Placebo Effect

A Placebo Effect is a medical treatment effect seen in the experiment results of a Placebo Experiments where the expected behavior is reported.

• Context:
  • It can (typically) occur when a patient experiences a perceived improvement in their condition after receiving a placebo, a treatment with no therapeutic effect, due to their belief in the treatment's efficacy.
  • It can (often) be used in clinical trials to test the effectiveness of new drugs or treatments by comparing the results of patients receiving the actual treatment versus those receiving a placebo.
  • It can (often) be influenced by the patient's expectations, the healthcare provider's attitude, and the overall environment in which the treatment is administered.
  • It can (often) lead to measurable physiological changes in patients, such as pain relief, reduction in symptoms, or improved mood, even though the placebo has no active ingredients.
  • It can (often) be stronger in conditions that are subjective or influenced by the mind, such as pain, depression, or anxiety, where the belief in the treatment plays a significant role.
  • It can be considered a demonstration of the mind-body connection, where psychological factors can influence physical health outcomes.
  • It can be both beneficial, as in improving patient outcomes in clinical settings, and a challenge, as it can complicate the interpretation of clinical trial results by introducing a response not attributable to the actual treatment.
  • It can also occur in various forms, such as the "placebo by proxy," where caregivers' beliefs about a treatment's effectiveness can influence the perceived outcomes in the person receiving the treatment.
  • ...
• Example(s):
  • One in which a patient with chronic pain reports a significant reduction in pain after taking a placebo pill, believing it to be an effective painkiller.
  • One in which participants in a clinical trial for a new antidepressant report improved mood and reduced symptoms of depression after taking a placebo, despite the pill containing no active ingredients.
  • One in which patients with hypertension experience a drop in blood pressure after receiving a placebo treatment, demonstrating the physiological effects of the placebo effect.
  • One in which a placebo cream is applied to a patient's skin, leading to a perceived reduction in inflammation or discomfort, even though the cream contains no active medicinal ingredients.
  • One in which a patient experiences relief from anxiety after receiving a placebo pill, due to the belief that the pill is a powerful anti-anxiety medication.
  • ...
• Counter-Example(s):
  • Nocebo Effect, where negative expectations about a treatment lead to the experience of adverse side effects or worsening of symptoms, even though the treatment is inactive.
  • Drug-Drug Interaction, where the combination of two or more drugs leads to a modified effect, either enhancing or reducing the efficacy of one or both drugs, unlike the purely psychological nature of the placebo effect.
  • Moth & Electric Lamp Effect, where the behavior of insects is influenced by artificial light sources, representing a physical attraction rather than a psychological response.
  • Drug-Dependent Effect,
  • Drug-Limiting Effect,
  • Side Effect.
• See: Cognitive Bias, Placebo-Controlled Experiment, Side Effect, Medication, Dose, Clinical Trial Participant, Clinical Trial Protocol, Drug Development Clinical Trial, Pharmaceutical Drug, Illicit Drug, Drug Interaction, Pharmacology, Drug Reaction, Test Treatment.

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References

2021

• (Wikipedia, 2021) ⇒ https://en.wikipedia.org/wiki/Placebo Retrieved:2021-12-19.
  • A placebo is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures. In general, placebos can affect how patients perceive their condition and encourage the body's chemical processes for relieving pain and a few other symptoms, but have no impact on the disease itself. Improvements that patients experience after being treated with a placebo can also be due to unrelated factors, such as regression to the mean (a statistical effect where an unusually high or low measurement is more likely to be followed by a less extreme one). The use of placebos in clinical medicine raises ethical concerns, especially if they are disguised as an active treatment, as this introduces dishonesty into the doctor–patient relationship and bypasses informed consent. While it was once assumed that this deception was necessary for placebos to have any effect, there is now evidence that placebos can have effects even when the patient is aware that the treatment is a placebo. 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. In a placebo-controlled clinical trial any change in the control group is known as the placebo response, and the difference between this and the result of no treatment is the placebo effect. Some researchers now recommend comparing the experimental treatment with an existing treatment when possible, instead of a placebo. The idea of a placebo effect—a therapeutic outcome derived from an inert treatment—was discussed in 18th century psychology but became more prominent in the 20th century. An influential 1955 study entitled The Powerful Placebo firmly established the idea that placebo effects were clinically important, and were a result of the brain's role in physical health. A 1997 reassessment found no evidence of any placebo effect in the source data, as the study had not accounted for regression to the mean.

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