Know it's a placebo? Study shows the 'medicine' could still work

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Know it's a placebo? Study shows the 'medicine' could still work

You don't realized you're hungry, then a friend mentions how hungry he is or you smell some freshly baked pizza and suddenly you feel hungry. Or, you've had surgery and need a bit of morphine for pain. As soon as you hit that button you feel relief even though the medicine hasn't even hit your bloodstream.

These are two examples of the oft-studied placebo effect that demonstrate the amazing and still somewhat confounding powers of the human brain.

CU-Boulder graduate student Scott Schafer, who works in Associate Professor Tor Wager's Cognitive and Affective Neuroscience Lab in the Department of Psychology and Neuroscience, discovered the placebo effect still works even if research participants know the treatment they are receiving to ease pain has no medical value whatsoever.

The subjects need ample time in this case four sessions -- to be conditioned to believe the placebo works. Then, even after it is revealed that the treatment is fake, they continue to get pain relief. When participants are told the truth about the treatment after one session, they don't show a placebo effect.

The findings suggest that reinforcing treatment cues with positive outcomes can create placebo effects that are independent of reported expectations for pain relief. Wager, think that they require both belief in the power of the treatment and experiences that are consistent with those beliefs. Those experiences make the brain learn to respond to the treatment as a real event. After the learning has occurred, your brain starts responding to the placebo even if you no longer believe in it."

Schafer, Wager, and co-author Luana Colloca, of the University of Maryland Baltimore, had published their paper in the May issue of The Journal of Pain, "Conditioned Placebo Analgesia Persists When Subjects Know They Are Receiving a Placebo"

My general interests "Digging into how placebos occur and when and why they arise is really interesting."

Schafer and Colloca conduct a research, applied a ceramic heating element to research subjects forearms. Heat induce strong pain sensations, though not enough to burn the skin.

After applying heat of up to 117.5 degrees Fahrenheit to the research subjects who passed the initial screening. All subjects thought that Schafer applied analgesic gel on the affected skin, but the treatment was Vaseline with blue food coloring in an official-looking pharmaceutical container. To aid in the charade, the subject was asked to read drug forms and indicate whether they had liver problems or were taking other medications prior to receiving the treatment.

Schafer said "They believed the treatment was effective in relieving pain", 

After this process, they had acquired the placebo effect. We tested them with and without the treatment on medium intensity. They reported less pain with the placebo."

Schafer believes the brain plays a key role in subjects for whom the placebo gel worked, and that more research is warranted.

"We know placebos induce the release of pain-relieving substances in the brain, but we don't yet know whether this expectation-independent placebo effect is using the same or different systems," Schafer said.

University of Colorado at Boulder
Exploratory, Placebo, Pain, Brain
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