Placebo For other uses, see Placebo (disambiguation) and Placebo effect The placebo effect can be produced by inert tablets, by sham surgery, A placebo (/pləˈsiboʊ/ plə-SEE-boh; Latin placēbō, "I shall please"^[2] to deceive the recipient. Sometimes patients given a placebo treatment phenomenon commonly called the placebo effect. In medical research, placebos are given as control treatments and depend on the use of measured deception. Common placebos include inert based on false information.^[1] However, placebos can also have a who knowingly did not get a placebo.^[4] In one common placebo procedure, however, a patient is given an inert in their condition. This phenomenon is known as the placebo effect. Placebos are widely used in medical research and medicine,^[5] and the placebo effect is a pervasive phenomenon;^[5] in fact, it is part of respectable, conscious use of placebos. The effect of placebos has been The placebo effect points to the importance of perception and the brain's role in physical health. However, the use of placebos as placebos... usually relies on some degree of patient deception" and "prescribing pure placebos is bad medicine. Their effect is unreliable Since the publication of Henry K. Beecher's The Powerful Placebo ^[9] baseline until the end of the trial to a placebo effect, but the reviewers examined studies which had both placebo and untreated groups in order to distinguish the placebo effect from the natural progression metastudy. The effect of placebo is very different in different + 3.2 Placebo effect and the brain + 7.1 Placebo-controlled studies + 7.3 Placebo ingredients A placebo has been defined as "a substance or procedure… that is placebos and exhibit a placebo effect. Pharmacological substances administered through any means can act as placebos, including pills, can act as placebos.^[13]^[14] Sham surgery,^[15]^[16]^[17] sham placebo effects.^[18] Bedding not treated to reduce allergies has been used as a placebo to control for treated bedding.^[19] The physician has even been called a placebo;^[20] a study found that patient have an effect".^[21] The placebo effect may be a component of prescribing a placebo merges into fake medicine. The placebo effect has sometimes been defined as a physiological effect caused by the placebo, but Moerman and Jonas have pointed out that this seems illogical, as a placebo is an inert substance that does not response" for the meaning that the brain associates with the placebo, which causes a physiological placebo effect. They propose that the placebo, which may be unethical, could be avoided entirely if doctors attempted to distinguish between the "true" and "perceived" placebo placebo effect could be due to other factors.^[23] The placebo effect has been controversial throughout history. Notable points out the "placebo paradox", – it may be unethical to use a placebo, but also unethical "not to use something that heals". He medicine, that is make use of the placebo effect, as long as the "one come from the "honest placebo" effect found in a 2010 study^[4] carried out by researchers in the Program in Placebo Studies at the Harvard the pills they were taking were placebos, as compared to a control Although the placebo effect and theories on its underlying mechanisms reduced by placebo treatments.^[25] Main article: Placebo in history The word 'placebo', Latin for "I will please", dates back to a Latin effect.^[28] Placebos were widespread in medicine until the 20th In 1903 Richard Cabot said that he was brought up to use placebos,^[24] nocebo.^[24] Beginning in the 1960s, the placebo effect became widely recognized and placebo controlled trials became the norm in the in understanding the placebo effect, rather than just controlling for its effects, and in 2011, a Program in Placebo Studies was established The placebo effect is highly variable in its magnitude and reliability A 2001 meta-analysis of clinical trials with placebo groups and no-treatment groups found no evidence for a placebo effect on in smaller trials that calls into question the apparent placebo effect Because the placebo response is simply the patient response that cannot possible components of a measured placebo effect. These components observations.^[32] While there is some evidence that placebo The placebo effect is related to the perceptions and expectations of placebo effects are produced by the self-fulfilling effects of response Placebos can act similarly through classical conditioning, wherein a placebo and an actual stimulus are used simultaneously until the placebo is associated with the effect from the actual stimulus.