CINXE.COM

<!DOCTYPE html> <html class="client-nojs" lang="en" dir="ltr"> <head> <meta charset="UTF-8"/> <title>Placebo effect - RationalWiki</title> <script>document.documentElement.className="client-js";RLCONF={"wgBreakFrames":!1,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy","wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"Z-q57HZ4BkAg7_rwq4OB-QAAAEY","wgCSPNonce":!1,"wgCanonicalNamespace":"","wgCanonicalSpecialPageName":!1,"wgNamespaceNumber":0,"wgPageName":"Placebo_effect","wgTitle":"Placebo effect","wgCurRevisionId":2721902,"wgRevisionId":2721902,"wgArticleId":6947,"wgIsArticle":!0,"wgIsRedirect":!1,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["Pages using DynamicPageList parser function","Psychology","Bronze-level articles","Biology","Medicine","Alternative medicine","Research terms"],"wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Placebo_effect","wgRelevantArticleId":6947,"wgIsProbablyEditable":!0, "wgRelevantPageIsProbablyEditable":!0,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgRedirectedFrom":"Placebo","wgMediaViewerOnClick":!0,"wgMediaViewerEnabledByDefault":!0,"wgInternalRedirectTargetUrl":"/wiki/Placebo_effect"};RLSTATE={"site.styles":"ready","noscript":"ready","user.styles":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","ext.embedVideo.styles":"ready","skins.vector.styles.legacy":"ready","mediawiki.toc.styles":"ready"};RLPAGEMODULES=["mediawiki.action.view.redirect","ext.cite.ux-enhancements","ext.embedVideo","site","mediawiki.page.startup","mediawiki.page.ready","mediawiki.toc","skins.vector.legacy.js","ext.gadget.ReferenceTooltips","mmv.head","mmv.bootstrap.autostart"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.implement("user.options@1hzgi",function($,jQuery,require,module){/*@nomin*/mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); });});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cext.embedVideo.styles%7Cmediawiki.toc.styles%7Cskins.vector.styles.legacy&only=styles&skin=vector"/> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector"></script> <meta name="ResourceLoaderDynamicStyles" content=""/> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector"/> <meta name="generator" content="MediaWiki 1.35.6"/> <meta name="description" content="The placebo effect is a psychosomatic phenomenon in which symptoms of a disease or condition lessen — or even appear to be cured completely — from the patient being merely exposed to a treatment, as a result of the body releasing endorphins.&#91;1&#93; Believing that their condition will be improved, they will begin to feel better and perhaps identifiable symptoms may disappear, irrespective of whether the treatment has any chemical or pharmacological effect. Because of this, controlling for the placebo effect is an essential part of medicine. For example, sugar pills or saline solutions, which have no pharmacological properties, are commonly prescribed as placebo treatments to control for the effect of the simple act of intervening in a patient's illness."/> <link rel="alternate" type="application/x-wiki" title="Edit" href="/w/index.php?title=Placebo_effect&action=edit"/> <link rel="edit" title="Edit" href="/w/index.php?title=Placebo_effect&action=edit"/> <link rel="shortcut icon" href="/favicon.ico"/> <link rel="search" type="application/opensearchdescription+xml" href="/w/opensearch_desc.php" title="RationalWiki (en)"/> <link rel="EditURI" type="application/rsd+xml" href="https://rationalwiki.org/w/api.php?action=rsd"/> <link rel="license" href="/wiki/RationalWiki:Copyrights"/> <link rel="alternate" type="application/atom+xml" title="RationalWiki Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"/> <link rel="canonical" href="https://rationalwiki.org/wiki/Placebo_effect"/> <meta property="og:type" content="article"/> <meta property="og:site_name" content="RationalWiki"/> <meta property="og:title" content="Placebo effect"/> <meta property="og:description" content="The placebo effect is a psychosomatic phenomenon in which symptoms of a disease or condition lessen — or even appear to be cured completely — from the patient being merely exposed to a treatment, as a result of the body releasing endorphins.&#91;1&#93; Believing that their condition will be improved, they will begin to feel better and perhaps identifiable symptoms may disappear, irrespective of whether the treatment has any chemical or pharmacological effect. Because of this, controlling for the placebo effect is an essential part of medicine. For example, sugar pills or saline solutions, which have no pharmacological properties, are commonly prescribed as placebo treatments to control for the effect of the simple act of intervening in a patient's illness."/> <meta property="og:url" content="https://rationalwiki.org/wiki/Placebo_effect"/>  </head> <body class="mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Placebo_effect rootpage-Placebo_effect skin-vector action-view minerva--history-page-action-enabled skin-vector-legacy"> <div id="mw-page-base" class="noprint"></div> <div id="mw-head-base" class="noprint"></div> <div id="content" class="mw-body" role="main"> <a id="top"></a> <div id="siteNotice" class="mw-body-content"><div id="localNotice" lang="en" dir="ltr"><div id="2025_RationalWiki_.27Oregon_Plan.27_Fundraiser"> <table role="presentation" style="margin: 1em auto 1em auto; width: 100%;"> <tbody><tr> <td style="width: 60%; text-align: left;"><big><center><b><a href="/wiki/RationalWiki:Fundraiser" title="RationalWiki:Fundraiser">2025 RationalWiki 'Oregon Plan' Fundraiser</a></b></center></big> <p><b>There is no RationalWiki without you.</b> We are a small non-profit with no staff—we are hundreds of volunteers who document pseudoscience and crankery around the world every day. We will never allow ads because we must remain independent. We cannot rely on big donors with corresponding big agendas. We are not the largest website around, but <a href="/wiki/RationalWiki:Fundraiser" title="RationalWiki:Fundraiser">we believe we play an important role in defending truth and objectivity</a>. </p> </td> <td style="width: 40%; text-align: center;"><big><b><a href="/wiki/RationalWiki:Fundraiser" title="RationalWiki:Fundraiser">Fighting pseudoscience isn't free</a>.<br />We are 100% user-supported! Help and donate $5, $10, $20 or whatever you can today with <img alt="PayPal Logo.png" src="/w/images/thumb/f/fb/PayPal_Logo.png/61px-PayPal_Logo.png" decoding="async" width="61" height="17" srcset="/w/images/thumb/f/fb/PayPal_Logo.png/92px-PayPal_Logo.png 1.5x, /w/images/thumb/f/fb/PayPal_Logo.png/122px-PayPal_Logo.png 2x" data-file-width="883" data-file-height="244" />!</b></big><a href="https://www.paypal.com/donate/?hosted_button_id=67BJMQC85CUFW" title="Donate via PayPal" rel="nofollow"><img alt="" src="/w/images/thumb/1/10/DonateButton.png/100px-DonateButton.png" decoding="async" width="100" height="32" srcset="/w/images/thumb/1/10/DonateButton.png/150px-DonateButton.png 1.5x, /w/images/thumb/1/10/DonateButton.png/200px-DonateButton.png 2x" data-file-width="759" data-file-height="241" /></a> </td></tr></tbody></table> <div role="progressbar" style="width: 100%; border: 2px solid black; position: relative; padding: 2px; border-radius: 18px;"> <a href="/wiki/RationalWiki:Fundraiser" title="RationalWiki:Fundraiser"><span style="text-shadow: -1px -1px 0 #FFFFFF, 1px -1px 0 #FFFFFF, -1px 1px 0 #FFFFFF, 1px 1px 0 #FFFFFF; color: black; font-size: 125%; position: absolute; left: 0%; margin: 0 0 0 10px"><b>Donations so far: $8765.50</b></span></a><a href="/wiki/RationalWiki:Fundraiser" title="RationalWiki:Fundraiser"><span style="text-shadow: -1px -1px 0 #FFFFFF, 1px -1px 0 #FFFFFF, -1px 1px 0 #FFFFFF, 1px 1px 0 #FFFFFF; color: black; font-size: 125%; position: absolute; right: 0%; margin: 0 10px 0 0"><b>Goal: $10000</b></span></a><div style="height: 28px; border-radius: 14px; background-color: hsl(70.124,100%,45%); width: 87.655%;"></div> </div></div></div></div> <div class="mw-indicators mw-body-content"> <div id="mw-indicator-bronze" class="mw-indicator"><a href="/wiki/Category:Bronze-level_articles" title="Category:Bronze-level articles"><img alt="Bronze-level article" src="/w/images/thumb/3/3d/Copperbrain.png/25px-Copperbrain.png" decoding="async" width="25" height="25" style="vertical-align: