The power of the placebo effect - Emma Bryce - video Dailymotion

TED-Ed

The placebo effect is 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. What’s going on? Emma Bryce dives into the mystery of placebos’ bizarre benefits.   Lesson by Emma Bryce, animation by Globizco.

Transcript

00:00In 1996, 56 volunteers took part in a study

00:11to test a new painkiller called Trivaricaine.

00:14On each subject, one index finger was covered in the new painkiller,

00:19while the other remained untouched.

00:21Then, both were squeezed in painful clamps.

00:25The subjects reported that the treated finger hurt less than the untreated one.

00:29This shouldn't be surprising,

00:31except Trivaricaine wasn't actually a painkiller,

00:34just a fake concoction with no pain-easing properties at all.

00:39What made the students so sure this dummy drug had worked?

00:43The answer lies in the placebo effect,

00:45an unexplained phenomenon wherein drugs, treatments, and therapies

00:50that aren't supposed to have an effect and are often fake

00:53miraculously make people feel better.

00:56Doctors have used the term placebo since the 1700s,

01:00when they realized the power of fake drugs to improve people's symptoms.

01:05These were administered when proper drugs weren't available,

01:08or if someone imagined they were ill.

01:11In fact, the word placebo means I shall please in Latin,

01:15hinting at a history of placating troubled patients.

01:19Placebos had to mimic the real treatments in order to be convincing,

01:23where they took the form of sugar pills, water-filled injections,

01:26and even sham surgeries.

01:29Soon, doctors realized that duping people in this way had another use,

01:34in clinical trials.

01:35By the 1950s, researchers were using placebos as a standard tool

01:40to test new treatments.

01:41To evaluate a new drug, for instance,

01:44half the patients in a trial might receive the real pill.

01:47The other half would get a placebo that looked the same.

01:50Since patients wouldn't know whether they'd receive the real thing or a dud,

01:54the results wouldn't be biased, researchers believed.

01:57Then, if the new drug showed a significant benefit compared to the placebo,

02:02it was proved effective.

02:04Nowadays, it's less common to use placebos this way because of ethical concerns.

02:09If it's possible to compare a new drug against an older version or another existing drug,

02:15that's preferable to simply giving someone no treatment at all,

02:18especially if they have a serious ailment.

02:21In these cases,

02:22placebos are often used as a control to fine-tune the trial,

02:26so that the effects of the new versus the old or alternative drug

02:30can be precisely compared.

02:33But of course, we know that placebos exert their own influence, too.

02:37Thanks to the placebo effect, patients have experienced relief from a range of ailments,

02:42including heart problems, asthma, and severe pain,

02:45even though all they'd received was a fake drug or sham surgery.

02:49We're still trying to understand how.

02:52Some believe that instead of being real,

02:54the placebo effect is merely confused with other factors,

02:58like patients trying to please doctors by falsely reporting improvements.

03:02On the other hand, researchers think that if a person believes a fake treatment is real,

03:07their expectations of recovery actually do trigger physiological factors

03:12that improve their symptoms.

03:14Placebos seem to be capable of causing measurable change in blood pressure,

03:18heart rate,

03:19and the release of pain-reducing chemicals like endorphins.

03:23That explains why subjects in pain studies often say placebos ease their discomfort.

03:28Placebos may even reduce levels of stress hormones like adrenaline,

03:32which can slow the harmful effects of an ailment.

03:36So shouldn't we celebrate the placebo's bizarre benefits?

03:39Not necessarily.

03:41If somebody believes a fake treatment has cured them,

03:44they may miss out on drugs or therapies that are proven to work.

03:48Plus, the positive effects may fade over time, and often do.

03:53Placebos also cloud clinical results,

03:55making scientists even more motivated to discover how they wield such power over us.

04:02Despite everything we know about the human body,

04:04there are still some strange and enduring mysteries, like the placebo effect.

04:09So what other undiscovered marvels might we contain?

04:13It's easy to investigate the world around us

04:15and forget that one of its most fascinating subjects lies right behind our eyes.

04:31is

The power of the placebo effect - Emma Bryce

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