What are placebos?

Originally, placebos were thought of as inert pills or medications that were presented by physicians in the medical context or by researchers in clinical or experimental studies. Today, the term has a broader definition and it is used in a variety of settings. Placebos are present in our everyday lives, and sometimes have profound impacts on behaviors, and experiences (different types of placebo effects). The word Placebo is derived from a Latin phrase meaning “to please”.

“A placebo is a substance or procedure that has no inherent power to produce an effect that is sought or expected.” (Williams & Podd, 2004)

In general terms, when considering placebo, the entire ritual surrounding the administration of the substance or procedure is considered. Placebos are context specific. What might be a placebo in one condition may actually serve as a nocebo (opposite placebo, negative outcome) in another context. Also, a placebo in one context may serve as an active treatment (substance, procedure) in another context. Learning and cultural influences play a large role in determining whether a substance or procedure serve as a placebo. The study of placebos has advanced substantially over the past few years, and has provided important information in regards to neurobiology, and various other biological mechanisms. Coming Soon The Amazing World of Placebo Effects: The Neurobiology of Placebo Effects

Investigating Placebo Effects 2- Sham Knee Surgery

Mosley et al. (2002) conducted a randomized, placebo-controlled trial to evaluate the efficacy of arthroscopy for osteoarthritis of the knee. Patients were assigned to receive an arthroscopic debridement, arthroscopic lavage or placebo surgery. Patients and assessors of outcome were blinded to which condition the patients were in. Outcomes were assessed at multiple points over a 24-month period. Five self-reported scores and one objective test of walking and stair climbing was used as measures. Neither of the intervention groups reported less pain or better function than the group receiving the sham surgery. In fact, at two weeks participants that received the sham surgery performed better on an objective walking and stair climbing measure than those in the debridement group. This was also found at one year and the debridement group showed a trend towards worse functioning at two years. However, it is not clear if this outcome occurred due to a placebo (via expectation) effect or natural history.

Placebo Effects- Sham Knee Surgery (video)

Coming Soon! The Amazing World of Placebo Effects

Investigating Placebo Effects

This is the first in a series of articles that will investigate
placebo and nocebo effects. Currently, there is some exciting
research being done in these areas. This series will explore
placebo and placebo - related effects in many different areas.

The individual's mind, emotions, and beliefs play a central role
in any treatment or therapy (procedure, protocol). Placebo effects
are mediated by many molecules in the brain which may affect the
course of a disease or response to treatment. Many misconceptions
exist regarding placebo effects- in the lay public and scientific
community. Probably, the most common misconception is in how
the words 'placebo effect' and 'placebo response' are defined.
Commonly the words refer to outcomes in placebo groups, without
consideration that a variety of factors are responsible for the
reduction of a symptom when taking a placebo or receiving a placebo
-related treatment. The reduction of the symptom could be due to:

Spontaneous remission
Regression to the mean
Effects of co-intervention
Biases
Real placebo response (Neurobiological& various physiological responses)

Another common misconception is that there is only one placebo effect. There is not one, but many (various mechanisms underlie placebo effects). It is more appropriate to think in terms of effects not effect.

Placebo effects have been shown in many different areas in science. Sometimes placebo effects have been shown to mimic or even exceed effects produced by active treatments (such as therapies or medications).

The content featured in this series of articles will be the same type of content featured in my new book - The Amazing World of Placebo Effects.