Placebo

placebo effectplacebosplacebo studiesPlacebo (origins of technical term)sugar pillplacebo responsepower of suggestion in perceptionsham therapysham treatmentsubconsciously
A placebo is an inert substance or treatment which is designed to have no therapeutic value.wikipedia
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Clinical trial

clinical trialsclinical studiesclinical study
In a clinical trial any change in the placebo arm is known as the placebo response, and the difference between this and the result of no treatment is the placebo effect.
While most clinical trials test one alternative to the novel intervention, some expand to three or four and may include a placebo.

Scientific control

controlcontrolscontrolled
In drug testing and medical research, a placebo can be made to resemble an active medication or therapy so that it functions as a control; this is to prevent the recipient or others from knowing (with their consent) whether a treatment is active or inactive, as expectations about efficacy can influence results.
Some improvement is expected in the placebo group due to the placebo effect, and this result sets the baseline which the treatment must improve upon.

Sham surgery

shamsham-operatedsham-operated group
Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures.
Thus sham surgery serves an analogous purpose to placebo drugs, neutralizing biases such as the placebo effect.

Blinded experiment

double-blinddouble blindblinded
In drug testing and medical research, a placebo can be made to resemble an active medication or therapy so that it functions as a control; this is to prevent the recipient or others from knowing (with their consent) whether a treatment is active or inactive, as expectations about efficacy can influence results. It is harder still to tell the difference between the placebo effect and the effects of response bias, observer bias and other flaws in trial methodology, as a trial comparing placebo treatment and no treatment will not be a blinded experiment.
Success of blinding is assessed by questioning study participants about information that has been masked to them (e.g. did you receive the drug or placebo?).

Peter C. Gøtzsche

Peter C. Gotzsche
In their 2010 meta-analysis of the placebo effect, Asbjørn Hróbjartsson and Peter C. Gøtzsche argue that "even if there were no true effect of placebo, one would expect to record differences between placebo and no-treatment groups due to bias associated with lack of blinding."
Among his research findings are that placebo has surprisingly little effect

Irving Kirsch

In 2008, a controversial meta-analysis led by psychologist Irving Kirsch, analyzing data from the FDA, concluded that 82% of the response to antidepressants was accounted for by placebos.
Kirsch is a leading researcher within the field of placebo studies who is noted for his work on placebo effects, antidepressants, expectancy, and hypnosis.

Cochrane (organisation)

Cochrane reviewCochrane CollaborationCochrane
A 2001 Cochrane Collaboration meta-analysis of the placebo effect looked at trials in 40 different medical conditions, and concluded the only one where it had been shown to have a significant effect was for pain.
The Cochrane logo represents a meta-analysis of data from seven randomised controlled trials (RCTs), comparing one health care treatment with a placebo in a blobbogram or forest plot.

Jeremy Howick

Jeremy Howick has argued that combining so many varied studies to produce a single average might obscure that "some placebos for some things could be quite effective."
He is known for his research on evidence-based medicine and the philosophy of medicine, including the use of placebos in clinical practice.

Bad Science (Goldacre book)

Bad ScienceBad Science'' (Goldacre book)Bad Science: Quacks, Hacks, and Big Pharma Flacks
In his 2008 book Bad Science, Ben Goldacre argues that instead of deceiving patients with placebos, doctors should use the placebo effect to enhance effective medicines.
For example, the chapter on homeopathy becomes the point where he explains the placebo effect, regression to the mean (that is, the natural cycle of the disease), placebo-controlled trials (including the need for randomisation and double blinding), meta-analyses like the Cochrane Collaboration and publication bias.

Alternative medicine

complementary and alternative medicineholistic healthintegrative medicine
In an opinion piece about homeopathy, Ernst argues that it is wrong to support alternative medicine on the basis that it can make patients feel better through the placebo effect.
Research into alternative therapies often fails to follow proper research protocols (such as placebo-controlled trials, blind experiments and calculation of prior probability), providing invalid results.

Pain

physical painacute painnociceptive pain
Placebos can improve patient-reported outcomes such as pain and nausea.
This placebo effect is more pronounced in people who are prone to anxiety, and so anxiety reduction may account for some of the effect, but it does not account for all of it.

Homeopathy

homeopathichomeopathhomoeopathy
Referring specifically to homeopathy, the House of Commons of the United Kingdom Science and Technology Committee has stated:"In the Committee's view, homeopathy is a placebo treatment and the Government should have a policy on prescribing placebos. The Government is reluctant to address the appropriateness and ethics of prescribing placebos to patients, which usually relies on some degree of patient deception. Prescribing of placebos is not consistent with informed patient choice—which the Government claims is very important—as it means patients do not have all the information needed to make choice meaningful. A further issue is that the placebo effect is unreliable and unpredictable."
Some products with such relatively lower dilutions continue to be sold, but like their counterparts, they have not been conclusively demonstrated to have any effect beyond that of a placebo.

