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The American Journal of Medicine Sep 2019
Topics: Bias; Humans; Medication Adherence; Nocebo Effect; Placebo Effect
PubMed: 30998924
DOI: 10.1016/j.amjmed.2019.03.037 -
The Canadian Journal of Cardiology Dec 2017The placebo effect is the clinical benefit caused by interaction with a caregiver and health care system in the absence of a biologically active intervention and has... (Review)
Review
The placebo effect is the clinical benefit caused by interaction with a caregiver and health care system in the absence of a biologically active intervention and has been used successfully for millennia. The placebo response results from the interaction of psychosocial mechanisms, human relationships, and preconceptions functioning in specific neuroanatomic locations with known genes and neurotransmitters. It occurs with or without the administration of an inactive substance to deliberately deceive patients. Our purpose is to review the history, benefits, and mechanisms of the placebo effect. The placebo response results from classic conditioning and positive expectations about outcome expressed by the caregiver. The outcomes are usually symptoms such as pain rather than biological outcomes such as death, and the powerful placebo may account for more than half the effect of treatment in many situations. The placebo effect results from activation of opioid, cannabinoid, and dopaminergic pathways involved in reward, expectancy, conditioning, and pain modulation. Eleven specific anatomic features in the brain identified by positron emission tomography and magnetic resonance imaging are involved. Polymorphisms in the structural genes for catecholamine O-methyltransferase and fatty acid amide oxidase significantly influence the placebo response. The placebo effect may be important in symptom suppression in angina, paroxysmal atrial fibrillation, and congestive heart failure. In the absence of deliberate deception, there are no ethical issues and given its potency, the time has come to consider how best to use the placebo in clinical practice.
Topics: Cardiology; Cardiovascular Diseases; Clinical Trials as Topic; Humans; Placebo Effect
PubMed: 29173596
DOI: 10.1016/j.cjca.2017.09.017 -
Menopause (New York, N.Y.) Jan 2023
Topics: Humans; Artifacts; Hot Flashes; Menopause; Placebo Effect; Treatment Outcome; Female
PubMed: 36413712
DOI: 10.1097/GME.0000000000002122 -
Handbook of Clinical Neurology 2021The study of the placebo effect, or response, is related to the investigation of the psychologic component of different therapeutic rituals. The high rate of placebo... (Review)
Review
The study of the placebo effect, or response, is related to the investigation of the psychologic component of different therapeutic rituals. The high rate of placebo responses in Parkinson's disease clinical trials provided the impetus for investigating the underlying mechanisms. Ruling out spontaneous remission and regression to the mean through the appropriate experimental designs, genuine psychologic placebo effects have been identified, in which both patients' expectations of therapeutic benefit and learning processes are involved. Specifically, placebo effects are associated with dopamine release in the striatum and changes in neuronal activity in the subthalamic nucleus, substantia nigra pars reticulata, and motor thalamus in Parkinson's disease, as assessed through positron emission tomography and single-neuron recording during deep brain stimulation, respectively. Conversely, verbal suggestions of clinical worsening or drug dose reduction induce nocebo responses in Parkinson's disease, which have been detected at both behavioral and electrophysiologic level. Important implications and applications emerge from this new knowledge. These include better clinical trial designs, whereby patients' expectations should always be assessed, as well as better drug dosage in order to reduce drug intake.
Topics: Deep Brain Stimulation; Humans; Nocebo Effect; Parkinson Disease; Placebo Effect; Subthalamic Nucleus; Thalamus
PubMed: 34225946
DOI: 10.1016/B978-0-12-820107-7.00027-6 -
The American Journal of Medicine Nov 2022The placebo effect can be defined as any improvement of illnesses or reduction of subjective symptoms that result from interventions possessing no known physical... (Review)
Review
The placebo effect can be defined as any improvement of illnesses or reduction of subjective symptoms that result from interventions possessing no known physical effects. By contrast, the nocebo effect refers to undesirable symptoms or illnesses that follow interventions also lacking known physical effects. It may also play a role in chronic illnesses that lack objective confirmation. Both placebo and nocebo effects can be potent and must be understood by both practitioners and researchers for proper application in clinical medicine. Individual caregivers can apply these principles to modify results in the daily care of patients.
Topics: Humans; Nocebo Effect; Placebo Effect; Clinical Medicine; Physical Examination
PubMed: 35820462
DOI: 10.1016/j.amjmed.2022.06.007 -
Hormones (Athens, Greece) Mar 2021The clinical role of the placebo effect is a topic of increasing interest for the scientific community. Focus is shifting from the inert role of placebos in randomized... (Review)
Review
The clinical role of the placebo effect is a topic of increasing interest for the scientific community. Focus is shifting from the inert role of placebos in randomized controlled trials (RCTs) to potential effects in clinical applications, since the phenomenon is thought to be inherent in routine clinical practice, affecting therapy success rates. Mediation of the mind-brain-body relationship involves both psychosocial and neurobiological factors, the interaction of which comprises the placebo mechanisms. Psychosocial factors include environmentally induced expectations, reward expectations, and even conditioned responses to certain stimuli. Expectations also depend on previous experience of the patient with a similar procedure and can affect future responses. Moreover, the supportive bedside behavior of the clinician and the positive framing of information provided to the patient have proven to be of great importance, setting the foundations for reconsideration of standardized practices. Neurobiological mechanisms mediate these effects through neurotransmitter and neuromodulator pathways. The best understood mechanisms are those regulating non-opioid- and opioid-mediated analgesic responses that implicate specific brain regions of pain control and activation of endogenous opioids. Other responses concern, among others, hormonal control, motor performance, and antidepressant responses. Although mechanisms underlying placebo responses are not as yet completely elucidated, there is substantial evidence suggesting that placebo effects are indicative of healthy functioning of intact brain structures and occur through actual functional changes, and are not simply subjective symptom reports. These effects can be utilized in treatment optimization while maintaining an ethical and respectful manner toward the patient and the standardized disclosure procedures.