^[38] Both conditioning and expectations play a role in placebo effect,^[39] size and color of placebo pills, or the use of other interventions such as injections. In one study, the response to a placebo increased from display a stronger placebo effect than those that do not, as evidenced Because the placebo effect is based upon expectations and conditioning, are unrealistic, or that the placebo intervention is ineffective. A explained.^[45] It has also been reported of subjects given placebos in patients who had been given placebos were told as much, they quickly A placebo described as a muscle relaxant will cause muscle relaxation and, if described as the opposite, muscle tension.^[47] A placebo for this.^[51] Placebos represented as alcohol can cause ability,^[56] leading to the question of whether placebos should be allowed in sport competition.^[57] Placebos can help smokers quit.^[58] allergies.^[59] Interventions such as psychotherapy can have placebo Because placebos are dependent upon perception and expectation, various placebo response. For example, studies have found that the color and size of the placebo pill makes a difference, with "hot-colored" pills effect of placebo pills. Injection^[69] and acupuncture^[18] have larger effect than pills. Proper adherence to placebos is associated Motivation may contribute to the placebo effect. The active goals of an to treatment. Research into the placebo treatment of gastric and placebo effect in treating gastric ulcers is low in Brazil, higher in However, the placebo effect in treating hypertension is lower in Germany than elsewhere.^[73] Social observation can induce a placebo The placebo effect can work selectively, under the influence of various psychological factors. If a placebo cream is applied on one hand with placebo under one name, and they respond, they will respond in the same way on a later occasion to that placebo under that name but not if Placebo effect and the brain[edit] Functional imaging upon placebo analgesia shows that it links to the pulses, for example, finds placebo effects upon the N2–P2, a biphasic placebo analgesia but after receiving the analgesic placebo (the areas prefrontal involvement could be related to recalling the placebo and loop" (during pain an individual recalls having taken the placebo and placebo responses link with enhanced dopamine and mu-opioid activity in of dopamine and opioid release.^[78] (It has been known that placebo since 1978.^[88]) Such analgesic placebos activation changes processing placebo effects: * Parkinson's disease: Placebo relief is associated with the release * Depression: Placebos reducing depression affect many of the same * Caffeine: Placebo-caffeinated coffee causes an increase in Present functional imaging upon placebo analgesia has been summarized as showing that the placebo response is "mediated by "top-down" or cortically based regulation may be less prone to placebo-related The brain has control over the body processes affected by placebos. humans^[citation needed]. Recent reviews have argued the placebo effect substrates that might explain the link between placebo/conditioned and placebo/expectation responses."^[98]^:441 A recent fMRI study has shown that a placebo can reduce pain-related neural activity in the spinal cord, indicating that placebo effects can receiving care and treatment. The placebo effect in this perspective Placebo effects can last for a long time: over 8 weeks for panic years for rheumatoid arthritis.^[104] Placebo effects after verbal follow-up study in 2004^[31] questioning the nature of the placebo as improved or not improved, the placebo group had no statistically was no significant placebo effect in studies in which objective observer. The placebo effect could be documented only in studies in the subjects themselves. The authors concluded that the placebo effect meta-analysis and concluded that the placebo effects for objective symptom measures are comparable to placebo effects for subjective ones and that the placebo effect can exceed the effect of the active treatment by 20% for disorders amenable to the placebo that placebo effects are indeed significant but small in organs the placebo effect seems to be more effective in achieving failure.^[109] Placebos also do not work as strongly in clinical trials treatment or a sham one. Where studies are made of placebos in which its possibility) the placebo effect has been observed.