Efficacy

efficaciouseffectivenesseffective
In drug testing and medical research, a placebo can be made to resemble an active medication or therapy so that it functions as a control; this is to prevent the recipient or others from knowing (with their consent) whether a treatment is active or inactive, as expectations about efficacy can influence results.

Response bias

response distortionscale use bias
It is harder still to tell the difference between the placebo effect and the effects of response bias, observer bias and other flaws in trial methodology, as a trial comparing placebo treatment and no treatment will not be a blinded experiment.
Another way to prevent demand characteristics is to use blinded experiments with placebos or control groups.

Declaration of Helsinki

Helsinki DeclarationHelsinki Committeeethical
The ethics of placebo-controlled studies have been debated in the revision process of the Declaration of Helsinki.
This was a placebo controlled trial which showed a reduction of nearly 70% in the risk of transmission, and Zidovudine became a de facto standard of care.

Asbjørn Hróbjartsson

In their 2010 meta-analysis of the placebo effect, Asbjørn Hróbjartsson and Peter C. Gøtzsche argue that "even if there were no true effect of placebo, one would expect to record differences between placebo and no-treatment groups due to bias associated with lack of blinding."
He received his Ph.D. in June 2001 from the University of Copenhagen, with a thesis entitled Are placebo interventions associated with clinically important effects? He is best-known for a 2001 article he co-authored with Peter C. Gotzsche on the placebo effect.

Analgesic

analgesiaanalgesicspainkillers
Functional imaging upon placebo analgesia suggests links to the activation, and increased functional correlation between this activation, in the anterior cingulate, prefrontal, orbitofrontal and insular cortices, nucleus accumbens, amygdala, the brainstem periaqueductal gray matter, and the spinal cord.
There is some evidence that some treatments using alternative medicine can relieve some types of pain more effectively than placebo.

Stimulant

stimulantspsychostimulantpsychostimulants
A placebo presented as a stimulant may trigger an effect on heart rhythm and blood pressure, but when administered as a depressant, the opposite effect.
Notably, two recent large phase III studies of lisdexamfetamine (a prodrug to amphetamine) as an adjunct to an SSRI or SNRI in the treatment of major depressive disorder showed no further benefit relative to placebo in effectiveness.

Opioid

opioidsopioid-induced constipationopioid analgesic
It has been known that placebo analgesia depends upon the release in the brain of endogenous opioids since 1978.
Some recent placebo-controlled trials have found that it may be no better than a placebo for some causes including acute cough in children.

Nucleus accumbens

nucleus accumbens shellnucleus accumbens coreaccumbal
Functional imaging upon placebo analgesia suggests links to the activation, and increased functional correlation between this activation, in the anterior cingulate, prefrontal, orbitofrontal and insular cortices, nucleus accumbens, amygdala, the brainstem periaqueductal gray matter, and the spinal cord.
The nucleus accumbens plays a lesser role in processing fear (a form of aversion), impulsivity, and the placebo effect.

Hormone replacement therapy

menopausal hormone therapyhormone therapyestrogen replacement therapy
This was found, for example, after the discontinuation of the Women's Health Initiative study of hormone replacement therapy for menopause.
One portion of the parallel studies followed over 16,000 women for an average of 5.2 years, half of whom took placebo, while the other half took a combination of CEEs and MPA (Prempro).

Henry K. Beecher

Henry Beecher
In 1955 Henry K. Beecher published an influential paper entitled The Powerful Placebo which proposed idea that placebo effects were clinically important.
Henry Knowles Beecher (February 4, 1904 – July 25, 1976 ) was a pioneering American anesthesiologist, medical ethicist, and investigator of the placebo effect at Harvard Medical School.

Adverse effect

adverse effectsside effectsside effect
Another negative consequence is that placebos can cause side-effects associated with real treatment.

Ben Goldacre

Dr Ben GoldacreBad ScienceGoldacre, Ben
In his 2008 book Bad Science, Ben Goldacre argues that instead of deceiving patients with placebos, doctors should use the placebo effect to enhance effective medicines.
In March 2014, he worked on a systematic review of the side effects of statins compared with placebos, published in the European Journal of Preventive Cardiology.

List of topics characterized as pseudoscience

List of topics characterised as pseudosciencea number of claimsalternative