pharmacological placebo groups (odds ratio, 1.88 [95% CI, 1.30-2.72]). Corresponding analyses for continuous outcomes showed similar findings.
CONCLUSIONS AND RELEVANCE
Sham acupuncture and sham surgery are associated with higher responder ratios than oral pharmacological placebos. Clinicians who treat patients with migraine should be aware that a relevant part of the overall effect they observe in practice might be due to nonspecific effects and that the size of such effects might differ between treatment modalities.
Topics: Acupuncture Therapy; Drug Administration Schedule; Humans; Migraine Disorders; Neurosurgical Procedures; Placebo Effect; Placebos; Randomized Controlled Trials as Topic; Treatment Outcome
PubMed: 24126676
DOI: 10.1001/jamainternmed.2013.10391 -
Clinical Nursing Research Dec 2016
Topics: Clinical Trials as Topic; Empathy; Humans; Nurse's Role; Nursing Process; Placebos
PubMed: 27807195
DOI: 10.1177/1054773816675562 -
The Journal of Family Practice Jul 2000The placebo response is commonly invoked as a factor in the therapeutic relationship between the family physician and the patient, but important recent literature can be... (Review)
Review
The placebo response is commonly invoked as a factor in the therapeutic relationship between the family physician and the patient, but important recent literature can be difficult for family physicians to access. Coordinated interdisciplinary research into the placebo response as it occurs in primary care settings is lacking. Although there is controversy about the nature and scope of the placebo response, important suggestions are emerging about its psychological mechanisms (expectancy and conditioning) and the biochemical pathways that act as psychosomatic linkages (endorphins, catecholamines and cortisol, psychoneuroimmumunology). The available research justifies interventions by family physicians that maximize the placebo response in everyday patient encounters. These include the sustained partnership approach, working with patients on the narratives they construct to explain illness, listening to patients, providing them with satisfactory explanations, expressing care and concern, and enhancing their sense of control. Notable opportunities exist for family medicine investigators to expand the understanding of this phenomenon.
Topics: Endorphins; Family Practice; Humans; Models, Psychological; Physician-Patient Relations; Placebo Effect; Placebos; Research
PubMed: 10923577
DOI: No ID Found -
Homeopathy : the Journal of the Faculty... Jul 2014Samuel Hahnemann (1755-1843) known today as the founder of homoeopathy, was - as far as we know - the first physician who administrated placebos to his patient on a...
Samuel Hahnemann (1755-1843) known today as the founder of homoeopathy, was - as far as we know - the first physician who administrated placebos to his patient on a systematic and regular basis. This study is based upon unpublished documents (e.g. patients' letters) in the Archives of the Institute for the History of Medicine of the Robert Bosch Foundation in Stuttgart. It also profited from the critical edition of Hahnemann's case journals and the editorial comments which have also been published in this series. Hahnemann differentiated clearly between homeopathic drugs and pharmaceutical substances which he considered as sham medicine (e.g. milk sugar). A close look at Hahnemann's case journals reveals that the percentage of placebo prescriptions was very high (between 54 and 85 percent). In most instances Hahnemann marked placebos with the paragraph symbol (§). The rationale behind this practice was that Hahnemann had encountered the well-known problem that patients were used to taking medicine on a daily basis as it was typical for the age of heroic medicine. The main reason for giving placebo was therefore to please the impatient patient who was used to frequent medications in allopathic medicine, not only every day but sometimes also hourly.
Topics: Famous Persons; Germany; History, 18th Century; History, 19th Century; Homeopathy; Humans; Male; Materia Medica; Pharmaceutical Preparations; Placebo Effect; Placebos
PubMed: 24931754
DOI: 10.1016/j.homp.2014.03.003 -
Journal of the American Dental... Apr 2016
Topics: Anesthesia, Dental; Humans; Nocebo Effect; Placebo Effect; Placebos
PubMed: 27017587
DOI: 10.1016/j.adaj.2016.02.009 -
International Review of Neurobiology 2018
Topics: Animals; Biomedical Research; Humans; Placebo Effect; Placebos
PubMed: 29681338
DOI: 10.1016/S0074-7742(18)30027-8 -
European Neuropsychopharmacology : the... Nov 2012Substances and interventions with no specific therapeutic effect have been in use since the dawn of history. The term placebo has first been mentioned in the Scriptures,...
Substances and interventions with no specific therapeutic effect have been in use since the dawn of history. The term placebo has first been mentioned in the Scriptures, but it was not until the 19th century that it appeared in a medical context. Although lay people like Voltaire, and physicians such as Sir William Osler, have raised the possibility that much of what physicians did had no specific therapeutic effect, this notion was not shared by the public at large or by the medical profession. It was only by the end of the 18th century that a placebo-controlled trial has been conducted, repudiating the therapeutic effect of mesmerism. The advent, in the late 1940s, of effective treatments, which also had serious adverse effects, made the distinction between placebo and putative, active drug effects more relevant and urgent, and cleared the way for double-blind, randomized, placebo-controlled trials. This in turn triggered an ethical debate on the use of placebo, both in research and in clinical practice. Anthropologists, sociologists, physiologists, and medical researchers are all focusing their efforts on understanding the mechanism, role and modulating factors of placebo.
Topics: Controlled Clinical Trials as Topic; History, 16th Century; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; History, 21st Century; History, Ancient; Humans; Placebo Effect; Placebos; Psychopharmacology
PubMed: 22608298
DOI: 10.1016/j.euroneuro.2012.04.003 -
European Neuropsychopharmacology : the... Jul 2008An emerging literature has started to document the neuronal changes associated with the placebo phenomenon. This has altered placebo from being considered a nuisance... (Review)
Review
An emerging literature has started to document the neuronal changes associated with the placebo phenomenon. This has altered placebo from being considered a nuisance factor in clinical research to a target of scientific investigation per se. This paper reviews the neuroimaging literature on the placebo effect, and illustrates how imaging tools can improve current understanding of brain mechanisms underlying the placebo response. Imaging studies provide evidence of specific, predictable and replicable patterns of neural changes associated with placebo administration. In general, placebo responses seem mediated by "top-down" processes dependent on frontal cortical areas that generate and maintain cognitive expectancies. Dopaminergic reward pathways may underlie these expectancies. Placebo-induced clinical benefits also involve disorder-specific neuronal responses, yielding neurofunctional or neurochemical alterations similar to those produced by pharmacological treatments.
Topics: Brain; Humans; Immunologic Tests; Nervous System Diseases; Placebo Effect; Placebos
PubMed: 18495442
DOI: 10.1016/j.euroneuro.2008.03.002