baseline" srcset="/w/images/thumb/3/3d/Copperbrain.png/38px-Copperbrain.png 1.5x, /w/images/thumb/3/3d/Copperbrain.png/50px-Copperbrain.png 2x" data-file-width="800" data-file-height="800" /></a></div> </div> <h1 id="firstHeading" class="firstHeading" lang="en">Placebo effect</h1> <div id="bodyContent" class="mw-body-content"> <div id="siteSub" class="noprint">From RationalWiki</div> <div id="contentSub"><span class="mw-redirectedfrom">(Redirected from <a href="/w/index.php?title=Placebo&redirect=no" class="mw-redirect" title="Placebo">Placebo</a>)</span></div> <div id="contentSub2"></div> <div id="jump-to-nav"></div> <a class="mw-jump-link" href="#mw-head">Jump to navigation</a> <a class="mw-jump-link" href="#searchInput">Jump to search</a> <div id="mw-content-text" lang="en" dir="ltr" class="mw-content-ltr"><div class="mw-parser-output"><div class="thumb tright"><div class="thumbinner" style="width:167px;"><a href="/wiki/File:Antilirium_Placebo.jpg" class="image"><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Antilirium_Placebo.jpg/165px-Antilirium_Placebo.jpg" decoding="async" width="165" height="272" class="thumbimage" srcset="https://upload.wikimedia.org/wikipedia/commons/f/f1/Antilirium_Placebo.jpg 1.5x" data-file-width="166" data-file-height="274" /></a> <div class="thumbcaption"><div class="magnify"><a href="/wiki/File:Antilirium_Placebo.jpg" class="internal" title="Enlarge"></a></div>Prescription placebos used in research and medical practice</div></div></div> <table class="infobox" cellpadding="1" cellspacing="0" style="float: right; margin: 0 0 0.5em 0.5em; text-align:left; border: 1px solid #66637f; width:175px;"> <tbody><tr> <td style="font-size: 95%; text-align:center; color:white; background-color:#66637f"><b>Tell me about<br />your mother</b><br /><a href="/wiki/Psychology" title="Psychology"><font size="4" color="white"><b>Psychology</b></font></a> </td></tr> <tr> <td style="background-color:#f2f0fe;" align="center"><a href="/wiki/Category:Psychology" title="Category:Psychology"><img alt="Icon psychology.svg" src="/w/images/thumb/4/49/Icon_psychology.svg/100px-Icon_psychology.svg.png" decoding="async" width="100" height="100" srcset="/w/images/thumb/4/49/Icon_psychology.svg/150px-Icon_psychology.svg.png 1.5x, /w/images/thumb/4/49/Icon_psychology.svg/200px-Icon_psychology.svg.png 2x" data-file-width="200" data-file-height="200" /></a> </td></tr> <tr> <td style="font-size: 95%; color:white; background-color:#66637f; text-align:center;"><b>For our next session...</b> </td></tr> <tr> <td style="font-size: 95%; background-color:#f2f0fe;"> <ul><li><a href="/wiki/Category:Cognitive_biases" title="Category:Cognitive biases">Cognitive biases</a><br /></li> <li><a href="/wiki/Category:Mental_health" title="Category:Mental health">Mental health</a><br /></li> <li><a href="/wiki/Category:Superstition" title="Category:Superstition">Superstition</a><br /></li> <li><a href="/wiki/Category:Psychologists" title="Category:Psychologists">Famed psychologists</a><br /></li></ul> </td></tr> <tr> <td style="font-size: 95%; color:white; background-color:#66637f; text-align:center;"><b>Popping into your mind</b> </td></tr> <tr> <td style="font-size: 95%; background-color:#f2f0fe;"> <ul><li><a href="/wiki/Crowd_psychology" title="Crowd psychology">Crowd psychology</a></li> <li><a href="/wiki/Herd_mentality" title="Herd mentality">Herd mentality</a></li> <li><a href="/wiki/Psychopath" title="Psychopath">Psychopath</a></li> <li><a href="/wiki/Self-fulfilling_prophecy" title="Self-fulfilling prophecy">Self-fulfilling prophecy</a></li> <li><a href="/wiki/Feeling_the_Future" title="Feeling the Future">Feeling the Future</a></li> <li><a href="/wiki/Trigger_warning" title="Trigger warning">Trigger warning</a></li> <li><a href="/wiki/Outcome_bias" title="Outcome bias">Outcome bias</a></li> <li><a href="/wiki/Diana_Fleischman" title="Diana Fleischman">Diana Fleischman</a></li> <li><a href="/wiki/EMDR" title="EMDR">EMDR</a></li></ul> <div class="vte plainlinks" style="font-size:smaller; text-align:center;"><a href="/wiki/Template:Psychology" title="Template:Psychology">v</a> - <a href="/wiki/Template_talk:Psychology" title="Template talk:Psychology">t</a> - <a rel="nofollow" class="external text" href="https://rationalwiki.org/w/index.php?title=Template:Psychology&action=edit">e</a></div> </td></tr></tbody></table> <table style="margin: auto; border-collapse:collapse; border-style:none; background-color:transparent;" class="cquote"> <tbody><tr> <td><div style="padding:4px 50px;position:relative;"><span style="position:absolute;left:10px;top:-6px;z-index:1;font-family:'Times New Roman',serif;font-weight:bold;color:#B2B7F2;font-size:36px">“</span><span style="position:absolute;right:10px;bottom:-20px;z-index:1;font-family:'Times New Roman',serif;font-weight:bold;color:#B2B7F2;font-size:36px">”</span>No one doubts—certainly not I—that the mind exercises a powerful influence over the body. From the beginning of time, the sorcerer, the <a href="/wiki/Dream_interpretation" title="Dream interpretation">interpreter of dreams</a>, the <a href="/wiki/Fortune-telling" title="Fortune-telling">fortune-teller</a>, the <a href="/wiki/Charlatan" title="Charlatan">charlatan</a>, the <a href="/wiki/Quack" class="mw-redirect" title="Quack">quack</a>, the wild medicine-man, the educated physician, the mesmerist, and the <a href="/wiki/Hypnosis" title="Hypnosis">hypnotist</a> have made use of the client's imagination to help them in their work. They have all recognized the potency and availability of <a href="/wiki/Credulity" title="Credulity">that force</a>. Physicians cure many patients with a bread pill; they know that where the disease is only a fancy, the patient's confidence in the doctor will make the bread pill effective.</div> </td></tr> <tr> <td style="padding:4px 10px 8px;font-size:smaller;line-height:1.6em;text-align:right;"><cite style="font-style:normal;position:relative;z-index:2">—<a href="/wiki/Mark_Twain" title="Mark Twain">Mark Twain</a>, <a rel="nofollow" class="external text" href="http://www.gutenberg.org/files/3187/3187-h/3187-h.htm#link2HCH0004"><i>Christian Science</i></a>, 1907.</cite> </td></tr></tbody></table> <p>The <b>placebo effect</b> is a <a href="/wiki/Psychosomatic" title="Psychosomatic">psychosomatic</a> phenomenon in which symptoms of a disease or condition lessen — or even appear to be cured completely — from the patient being merely exposed to a treatment, as a result of the body releasing endorphins.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1">[1]</a></sup> Believing that their condition will be improved, they will begin to feel better and perhaps identifiable symptoms may disappear, irrespective of whether the treatment has any chemical or pharmacological effect. Because of this, controlling for the placebo effect is an essential part of medicine. For example, <a href="/wiki/Sugar" title="Sugar">sugar</a> pills or saline solutions, which have no pharmacological properties, are commonly prescribed as placebo treatments to control for the effect of the simple act of intervening in a patient's illness. </p><p>Most <a href="/wiki/Alternative_medicine" title="Alternative medicine">alternative medicine</a> is suggested to work through this method<sup id="cite_ref-2" class="reference"><a href="#cite_note-2">[2]</a></sup> — mostly because any treatment that actually works through something <i>other</i> or <i>more</i> than this method is labelled "medicine". Under placebo control, alternative medicines do not perform <a href="/wiki/Statistical_significance" title="Statistical significance">significantly</a> better. </p> <div id="toc" class="toc" role="navigation" aria-labelledby="mw-toc-heading"><input type="checkbox" role="button" id="toctogglecheckbox" class="toctogglecheckbox" style="display:none" /><div class="toctitle" lang="en" dir="ltr"><h2 id="mw-toc-heading">Contents</h2><span class="toctogglespan"><label class="toctogglelabel" for="toctogglecheckbox"></label></span></div> <ul> <li class="toclevel-1 tocsection-1"><a href="#Causes"><span class="tocnumber">1</span> <span class="toctext">Causes</span></a> <ul> <li class="toclevel-2 tocsection-2"><a href="#Statistical_vs_individual_experience"><span