Placebo Effect

What’s the coolest, strangest thing in medicine?Some people think it’s the placebo effect.While we can’t predict the future or move objects with our minds, the placebo effect is almost as magical as those two.

The “placebo effect” refers to the idea that simply “believing it works” for an ineffective therapy or intervention can improve health and alter cognition – seeminglyirrefutable evidence of the almost magical power of the mind to transcend matter.

Of course it’s not really magic.What are our beliefs?It is a subjective response to physical processes in the brain.And it is the neurochemical and current events in the brain, and their downstream effects, that produce the placebo effect.In some instances, the placebo effect can also be seen as a conditioned reflex: the learned mental response occurs despite the absence of the initial stimulus.

For scientists, the placebo effect is not only a surprising phenomenon, but also a methodological problem.Researchers must go out of their way to exclude the effects of subjects’ expectations so that they can determine which of the observed effects are actually the result of the intervention.

In honor of the mysterious and gripping placebo effect, and to promote the study of this most fascinating manifestation of the human psyche, we’ve rounded up 10 amazing placebo-related discoveries below.

I Even if you know it’s a placebo, it still works

It is generally accepted that deception is essential to induce the placebo effect, with physicians inducing patients to believe that an ineffective treatment is a powerful drug, or has similar efficacy.This element of deception has led to the fact that mainstream medicine has long viewed the deliberate induction of the placebo effect as unethical.

Nearly a decade ago, however, researchers noted that patients with irritable bowel syndrome who were given an open placebo, which they knew was ineffective, still had improved symptoms compared to those who did not receive any treatment.This must be due to the belief and expectation that the treatment will work, even though they know it won’t work (or perhaps it’s a conditioned response to the placebo that doesn’t require positive belief on the part of the patient).

Since then, additional studies have shown the effectiveness of open placebos for a number of conditions, including back pain and hay fever.Some experts say that open placebos “at least partially circumvent ethical barriers to the clinical use of placebos.”But other experts say there is a lack of sound research in this area.

It is also important to note that some studies did not produce positive results, such as disclosing that placebo did not accelerate wound healing.

II Branding, colors, and medically related items all enhance the placebo effect

In addition to overt placebos, there is evidence that the efficacy of placebos is related to their form of deception.The stronger the effect we imagine, the greater the benefit.

This means that four placebos are better than two, and placebo injections (which have nothing but saline in them) are stronger than placebo pills.One study even found that a placebo injection works better than taking real medicine when treating osteoarthritis.

In addition, depending on the disease being treated, tablets with certain colors and descriptive text are particularly effective, e.g., blue placebo tablets are more sedating than pink ones, and branded placebos are more efficacious than unbranded ones.

The effect of a placebo’s credibility on its subsequent efficacy may explain one of the most amazing placebo demonstrations I’ve ever seen.It was a “placebo brain surgery” – and what better way to inspire hope for therapeutic results when undergoing brain surgery than with the sophisticated equipment and procedures used by experts?In particular, the study showed that Parkinson’s patients who underwent a placebo brain surgery (pretending to be injected with stem cells) showed a more pronounced improvement in their symptoms than those who actually received the stem cell treatment but didn’t know it.The researchers said, “This study had a strong placebo effect, and it demonstrates the value of having a placebo control in surgical trials.”

III Some people are more susceptible to the placebo effect than others

People with certain personality traits are more prone to the placebo effect.This is understandable because the placebo effect depends on our beliefs and expectations, which some people may share more readily and enthusiastically than others.

Findings in this area include that optimists are more likely to respond to pain-relieving placebos.Those who scored higher on toughness of character and friendliness to others also responded better to pain-relieving placebos, which may be related to the physician’s interactions with the patient while inducing the placebo effect.

Curiously, the traits associated with placebo response vary with the condition being treated – for example, in the context of stress treatment, one study found that conversely, subjects with pessimistic personalities and poor empathy responded better to placebo.

Current evidence also suggests that personality traits appear to have a significant effect on placebo effect responses, whereas age and gender have little effect.

IV Some doctors are better at inducing the placebo effect than others

The placebo effect depends on the patient believing that the treatment he or she is receiving is effective.And some doctors are better than others at reinforcing hope and expectation of treatment.

This is also confirmed by research: a study of allergic reactions treated with placebo injections noted that patients’ symptoms improved more if the injections were administered by a gentle and trustworthy physician.

It may also be helpful for patients to feel that they are “on the same page” as their doctors: another study found that when patients perceived that their primary care physicians shared their values and personal beliefs, they experienced less subjective pain after clinical procedures.

V Placebo also improves creativity and cognitive performance

We usually think of the placebo effect in terms of medical interventions, particularly pain relief.Yet there is growing evidence that placebos have other effects, including improving our physical and mental performance.

In terms of athleticism, several studies have found placebo effects in speed, strength and endurance.In one placebo-like study, researchers asked cyclists to train to the point of exhaustion and found that if their clocks were secretly modified to go slower, these cyclists lasted significantly longer as well.

