"A placebo is inactive and therefore it is not from any physical effect of the placebo that it works."
- It is essential that the placebo does not have any physical effects, whether "direct" or "indirect". The effect of a placebo is due to the patient "knowing" they are receiving a treatment. For example, if you had a headache and I slipped you a placebo without you knowing it, it would not have an effect. This is because a placebo does not have any direct or indirect physical effects. The placebo itself it completely inactive, inert, what have you. If it did have an effect, it wouldn't be a placebo. It would be a headache reliever!DavidJohnson 14:24, 2 December 2008 (EST)
- I already understood about "slipping". I'm wondering about the indirect physical effect, in a mind/body sense. My coworker told me last month, after I brewed a pot of coffee, that he already felt perked up - even before he went to fill his cup. And Pavlov's dogs certainly did salivate (a physical effect) after hearing the bell. I'd call that an indirect physical effect. --Ed Poor Talk 14:27, 2 December 2008 (EST)
- As I understand it, the placebo does not cause any physical effects itself, but can have psychological effects which manifest physical effects. Also, I think there are distinctions made when a placebo is used for studying psychology, and when they are used as controls in drug trials. -DrSandstone 14:34, 2 December 2008 (EST)
- (EC with the Dr.)I would call those direct physical effects. The smell of coffee and the ringing of the bell have direct effects on the brain of the people who hear them. Placebos do not have direct effects on the brains of the people who take them. Knowing or believing that they are taking a treatment has an effect. Again, the placebo itself does not.
- Being physically or chemically inert is part of the meaning of 'placebo'. If you have philosophical questions about what this means in light of the mind/body debate, that's great. But the article should still be clear about what a placebo is. DavidJohnson 14:34, 2 December 2008 (EST)
- (ECx2) Ed as you illustrated above there is a psychological component to how we are able to control our own bodies. That's really how a lot of these liberal new-age talking or touching therapies work (also a good old-fashioned mom's "let me kiss it better"). Because people often feel better fom getting personal attention rather than being palmed of with a couple of apsirin. I guess it's because we all need to be loved and I suspect this is why Christians can withstand greater apparent suffering because they know they are loved by God and Jesus. Placebos tend to work well for things like pain control but are generally ineffective against serious infectious diseases like polio or tetanus, however they can affect how a patient perceives the disease so when testing the efficacy of a new drug placebos are used to establish a baseline against which to measure the effectiveness of the drug. Interestingly when people are told that the placebo is more expensive (obviously they don't know it's a placebo) then it is found to have an even greater effect. Of course, Hollywood stars require incredibly expensive placebos! BrianCo 14:58, 2 December 2008 (EST)
- This is also why brand name drugs are perceived by many people to work better, even though the active ingredients are exactly the same as a generic medication. -DrSandstone 15:31, 2 December 2008 (EST)
So, one of the reasons a placebo might work is classical conditioning? We should mention that in the article, along with any other theories that doctors have come up with. --Ed Poor Talk 16:52, 2 December 2008 (EST)
"It is well known to medical researchers that merely assuring someone that a treatment will be successful, greatly increases the chance of the treatment actually working" This is the line I could not find a citation for yet. If narrowed to pain management it would be ok. Would a general cite on patient faith affecting outcomes be relevant ? Markr 16:08, 2 December 2008 (EST)
- Not sure this fits exactly, but it speaks to the basic concept. Can you help me restructure the section to reflect this accurately?  -DrSandstone 16:21, 2 December 2008 (EST)
It is not nonsense that a placebo is defined as a substance that has no effect on human beings. The placebo effect is a phenomenon that deserves its own entry, but can be considered separately from the issue of the definition of placebo. Someone who is administered an active agent like epinepherine or insulin will show physiological effects even if they are unaware of the administration; the same is not true for placebos, which cause no physiological changes if the subject is unaware of the administration. To claim that a placebo is not inert because the placebo effect exists ignores the defining characteristic of a placebo.
- I inserted the definition from the CDC mainly because the only reference at that point in the article was to the definition, yet the definition (which was the only mention of "placebo" on the cited page) was nowhere in the article. It was a choice of either ditch the reference or use the definition, and as there were no other references I went with the latter. Please try to be kinder in your edit comments - we are all doing our little bit to improve the article, even if it's not perfect. (Also - I'm glad to see there are now references - medical articles with no references (or with only a reference to a definition) scare me.) --Hsmom 16:58, 2 December 2008 (EST)
The Atlanta CDC used to be highly respectable, but during the AIDS furor, they became politicizied. Here's your reference, but I have no idea why you'd want it in the article:
- The US Centers for Disease Control and Prevention's Vaccines and Immunizations Glossary defines a placebo as "A substance or treatment that has no effect on human beings." 
- There's no active ingredient in a placebo, so any effect is either psychological or a mistaken perception. In other words, the placebo itself does nothing, it's the subject doing all the work or seeing a change when there really wasn't any. Additionally the "placebo effect" is different than a "placebo". LiamG 17:29, 2 December 2008 (EST)
- US Centers for Disease Control and Prevention, Vaccines and Immunizations Glossary, entry for "placebo"