class="tocnumber">1.1</span> <span class="toctext">Statistical vs individual experience</span></a></li> <li class="toclevel-2 tocsection-3"><a href="#Expectation_effects"><span class="tocnumber">1.2</span> <span class="toctext">Expectation effects</span></a></li> </ul> </li> <li class="toclevel-1 tocsection-4"><a href="#Ethical_considerations"><span class="tocnumber">2</span> <span class="toctext">Ethical considerations</span></a></li> <li class="toclevel-1 tocsection-5"><a href="#Use_in_medical_trials"><span class="tocnumber">3</span> <span class="toctext">Use in medical trials</span></a></li> <li class="toclevel-1 tocsection-6"><a href="#The_strangeness_of_the_placebo_effect"><span class="tocnumber">4</span> <span class="toctext">The strangeness of the placebo effect</span></a></li> <li class="toclevel-1 tocsection-7"><a href="#Nocebo_effect"><span class="tocnumber">5</span> <span class="toctext">Nocebo effect</span></a></li> <li class="toclevel-1 tocsection-8"><a href="#False_placebo"><span class="tocnumber">6</span> <span class="toctext">False placebo</span></a></li> <li class="toclevel-1 tocsection-9"><a href="#Side_effects_as_evidence_of_effectiveness"><span class="tocnumber">7</span> <span class="toctext">Side effects as evidence of effectiveness</span></a></li> <li class="toclevel-1 tocsection-10"><a href="#In_a_nutshell"><span class="tocnumber">8</span> <span class="toctext">In a nutshell</span></a></li> <li class="toclevel-1 tocsection-11"><a href="#See_also"><span class="tocnumber">9</span> <span class="toctext">See also</span></a></li> <li class="toclevel-1 tocsection-12"><a href="#External_links"><span class="tocnumber">10</span> <span class="toctext">External links</span></a></li> <li class="toclevel-1 tocsection-13"><a href="#References"><span class="tocnumber">11</span> <span class="toctext">References</span></a></li> </ul> </div> <h2><span class="mw-headline" id="Causes">Causes</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=1" title="Edit section: Causes">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <table style="margin: auto; border-collapse:collapse; border-style:none; background-color:transparent;" class="cquote"> <tbody><tr> <td><div style="padding:4px 50px;position:relative;"><span style="position:absolute;left:10px;top:-6px;z-index:1;font-family:'Times New Roman',serif;font-weight:bold;color:#B2B7F2;font-size:36px">“</span><span style="position:absolute;right:10px;bottom:-20px;z-index:1;font-family:'Times New Roman',serif;font-weight:bold;color:#B2B7F2;font-size:36px">”</span>Reject your sense of injury, and the injury itself disappears.</div> </td></tr> <tr> <td style="padding:4px 10px 8px;font-size:smaller;line-height:1.6em;text-align:right;"><cite style="font-style:normal;position:relative;z-index:2">—<a href="https://en.wikipedia.org/wiki/Marcus_Aurelius" class="extiw" title="wp:Marcus Aurelius" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: Marcus Aurelius">Marcus Aurelius</span></a>,<sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> <i><a href="https://en.wikipedia.org/wiki/Meditations" class="extiw" title="wp:Meditations" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: Meditations">Meditations</span></a><sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup></i></cite> </td></tr></tbody></table> <h3><span class="mw-headline" id="Statistical_vs_individual_experience">Statistical vs individual experience</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=2" title="Edit section: Statistical vs individual experience">edit</a><span class="mw-editsection-bracket">]</span></span></h3> <p>The placebo effect is quite a complex phenomenon. It is influenced by a multitude of things, including positive thought, reduced <a href="https://en.wikipedia.org/wiki/stress" class="extiw" title="wp:stress" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: stress">stress</span></a>,<sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> the intensity or "drama" of the medical intervention, a patient's expectations of what the treatment can do, and the wider cultural meaning of medical treatment. A particularly interesting observation is how much these factors can be influenced subconsciously; a doctor merely telling someone a treatment will work may not produce such a dramatic effect if the doctor doesn't actually believe it too. Because of the complexity of issues surrounding what causes a sick patient to get "better", it's difficult to say if an individual was cured by a placebo effect, real treatment, <a href="/wiki/Regression_to_the_mean" title="Regression to the mean">regression to the mean</a>, or a complicated combination of all three. So, the placebo effect is best described as a <a href="/wiki/Statistical" class="mw-redirect" title="Statistical">statistical</a> phenomenon, where prognosis improves for a certain percentage of patients simply exposed to a treatment of some kind. </p><p>However, as the placebo effect is powered by belief in a treatment and exposure to it, it can manifest in individuals to a certain extent. A <a href="/wiki/Homeopathy" title="Homeopathy">homeopathic</a> prescription of <a href="/wiki/Water" title="Water">water</a> containing a minute dilution of powdered <a href="/wiki/Mollusc" title="Mollusc">oyster</a> shell may bring some improvement to a patient who has total <a href="/wiki/Faith" title="Faith">faith</a> in the homeopathic method. A patient who is <a href="/wiki/Skepticism" title="Skepticism">skeptical</a> of homeopathy may experience a reduced effect or no effect at all, as demonstrated by <a href="/wiki/James_Randi" title="James Randi">James Randi</a> when he regularly consumes massive overdoses of homeopathic sleeping pills on stage. If these two hypothetical patients begin to feel better anyway, the former would be likely to attribute it to the treatment while the latter would be likely to dismiss it as just feeling better anyway. This leads to <a href="/wiki/Selective_reporting" title="Selective reporting">selective reporting</a>, and is why <a href="/wiki/Anecdotal_evidence" title="Anecdotal evidence">anecdotal evidence</a> shouldn't be trusted over statistical data. </p> <h3><span class="mw-headline" id="Expectation_effects">Expectation effects</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=3" title="Edit section: Expectation effects">edit</a><span class="mw-editsection-bracket">]</span></span></h3> <table style="margin: auto; border-collapse:collapse; border-style:none; background-color:transparent;" class="cquote"> <tbody><tr> <td><div style="padding:4px 50px;position:relative;"><span style="position:absolute;left:10px;top:-6px;z-index:1;font-family:'Times New Roman',serif;font-weight:bold;color:#B2B7F2;font-size:36px">“</span><span style="position:absolute;right:10px;bottom:-20px;z-index:1;font-family:'Times New Roman',serif;font-weight:bold;color:#B2B7F2;font-size:36px">”</span>When I was a boy a farmer's wife who lived five miles from our village had great fame as a <a href="/wiki/Faith_healing" title="Faith healing">faith-doctor</a> — that was what she called herself. Sufferers came to her from all around, and she laid her hand upon them and said, "Have faith—it is all that is necessary," and they went away well of their ailments. She was not a religious woman, and pretended to no <a href="/wiki/Occult" title="Occult">occult</a> powers. She said that the patient's faith in her did the work. Several times I saw her make immediate cures of severe toothaches. My mother was the patient.