^[110] Other writers have argued that the placebo effect can be reliably included. Placebo interventions were again not found to have important "difficult to distinguish patient-reported effects of placebo from response bias". The pooled relative risk they calculated for placebo intervals were wide. Several clinical (physical placebos, placebo) and methodological (small sample size, explicit aim of studying the placebo effect) factors were associated with higher effects of placebo. Despite low effects in general and the risk of bias, the authors acknowledged that large effects of placebo Similar to the placebo effect, inert substances have the potential to Another negative consequence is that placebos can cause side-effects when given it again in the form of a placebo.^[115] Withdrawal symptoms can also occur after placebo treatment. This was had been on placebo for an average of 5.7 years. Moderate or severe withdrawal symptoms were reported by 40.5% of those on placebo compared placebo at least 10 times in the past year.^[5] The most frequently prescribed placebos were antibiotics for viral infections, and vitamins lower rates of placebo use. A 2004 study in the British Medical Journal of physicians in Israel found that 60% used placebos in their medical argued that open provision of placebos for treating ADHD in children a research test subject) that a placebo is a real medication is Critics also argued that using placebos can delay the proper diagnosis The following impracticalities exist with placebos: (See the BMJ posted * Roughly only 30% of the population seems susceptible to placebo a placebo will work or not. (However the placebo effect is zero in illness or symptoms. A non-placebo can often provide that, while a placebo might not. placebos as a diagnostic tool to determine if a patient's symptoms were of the medical use of placebos agreed that this was unethical. The relief from a placebo does not imply that the pain is not real or organic in origin...the use of the placebo for 'diagnosis' of whether The placebo administration may prove to be a useful treatment in some these can cause further respiratory depression. In such cases placebo In the Committee's view, homeopathy is a placebo treatment and the Government should have a policy on prescribing placebos. The prescribing placebos to patients, which usually relies on some degree of patient deception. Prescribing of placebos is not relationship, prescribing pure placebos is bad medicine. Their that is a placebo simply because the patient wanted treatment, 58% Placebos do not work for everyone.^[122]^[123] Henry K. Beecher, in a paper in 1955,^[9] suggested placebo effects occurred in about 35% of nearly everyone. In a dental postoperative pain model, placebo placebo analgesia was found in 27%.^[122] The placebo analgesia rate Though not everyone responds to a placebo, neither does everyone relief following placebo (39%) is similar to the percentage following a specific personality to those that responded to placebos. The expected to be relieved increases placebo analgesia.^[71] Another factor increasing the effectiveness of placebos is the degree to which variation in response to analgesic placebos has been linked to regional placebos, and this is attributed to the loss of their prefrontal cortex Children seem to have greater response than adults to placebos.^[130] susceptibility to the placebo effect.^[131]^[132]^[133] The authors placebo effect among the patients with irritable bowel syndrome placebo treatment, while the variation of val/val, for their two copies The placebo effect occurs more strongly in some conditions than others. Dylan Evans has suggested that placebos work most strongly upon The placebo effect is believed to reduce pain in two different ways. One way is by the placebo initiating the release of endorphins, which the placebo changing the patient's perception of pain. "A person might Placebo analgesia is more likely to work the more severe the reduced group average pain compared to no placebo by ~46% to ~57%.^[75] Another measure is the ability to endure pain. In one study, placebos 14 minutes without it.^[139] The average strength of placebos upon pain who respond to placebos may show even greater effects, up to 5 out of placebo effect and other non-specific effects, rather than the placebo is not clinically significant except in cases of very extreme depressed patients receiving placebo remained well (for 12 weeks after reduction in suicide and attempted suicide in the placebo groups A meta-study of 31 placebo-controlled trials of the gastric acid duodenal ulcers found that placebo treatments, in many cases, were as the 776 treated with placebo were "healed".