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This Is Your Brain on the Placebo Effect

An arrangement of pink and white pills that is shaped like a human brain on a green-blue background.

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Key Takeaways

  • The placebo effect is a phenomenon that happens when people experience an effect from a treatment that they think contains active medicinal properties but actually does not.
  • In a new study, participants who reported less pain also showed greater reductions of activity in areas of the brain related to pain construction and subjective experience of pain.
  • Pain is not "all in your head," but in some cases, changing how you think about pain can help you manage it.

Imagine that a patient is given a pill and told that it will help ease their pain. In actuality, the pill contains no medicine—it's only a sugar pill. You might expect the patient not to see improvements because they weren't given treatment. However, sometimes, people who take these "fake" pills or shots do feel better.

This phenomenon is called the placebo effect. Scientists are not sure why, or how, it happens, but a new study has shed some light on the mystery.

In a March meta-analysis published in the journal Nature Communications, the researchers found that people who reported the most reduction in pain when taking a placebo also had less brain activity in areas of the brain associated with pain.

What Is the Placebo Effect?

A placebo looks like "real" medicine but doesn't contain any medicinal properties. For example, it could be a pill or shot that a patient believes contains medicine, but is really just sugar water. When a patient reports effects (wanted or unwanted) from treatments with no active medicine, it is known as the placebo effect.

What's even more intriguing is that people can also experience the placebo effect when they know they are taking a placebo.

While we know the placebo effect is real, it hasn't always been clear what may be happening in the brain when someone is experiencing the effect of a placebo.

Changes in the Brain

A team of researchers in the United States and Germany has provided insight into the neural underpinnings of the placebo effect.

"I've been interested in studying placebos primarily because they're a wonderful example of how one's thoughts, beliefs, and mindset can impact various kinds of outcomes," study co-author Tor Wager, PhD, a neuroscience professor at Dartmouth College in New Hampshire, tells Verywell.

In the past, neuroimaging research has monitored participants' whole-brain responses to placebos. For the new study, the research team combined and analyzed 20 independent studies to see if there were any overarching patterns.

The 20 studies included 603 healthy participants. The placebo effect was tested by exposing participants to a painful stimulus (such as heat) and then giving them a placebo treatment (an IV-infusion, a topical cream, or a nasal spray).

When some of the participants who took the "fake" treatment reported reduced pain (demonstrating the placebo effect), the researchers wanted to see if they were really feeling less pain.

To find out, they looked at the participants' brain activity compared to controls. By comparing the studies, the researchers found commonalities that indicated there was reduced processing in the areas and pathways of the brain associated with the construction of pain.

The researchers found changes in three areas of the brain:

  • The thalamus (which serves to gateway sensory input of the body to the brain)
  • The basal ganglia (which are involved in connecting pain to action and motivation)
  • The somatosensory cortex (which is involved in the early processing of pain)

The researchers also noted reduced activity in the posterior insula—a part of the brain that contributes to the early construction of painful experiences. The pathway from the thalamus to the posterior insula is important in how we recognize and understand pain.

"We show the largest brain relief in a number of areas that are involved in constructing that pain experience, or are close by them, interacting with them," Wager says. "And that's something people hadn't been able to see before."

What This Means For You

Pain is real and oftentimes can indicate damage that needs medical attention. But researchers found that you may be able to help ease some pain with mindset shifts. For people experiencing pain that may be chronic or associated with labor, thinking and internalizing that this pain isn't damaging or dangerous may help soothe pain overall.

What the Findings Mean

Although previous research has highlighted the role of the prefrontal cortex in the anticipation and experience of pain, results have been mixed across studies. The mixed results could be related to individual factors, whereas the new findings were more consistent across all individuals.

If someone thinks a placebo is a "real" treatment and that the pain will decrease when they take it, it appears likely that their brain will show changes in activity that lead them to subjectively feeling less pain.

"I think about the sensory changes as being a small part of placebo effects," Wager says. "But about these changes in motivation, value, and decision-making that come from the pain, as being the bigger part of what's effective."

Is Pain "All In Your Head?"

The new study looks at the pain caused by sensory inputs like heat, but could potentially help explain the pain we experience in daily life.

Tor Wager, PhD

It's not your fault if you're in pain, because it's real, but [the] consistent practice of reappraisal can help to adopt another mindset.

— Tor Wager, PhD

If you're wondering if the pain you're experiencing is "all in your head" and want to know if you should "push through it," the answer is both yes and no.

Wager says that ignoring pain or being distracted by something external can be powerful for a few seconds, but if the pain is consistent and intense, it will break through because your body is trying to motivate you to get help.

"People often, for example, will think that if you try to ignore and suppress the pain, then that's a good strategy," Wager says. "And that's actually probably the worst strategy."

Understanding Chronic Pain

Wager hopes that the research will improve our understanding of chronic pain and conditions like fibromyalgia. "A lot of what creates the feelings of suffering and long-term harm in chronic pain is avoidance and fear, which causes inflammation," Wager says. For these cases, strategies that are instigated by the person's beliefs could help.

New Ways of Thinking About Pain

The first strategy is what Wager says is called reappraisal of pain. "It's sort of talking to yourself. It's sparking a different mindset," Wager says. "That this pain is just pain. It's not dangerous. It's not damaging."

A new way of thinking about and relating to pain is one of the main takeaways from the study. "In many ways, it really is about your mindset," Wager says.

Still, we can't expect ourselves to change our mindset with the snap of a finger. "It's not your fault if you're in pain, because it's real," Wager says. "But [the] consistent practice of reappraisal can help to adopt another mindset."

Mindful Acceptance

Another strategy is called mindful acceptance, a process that therapists often help guide people with chronic pain through.

"This is the strategy of don't try it to get rid of the pain," Wager says. "Don't even try to ignore it. You have to realize and get to the point where you sort of believe that the pain isn't damaging you."

How Others Can Ease Our Pain

Wager emphasizes that if someone doesn't find it easy to practice these strategies or get results from them, that's not a negative reflection of who they are.

"It really does come down to the core belief about what the pain means," Wager says. "Is it dangerous? Is it a sign of damage? The placebo treatment is just one of the many ways of changing the mindset a little bit."

We can experience a placebo effect through support and care from other people. Take doulas, for example. "Having a doula can have remarkably good benefits," Wager says, adding that when people use a doula for pregnancy and childbirth, "labor time is cut almost in half on average."

The reason? "When you have a person who's helping you, and they're supporting you, and they're holding your hand, they're basically coaching into the right kind of mindset," Wager says. "Where your honest and your true belief is that this is going to be OK."

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  1. Zunhammer M, Spisák T, Wager T, Bingel U. Meta-analysis of neural systems underlying placebo analgesia from individual participant fMRI dataNat Commun. 2021;12(1). doi:10.1038/s41467-021-21179-3

  2. Harvard Health Publishing. The power of the placebo effect. Updated August 9, 2019.