Northwestern scientists find region of brain responsible for placebo effect

Emre Turkolmez, Reporter

Northwestern scientists discovered the area of the brain responsible for the placebo effect, the University announced.

Feinberg Prof. Apkar Vania Apkarian, who co-led a study on placebos, said the discovery will significantly help people dealing with chronic pain.

The study found a region of the mid-frontal gyrus, part of the frontal lobe, to be responsible for the placebo effect. In the study, published last month, scientists found that 50 percent of participants benefited from placebos.

Knowing the region of the brain responsible for the placebo effect can help doctors predict whether placebos can replace drugs for certain patients, postdoctoral fellow Etienne Vachon-Presseau said.

Using placebos can result in substantial reduction of pain, according to the study. They can help people stop using drugs for treatment, at least for a few months.

Placebos are better than administered drugs because they do not lead to side effects, according to the study. However, because the pills do not have any medicinal products, their effects are only psychological. The ability to predict the brain’s reaction to different types of medication will lead to a large improvement in treating chronic patients.

“This discovery will help us apply the best suited treatment for the person, rather than using trial and error with multiple drugs,” Vachon-Presseau said.

The finding will also lead to more precise and accurate clinical trials for pain medications by eliminating individuals with high placebo responses before trials, he said.

“Most studies about placebo were done on healthy people in highly controlled environments,” Vachon-Presseau said. “What we want to achieve here is a long-term clinical treatment with just sugar pills.”

These studies translate poorly to clinics, where most patients’ pain is chronic, Feinberg Prof. Marwan Baliki said in a news release.

In the study, scientists scanned every participant’s brain before the participant ingested the placebo pill. By rescanning the brains of patients who felt relief of pain symptoms after ingestion, scientists were able to identify the portion of the brain that was activated.

After the first set of findings, scientists moved on to a second group of subjects, this time focusing only on the specified area of the brain. Apkarian said the validation of the theory turned out a 85 to 90 percent rate of correct prediction.

Apkarian added that for some participants who were taking administered drugs, they did not experience the full effect of placebo pills.

This project, funded by the National Institute of Neurological Disorders and Stroke, began when a preliminary project’s data suggested there should be a place in the brain responsible for the placebo effect, Apkarian said.

The project’s initiation “was a surprising outcome of another project,” he said.

Northwestern scientists have already begun a new project building off their most recent findings, Vachon-Presseau said.

“The design of this new study will allow us to answer some fundamental questions about the placebo effect, such as its reproducibility, stability,” postdoctoral fellow Pascal Tetreault said.

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