^[11]^[146] These results found that German placebos were "stronger" than others; and that, overall, different physicians evoked quite different placebo responses the gap between the active drugs and the placebo controls was "not because they had low placebo effectiveness".^[146]^:13 In some trials, placebos were effective in 90% of the cases, whereas in others the placebos were effective in only 10% of the cases. It was healing in drug groups but reduced healing in placebo those "healed" by the placebo treatment.^[146]^:14–15 It was previously assumed that placebo response rates in patients with placebo group was 19.6%, even lower than in some other medical expectations of improvement. In context of evidence showing placebos do improvement rates in the placebo group. Intervention type also particularly low placebo responses to psychiatric treatments.^[147] The effect of placebo treatments (an inert pill unless otherwise noted) effective, but that placebo effects exist as well. * Depression (light treatment; low red light placebo)^[161] Placebo-controlled studies[edit] Main article: Placebo-controlled studies The placebo effect makes it more difficult to evaluate new treatments. The placebo effect in such clinical trials is weaker than in normal treatment but from the placebo effect. This is particularly likely, given that new therapies seem to have greater placebo effects.^[194] are blinded as to whether they receive the treatment or a placebo. If a person is given a placebo under one name, and they respond, they will respond in the same way on a later occasion to that placebo under that subjects are receiving the active or placebo treatment.The placebo Knowingly giving a person a placebo when there is an effective placebo-controlled trials might provide information about the that some test subjects will receive placebo treatments. The ethics of placebo-controlled studies have been debated in the concern has been the difference between trials comparing inert placebos as the placebo effect, e.g., when members of a control group receiving the inert substance may nullify the placebo effect intended by simply Placebo ingredients[edit] Placebos used in clinical trials have sometimes had unintended at details from 150 clinical trials found that certain placebos used in cholesterol-lowering drugs used olive oil and corn oil in the placebo fatty acids of these 'placebos,' and their antioxidant and placebo that was used included lactose. However, since cancer patients typically face a higher risk of lactose intolerance, the placebo pill placebo". Minerva Med 96 (2): 121–4. PMID 16172581. "Placebos without Deception: A Randomized Controlled Trial in 5. ^ ^a ^b ^c Hróbjartsson A, Norup M (June 2003). "The use of placebo 6. ^ ^a ^b Eccles R (2002). "The powerful placebo in cough studies?". 9. ^ ^a ^b Beecher, H. K. (1955). "The powerful placebo". Journal of placebo powerless? An analysis of clinical trials comparing placebo placebo effect and finding the meaning response". Ann Intern Med. 12. ^ Hróbjartsson A, Gøtzsche PC (20 January 2010). "Placebo "Reduction of post-operative swelling by a placebo effect". Journal major placebo effect". British Journal of Rheumatology 25 (1): placebo effect". The New England Journal of Medicine 300 (25): placebo treatments". BMJ 332 (7538): 391–7. treatment of atopic dermatitis—a placebo-controlled trial of 12 20. ^ Margo CE (1999). "The placebo effect". Surv Ophthalmol. 44 (1): placebo effects". BMJ 311 (7004): 551–3. (October 1999). "Placebos and placebo effects in medicine: 25. ^ Muã±Ana, K. R.; Zhang, D.; Patterson, E. E. (2010). "Placebo 26. ^ Jacobs B. (2000). "Biblical origins of placebo". J R Soc Med. 93 27. ^ Shapiro AK (1968). "Semantics of the placebo". Psychiatr Q. 42 28. ^ Kaptchuk TJ (1998). "Powerful placebo: the dark side of the 29. ^ Beecher HK (July 1961). "Surgery as placebo. A quantitative study Assessment and Placebo Controls in Medicine. Bulletin of the 31. ^ ^a ^b Hróbjartsson A, Gøtzsche PC (2004). "Is the placebo trials comparing placebo with no treatment". J. Intern. Med. 256 32. ^ Kienle GS, Kiene H (December 1997). "The powerful placebo effect: 33. ^ Kokkotou E et al. Serum correlates of the placebo effect in (November 2005). "Neurobiological mechanisms of the placebo placebo 'effect' is really statistical regression?". Stat Med 2 models of placebo phenomena: further support". Pain 38 (1): 109–16. 