</div> </td></tr> <tr> <td style="padding:4px 10px 8px;font-size:smaller;line-height:1.6em;text-align:right;"><cite style="font-style:normal;position:relative;z-index:2">—<a href="/wiki/Mark_Twain" title="Mark Twain">Mark Twain</a><sup id="cite_ref-3" class="reference"><a href="#cite_note-3">[3]</a></sup></cite> </td></tr></tbody></table> <p>Expectations of what drugs and medical treatments are capable of can, and do, change over time. Often, the efficacy of real drugs <i>decreases</i> when a new version is released, as people expect the new one to be better. New treatments, which are perceived to be more effective because they exploit new technologies, induce a placebo effect <i>in addition to</i> their real effect and, sometimes, this can lead to an overestimate of their real efficacy over an existing treatment. This is why in <a href="/wiki/Experimental_control" title="Experimental control">controlled studies</a> of new treatments, they are compared not with inactive placebos, but the best effective treatment available (and not least <a href="/wiki/Precautionary_principle" title="Precautionary principle">because it is unethical to use placebos where a working treatment is known</a>), and the experience between patients is minimised so that they genuinely cannot tell the difference between treatment A and treatment B. </p><p>It is an observed phenomenon that placebo drugs distributed in flashier packaging tend to produce a stronger reaction than their plain packaging counterparts.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4">[4]</a></sup> There is also evidence that the placebo effect can work even if the person knows that it is a placebo, as observed in a study of patients with <a href="/wiki/Irritable_bowel_syndrome" title="Irritable bowel syndrome">irritable bowel syndrome</a> (IBS).<sup id="cite_ref-Kaptchuk_5-0" class="reference"><a href="#cite_note-Kaptchuk-5">[5]</a></sup> However, the statement issued to patients reads "placebo pills made of an inert substance, like sugar pills, that have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes" — which still creates an <i>expectation</i> of treatment despite being told there was no chemical reason that such treatment would help. </p><p>In short, the placebo effect works if you expect the placebo effect to work. </p> <h2><span class="mw-headline" id="Ethical_considerations">Ethical considerations</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=4" title="Edit section: Ethical considerations">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <div role="note" class="hatnote">See the main article on this topic: <a href="/wiki/Ethics" class="mw-redirect" title="Ethics">Ethics</a></div> <div role="note" class="hatnote">For more information, see: <a href="/wiki/False_hope" title="False hope">False hope</a></div> <p>There are a number of ethical issues surrounding the wilful use of placebos as a treatment — known as placebopathy. Many casual complaints can be dealt with by inactive placebo treatments (involving a sugar pill and a reassuring visit to a doctor), and this would save a significant amount of time and money and lowers the risk of drug dependency and overdose. Yet, despite these potential benefits to willingly issuing placebos, it is not considered ethical in modern medicine. Firstly, placebopathy involves medical professionals <a href="/wiki/Deceit" title="Deceit">deceiving</a> their patients, which is considered bad ethical practice, and secondly, there is a risk in delaying the treatment of a real condition due to a doctor mistrusting or underestimating their patient's symptoms. If a patient complaining of a headache is given a sugar pill to placate it, and it turns out to be a serious condition that requires non-placebo treatment, then at the very least this would be <a href="https://en.wikipedia.org/wiki/Medical_malpractice" class="extiw" title="wp:Medical malpractice" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: Medical malpractice">a serious lawsuit waiting to happen</span></a>.<sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> </p><p>Conversely, some medications that have been prescribed have later turned out to be no more effective than inactive placebos, yet can be an effective treatment for <a href="/wiki/Psychosomatic" title="Psychosomatic">psychosomatic</a> conditions or short-term illnesses. Because any treatment tends to produce a better effect than no treatment at all (hence the need for placebo control in trials, see below), it could be considered unethical to stop this practice of effective placebopathy. </p> <h2><span class="mw-headline" id="Use_in_medical_trials">Use in medical trials</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=5" title="Edit section: Use in medical trials">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <div class="thumb tright"><div class="thumbinner" style="width:165px;"><a href="/wiki/File:DoseOscillococcinum.jpg" class="image"><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/0/0d/DoseOscillococcinum.jpg" decoding="async" width="163" height="130" class="thumbimage" data-file-width="163" data-file-height="130" /></a> <div class="thumbcaption"><div class="magnify"><a href="/wiki/File:DoseOscillococcinum.jpg" class="internal" title="Enlarge"></a></div><a href="/wiki/Oscillococcinum" title="Oscillococcinum">Oscillococcinum</a>, a well-known <a href="/wiki/Homeopathic" class="mw-redirect" title="Homeopathic">homeopathic</a> remedy that "works" by the placebo effect.</div></div></div> <p>Because the placebo effect is so powerful, efficacy claims for medical treatments must be tested in an experiment that controls for this effect. This is usually achieved by running a <a href="/wiki/Double-blind" class="mw-redirect" title="Double-blind">double-blind</a> test, where some patients receive the treatment being examined, and others get a placebo. Neither the patients or the administrators of the treatment know who is in which group. In order for the treatment to be proved useful, it must produce results that are better than the placebo at a <a href="/wiki/Statistical_significance" title="Statistical significance">statistically significant</a> level. In practice, the "placebo" is usually an existing treatment, as being better than a placebo isn't enough — a new treatment has to be better than the existing one! For example, in trials of keyhole surgery over conventional open heart surgery, elaborate schemes were undertaken to make patients all feel as if they had the same treatment — but all were treated for their condition, none received a full "fake" treatment that did <i>nothing</i>. Similarly, new pills would be compared with the existing treatments they aim to replace, not necessarily sugar pills or more "powerful" (but more restricted) drugs. </p><p>Placebo treatments can often be quite difficult to design, but are still possible. As mentioned above, placebo surgeries have been performed using quite elaborate theatre, and often the precise wording that a doctor must use to describe a treatment to a patient is strictly controlled. Such treatments can be used to test not just efficacy, but the explanations offered by alternative medicine practitioners. A placebo treatment to test <a href="/wiki/Acupuncture" title="Acupuncture">acupuncture</a>, for example, could be designed to test claims about meridian lines would involve sticking the needles into a patient but in more randomised areas rather than the specific places the technique claims are "special". A second placebo treatment could test the effect of needles by changing the depth which they penetrate into the skin — acupuncture needles often go deeper than you think, while placebo needles penetrate only the top layer of the skin. Thirdly the effect of a visit to a practitioner can be controlled for by using entirely "sham" needles which prick the skin, causing indistinguishable pain sensations, but otherwise don't penetrate or cause any lasting effect. These three methods combine to test three separate areas whereby an alternative medicine can work. </p><p><a href="/wiki/Quack" class="mw-redirect" title="Quack">Quacks</a> who push <a href="/wiki/Woo" title="Woo">woo</a> treatments rely on the placebo effect when arguing that their "cures" have an effect. This is exactly <i>why</i> medical tests need to pit a drug against a placebo: <i>anything</i> will usually perform better than nothing. Often, proponents of alternative medicine will reject placebo controlled experiments for any number of excuses. For example, many homopathic practitioners assert that treatments must be assigned individually and so are unsuited to the format of a <a href="/wiki/Randomised_controlled_trial" class="mw-redirect" title="Randomised controlled trial">randomised controlled trial</a>. Yet, such things can be overcome by simply exposing the patient to everything about the treatment, including this individual treatment "design", and simply swapping the medication at the last moment, unknown to both the patient and practitioner. This sort of assertion is common in alternative medicine, but is obviously at odds with the mass-produced remedies that are sold to the public. Such trials <i>have</i> been done (very rarely does the alternative medicine world foot the bill for these), and they invariably come up negative. </p><p>Studies can be undermined by an insufficiently similar placebo, as small variations can create big differences expectations among patients. The classic example of this is pills versus capsules. Western patients expect (and thus tend to experience) more dramatic effects from medicine delivered in capsule form.