Tag: placebo effect

The Brain's Medicine: Natural Marijuana-Like Chemicals Play Important Role in Placebo Effect

By Douglas Main | October 7, 2011 12:03 pm

Placebos are inactive treatments that shouldn’t, in some sense, have a real effect. And yet they often do. But the chemical basis of the placebo effect, despite its enormous importance, is still largely a mystery. A study published this week in Nature Medicine shows that cannabinoid receptors are involved in the placebo response to pain, which hasn’t been demonstrated before. The finding implies that the brain’s own endocannabinoids can fight pain, and actually do it via the same pathway as several compounds in the cannabis plant.

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CATEGORIZED UNDER: Health & Medicine, Mind & Brain

Study: Placebos Can Work Even if Patients Know They're Placebos

By Andrew Moseman | December 27, 2010 9:56 am

You’ve heard of the placebo effect—the tendency for patients who receive a phony treatment like a sugar pill to feel better just because they think the treatment will help them. That standard definition relies on deception. Surely the placebo effect doesn’t work if you tell the patients they’re taking placebos, right?

Not necessarily, a new study finds. And, as DISCOVER blogger Ed Yong notes, this brings up an interesting ethical question:

Can doctors justifiably prescribe placebos to their patients? The standard answer is no. Doing so patronises the patient, undermines their trust, and violates the principles of informed consent. It compromises the relationship between doctor and patient. At worst, it could do harm.

But many of these arguments are based on the idea that placebo effects depend on belief; people must expect that treatments will work in order to experience any benefits. For a doctor to prescribe a placebo, they’d need to deceive. But according to Ted Kaptchuk from Harvard Medical School, deception may not be necessary. In a clinical trial, he found that patients with irritable bowel syndrome (IBS) felt that their symptoms improved when they took placebo pills, even if they were told that the pills were inactive.

For plenty more about this, check out the rest of Ed’s post at Not Exactly Rocket Science.

Related Content:
Not Exactly Rocket Science: The Placebo Effect Affects Pain Signaling in the Spine
Not Exactly Rocket Science: A Biological Basis for Acupuncture, or More Evidence for a Placebo Effect?
80beats: 50% of U.S. Doctors Secretly Dose Their Patients—With the Placebo Effect
DISCOVER: Is the Placebo Effect a Myth?

Image: flickr/Fillmore Photography

CATEGORIZED UNDER: Health & Medicine

Placebo Effect Isn't Only in the Brain—It's Also in the Spine

By Brett Israel | October 20, 2009 7:00 am

placebo-webWith a little deception and an fMRI machine, scientists have traced the placebo effect to the spinal cord, according to new research published in the journal Science. The placebo effect, of course, is the well-known phenomenon in which patients who think they are getting medical treatment report that they feel better, even when they get only a sugar pill or other fake therapy [Los Angeles Times]. To test the limits of the placebo effect, researchers applied an anesthetic “lidocaine” cream to one arm, and a “control” cream to the other, making sure to tell the subjects which cream was which. The researchers applied a hot stimulus for 20 seconds to the skin where the each cream was applied. Participants said the “lidocaine” cream reduced pain by an average of 26 percent.

This would all be fairly straightforward had the researchers not been lying to their test subjects. You see, neither cream had active ingredients. They also primed a response by turning down the painful heat for the painkiller cream in a first test run, and so tricked volunteers into thinking that the cream would work the next time. But actual tests with an MRI scanner on involved the same level of heat for both creams. Volunteers nonetheless reported less pain with the painkiller cream [Popular Science].

The fMRI data backed up the participants’ pain perception. Normally when a person experiences pain, the dorsal horn area of the spinal cord near the lower neck will appear to be on fire with activity, but the fMRI scans showed nerve activity was reduced significantly when subjects believed they were getting the anesthetic [Reuters]. The researchers say this indicates that “psychological factors” can have an effect on pain outside of the brain. They hope to develop new treatments that can exploit the placebo effect’s painkiller effect.

Related Content:
80beats: 50% of U.S. Doctors Secretly Dose Their Patients—With the Placebo Effect
80beats: Fake Surgery Eases Spinal Pain as Well as the “Real” Thing
80beats: When Surgery Is Over, Anesthetics Actually Increase Pain

Image: flickr / fbaett

CATEGORIZED UNDER: Health & Medicine
MORE ABOUT: pain, placebo effect

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