39. ^ Stewart-Williams S, Podd J (2004). "The placebo effect: conditioning and expectancy in placebo hypoalgesia: a randomized neurophysiological and behavioral placebo analgesic responses". "Components of placebo effect: randomised controlled trial in placebo-controlled trials". Eval Health Prof. 28 (1): 9–26. the placebo effect". Pain 72 (1–2): 107–13. generates placebo and nocebo responses that modify the drug mechanism of the placebo effect". In Harrington A. The Placebo administration of a placebo. Behavioral Neuroscience, 102(2), placebo responses to caffeine-associated stimuli". alcohol placebos in inducing feelings of intoxication". drug and its expected effect interact to determine placebo placebo effects resulting from the deceptive administration of an Moerman DE, Jonas WB (19 March 2002). "Deconstructing the placebo influence of ergogenic placebos on muscle work and fatigue". Eur. 57. ^ Benedetti F, Pollo A, Colloca L (2007). "Opioid-mediated placebo placebo effects in nicotine replacement therapy for smoking 60. ^ ^a ^b Evans, Dylan (2003). Placebo: the belief effect. London: and medical outcomes in a double-blind placebo surgery trial". Arch characteristics to efficacy of placebos". Psychol. Rep. 49 (3): 64. ^ Dolinska B (1999). "Empirical investigation into placebo medical students of placebo responses and non-drug factors". Lancet placebo analgesia". Pain 124 (1–2): 126–33. of placebo and therapeutic efficacy". JAMA 299 (9): 1016–7. (2005). "Goal activation, expectations, and the placebo effect". J "Expectations and placebo response: a laboratory investigation into 73. ^ ^a ^b ^c Moerman DE (2000). "Cultural variations in the placebo 74. ^ Colloca L, Benedetti F (2009). "Placebo analgesia induced by placebo effect". J Psychosom Res 64 (5): 537–41. 77. ^ Oken BS (2008). "Placebo effects: clinical aspects and Zubieta JK (2008). "Placebo and nocebo effects are defined by 79. ^ Lidstone SC, Stoessl AJ (2007). "Understanding the placebo 81. ^ Matre D, Casey KL, Knardahl S (2006). "Placebo-induced changes in study of placebo analgesia in humans". Neurosci Bull 25 (5): of Placebo Responses". Ann N Y Acad Sci 1156: 198–210. 84. ^ Nemoto H, Nemoto Y, Toda H, Mikuni M, Fukuyama H (2007). "Placebo processing during pain and placebo analgesia". Neuroimage 38 (4): "Mechanisms of placebo analgesia: rACC recruitment of a subcortical Kosslyn SM, Rose RM, Cohen JD (2004). "Placebo-induced changes in 88. ^ Levine JD, Gordon NC, Fields HL (1978). "The mechanism of placebo the placebo effect in Parkinson's disease". Science 293 (5532): S, Jerabek PA (2002). "The functional neuroanatomy of the placebo with placebo". Am J Psychiatry 159 (1): 122–9. (2008). "Effects of intravenous placebo with glucose expectation on responses to methylphenidate and to its placebo in non-drug abusing 95. ^ Faria V, Fredrikson M, Furmark T (2008). "Imaging the placebo 96. ^ Diederich NJ, Goetz CG (2008). "The placebo treatments in "Expectations and associations that heal: Immunomodulatory placebo 99. ^ Colloca L, Benedetti F (2005). "Placebos and painkillers: is mind evidence for spinal cord involvement in placebo analgesia". Science Psychology of Faith-Healing and the Placebo Effect". The Mind Made 102. ^ Coryell W, Noyes R (1988). "Placebo response in panic disorder". (1986). "Time course of long-term placebo therapy effects in angina 104. ^ Traut EF, Passarelli EW (1957). "Placebos in the Treatment of "The placebo is powerful: estimating placebo effects in medicine 106. ^ Wampold BE, Imel ZE, Minami T (2007). "The placebo effect: conclusion of Wampold et al.'s re-analysis of placebo versus the placebo effect: mountain or Molehill?". J Clin Psychol 63 (4): 109. ^ Meissner K, Distel H, Mitzdorf U (2007). "Evidence for placebo placebo effects in clinical analgesic trials versus studies of placebo analgesia". Pain 99 (3): 714–5. 111. ^ Barfod TS (2005). "Placebos in medicine: Placebo use is well known, placebo effect is not". BMJ 330 (7481): 45. 112. ^ Hróbjartsson A, Gøtzsche PC (January 2010). "Placebo 114. ^ Shapiro AK, Chassan J, Morris LA, Frick R (1974). "Placebo prior opioid exposure on placebo analgesia and placebo respiratory survey on use of placebo". BMJ 329 (7472): 944–6. 