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6">[6]</a></sup> Trials for non-medicine treatments typically refer to the equivalent control as a "sham" rather than a placebo. Sham treatments, particularly ones that involve a great deal of human contact, tend to have larger effects than pill-based placebos. </p> <h2><span class="mw-headline" id="The_strangeness_of_the_placebo_effect">The strangeness of the placebo effect</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=6" title="Edit section: The strangeness of the placebo effect">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <p>The power of the placebo effect produces many strange and interesting quirks. These indicate that the placebo effect may well be more than mere <a href="/wiki/Mind-body_woo" title="Mind-body woo">"mind over matter"</a>, and stem from what is known as a <b>complex intervention</b>. This is where any given treatment consists of not just the medicine issued, but the bedside manner of the doctor, how the treatment is described and sold, and how society and environment shape our expectations of what a treatment can and cannot do. Many of these examples and their ramifications are discussed in slightly more detail in <a href="/wiki/Ben_Goldacre" title="Ben Goldacre">Ben Goldacre</a>'s book <i>Bad Science</i>. </p> <ul><li>The effect has been observed in animals and babies. However, in practice this requires conditioning first, which is analogous to just telling someone a treatment will work when you can't communicate more directly.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7">[7]</a></sup><sup id="cite_ref-8" class="reference"><a href="#cite_note-8">[8]</a></sup> This is contrary to claims by <a href="/wiki/Homeopathy" title="Homeopathy">homeopaths</a> who claim that their remedies work in babies and animals and so cannot be due to the placebo effect. (Homeopathic teething tablets can make babies stop crying, but this is most likely because they're made of lactose and sucrose (milk and sugar), not because of the homeopathic water.)</li></ul> <ul><li>Placebos that are "more expensive" work better,<sup id="cite_ref-9" class="reference"><a href="#cite_note-9">[9]</a></sup><sup id="cite_ref-10" class="reference"><a href="#cite_note-10">[10]</a></sup><sup id="cite_ref-11" class="reference"><a href="#cite_note-11">[11]</a></sup> as do ones that come in fancier packaging.<sup id="cite_ref-12" class="reference"><a href="#cite_note-12">[12]</a></sup></li></ul> <ul><li>The effect shows a dose-response relationship like a real medical intervention; two pills are more effective than one.</li></ul> <ul><li>More dramatic placebos are more effective. Injections work better than pills. A full consultation session with a doctor prior to a placebo is more effective than just giving a patient a pill dismissively.</li></ul> <ul><li>The placebo effect may possibly have the ability to overpower real pharmacological effects. People who were given very strong drugs to <i>induce</i> nausea didn't develop symptoms as they were told the treatment would actually <i>relieve</i> nausea.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13">[13]</a></sup></li></ul> <ul><li>There are reports from war zones where saline solutions were used due to shortages of morphine, and proved just as effective in battlefield surgery.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14">[14]</a></sup> In addition, one man had a vasectomy and was mistakenly injected with saline solution instead of anesthetic, but because of the placebo effect, he experienced pain relief anyway.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15">[15]</a></sup></li></ul> <ul><li>In one trial, the placebo effect was induced even though the individuals were <i>told</i> that it was a placebo that contains no medicine; although they were told that it was shown to be of help to people with such a condition.<sup id="cite_ref-Kaptchuk_5-1" class="reference"><a href="#cite_note-Kaptchuk-5">[5]</a></sup></li></ul> <ul><li>As an indication of the wider cultural meaning and subconscious activity of the effect, it is observed that the colour of a sugar pill also affects the placebo response. Certain colours boost the efficacy of placebos for different illnesses, and can even correlate with gender.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16">[16]</a></sup></li></ul> <ul><li>The placebo effect may actually be getting <i>stronger</i> over time, as expectations about the power of medicine change,<sup id="cite_ref-17" class="reference"><a href="#cite_note-17">[17]</a></sup> but at the same time it can cause drugs that are old to become weaker as the expectation is that new and novel treatments must be better.</li></ul> <ul><li>The placebo effect may be transferable; a patient being around someone who believes that the treatment will work can cause the patient to do better — even if that person is a doctor.<sup id="cite_ref-18" class="reference"><a href="#cite_note-18">[18]</a></sup> This is the reason for double-blinding in drug trials. It may also mean that prayer can affect patients if they know they're being prayed for; rigorous studies of prayer therefore make sure that there is no contact between prayers and patients.</li></ul> <ul><li>There may be some <a href="/wiki/Gene" class="mw-redirect" title="Gene">genes</a> that make some people more susceptible to the placebo effect.<sup id="cite_ref-19" class="reference"><a href="#cite_note-19">[19]</a></sup></li></ul> <h2><span class="mw-headline" id="Nocebo_effect">Nocebo effect</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=7" title="Edit section: Nocebo effect">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <p>The placebo effect has a somewhat less well-known, slightly evil cousin; the <b>nocebo effect</b>.<sup id="cite_ref-20" class="reference"><a href="#cite_note-20">[20]</a></sup><sup id="cite_ref-21" class="reference"><a href="#cite_note-21">[21]</a></sup> This occurs when an individual's expectation of negative effects generates or aggravates those effects, much like a hypochondriac developing symptoms because they are actively watching for something to go wrong with their health. This is particularly important when looking at side-effects of drugs, as a placebo pill can generate the negative side-effects associated with drugs, and in some cases, specific side-effects can be increased by mentioning them prominently or adding an extra layer of suggestion, such as complex consent forms.<sup id="cite_ref-22" class="reference"><a href="#cite_note-22">[22]</a></sup> </p><p>For ethical reasons, the nocebo effect has not been well studied <i>directly</i>, but it is probably behind the <a href="https://en.wikipedia.org/wiki/witch_doctor" class="extiw" title="wp:witch doctor" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: witch doctor">witch doctor</span></a>'s<sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> ability to cause illness in those people he <a href="/wiki/Curse" title="Curse">curses</a>. It has also been used to explain unusual phenomenon like the <a href="https://en.wikipedia.org/wiki/culture-bound_syndrome" class="extiw" title="wp:culture-bound syndrome" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: culture-bound syndrome">culture-bound syndrome</span></a><sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> SUNDS (Sudden Unexpected Nocturnal Death Syndrome) in immigrants from the Hmong people of <a href="/wiki/Laos" title="Laos">Laos</a>; belief in angry <a href="/wiki/Supernatural" title="Supernatural">supernatural</a> forces combined with the phenomenon of <a href="/wiki/Sleep_paralysis" title="Sleep paralysis">sleep paralysis</a> to convince sufferers that they were under attack, leading to extremely high levels of stress which could trigger dormant heart defects.