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chaloobi
SFN Regular
1620 Posts |
 Posted - 12/04/2008 : 07:59:39
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What does this say about drug trials if certain people are predisposed to the placebo effect? Shouldn't those people be screened out? The article suggests screening them out would be a bad thing, though I'm not sure I understand why.
Seems like there's money to be saved here too. Patients known to be susceptable to the placebo effect don't need actual medication. They can take sugar pills and get the same effect, so long as they don't know about it. Would that be ethical?
http://sciencenow.sciencemag.org/cgi/content/full/2008/1202/1?rss=1
The Placebo Effect: Not All in Your Head
By Rachel Zelkowitz
ScienceNOW Daily News
2 December 2008
To get a drug to market, pharmaceutical companies have to show that it works better than a placebo. But sometimes the placebo is just as powerful as the real thing. Just why our bodies respond so strongly to fake medicine has long been a mystery, but researchers are a step closer to solving that riddle, having picked out a particular gene that may be responsible for one type of placebo effect.
The placebo effect works because patients believe they are actually receiving treatment. Expecting treatment is similar to anticipating reward, studies have shown, and reward anticipation triggers the release of the neurotransmitter dopamine in the brain, which can help alleviate symptoms of chronic pain and depression. But what about placebo effects for other conditions?
Tomas Furmark, a psychologist at Uppsala University in Sweden, suspected that a different neurotransmitter plays a role in placebo responses to social anxiety disorder (SAD)--an abnormal fear of being judged by others. Brain imaging studies have shown that the amygdala, an area of the brain that regulates the fear response, is unusually active in patients with SAD. What's more, healthy people with certain variations of two genes that regulate the neurotransmitter serotonin have more active amygdalas.
Based on these results, Furmark and his colleagues--in collaboration with the pharmaceutical company GlaxoSmithKline--ran a placebo-controlled trial with 108 patients who had been previously diagnosed with SAD. The volunteers were randomly assigned to receive either a new serotonin medication or a sugar pill for 8 weeks. At the beginning of the trial, the patients had to prepare and deliver a speech in front of small group of people--an anxiety-triggering event--while the researchers tracked their amygdala activity using positron emission tomography. The technique allows researchers to track blood flow--and thus activity--in different areas of the brain. The study participants had to give a similar speech at the end of the treatment period, so researchers could assess whether their patterns of brain activity had changed.
Even sugar was enough to conquer some cases of SAD. Of the 25 patients who received the placebo, 10 reported reduced anxiety by the end of the study. (Numbers for the treatment group were not released because the trial is ongoing.) Brain scans during the second speech showed their amygdalas were also less active. Genetic analysis revealed that eight people who got relief from the placebo had a particular version of a gene that regulates serotonin production called the tryptophan hydroxylase-2 promoter (TPH2), the researchers report tomorrow in the Journal of Neuroscience. This is one of the same genetic variants linked to heightened amygdala activity in healthy people. TPH2 is the first genetic marker tied to any placebo response, the team reports.
Finding genetic markers for the placebo effect could raise ethical questions about how companies design their clinical trials, Furmark says. For example, "it could be tempting to screen all individuals and ... select only those with [the] nonresponsive phenotype [for the trial]."
Psychiatrist Helen Mayberg of Emory University in Atlanta, Georgia, who has studied the placebo effect in depression, agrees that the findings could have major implications for research design. But first, more research is needed to determine if the genetic markers for placebo relief from SAD can be generalized to other diseases, and what other genes might contribute to the phenomena, she says. |
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-Chaloobi
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Simon
SFN Regular
USA
1992 Posts |
Posted - 12/04/2008 : 09:02:48 [Permalink]
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Makes a lot of sense, actually.
Of course, the title is a bit misleading. Placebo effect is still all in your head, we just now where precisely...
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Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.
Carl Sagan - 1996 |
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tomk80
SFN Regular
Netherlands
1278 Posts |
 Posted - 12/04/2008 : 09:52:31 [Permalink]
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Originally posted by chaloobi
What does this say about drug trials if certain people are predisposed to the placebo effect? Shouldn't those people be screened out? The article suggests screening them out would be a bad thing, though I'm not sure I understand why. |
From a research technical point it might be a good idea to screen those people out. However, this would necessitate a genetic screening for each and every trial. That gives an ethical problem.
| Seems like there's money to be saved here too. Patients known to be susceptable to the placebo effect don't need actual medication. They can take sugar pills and get the same effect, so long as they don't know about it. Would that be ethical? |
It wouldn't be considered ethical as you are breaching doctor/patient confidence. Basically, you "force" doctors to lie to their patients. This can undermine the trust of the patient, who should be informed about his/her treatment.
Also, that some people are more susceptible to a placebo effect doesn't mean the medication itself wouldn't have an added effect.
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Tom
`Contrariwise,' continued Tweedledee, `if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic.'
-Through the Looking Glass by Lewis Caroll- |
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dglas
Skeptic Friend
Canada
397 Posts |
Posted - 12/04/2008 : 10:02:19 [Permalink]
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I find this very, very exciting!
The placebo effect is one of those things I find hard to discuss with mystical sorts. it's one of those things they mistakenly clutch at as proof of "he power of the mind" in their peculiar meaning and their mysticism-of-the-gaps thinking. To discover a mechanism for the operation of the placebo effect rather than just an unexplained tendency is wonderful news.
I can see the problem with selection though. Responsive/non-responsive phenotyping may have to become a standardized part of every drug trial - as it represents a source of error. But is that really so much different that any other controls? |
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- dglas (In the hell of 1000 unresolved subplots...)
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The Presupposition of Intrinsic Evil
+ A Self-Justificatory Framework
= The "Heart of Darkness"
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dglas
Skeptic Friend
Canada
397 Posts |
Posted - 12/04/2008 : 10:21:16 [Permalink]
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[i]Originally posted by tomk80
| Seems like there's money to be saved here too. Patients known to be susceptable to the placebo effect don't need actual medication. They can take sugar pills and get the same effect, so long as they don't know about it. Would that be ethical? |
It wouldn't be considered ethical as you are breaching doctor/patient confidence. Basically, you "force" doctors to lie to their patients. This can undermine the trust of the patient, who should be informed about his/her treatment.
Also, that some people are more susceptible to a placebo effect doesn't mean the medication itself wouldn't have an added effect.
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Roleplayng...
I can see the nightmare scenario now: The new Eugenics - Let's breed for people subject to the placebo effect and save on national health care expenses!
Every doctor now keeps a "gullibility index" for each patient which dictates placebo prescription as determined by an oversight committee. Perhaps it'll be a branch of Homeland Security. But then, we may yet see Dopamine administration along political lines and in creationist classrooms, right?
If using a placebo effect is lying then doctors who wear white coats lie to their patients all the time.
Sorry, just having fun with doomsday scenarios... 
But seriously, folks. A placebo effect may make one feel better (according to this particular study.) That does not necessarily mean that the cause of the initial problem is being dealt with. need more information, although this seems to bear great promise. |
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- dglas (In the hell of 1000 unresolved subplots...)
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The Presupposition of Intrinsic Evil
+ A Self-Justificatory Framework
= The "Heart of Darkness"
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| Edited by - dglas on 12/04/2008 10:24:16 |
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Simon
SFN Regular
USA
1992 Posts |
Posted - 12/04/2008 : 10:56:23 [Permalink]
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Well; placebo works on a person's brain but not on the bacteria in this person's bloodstream.
So, placebo acts as a natural anti-depressor and a slight painkiller but it will not replace antibiotics. |
Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.
Carl Sagan - 1996 |
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A Genetic Basis for the Placebo Effect
