What Is the Placebo Effect, and Why Does It Matter?

In 1955, Harvard anesthesiologist Dr. Henry K. Beecher described a powerful force our brains can have over our bodies: the placebo effect (Kienle & Kienle). Since its discovery, the placebo effect has been considered a scientific fact, not a wacky magic trick your brain does. In his work “The Powerful Placebo”, Dr. Beecher conducted more than 15 trials with different diseases, claiming that 35% of 1082 patients were relieved of their pain by placebo effects on their own (Kienle & Kienle). But what exactly are the mechanics of this function? And how is it essential to our understanding of medicine? Today, we aim to understand this mysterious effect. 

“The placebo effect is triggered by the person's belief in the benefit from the treatment and their expectation of feeling better, rather than the characteristics of the placebo” ​​(Department of Health & Human Services, 2002). The very word “placebo” comes from the Latin phrase “I will please”, a fitting name for a phenomenon rooted in belief and expectation. Studies like Dr. Beecher’s have proven how practical this effect can be (Shmerling, 2022). Not only that, but your body shows many indicators of the effect working on you. While your mind is a huge contributor to how you feel pain, there are many more organs in your body that help process it as well. 

For example, the placebo effect has been shown to cause changes in blood pressure, heart rate, and changes in blood tests (Shmerling, 2022). These effects are similar to those that we would see after your body takes medication, yet in these cases, medication isn’t exactly needed. Still, placebos, as powerful and helpful as they are, aren't universal. It works better for some people than others, and not all conditions respond to it, which is why we still require medication (Shmerling, 2022).

Psychology also plays a role in how placebos work. One of the most accepted theories is from a type of learning called “classical conditioning.” This happens when a certain object or experience is associated with a specific response (Seladi-Schulman, 2020). For example, in a hypothetical scenario, a patient ate some bad tuna once, causing them to throw up. The classical conditioning in the brain will cause that patient to associate tuna with that reaction, which will create the desire to stay away from it. 

This is exactly how classical conditioning works in the placebo effect. If a patient has a headache, and they decide to take a placebo pill that looks like one that they usually take for headaches, then their brain will take that placebo and reduce the headache thanks to it. In short, placebos are often based on our expectations of a certain medication. If you have prior expectations of something, they will affect the perception of the experience (Seladi-Schulman, 2020). We can tell the expectations of something through communication, actions, and social perception of the environment of the situation. 

Now, a placebo isn’t always that helpful. In certain situations, if our given expectations for a specific treatment or medication are worse than what they are, then there is a possibility to experience the nocebo effect. The nocebo effect is basically placebo’s counterpart, “And if you expect a treatment will be harmful, you are more likely to experience negative effects. That phenomenon is called the "nocebo effect" (from the Latin "I shall harm")” (Shmerling, 2022).

The nocebo effect works in the way a placebo does, but in reverse. For example, if you tell a person that the common side effect of a pill is going to be a headache, but the pill is a placebo, then that person will experience the headache. This is because their perceived expectations of a pill are that there is going to be a headache, therefore shaping their perceptions. 

The placebo effect isn’t magic; it’s a powerful example of just how much power our brains have over our physiques. However, it’s important to keep in mind how much our expectations can influence something, because we could get hurt by the wrong side of this effect. 

References 

Department of Health & Human Services, V. (2002, February 15). Placebo effect. Better Health Channel. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/placebo-effect   

Kienle GS, Kiene H. The powerful placebo effect: fact or fiction? J Clin Epidemiol. 1997 Dec;50(12):1311-8. doi: 10.1016/s0895-4356(97)00203-5. PMID: 9449934.

Robert H. Shmerling, M. (2020, June 22). The placebo effect: Amazing and real. Harvard Health. https://www.health.harvard.edu/blog/the-placebo-effect-amazing-and-real-201511028544 

Seladi-Schulman, J. (2020, February 13). Placebo effect: What it is, examples, and more. Healthline. https://www.healthline.com/health/placebo-effect#the-psychology