The power of the placebo effect Emma Bryce

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.

1996 年,56 名志愿者参加
了一项研究,

以测试一种名为 Trivaricaine 的新型止痛药

在每个受试者中,一个食指
都被新的止痛药覆盖,

而另一个则保持不变。

然后,两人都被
夹在痛苦的夹子里。

受试者报告说,治疗过的
手指比未治疗过的手指伤害小。

这应该不足为奇,

除了 Trivaricaine 实际上
不是止痛药,

只是一种完全
没有镇痛特性的假药。

是什么让学生们如此确定
这种假药有效?

答案在于安慰剂效应,这

是一种无法解释的现象,在这种现象中

,不应该产生效果

并且通常是假的药物、治疗和疗法

奇迹般地让人感觉更好。

自 1700 年代,

当医生意识到
假药可以改善人们的症状时,他们就开始使用安慰剂这个词。

这些是在没有合适的药物
时使用的,

或者如果有人认为他们生病了。

事实上,安慰剂这个词
在拉丁语中的意思是“我会取悦”,

暗示着安抚
困扰患者的历史。

安慰剂必须模仿真实的治疗方法
才能令人信服,

所以他们采取了糖丸、

注水

甚至假手术的形式。

很快,医生们意识到
以这种方式欺骗他人还有另一个用途:

在临床试验中。

到 1950 年代,研究人员将
安慰剂用作

测试新疗法的标准工具。

例如,为了评估一种新药,

试验中一半的患者可能会
接受真正的药丸。

另一半会得到
看起来一样的安慰剂。 研究人员认为,

由于患者不知道
他们收到的是真货还是哑货

,因此结果不会有偏见

然后,如果新药与安慰剂相比显示出显着的
益处,

则证明它是有效的。

如今,出于道德考虑,以这种方式使用安慰剂的情况已不常见

如果可以将一种新药
与旧版本

或另一种现有药物进行比较,

那比简单地不给
某人治疗

要好,尤其是当他们患有严重疾病时。

在这些情况下,通常使用安慰剂
作为对照来微调试验,

以便可以精确比较
新药与旧药或替代药物的效果

但当然,我们知道安慰剂
也会发挥自己的影响。

由于安慰剂效应,

患者
的一系列疾病得到缓解,

包括心脏病、

哮喘

和剧烈疼痛,

尽管他们接受的
只是假药或假手术。

我们仍在试图了解如何。

一些人认为,安慰剂效应并非真实存在,而是

与其他因素混淆,

例如患者试图
通过虚假报告改善来取悦医生。

另一方面,

研究人员认为,如果一个人
认为假治疗是真实的,

他们对康复的期望实际上

触发改善症状的生理因素。

安慰剂似乎能够
引起血压、

心率

和减轻疼痛的
化学物质(如内啡肽)的可测量变化。

这就解释了为什么疼痛研究中的受试者
经常说安慰剂可以缓解他们的不适。

安慰剂甚至可以
降低压力荷尔蒙的水平,

比如肾上腺素,

这可以减缓疾病的有害
影响。

所以我们不应该
庆祝安慰剂的奇异好处吗?

不必要。

如果有人认为假治疗
已经治愈了他们,

他们可能会错过
被证明有效的药物或疗法。

此外,积极影响
可能会随着时间的推移而消退,

而且经常会消退。

安慰剂还掩盖了临床结果,

使科学家
更有动力去发现

他们如何对我们行使这种权力。

尽管我们
对人体了如指掌,

但仍有一些奇怪
而持久的谜团,

比如安慰剂效应。

那么我们还有哪些未被发现的奇迹
呢?

调查我们周围的世界很容易

,却忘记了其中最
迷人的主题之一

就在我们眼前。