The placebo effect – one of the more baffling aspects of health and medicine.  It is, in essence, when you take a fake treatment and get real benefits.

Why getting a pill, for instance, with nothing in it but sugar can often make you feel significantly better, versus getting nothing at all, is a real mystery.

Fortunately, research continues to show more and more about how it works and why as well as what it means.  In particular, specific biochemical analysis has shown that the placebo effect has very real effects on the body that can be measured and analyzed.

The history

As a concept, the placebo effect stems from a mistranslation by St. Jerome of a Hebrew prayer, using the Latin word placebo, which means “I shall please,” instead of the Latin for “I shall walk.”

Those who would pray using this prayer, which was considered invalid, were called placebos.

This concept evolved with time.  At least from the end of the 18th century, the placebo effect was recognized as medical phenomenon when a fake treatment produces real results.

After World War II, with the advent of randomized, controlled trials, scientists began to notice that a high percentage of people given a fake treatment showed significant improvement.

What causes the placebo effect?

It is believed that two main causes of the placebo effect are conditioning and expectation.

Conditioning is a concept made famous by Pavlov in his studies of dogs.  He noticed that dogs would salivate upon seeing food.  Pavlov was able, by ringing a bell when serving food, to train dogs to eventually start salivating upon hearing a bell alone.

This is a trained response.  The theory of conditioning in placebo effect is that similarly, we are trained to respond in a certain way to being given a pill and seeing a doctor/being in a medical setting.

Just like the bell can cause a dog to salivate, a pill or other treatment can cause us – at least in theory – to have a variety of responses, such as feeling less depressed or less pain or having a better heart rate.

The other cause, expectation, focuses on the powerful effect that expectations can have.  We naturally expect a treatment to have benefit.  This can translate into a sham treatment having real benefits.

For instance, take the case that a cream is rubbed on a painful spot.  If you are told that the cream will reduce pain, and so expect it, you are more likely to report pain reduction than someone who is not told that.

What is the placebo effect?

Research has shown that the placebo effect is not simply just psychological.  Rather, a placebo treatment can produce a variety of specific, measurable biochemical differences.

Studies have shown that a placebo for depression can cause changes in electrical and metabolic behavior in the brain.  A placebo for a heart condition can affect the beta-adrenergic hormonal system, and one for an immune condition can alter interleukins and interferon among others.

Proving that placebos have real, physical effects is the ability to block the placebo effect with medication.

Administration of naloxone, in particular, which is used to treat addictions, can prevent and reverse the pain-blocking effects of a placebo.

In summary

The placebo effect remains a mystery because it simply doesn’t make sense that a fake treatment can have real health benefits.  That said, we now know that it has real biochemical effects that can be measured and even blocked.

A better understanding of this phenomenon could lead to improved healthcare in a variety of ways.