In 1996, 56 volunteers took part in a study to test a new painkiller called Trivaricaine. On each subject, one index finger was covered in the new painkiller while the other remained untouched. Then, both were squeezed in painful clamps. The subjects reported that the treated finger hurt less than the untreated one. This shouldn't be surprising, except Trivaricaine wasn't actually a painkiller, just a fake concotion with no pain-easing properties at all. What made the students so sure this dummy drug had worked? The answer lies in the placebo effect, an unexplained phenomenon wherein drugs, treatments, and therapies that aren't supposed to have an effect, and are often fake, miraculously make people feel better. Doctors have used the term placebo since the 1700s when they realized the power of fake drugs to improve people's symptoms. These were administered when proper drugs weren't available, or if someone imagined they were ill. In fact, the word placebo means "I shall please" in Latin, hinting at a history of placating troubled patients. Placebos had to mimic the real treatments in order to be convincing, so they took the form of sugar pills, water-filled injections, and even sham surgeries. Soon, doctors realized that duping people in this way had another use: in clinical trials. By the 1950s, researchers were using placebos as a standard tool to test new treatments. To evaluate a new drug, for instance, half the patients in a trial might receive the real pill. The other half would get a placebo that looked the same. Since patients wouldn't know whether they'd received the real thing or a dud, the results wouldn't be biased, researchers believed. Then, if the new drug showed a significant benefit compared to the placebo, it was proved effective. Nowadays, it's less common to use placebos this way because of ethical concerns. If it's possible to compare a new drug against an older version, or another existing drug, that's preferable to simply giving someone no treatment at all, especially if they have a serious ailment. In these cases, placebos are often used as a control to fine-tune the trial so that the effects of the new versus the old or alternative drug can be precisely compared. But of course, we know the placebos exert their own influence, too. Thanks to the placebo effect, patients have experienced relief from a range of ailments, including heart problems, asthma, and severe pain, even though all they'd received was a fake drug or sham surgery. We're still trying to understand how. Some believe that instead of being real, the placebo effect is merely confused with other factors, like patients trying to please doctors by falsely reporting improvements. On the other hand, researchers think that if a person believes a fake treatment is real, their expectations of recovery actually do trigger physiological factors that improve their symptoms. Placebos seem to be capable of causing measurable change in blood pressure, heart rate, and the release of pain-reducing chemicals, like endorphins. That explains why subjects in pain studies often say placebos ease their discomfort. Placebos may even reduce levels of stress hormones, like adrenaline, which can slow the harmful effects of an ailment. So shouldn't we celebrate the placebo's bizarre benefits? Not necessarily. If somebody believes a fake treatment has cured them, they may miss out on drugs or therapies that are proven to work. Plus, the positive effects may fade over time, and often do. Placebos also cloud clinical results, making scientists even more motivated to discover how they wield such power over us. Despite everything we know about the human body, there are still some strange and enduring mysteries, like the placebo effect. So what other undiscovered marvels might we contain? It's easy to investigate the world around us and forget that one of its most fascinating subjects lies right behind our eyes.
Leta 1996 je 56 prostovoljcev sodelovalo v študiji, kjer so testirali novo protibolečinsko zdravilo Trivaricaine. Vsakemu so en kazalec prekrili z novim protibolečinskim zdravilom, drugi pa je ostal nedotaknjen. Oba so nato stisnili z bolečimi kleščami. Prostovoljci so poročali, da jih je kazalec z zdravilom bolel manj. To ne bi smelo biti presenetljivo, ampak Trivaricaine v resnici ni bil protibolečinsko zdravilo, samo lažna mešanica brez protibolečinskih lastnosti. Zakaj so torej mislili, da to lažno zdravilo deluje? Odgovor leži v placebo učinku, nepojasnjenem fenomenu, ko zdravila, zdravljenja in terapije, ki naj ne bi imele učinka in so pogosto lažne, čudežno pomagajo ljudem. Zdravniki uporabljajo izraz placebo že od 17. stoletja, ko so spoznali moč lažnih zdravil, da olajšajo simptome. Dali so jih, ko prava zdravila niso bila na voljo ali če si je nekdo domišljal, da je bolan. Pravzaprav, beseda placebo v latinščini pomeni "ustregel bom", kar namiguje na zgodovino pomirjanja nemirnih pacientov. Placebo je moral biti podoben pravim zdravilom, da bi bil prepričljiv, zato so bili v obliki sladkornih tablet, z vodo napolnjenih injekcij, in celo lažnih operacij. Kmalu so zdravniki spoznali, da ima tak način prevare tudi drugačno uporabo: v kliničnih raziskavah. V 50-ih so raziskovalci uporabljali placebo kot standardno orodje za preizkušanje novih zdravil. Da so ocenili na primer novo zdravilo, je polovica bolnikov dobila pravo tableto. Druga polovica je dobila placebo, ki je izgledal enako. Ker bolniki niso vedeli ali so dobili pravo stvar ali ne, rezultati ne bi bili pristranski, so verjeli raziskovalci. Če je bilo novo zdravilo boljše od placeba, je bilo potrjeno kot učinkovito. Danes je uporaba placeba manj pogosta zaradi etičnih zadržkov. Če je možno primerjati novo zdravilo s starejšo različico, ali z drugim obstoječim zdravilom, je to boljše kot, da nekomu preprosto ne damo zdravila, še posebej, če so resno bolni. V teh primerih se placebo pogosto uporablja kot nadzor umeritve, da so učinki novega proti staremu ali drugemu zdravilu lahko natančno primerjani. Seveda vemo, da ima placebo tudi svoj učinek. Zahvaljujoč učinku placeba, bolniki občutijo olajšanje pri celem spektru težav vključno z boleznimi srca, astmo in hudo bolečino, čeprav so morda prejeli lažno zdravilo ali imeli lažno operacijo. Še danes poskušamo razumeti, kako. Nekateri verjamejo, da ni resničen in da je učinek placeba zamešan z drugimi faktorji, kot ko pacienti skušajo ugoditi zdravnikom in lažno poročajo o izboljšanju. Po drugi strani raziskovalci menijo, če oseba misli, da je lažno zdravljenje resnično, njihovo pričakovanje ozdravitve sproži fiziološke faktorje, ki izboljšajo njihove simptome. Placebo je očitno sposoben povzročiti spremembe v krvnem pritisku, bitju srca in sproščanju protibolečinskih kemikalij, na primer endorfinov. To pojasni, zakaj preiskovanci v študiji rečejo, da jim placebo zmanjša bolečino. Placebo lahko celo zniža raven stresnih hormonov, naprimer adrenalina, kar lahko upočasni škodljive učinke bolezni. Ne bi morali torej slaviti teh nenavadnih ugodnih učinkov placeba? Ne nujno. Če nekdo verjame, da ga je lažno zdravljenje pozdravilo, morda ne bodo dobili zdravil ali terapij, ki dokazano delujejo. Plus, pozitivni učinki lahko sčasoma zbledijo in pogosto se to dejansko zgodi. Placebo lahko zamegli klinične rezultate, kar znanstvenike še bolj motivira, da bi odkrili, kakšno moč imajo nad nami. Kljub vsemu, kar vemo o človeškem telesu, so tu še vedno nekatere nenavadne in vztrajne skrivnosti, kot je učinek placeba. Kakšna neodkrita čudesa še skrivamo v sebi? Zlahka raziskujemo svet okrog nas in pozabimo, da eden izmed najbolj zanimivih subjektov, leži prav za našimi očmi.