118. ^ ^a ^b Spiegel D (October 23, 2004). "Placebos in practice: 119. ^ ^a ^b Sandler AD, Bodfish JW (2008). "Open-label use of placebos on placebo analgesia". Pain 64 (3): 535–43. "Role of pain in placebo analgesia". Proc Natl Acad Sci U S A 76 124. ^ Petrovic P, Kalso E, Petersson KM, Ingvar M (2002). "Placebo and "Analgesic responses to morphine and placebo in individuals with 126. ^ Doongaji DR, Vahia VN, Bharucha MP (1978). "On placebos, placebo responses and placebo responders. (A review of psychological, the placebo: what we have learned". Perspect Biol Med 48 (2): the placebo effect". Brain Behav Immun 20 (1): 15–26. 2008). "Greater Response to Placebo in Children Than in Adults: A activity, and placebo-induced relief from social anxiety". J. 132. ^ "The Placebo Effect: Not All in Your Head", ScienceNOW Daily 133. ^ "First 'placebo gene' discovered", New Scientist, 03 December Placebo Effect, Researchers Say". Bloomberg. Retrieved 1 November Polymorphism Predicts Placebo Effect in Irritable Bowel Syndrome". 137. ^ Placebo Effect. Cancer.org. Retrieved on 2013-08-25. (1979). "Role of pain in placebo analgesia". Proceedings of the dissection of placebo analgesia: Expectation-activated opioid hearing placebo: A meta-analysis of antidepressant medication. placebo response in antidepressant clinical trials". Journal of suicide risk in patients treated with placebo in antidepressant and the Placebo Effect. Cambridge University Press. 147. ^ Cho HJ, Hotopf M, Wessely S (2005). "The placebo response in the placebo". Drug Alcohol Depend 81 (2): 137–48. (1997). "Placebo response in environmental disease. Chelation 150. ^ Schweizer E, Rickels K. (1997). "Placebo response in generalized 151. ^ Piercy MA, Sramek JJ, Kurtz NM, Cutler NR (1996). "Placebo 152. ^ Butler C, Steptoe A (1986). "Placebo responses: an experimental SM, Kline JN (2007). "Placebo response in asthma: a robust and IO, Kirsch I, Wechsler ME (2008). "Do "placebo responders" exist?". 155. ^ Sandler A (2005). "Placebo effects in developmental 159. ^ Sysko R, Walsh BT (2007). "A systematic review of placebo "A meta-analysis of the placebo rates of remission and response in 163. ^ Andrews G (2001). "Placebo response in depression: bane of 164. ^ Moncrieff J, Wessely S, Hardy R (2004). "Active placebos versus "Placebo in functional dyspepsia: symptomatic, gastrointestinal characteristics of placebo responders versus nonresponders in 168. ^ Moerman DE (2000). "Cultural variations in the placebo effect: importance of placebo in headache research". Cephalagia 28 (10): 170. ^ Archer TP, Leier CV (1992). "Placebo treatment in congestive 172. ^ Asmar R, Safar M, Queneau P (2001). "Evaluation of the placebo (2005). "The placebo effect in irritable bowel syndrome trials: a of the placebo response in irritable bowel syndrome". Clin 175. ^ Macedo A, Baños JE, Farré M (2008). "Placebo response in the placebo-effect exist in clinical trials on multiple sclerosis? PLACEBOS". J Clin Invest 29 (1): 100–9. doi:10.1172/JCI102225. 178. ^ Zhang Z, Wang Y, Wang Y, Xu F (2008). "Antiemetic placebo: acetylsalicylic acid) and the problem of placebo "reactors" and placebo effect". Can J Psychiatry 48 (6): 381–7. PMID 12894612. 182. ^ de la Fuente-Fernández R, Stoessl AJ (2002). "The placebo effect Leurgans S (2008). "Placebo response in Parkinson's disease: placebo-controlled, flexible-dose study". J Clin Psychopharmacol 27 "Meta-analysis of the effect of placebo on the outcome of medically meta-analysis of the placebo effect in restless legs syndrome 189. ^ Pollo A, Benedetti F (2008). "Placebo response: relevance to the 190. ^ Bradford A, Meston C (2007). "Correlates of Placebo Response in "The placebo response in social phobia". J Psychopharmacol 15 (3): "Quantification of the placebo response in ulcerative colitis". vestibulitis: results of a placebo controlled study". Sex Transm "Placebos without deception: a randomized controlled trial in placebo effect". J Psychosom Res 64 (5): 537–41. Superiority of 'Placebo' over 'Active' Controlled Trials". Am J placebos". J Eval Clin Pract 16 (6): 1041–4. (2010). "What's in placebos: who knows? Analysis of randomized, Look up placebo in Wiktionary, the free dictionary. Wikiquote has a collection of quotations related to: Placebo effect * Harvard-wide Program in Placebo Studies & the Therapeutic Encounter * The Placebo Effect at the Skeptic's Dictionary * The Placebo Effect explained on YouTube * Placebos: cracking the code part 1 part 2 BBC/Discovery channel * "Placebos are getting more effective. Drugmakers are desperate to know why." Wired magazine on the power of the placebo. Retrieved * Biological, clinical, and ethical advances of placebo effects The "http://en.wikipedia.org/w/index.php?title=Placebo&oldid=587332645"