Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
A placebo is a substance with no therapeutic effect used as a control in testing new drugs. It helps to determine the efficacy of the actual drug being tested.
5 Must Know Facts For Your Next Test
Placebos are often used in clinical trials to act as a control group.
The placebo effect occurs when patients experience improvements despite receiving a non-active treatment.
Placebos are crucial in double-blind studies where neither participants nor researchers know who receives the active treatment.
Ethically, participants must be informed they could receive a placebo when they consent to join a study.
Understanding placebos helps differentiate between psychological and physiological effects of treatments.
Review Questions
Related terms
Clinical Trial: A research study performed on humans to evaluate medical, surgical, or behavioral interventions.
Double-Blind Study: An experimental procedure where neither the participants nor the researchers know who is receiving the active treatment.
Control Group: In an experiment, this group does not receive the experimental treatment and is used for comparison against those that do.