power of placebo

[LMC]

There are enough threads on homeopathy here but i wanted to start one exclusively for placebo effect, which is one of the supporting claims of homeopathy other than water's memory retention,
this is in continuation from facebook's discussion here
some links referred during discussion
http://www.ncbi.nlm.nih.gov/pubmed/15266510 posted by pratibha preview:

Quote:Abstract
BACKGROUND:
Placebo interventions are often claimed to improve patient-reported and observer-reported outcomes, but this belief is not based on evidence from randomised trials that compare placebo with no treatment.
OBJECTIVES:
To assess the effect of placebo interventions.

full article

posted by ajita
http://www.sciencebasedmedicine.org/inde...bo-effect/
http://www.sciencebasedmedicine.org/inde...revisited/
context:

Quote:"placebo's have been found to be very effective. one of those weird still-unexplained things in medicine, apparently."
The placebo effect is highly exaggerated and completely misunderstood by the general public. Please read these two blog posts.

and this an article posted by another member by the end of the discussion,about how strong placebos are,or biases are and it is about this "power of placebo" that i wanted to discuss in this thread
preview

Quote:A man whom his doctors referred to as “Mr. Wright” was dying from cancer of the lymph nodes. Orange-size tumors had invaded his neck, groin, chest and abdomen, and his doctors had exhausted all available treatments. Nevertheless, Mr. Wright was confident that a new anticancer drug called Krebiozen would cure him, according to a 1957 report by psychologist Bruno Klopfer of the University of California, Los Angeles, entitled “Psychological Variables in Human Cancer.”

Mr. Wright was bedridden and fighting for each breath when he received his first injection. But three days later he was cheerfully ambling around the unit, joking with the nurses. Mr. Wright’s tumors had shrunk by half, and after 10 more days of treatment he was discharged from the hospital. And yet the other patients in the hospital who had received Krebiozen showed no improvement.

Over the next two months, however, Mr. Wright became troubled by press reports questioning the efficacy of Krebiozen and suffered a relapse. His doctors decided to lie to him: an improved, doubly effective version of the drug was due to arrive the next day, they told him. Mr. Wright was ecstatic. The doctors then gave him an injection that contained not one molecule of the drug—and he improved even more than he had the last time. Soon he walked out of the hospital symptom-free. He remained healthy until two months later, when, after reading reports that exposed Krebiozen as worthless, he died within days.

As Mr. Wright’s experience illustrates, a patient’s expectations and beliefs can greatly affect the course of an illness. When psychological factors tied to an inactive substance such as Krebiozen lead to recovery, doctors call the improvement a placebo effect.

In recent decades reports have confirmed the efficacy of such sham treatments in nearly all areas of medicine. Placebos can help not only to alleviate illnesses with an obvious psychological component, such as pain, depression and anxiety, but also to lessen the symptoms of Parkinson’s disease and inflammatory disorders. Occasionally, as in Mr. Wright’s case, placebos have shrunk tumors.

The latest research has shown that the placebo effect does not always arise from a conscious belief in a drug. Alternatively, it may grow out of subconscious associations between recovery and the experience of being treated, from the pinch of a shot to a doctor’s white coat. Such subliminal conditioning can control bodily processes, including immune responses and the release of hormones. Meanwhile researchers have decoded some of the biology of placebo responses, demonstrating that they stem from active processes in the brain.

[geetha]

Dr.Steven Novella has made a comprehensive list of 'why' placebos appear to work in his latest article:
http://theness.com/neurologicablog/index...ed-for-me/
Quote:
"Placebo effects are largely an illusion of various well-known psychological factors and errors in perception, memory, and cognition – confirmation bias, regression to the mean, post-hoc fallacy, optimism bias, risk justification, suggestibility, expectation bias, and failure to account for multiple variables. There are also variable (depending on the symptoms being treated) and subjective effects from improved mood and outlook."

[LMC]

A question from a facebook discussion , does placebo effect work even if you know it is a placebo?
Please post your views,excerpts from an article Placebo effects without deception? Well, not exactly

Quote:No, the reason I say this is because, all their claims otherwise notwithstanding, this study doesn’t really tell us anything new about placebo effects. The reason is that, even though they did tell their subjects that the sugar pills they were being given were inert, the investigators also used suggestion to convince their subjects that these pills could nonetheless induce powerful “mind-body” effects. In other words, the investigators did the very thing they claimed they weren’t doing; they deceived their subjects to induce placebo effects by exaggerating the strength of the evidence for placebo effects and using rather woo-ish terminology (“self-healing,” for instance).