Study on Placebo Effect: How The Brain Uses Expectations

[HuckleB]

Great (taste) Expectations: Brain Anticipates Taste And Shifts Gears, Study Shows:
http://www.medicalnewstoday.com/medicalnews.php?newsid=38186

"As the prism of our senses, the human brain has ways of refracting sensory input in defiance of reality.

This is seen, for example, in the placebo effect, when simple sugar pills or inert salves taken by unwitting subjects are seen to ease pain or have some other beneficial physiological effect. How the brain processes this faked input and prompts the body to respond is largely a mystery of neuroscience.

Now, however, scientists have begun to peel back some of the neurological secrets of this remarkable phenomenon and show how the brain can be rewired in anticipation of sensory input to respond in prescribed ways. Writing in the current issue (March 1, 2006) of the journal Brain, Behavior, and Immunity, a team of University of Wisconsin-Madison scientists reports the results of experiments that portray the brain in action as it is duped.

The new work, conducted by a team led by UW-Madison assistant professor of psychology and psychiatry Jack B. Nitschke, tested the ability of the human brain to mitigate foul taste through a ruse of anticipation. The work, conducted at the UW-Madison Waisman Center using state-of-the-art brain imaging techniques and distasteful concoctions of quinine on a cohort of college students, reveals in detail how the brain responds to a manipulation intended to mitigate an unpleasant experience.

..."

[bloom]

1. That sounds like an interesting study.

It's like all of the "positive thinking" concepts.

[RedOnce]

2. Nice! Thanks for posting this.

[Warpy]

3. Scans have been done of heroin addicts who were just starting

to have withdrawal symptoms. The news that a dose of methadone was being poured and was on the way relieved many of the symptoms of withdrawal before the drug even entered the room.

The placebo effect is very real and very powerful. It's just not a 100% effect, so it's nothing that can be counted upon in a clinical setting.

[RedOnce]

4. Do Docs typically attempt to make use of placebo effect?

[varkam]

5. Sham surgeries, inert asthma inhalers, and sugar pills, oh my!

It's somewhat morally questionable, but yes, doctors do sometimes resort to taking advantage of the placebo effect in the course of medical treatment. Here's a few I'm aware of:

Sham surgeries - These are especially helpful with fibromyalgia or arthritic conditions. A sham surgery consists of telling the patient they will be operated on to alleviate their condition, putting them under, cutting them open, doing absolutely nothing and patching them back up. Believe it or not, it helps in many cases. It's hypothesized that pain, with certain people, is largely a psychological phenomenon. That's not to say they're faking it or exaggerating. They do actually feel the pain, but there is no discernable physiological cause.

Asthma inhalers - Some asthma inhalers are essentially water vapor mixed with flavoring - makes it taste like medicine. I really don't know much else about it, but I know that they're used sometimes.

Sugar pills - Very useful for people who have developed a psychological dependence on potentially physically addictive medication (e.g. hypnotics). Just ween them off of their current meds and onto a sugar pill until it's completely out of their system.

Of course, like I said, things like these are somewhat morally ambiguous and smack of paternalism, but then again they do some good.

[RedOnce]

8. Very interesting. I wonder what else goes on?

[Warpy]

6. No, it's against the code of ethics in state practice acts

to give a patient sugar pills and tell him they're any sort of legitimate medication.

"Alternative medicine" practitioners, however, are under no such constraints.

[RedOnce]

7. In order to gain FDA approval, the benefit of drug must exceed

placebo effect. So,doesn't it follow; in order for a patient to receive full benefit of that drug the patient must "believe" that the drug will work? Do docs typically attempt to help the patient believe in the drug?

Second, given the power of placebo effect, how do you feel about being restrained from using sugar pills?

[varkam]

10. I don't know if I'd say that necessarily

Docs don't need to help patients 'believe' in the drug. Presumably, if a drug makes it to market there is a decent amount of data backing the drugs efficacy (e.g. randomized, double-blind, multi-site, placebo-controlled clinical trials). Placebo control here is key. People would tend to think that, especially for certain anxiety disorders (like GAD for example) effects of pharmacotherapy can be written off as the placebo effect in motion.

However, in most Phase III clinical trials, there is a control group that is (theoretically) identical in every respect to the treatment group with the exception that they're being given an inert substance. What's more, neither them nor the physician whose care they are under know whether or not the pill is the placebo or the real deal (double-blind). If there is a significant difference between the two groups on the dependent measure (such as a reduction in anxiety symptoms as measured by a validated scale), then it cannot be written off as the placebo effect, as that expectancy or belief of the patients would be operating in both groups (and thus, it still doesn't explain the difference).

However, as you imply, expectancy is very important. Take drugs that have the side effect of impotency for example - if you tell the patient that the possible side effect, though rare, is impotency, then the incidence increases.