<sup id="cite_ref-23" class="reference"><a href="#cite_note-23">[23]</a></sup> As a side note, these same deaths were what inspired film director Wes Craven to create the fictional dream-using serial killer Freddy Krueger. </p> <center> <div class="thumb embedvideo autoResize" style="width: 648px;"><div class="embedvideo autoResize" style=""><div class="embedvideowrap" style="width: 640px;"><iframe title="Play video" src="//www.youtube.com/embed/O2hO4_UEe-4?" width="640" height="360" frameborder="0" allowfullscreen="true"></iframe></div></div></div> </center> <h2><span class="mw-headline" id="False_placebo">False placebo</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=8" title="Edit section: False placebo">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <div role="note" class="hatnote">See the main article on this topic: <a href="/wiki/False_placebo" title="False placebo">False placebo</a></div> <p>A false placebo is a non-placebo factor that appears to cause an improvement of a disease. False placebos differ from actual placebos in that they occur regardless of whether the patient is treated or not. False placebos are the lesser-known things controlled for in the placebo arms of clinical trials. Some examples of false placebos include <a href="/wiki/Misdiagnosis" class="mw-redirect" title="Misdiagnosis">misdiagnosis</a>, <a href="/wiki/Regression_to_the_mean" title="Regression to the mean">regression to the mean</a>, and <a href="/wiki/Spontaneous_regression" class="mw-redirect" title="Spontaneous regression">spontaneous regression</a>. </p> <h2><span class="mw-headline" id="Side_effects_as_evidence_of_effectiveness">Side effects as evidence of effectiveness</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=9" title="Edit section: Side effects as evidence of effectiveness">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <p>A kind of placebo can be found when the treatments have actual side effects: the practitioner explains them as signs that the treatment is working. For example, if the patient gets nausea from a <a href="/wiki/PH_woo" title="PH woo">pH woo</a> treatment, the practitioner can explain that this is a "healing crisis",<sup id="cite_ref-24" class="reference"><a href="#cite_note-24">[24]</a></sup> a kind of an imagined <a href="https://en.wikipedia.org/wiki/Jarisch%E2%80%93Herxheimer_reaction" class="extiw" title="wp:Jarisch–Herxheimer reaction" rel="nofollow"><span style="color:#477979 !important;" title="Wikipedia: Jarisch–Herxheimer reaction">Jarisch–Herxheimer reaction</span></a>.<sup><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/12px-Wikipedia%27s_W.svg.png" decoding="async" width="12" height="12" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/18px-Wikipedia%27s_W.svg.png 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/5a/Wikipedia%27s_W.svg/24px-Wikipedia%27s_W.svg.png 2x" data-file-width="128" data-file-height="128" /></sup> A similar effect has been found even for legitimate medications: an antimalarial with worse side effects was interpreted as being more effective by patients.<sup id="cite_ref-25" class="reference"><a href="#cite_note-25">[25]</a></sup> </p> <h2><span class="mw-headline" id="In_a_nutshell">In a nutshell</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=10" title="Edit section: In a nutshell">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <center> <div class="thumb embedvideo autoResize" style="width: 648px;"><div class="embedvideo autoResize" style=""><div class="embedvideowrap" style="width: 640px;"><iframe title="Play video" src="//www.youtube.com/embed/rtPe5lsoHXY?" width="640" height="360" frameborder="0" allowfullscreen="true"></iframe></div></div></div> </center> <h2><span class="mw-headline" id="See_also">See also</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=11" title="Edit section: See also">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <ul><li><a href="/wiki/Alternative_medicine" title="Alternative medicine">Alternative medicine</a></li> <li><a href="/wiki/Big_Placebo" title="Big Placebo">Big Placebo</a></li> <li><a href="/wiki/Folk_remedy" title="Folk remedy">Folk remedy</a></li> <li><a href="/wiki/Correlation_does_not_equal_causation" class="mw-redirect" title="Correlation does not equal causation">Correlation does not equal causation</a></li> <li><a href="/wiki/Faith_healing" title="Faith healing">Faith healing</a></li> <li><a href="/wiki/Security_theatre" class="mw-redirect" title="Security theatre">Security theatre</a></li> <li><a href="/wiki/Regression_to_the_mean" title="Regression to the mean">Regression to the mean</a></li> <li><a href="/wiki/Spontaneous_improvement" class="mw-redirect" title="Spontaneous improvement">Spontaneous improvement</a></li> <li><a href="/wiki/Misdiagnosis" class="mw-redirect" title="Misdiagnosis">Misdiagnosis</a></li> <li><a href="/wiki/False_hope" title="False hope">False hope</a></li></ul> <h2><span class="mw-headline" id="External_links">External links</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=12" title="Edit section: External links">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <ul><li><a rel="nofollow" class="external text" href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2582668/">Challenging Received Wisdom: Antidepressants and the Placebo Effect</a>, Irving Kirsch</li> <li><a rel="nofollow" class="external text" href="http://www.bbc.com/news/magazine-34572482">Why are placebos getting more effective?</a>, BBC</li></ul> <h2><span class="mw-headline" id="References">References</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Placebo_effect&action=edit&section=13" title="Edit section: References">edit</a><span class="mw-editsection-bracket">]</span></span></h2> <div class="references-small" style="-moz-column-count:2; -webkit-column-count:2; column-count:2; font-size:90%;"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><a href="#cite_ref-1">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.news-medical.net/news/2005/08/23/12661.aspx">First direct evidence that endorphins play a role in the phenomenon known as the placebo effect</a></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><a href="#cite_ref-2">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.scientificamerican.com/article.cfm?id=placebo-effect-a-cure-in-the-mind">Scientific American — Placebo Effect: A Cure in the Mind</a></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><a href="#cite_ref-3">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.gutenberg.org/files/3187/3187-h/3187-h.htm#link2HCH0004">Christian Science</a></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><a href="#cite_ref-4">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1505530/">Analgesic effects of branding in treatment of headaches</a>, <i>A Branthwaite and P Cooper</i></span> </li> <li id="cite_note-Kaptchuk-5"><span class="mw-cite-backlink">↑ <sup><a href="#cite_ref-Kaptchuk_5-0">5.0</a></sup> <sup><a href="#cite_ref-Kaptchuk_5-1">5.1</a></sup></span> <span class="reference-text">Kaptchuk TJ, Friedlander E, Kelley JM, Sanchez MN, Kokkotou E, et al. (2010) <a rel="nofollow" class="external text" href="http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0015591">Placebos without Deception: A Randomized Controlled Trial in Irritable Bowel Syndrome.</a> PLoS ONE 5(12)</span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><a href="#cite_ref-6">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.skeptic.com/eskeptic/09-05-20#feature">eSkeptic The Placebo Effect</a></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><a href="#cite_ref-7">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.sciencebasedmedicine.org/?p=263">Science Based Medicine — Is There a Placebo Effect for Animals?