Create your own awesome maps

Even on the go

with our free apps for iPhone, iPad and Android

Get Started

Already have an account?
Log In

Placebo Effect by Mind Map: Placebo Effect
5.0 stars - 1 reviews range from 0 to 5

Placebo Effect


The treatment effect measured in the placebo arm of a clinical trial, which includes those subjects who have received a fake or inert treatment. If a trial is rigorously designed, placebo effects should include everything other than a physiological response to a biologically active treatment. Therefore, we can subtract placebo-effect findings from the treatment group, who will display treatment effects plus placebo effects, and we are left with a measurement of the treatment effect alone.

illusions of observation

regression to the mean

a statistical phenomenon that includes extreme symptoms becoming less extreme as a matter of course. For any variable symptom, periods of time when symptoms are at their worst are likely, by chance alone, to be followed by a return to more average symptoms.

self-limiting conditions

get better in time


of observers

researchers, want interventions to work, assessments may be biased to be positive

of subjects

who usually want, to receive an effective treatment, to justify, expense/time, their risk, to meet the expectations of the researcher

countered by

double-blind trials

who took what?, not known, to subjects, to observers


subjects associate a treatment ritual with feeling better

improved mood, reduces percep- tion of pain

expectation, may cause release of, natural endorphins, dopamine in the reward centers of the brain

Hawthorne effect

the very fact of being observed in a clinical trial results in a change in behavior and reporting (McCarney et al. 2007)

trial effects

subjects more likely to:

comply with treatment

get regular medical attention

take better care of themselves


the ritual of treatment

if treatment involves


a break from hectic daily routine

Believing one is being treated may reduce

anxiety about the illness


sympathetic activity

blood pressure

strain on the heart

levels of stress hormones

Hands-on treatments

benefit of human contact

improves mood

provides an overall feeling of well-being

based on

The Poor, Misunderstood Placebo

by Steven Novella

Skeptical Inquirer

Volume 34.6, Nov/Dec 2010