In my opinion, using placebo pills in medical treatment is wrong on it's face. Different people have different priorities in their medical care, and using placebo pills to achieve a therapeutic effect makes a pretty big paternalistic assumption (namely, that the number one priority is to get better faster). That's not always the case. I've seen cancer patients forgo chemotherapy because they value quality of life over quantity of life - even when it meant significant harm to the latter. In short, such paternalism violates autonomy, which, in my opinion, should be central to the patient / doctor relationship.

[RedOnce]

11. Excellent points!

My thinking is that expectancy could potentiate the benefit of the drug. As you point out, the use of placebo effect can get into a paternalistic assumption. But, if the drug is being prescribed anyway, it seems like a good questionnaire and screening could avoid this trap by uncovering the patient's true goals thereby allowing allopathic medicine access to a powerful tool.

[varkam]

9. Sure, it might be against the ethics code

But do you, in your heart of hearts, believe that every single practicing physician adheres strictly to both the letter and spirit of ethics laws?

[Warpy]

12. If he doesn't, he gets SUED

he also risks getting hauled up before various ethics boards and refused privileges at local hospitals, and yes, I've seen this happen.

That doesn't happen to herbalists, crystal healers, and other dubious practitioners, of course. They fear neither lawyers nor ethics panels.

[varkam]

13. Just so long as you're not equating...

homeopathic practitioners with 'dubious' ones.

And he only gets sued if someone finds out about his practices.

[Warpy]

14. When an allopathic doctor hurts somebody, people tend to find out

Homeopathic practitioners and others who practice outside accepted scientific methods generally don't have to worry about that unless they fleece somebody of a huge amount of money while they're pretending to cure cancer, which is why those folks are mainly in Mexico.

Honestly, I'm finding out doctor phobia runs deep.

[varkam]

15. Let's see...

homeopathic practitioners have scientific peer-reviewed journals dedicated to the field, codes of ethics and internal review. Yup, buncha quacks. Hell, St. John's Wort is the #1 prescribed agent in Germany for depression.

Look, there are quacks everywhere to be sure. Homeopathy has em too, without a doubt. But so does traditional medicine. But to paint the whole field with that broad a brush is just irresponsible and irrational.

[trotsky]

16. You are confused about what "homeopathy" means.

It is not the same as simply taking herbs or some other natural substance.

Homeopathy is completely and utterly phony. It purports water to have a "memory" of every molecule it has come in contact with. In addition, the bogus "Law of Infinitesimals" (http://www.homeowatch.org/basic/infinitesimals.html) claims that "the lower the concentration of a substance, the more potent it becomes."

[varkam]

17. Perhaps I am confused.

It certainly wouldn't be the first time and probably won't be the last. I guess what I am referring to is natural medicine, e.g. Natural Doctors.

[Warpy]

18. I'm amused by a lot of the "remedies" that homeopaths

prescribe here, arsenic in water that's far less than what's in tap water, "Oh, but it's mixed in a very precise manner to excite the water." What a total bunch of garbage!

Double blind studies have not been kind to herbs, either.

The herbs that actually do work have been banned either by the FDA or the DEA.

Again, homeopaths aren't subject to the same sort of review and litigation that doctors are because they're not actually DOING anything. The real quacks are in Mexico, though, the ones who claim to cure fatal diseases and only cure that surplus in the sufferer's bank account.

Again, if people want to waste their money on this stuff, the placebo effect might make them feel better. If they're really sick, though, they need to swallow their pride and go to a doctor.

[RedOnce]

19. As you imply, Germany is much more serious about herbs...

Roughly 600 to 700 plant-based medicines are available and are prescribed by approximately 70% of German physicians. http://www.umm.edu/altmed/ConsModalities/HerbalMedicinecm.html

The German government’s counterpart to the U.S. Food and Drug Administration is the German Federal Institute for Drugs and Medical Devices. In 1976, Germany passed a law that required all medicines then on the market (including conventional drugs) to be reviewed by scientific committees. In 1978, they established a special committee on herbal remedies called the Commission E.

The Commission E is a federally appointed panel of leading experts on herbs and plant-based medicines. Members of the commission, who serve three-year terms, were proposed by various health professional associations and appointed by the Minister of Health. The initial task of the Commission E was to evaluate the safety and effectiveness of herbal remedies.

Today, the 24 members of the commission include physicians, pharmacists, pharmacologists, toxicologists, representatives of the pharmaceutical industry and lay persons, among others. About half of the members are university researchers who study the theoretical scientific basis of herbal medicines. The other half is composed mainly of health-care professionals with experience in prescribing and dispensing plant medicines. One of the perceived strengths of the commission is its ability to utilize a broad range of experience and expertise from numerous academic disciplines.

[BuddhaGirl]

20. Homeopathy is medicine that is regulated by the FDA

I agree that quacks exist everywhere but it is pretty sad that people are so close-minded about alternative medicine. Heck, even animals respond well to homeopathy!