</a></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><a href="#cite_ref-8">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.psychosomaticmedicine.org/cgi/content/abstract/37/4/333">Behaviorally conditioned immunosuppression</a>, R Ader and N Cohen, Psychosomatic Medicine, Vol 37, Issue 4 333-340</span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><a href="#cite_ref-9">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.scienceagogo.com/news/20080204181613data_trunc_sys.shtml">Expensive Placebo Works Better Than Cheap One</a></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><a href="#cite_ref-10">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://jama.jamanetwork.com/article.aspx?articleid=181562">Commercial Features of Placebo and Therapeutic Efficacy</a> by Dan Ariely et al. <i>Journal of the American Medical Association</i>, March 5, 2008; 299: 1016-1017.</span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><a href="#cite_ref-11">↑</a></span> <span class="reference-text">Dan Ariely et al. won the 2008 <a href="/wiki/Ig_Nobel_Prize" title="Ig Nobel Prize">Ig Nobel Prize</a> in Medicine for this discovery.</span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><a href="#cite_ref-12">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1505530/">Analgesic effects of branding in treatment of headaches</a>, <i>A Branthwaite and P Cooper</i></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><a href="#cite_ref-13">↑</a></span> <span class="reference-text">Wolf S. Effects of suggestions and conditioning on the action of chemical agents in human subjects — the pharmacology of placebos. J Clin Invest 1950;29:100-9. PMCID <a rel="nofollow" class="external text" href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC439730">PMC439730</a></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><a href="#cite_ref-14">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://blog.placeboeffect.com/the-powerful-placebo/">The Powerful Placebo</a>.</span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><a href="#cite_ref-15">↑</a></span> <span class="reference-text">Harriet Hall, <i>Women Aren't Supposed to Fly: The Memoirs of a Female Flight Surgeon</i>, quoted in <a rel="nofollow" class="external text" href="http://skepdic.com/acupuncture.html"><i>Acupuncture</i></a>, Skepdic.</span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><a href="#cite_ref-16">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.springerlink.com/content/x2n5j6t71475632h/">Lucchelli, Cattaneo, Zattoni, Effect of capsule colour and order of administration of hypnotic treatments, <i>European Journal of Clinical Pharmacology</i>, <b>2004</b></a></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><a href="#cite_ref-17">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.wired.com/medtech/drugs/magazine/17-09/ff_placebo_effect?currentPage=all">Placebos Are Getting More Effective. Drugmakers Are Desperate to Know Why, Wired Magazine.</a></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><a href="#cite_ref-18">↑</a></span> <span class="reference-text">a) Gracely R.H,; Dubner, R.; Deeter, W.R.; Wolksee, P.J., Clinclicians' expectations influence placebo analgesia. <i>Lancet</i>, 1, 43 8419 (1985) b) via <a href="/wiki/Ben_Goldacre" title="Ben Goldacre">Ben Goldacre</a>, <i>Bad Science</i>, p.75.</span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><a href="#cite_ref-19">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://www.sciencenews.org/article/genes-may-influence-placebo-effect">Genes may influence placebo effect: Response to sham treatment depends on certain DNA details, analysis suggests</a> by Ashley Yeager (1:46pm, April 14, 2015) <i>Science News</i>.</span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><a href="#cite_ref-20">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.skepdic.com/nocebo.html">nocebo effect</a></span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><a href="#cite_ref-21">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.newscientist.com/article/mg20227081.100-the-science-of-voodoo-when-mind-attacks-body.html">New Scientist — when mind attacks body</a></span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><a href="#cite_ref-22">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.badscience.net/2009/11/all-bow-before-the-mighty-power-of-the-nocebo-effect/">Bad Science — All bow before the mighty power of the nocebo effect</a></span> </li> <li id="cite_note-23"><span class="mw-cite-backlink"><a href="#cite_ref-23">↑</a></span> <span class="reference-text">Adler, Shelley R. <i>Sleep Paralysis.</i> Rutgers: 2011.</span> </li> <li id="cite_note-24"><span class="mw-cite-backlink"><a href="#cite_ref-24">↑</a></span> <span class="reference-text">Example: section "Paranemiskriisi" in URL: <a rel="nofollow" class="external free" href="https://www.valmarin.fi/happo-ja-emastasapaino">https://www.valmarin.fi/happo-ja-emastasapaino</a></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><a href="#cite_ref-25">↑</a></span> <span class="reference-text"><a rel="nofollow" class="external free" href="https://www.tandfonline.com/doi/abs/10.1080/13648470903246854">https://www.tandfonline.com/doi/abs/10.1080/13648470903246854</a></span> </li> </ol></div></div>    </div></div><div class="printfooter">Retrieved from "<a dir="ltr" href="https://rationalwiki.org/w/index.php?title=Placebo_effect&oldid=2721902">https://rationalwiki.org/w/index.php?title=Placebo_effect&oldid=2721902</a>"</div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Special:Categories" title="Special:Categories">Categories</a>: <ul><li><a href="/wiki/Category:Psychology" title="Category:Psychology">Psychology</a></li><li><a href="/wiki/Category:Bronze-level_articles" title="Category:Bronze-level articles">Bronze-level articles</a></li><li><a href="/wiki/Category:Biology" title="Category:Biology">Biology</a></li><li><a href="/wiki/Category:Medicine" title="Category:Medicine">Medicine</a></li><li><a href="/wiki/Category:Alternative_medicine" title="Category:Alternative medicine">Alternative medicine</a></li><li><a href="/wiki/Category:Research_terms" title="Category:Research terms">Research terms</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden category: <ul><li><a href="/wiki/Category:Pages_using_DynamicPageList_parser_function" title="Category:Pages using DynamicPageList parser function">Pages using DynamicPageList parser function</a></li></ul></div></div> </div> </div> <div id="mw-navigation"> <h2>Navigation menu</h2> <div id="mw-head">  <nav id="p-personal" class="vector-menu" aria-labelledby="p-personal-label" role="navigation" > <h3 id="p-personal-label"> <span>Personal tools</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="pt-anonuserpage">Not logged in</li><li id="pt-anontalk"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n">Talk</a></li><li id="pt-anoncontribs"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y">Contributions</a></li><li id="pt-createaccount"><a href="/w/index.php?title=Special:CreateAccount&returnto=Placebo+effect" title="You are encouraged to create an account and log in; however, it is not mandatory">Create account</a></li><li id="pt-login"><a href="/w/index.php?title=Special:UserLogin&returnto=Placebo+effect" title="You are encouraged to log in; however, it is not mandatory [o]" accesskey="o">Log in</a></li></ul> </div> </nav> <div id="left-navigation">  <nav id="p-namespaces" class="vector-menu vector-menu-tabs vectorTabs" aria-labelledby="p-namespaces-label" role="navigation" > <h3 id="p-namespaces-label"> <span>Namespaces</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="ca-nstab-main" class="selected"><a href="/wiki/Placebo_effect" title="View the content page [c]" accesskey="c">Page</a></li><li id="ca-talk"><a href="/wiki/Talk:Placebo_effect" rel="discussion" title="Discussion about the content page [t]" accesskey="t">Talk</a></li></ul> </div> </nav>  <nav id="p-variants" class="vector-menu-empty emptyPortlet vector-menu vector-menu-dropdown vectorMenu" aria-labelledby="p-variants-label" role="navigation" > <input type="checkbox" class="vector-menu-checkbox vectorMenuCheckbox" aria-labelledby="p-variants-label" /> <h3 id="p-variants-label"> <span>Variants</span> </h3>  <div class="body vector-menu-content">  <ul class="menu vector-menu-content-list"></ul> </div> </nav> </div> <div id="right-navigation">  <nav id="p-views" class="vector-menu vector-menu-tabs vectorTabs" aria-labelledby="p-views-label" role="navigation" > <h3 