In terms of creativity, in one study, an experimental group outperformed a control group on a test of creativity after smelling an odor that was said to enhance creativity, and the control group smelled the same odor, but were not told that it was particularly beneficial.In another experiment, subjects received placebo noninvasive brain stimulation and completed a learning task.The placebo group thought that their brains were stimulated with a mild electric current, but they were not, and they thought that the stimulation would improve mental functioning.As a result, in a subsequent learning task, the placebo group subjects were more precise and had faster response time reduction than the control group.The researchers stated, “We conclude that anticipation induced in an experiment can influence cognitive functioning in healthy adult subjects.”

VI There’s even “placebo sleep”

The list of manifestations of the placebo effect is almost endless.For example, there is this curious example of researchers tricking subjects into believing that they slept longer than they actually did, and then observing how this affected their performance the next day.The researchers did this by having the subjects take various psychometric measures and then giving some of them false feedback on their deep sleep time (REM rapid eye movement sleep time).After hearing that they had gotten enough sleep, these subjects performed better on verbal and arithmetic tests.

There are other imaginative examples and manifestations of the placebo effect, such as a study that found that when hotel cleaners learned that their work counted as physical exercise, their health actually improved, including their weight, body mass index, body fat, waist-to-hip ratio, and blood pressure.Another interesting study might also be explained by the placebo effect: people who believed they exercised more than their peers tended to live longer than their peers, regardless of how much they actually exercised.

VII Animals can experience the placebo effect too

Drug trials using animals often compare effective therapies with placebos, similar to the process used in human drug trials.In these comparisons, researchers often find that a significant number of animals in the placebo group also respond to the treatment, such as in a trial of an anti-epileptic drug in dogs and a trial of a dietary intervention for muscle stiffness in horses.

But there’s a hole in the interpretation of these results: these placebo effects may be present in animal owners, who may treat their animals differently when they believe their animals are actually receiving medical treatment or nutritional supplements.

However, several laboratory studies on rodents have demonstrated that a certain placebo effect does show up in animals.Researchers have paired an effective drug (such as morphine) with a specific flavor or scent, and then they have shown that even removing the drug and just reproducing the flavor or scent can have an analgesic effect on rodents.

In this example, the source of the placebo effect is conditioning rather than the animal’s expectation, though this may be part of the rationale for the placebo effect in humans.As Edward Ernst, a medical expert who specializes in non-mainstream therapies, puts it, “A large part of what we think of as the placebo effect is also found in animals.”

VIII The placebo effect also has an evil twin, the nocebo effect

There is a placebo effect simply because you believe a certain treatment is beneficial.It can be argued that if you have negative expectations, your symptoms will worsen.Researchers have indeed found this phenomenon and call it the “nocebo effect”.

This twin of the placebo effect is also not to be underestimated.A meta-analysis of analgesic studies (in which some subjects were told that an ineffective cream or pill would increase pain in some people) showed that the size of the anti-placebo effect was roughly comparable to the placebo effect.

Interestingly, even when patients are given real painkillers instead of sham treatments, the anti-placebo effect still occurs.One study told subjects that their pain would intensify after the analgesic treatment was stopped.Normally, the psychological effects of analgesics continue for a while even after the medication is discontinued, but for these subjects, its effects suddenly disappeared, as if the subjects’ negative expectations dissolved the real effects of the analgesics.The relevance of these findings is obvious; at the very least, you need to be aware of them when you read the side effect descriptions of newly dispensed drugs.

IX For many psychological researchers, the placebo effect is a nuisance

The placebo effect, while interesting, can be maddening for researchers interested in proving the efficacy of psychological interventions.Psychological expectations strongly and pervasively influence our thinking, feelings, and behavior, making many studies have to be carefully designed or else it is difficult to interpret the results.

In a 2013 paper titled “The Pervasive Placebo Problem in Psychology”, Walter Boot’s team at Florida State University pointed out that many psychological studies (on topics such as brain training, expressive writing, and Internet therapy) have actually failed to hold subjects in different experimental subgroups to the same expectations.They explain that it is not enough to have a positive control group, because subjects in the control group may not expect the experiment to have beneficial or powerful effects, as they do in the intervention group.

Boot and colleagues note that the solution to this problem is to measure the subjects’ expectations and take steps to try to equalize the expectations of the control and intervention groups.They conclude, “We hope that future studies will have better designs and will be better able to contain the placebo effect and present more credible evidence on the efficacy of the intervention.”

X The placebo effect seems to be increasing

Curiously, the placebo effect seems to have increased in recent years, as shown for antipsychotics, antidepressants, and analgesics.

The placebo effect of one of the analgesics only got stronger in the United States.Study team leader Jeffrey Mogil told Natural News, “We were stunned to discover this effect.”Specifically, in the 1990s, they found that subjects taking an effective drug reported pain relief at a rate 27 percent higher than those taking a placebo, but by 2013, the gap had narrowed to 9 percent.One explanation is that new drug trials have become larger and more elaborate, especially in the U.S., so subjects taking placebos also experience more drama and tension.

Another possibility is that the public is more aware of the placebo effect and the fact that it really can affect symptoms (e.g., reduce brain activity related to pain), not just the illusion.In last year’s issue of the journal Pain, anesthesiologist Gary Bennett made this point.He even went so far as to argue that the word “placebo” should no longer be used in drug trials and should be avoided in all patient instructions and guidance texts, given that it causes such a strong placebo effect.　　　

In any case, the placebo effect will continue to exist, no matter how hard we try to control, hide and understand it.It will certainly continue to both confuse and amaze us for a long time to come.