placebo effect

(noun)

the tendency of any medication or treatment, even an inert or ineffective one, to exhibit results simply because the recipient believes that it will work

Related Terms

Examples of placebo effect in the following topics:

  • The Clofibrate Trial

    • The Clofibrate Trial was a placebo-controlled study to determine the safety and effectiveness of drugs treating coronary heart disease in men.
    • The purpose of the placebo group is to account for the placebo effect -- that is, effects from treatment that do not depend on the treatment itself.
    • Without a placebo group to compare against, it is not possible to know whether the treatment itself had any effect.
    • This apparent placebo effect may have occurred because:
    • Adhering to the protocol had a psychological effect, i.e. genuine placebo effect.

  • Case Studies

  • Alternatives to Traditional Health Care

    • In Western culture, it is often defined as any healing practice "that does not fall within the realm of conventional medicine," or "that which has not been shown consistently to be effective. " There is a debate among medical researchers over whether any therapy may be properly classified as "alternative medicine. " Some claim that there is only medicine that has been adequately tested and that which has not.
    • Its academic proponents sometimes recommend misleading patients by using known placebo treatments in order to achieve a placebo effect.

  • Experiments exercises

    • In order to assess the effectiveness of taking large doses of vitamin C in reducing the duration of the common cold, researchers recruited 400 healthy volunteers from staff and students at a university.
    • No significant differences were observed in any measure of cold duration or severity between the four medication groups, and the placebo group had the shortest duration of symptoms.
    • One group was given 25 grams of chia seeds twice a day, and the other was given a placebo.
    • Explanatory: Treatment, with 4 levels: placebo, 1g, 3g, 3g with additives.
    • However, we must consider that a placebo effect is possible.

  • The Salk Vaccine Field Trial

    • The Salk polio vaccine field trial incorporated a double blind placebo control methodolgy to determine the effectiveness of the vaccine.
    • By the conclusion of the study, roughly 440,000 received one or more injections of the vaccine, about 210,000 children received a placebo, consisting of harmless culture media, and 1.2 million children received no vaccination and served as a control group, who would then be observed to see if any contracted polio.
    • The Salk vaccine had been 60–70% effective against PV1 (poliovirus type 1), over 90% effective against PV2 and PV3, and 94% effective against the development of bulbar polio.
    • Therefore, randomized control tends to negate all effects (such as confounding variables) except for the treatment effect.

  • Introduction to Biomedical Therapies

    • In general, the effectiveness of medications is upwards of 80%, but some of the medications also contain serious side effects.
    • Two ways in which biological therapies are studied are through efficacy research and effectiveness studies.
    • Placebo-controlled randomized clinical trials, using strict exclusionary criteria when selecting subjects, have traditionally been used to study a psychiatric medication's efficacy (i.e., the ability of the medication to treat the condition better than placebo under controlled conditions).
    • For example, studies comparing an antidepressant to a placebo may use an eight-week double-blind parallel design and include subjects with major depression, but without any other medical or psychiatric comorbidities.
    • Biomedical therapies, such as the use of the antidepressant Zoloft, can be effective in reducing the symptoms of individuals with certain mental illnesses so that psychotherapeutic interventions can be more effective.

  • Difference Between Two Means

    • These researchers found that, compared to a placebo, this drug increased total sleep duration by a mean of 61.8 minutes.
    • For example, if in the Holbrook et al. study the mean total sleep time for the placebo group were 120 minutes, then the 61.8-minute increase would represent a 51% increase in sleep time.
    • On the other hand, if the mean sleep time for the placebo were 420 minutes, then the 61.8-minute increase would represent a 15% increase in sleep time.
    • Although there is no objective answer to this question, the guidelines suggested by Cohen (1988) stating that an effect size of 0.2 is a small effect, an effect size of 0.5 is a medium effect, and an effect size of 0.8 is a large effect have been widely adopted.
    • Based on these guidelines, the effect size of 0.87 is a large effect.

  • Case study exercises

    • (b) At first glance, does acupuncture appear to be an effective treatment for migraines?
    • Researchers studying the effect of antibiotic treatment for acute sinusitis compared to symptomatic treatments randomly assigned 166 adults diagnosed with acute sinusitis to one of two groups: treatment or control.
    • Study participants received either a 10-day course of amoxicillin (an antibiotic) or a placebo similar in appearance and taste.
    • The placebo consisted of symptomatic treatments such as acetaminophen, nasal decongestants, etc.
    • (b) Based on your findings in part (a), which treatment appears to be more effective for sinusitis?

  • Using Two Samples

    • For example, researchers are interested in the effect aspirin has in preventing heart attacks.
    • Typically, one group is given aspirin and the other group is given a placebo.

  • Introduction

    • For example, researchers are interested in the effect aspirin has in preventing heart attacks.
    • Typically, one group is given aspirin and the other group is given a placebo.