Topics: Analgesics; Brain; Humans; Placebo Effect; Psychology
PubMed: 32940864
DOI: 10.1007/s42000-020-00243-5 -
Journal of Neurotrauma Jun 2018In recent years, several randomized controlled trials evaluating pharmaceutical treatments for traumatic brain injury (TBI) have failed to demonstrate efficacy over... (Review)
Review
In recent years, several randomized controlled trials evaluating pharmaceutical treatments for traumatic brain injury (TBI) have failed to demonstrate efficacy over placebo, with both active and placebo arms improving at comparable rates. These findings could be viewed in opposing ways, suggesting on the one hand failure of the tested outcome, but on the other, representing evidence of robust placebo effects in TBI. In this article, we examine several of the primary psychological processes driving placebo effects (verbal suggestion, cognitive re-framing, interpersonal interactions, conditioning, therapeutic alliance, anxiety reduction) as well as placebo neurobiology (top-down cortical regulation, reward system activation, dopaminergic and serotonergic neurotransmission). We then extrapolate from the literature to explore whether something inherent in TBI makes it particularly responsive to placebos. Viewed as such here, placebos may indeed represent a powerful and effective treatment for a variety of post-TBI complaints.
Topics: Brain Injuries, Traumatic; Humans; Placebo Effect
PubMed: 29343158
DOI: 10.1089/neu.2017.5506 -
Clinical and Experimental Rheumatology 2019Osteoarthritis (OA) is the most common form of arthritis. Pain and its related function and stiffness are currently the major symptoms and primary outcomes for... (Review)
Review
Osteoarthritis (OA) is the most common form of arthritis. Pain and its related function and stiffness are currently the major symptoms and primary outcomes for treatment. However, the treatment in the past has been primarily targeting on the peripheral changes in the joint that has led to suboptimal outcomes. Recently, we find that people with OA respond better to treatment which targets on both peripheral and central pain abnormalities. We also find that placebo per se is very effective for OA. On average 75% pain reduction, 71% functional improvement and 83% stiffness improvement in the treatment of OA are attributable to the placebo/contextual effect. The effect varies between treatments, for example for pain, from 47% with intra-articular corticosteroid injection to 91% with joint lavage. This begs a question on how to improve the overall treatment effect of an OA therapy in clinical practice by enhancing the contextual effect, rather than to separate a specific treatment effect from the contextual effect as we normally do in clinical trials. The enhancement may be achieved by improving contextual factors such as patient-physician interaction or quality of care. Further research on the development of a simple contextual enhancement package that may be delivered by all physicians according to individual needs would be very helpful.
Topics: Adrenal Cortex Hormones; Humans; Injections, Intra-Articular; Osteoarthritis; Osteoarthritis, Knee; Pain Measurement; Placebo Effect
PubMed: 31621561
DOI: No ID Found -
International Review of Neurobiology 2018The placebo effect is closely related to many other constructs, including most prominently, conditioning and expectancy, but also natural history, regression to the... (Review)
Review
The placebo effect is closely related to many other constructs, including most prominently, conditioning and expectancy, but also natural history, regression to the mean, priming, mindset, context effects, the meaning response, specific and non-specific clinical effects, placebo-related effects, the patient-clinician relationship, and the common factors in psychotherapy. How are these various terms related to one another? To what degree do they overlap, and to what degree do they diverge? To form a better theoretical understanding of these constructs and to foster improved empirical research, is it better to lump these terms together in some fashion? Or will progress best be served by maintaining the splits between the constructs? Or would it perhaps be most effective to employ some mixture of lumping and splitting? I will address these and related questions with two major goals: (1) to delineate and clarify the relationship between these various terms and (2) to suggest some possible re-alignments in the way in which we conceptualize the relationships among these constructs that might prove useful in fostering research on placebo and related effects. In addition, clarifying the interconnections between the placebo effect and other related terms has the potential to spark innovative cross-fertilizations between related areas of research.
Topics: Classification; Conditioning, Psychological; Humans; Physician-Patient Relations; Placebo Effect; Placebos
PubMed: 30146051
DOI: 10.1016/bs.irn.2018.07.011 -
Cephalalgia : An International Journal... Dec 2023Treatments in medicine impact individuals beyond their intended effects, due to phenomena such as the placebo and nocebo effects. The placebo effect arises from the... (Review)
Review
PURPOSE
Treatments in medicine impact individuals beyond their intended effects, due to phenomena such as the placebo and nocebo effects. The placebo effect arises from the positive expectation of a treatment being beneficial, while the nocebo effect stems from the negative expectation of a treatment causing harm. Both in real-world practice and clinical trials, treatments can lead to outcomes unrelated to their intended mechanism of action, which we categorize as placebo and nocebo responses. These responses, combined with the inherent fluctuation in a condition's natural progression, regression to the mean, and random comorbidities, make up a significant part of the therapeutic experience. Particularly in pain management, placebo and nocebo effects play a substantial role. By addressing modifiable contextual factors such as patient expectations, lifestyle choices, and the therapeutic relationship, healthcare providers can enhance the effectiveness of migraine treatments, paving the way for a more comprehensive, individualized approach to patient care. We must also consider non-modifiable factors like personal experiences, beliefs, and information from social media and the internet.
CONCLUSION
This review offers a summary of our current understanding of the placebo and nocebo effects in migraine management.
Topics: Humans; Nocebo Effect; Migraine Disorders; Placebo Effect; Pain Management
PubMed: 38041833
DOI: 10.1177/03331024231218392