id="p-views-label"> <span>Views</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="ca-view" class="collapsible selected"><a href="/wiki/Placebo_effect">Read</a></li><li id="ca-edit" class="collapsible"><a href="/w/index.php?title=Placebo_effect&action=edit" title="Edit this page [e]" accesskey="e">Edit</a></li><li id="ca-history" class="collapsible"><a href="/w/index.php?title=Placebo_effect&action=history" title="Past revisions of this page [h]" accesskey="h">Fossil record</a></li></ul> </div> </nav>  <nav id="p-cactions" class="vector-menu-empty emptyPortlet vector-menu vector-menu-dropdown vectorMenu" aria-labelledby="p-cactions-label" role="navigation" > <input type="checkbox" class="vector-menu-checkbox vectorMenuCheckbox" aria-labelledby="p-cactions-label" /> <h3 id="p-cactions-label"> <span>More</span> </h3>  <div class="body vector-menu-content">  <ul class="menu vector-menu-content-list"></ul> </div> </nav> <div id="p-search" role="search"> <h3 > <label for="searchInput">Search</label> </h3> <form action="/w/index.php" id="searchform"> <div id="simpleSearch"> <input type="search" name="search" placeholder="Search RationalWiki" title="Search RationalWiki [f]" accesskey="f" id="searchInput"/> <input type="hidden" name="title" value="Special:Search"> <input type="submit" name="fulltext" value="Search" title="Search the pages for this text" id="mw-searchButton" class="searchButton mw-fallbackSearchButton"/> <input type="submit" name="go" value="Go" title="Go to a page with this exact name if it exists" id="searchButton" class="searchButton"/> </div> </form> </div> </div> </div> <div id="mw-panel"> <div id="p-logo" role="banner"> <a title="Visit the main page" class="mw-wiki-logo" href="/wiki/Main_Page"></a> </div>  <nav id="p-navigation" class="vector-menu vector-menu-portal portal portal-first" aria-labelledby="p-navigation-label" role="navigation" > <h3 id="p-navigation-label"> <span>Navigation</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="n-mainpage-description"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z">Main page</a></li><li id="n-recentchanges"><a href="/wiki/Special:RecentChanges" title="A list of recent changes in the wiki [r]" accesskey="r">Recent changes</a></li><li id="n-randompage"><a href="/wiki/Special:Random" title="Load a random mainspace article [x]" accesskey="x">Random page</a></li><li id="n-New-pages"><a href="/wiki/Special:NewPages">New pages</a></li><li id="n-All-logs"><a href="/wiki/Special:Log">All logs</a></li><li id="n-help"><a href="/wiki/Help:Contents" title="RTFM">Help</a></li></ul> </div> </nav>  <nav id="p-support" class="vector-menu vector-menu-portal portal" aria-labelledby="p-support-label" role="navigation" > <h3 id="p-support-label"> <span>Support</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="n-Donate"><a href="/wiki/RationalWiki:Site_support">Donate</a></li></ul> </div> </nav>  <nav id="p-community" class="vector-menu vector-menu-portal portal" aria-labelledby="p-community-label" role="navigation" > <h3 id="p-community-label"> <span>Community</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="n-Saloon-bar"><a href="/wiki/RationalWiki:Saloon_bar">Saloon bar</a></li><li id="n-To-do-list"><a href="/wiki/RationalWiki:To_do_list">To do list</a></li><li id="n-What-is-going-on.3F"><a href="/wiki/WIGO">What is going on?</a></li><li id="n-Best-of-RationalWiki"><a href="/wiki/RationalWiki:Contents">Best of RationalWiki</a></li><li id="n-About-RationalWiki"><a href="/wiki/RationalWiki">About RationalWiki</a></li><li id="n-Technical-support"><a href="/wiki/RationalWiki:Technical_support">Technical support</a></li><li id="n-Mod-noticeboard"><a href="/wiki/RationalWiki_talk:All_things_in_moderation">Mod noticeboard</a></li><li id="n-RMF-noticeboard"><a href="/wiki/RationalWiki_talk:RationalMedia_Foundation">RMF noticeboard</a></li></ul> </div> </nav>  <nav id="p-Social media" class="vector-menu vector-menu-portal portal" aria-labelledby="p-Social media-label" role="navigation" > <h3 id="p-Social media-label"> <span>Social media</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="n-Twitter"><a href="https://twitter.com/RationalWiki" rel="nofollow">Twitter</a></li><li id="n-Mastodon"><a href="https://mstdn.social/@rationalwiki" rel="nofollow">Mastodon</a></li><li id="n-Facebook"><a href="https://www.facebook.com/pages/Rationalwiki/226614404019306" rel="nofollow">Facebook</a></li><li id="n-Discord"><a href="/wiki/RationalWiki:Discord">Discord</a></li><li id="n-Reddit"><a href="/wiki/RationalWiki:Reddit">Reddit</a></li></ul> </div> </nav>  <nav id="p-tb" class="vector-menu vector-menu-portal portal" aria-labelledby="p-tb-label" role="navigation" > <h3 id="p-tb-label"> <span>Tools</span> </h3>  <div class="body vector-menu-content">  <ul class="vector-menu-content-list"><li id="t-whatlinkshere"><a href="/wiki/Special:WhatLinksHere/Placebo_effect" title="A list of all wiki pages that link here [j]" accesskey="j">What links here</a></li><li id="t-recentchangeslinked"><a href="/wiki/Special:RecentChangesLinked/Placebo_effect" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k">Related changes</a></li><li id="t-specialpages"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q">Special pages</a></li><li id="t-print"><a href="javascript:print();" rel="alternate" title="Printable version of this page [p]" accesskey="p">Printable version</a></li><li id="t-permalink"><a href="/w/index.php?title=Placebo_effect&oldid=2721902" title="Permanent link to this revision of the page">Permanent link</a></li><li id="t-info"><a href="/w/index.php?title=Placebo_effect&action=info" title="More information about this page">Page information</a></li></ul> </div> </nav> </div> </div> <footer id="footer" class="mw-footer" role="contentinfo" > <ul id="footer-info" > <li id="footer-info-lastmod"> This page was last edited on 3 March 2025, at 16:12.</li> <li id="footer-info-copyright">Unless explicitly noted otherwise, all content licensed as indicated by <a name="Copyright" href="//rationalwiki.org/wiki/RationalWiki:Copyrights">RationalWiki:Copyrights</a>. <br> For concerns on copyright infringement please see: <a name="Copyright infringement" href="//rationalwiki.org/wiki/RationalWiki:Copyright_violations">RationalWiki:Copyright violations</a></li> </ul> <ul id="footer-places" > <li id="footer-places-privacy"><a href="/wiki/RationalWiki:Privacy_policy" title="RationalWiki:Privacy policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/RationalWiki:About" class="mw-redirect" title="RationalWiki:About">About RationalWiki</a></li> <li id="footer-places-disclaimer"><a href="/wiki/RationalWiki:General_disclaimer" title="RationalWiki:General disclaimer">Disclaimers</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://creativecommons.org/licenses/by-sa/3.0/"><img src="/w/88x31.png" alt="CC-BY-SA 3.0, or any later version" width="88" height="31" loading="lazy"/></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/"><img src="/w/resources/assets/poweredby_mediawiki_88x31.png" alt="Powered by MediaWiki" srcset="/w/resources/assets/poweredby_mediawiki_132x47.png 1.5x, /w/resources/assets/poweredby_mediawiki_176x62.png 2x" width="88" height="31" loading="lazy"/></a></li> </ul> <div style="clear: both;"></div> </footer> <script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgPageParseReport":{"limitreport":{"cputime":"0.211","walltime":"0.536","ppvisitednodes":{"value":1005,"limit":1000000},"postexpandincludesize":{"value":13356,"limit":2097152},"templateargumentsize":{"value":4716,"limit":2097152},"expansiondepth":{"value":10,"limit":40},"expensivefunctioncount":{"value":0,"limit":100},"unstrip-depth":{"value":0,"limit":20},"unstrip-size":{"value":11180,"limit":5000000},"timingprofile":["100.00% 62.212 1 -total"," 38.19% 23.756 1 Template:Psychology"," 34.39% 21.395 1 Template:Navsidebar"," 27.24% 16.947 1 Template:Navsidebar2"," 24.56% 15.281 1 Template:Randomarticles"," 13.90% 8.648 1 Template:Reflist"," 9.65% 6.003 3 Template:Cquote"," 8.70% 5.412 1 Template:Bronze"," 6.42% 3.997 2 Template:Main"," 4.91% 3.057 7 Template:Wpl"]},"cachereport":{"origin":"apache5","timestamp":"20250331155108","ttl":86400,"transientcontent":false}}});mw.config.set({"wgBackendResponseTime":673,"wgHostname":"apache5"});});</script></body></html>