Placebo-Controlled Studies - Neuropedia

Placebo-Controlled Studies

A placebo-controlled study is a scientific trial in which there are two or more groups of participants — an experimental group that gets the active treatment, method, or drug and a control group that receives a placebo.[1][2]

Placebos are inactive substances or treatments designed to look, taste, or feel like the treatment being tested. However, they do not affect the disease or condition the study is intended to treat.[3][4]

Placebo treatments could be anything from sugar or “dummy” pills to fake injections and even sham surgeries. 

In placebo-controlled studies, both groups of participants receive identical treatment, except for the placebo. After the trial, if the experimental group exhibits statistically significant improvements over the control group, researchers will be able to determine if and how the active ingredient was responsible.[5][6]

There are different types of placebo-controlled studies. For example, in open-label trials, both the participants and the researchers know which group that’s getting the placebo. 

In single-blind trials, only the researchers know which group is getting the placebo. 

And, in double-blind trials, neither the researchers nor the participants know which group is getting the placebo. In these cases, an independent group of researchers will select the control and experimental participants and administer the drug or placebo.

The Placebo Effect

The placebo effect is a phenomenon that occurs when a patient feels better when they think they’re receiving an effective drug or therapy. The effects are usually temporary and can occur even when a patient’s health is getting objectively worse. 

Benefits of Placebo-Controlled Studies

  • Placebo-controlled studies significantly reduce the chances of the placebo effect.
  • They reduce biases from both participants and researchers (particularly double-blind, placebo-controlled studies). 
  • They provide researchers with a comparison point for what works and what doesn’t.
  • Diversity in a patient population and disease progression is spread equally between each group. This increases the chances that any improvements will be in differences of treatment, not differences inpatient population.

Ethically Permissive Situations for Placebo-Controlled Studies 

While placebo-controlled studies are considered the gold standard in research, there are some ethical concerns. Some argue that they’re deceptive because trial participants don’t know whether or not they’re getting an active ingredient or a placebo. However, some conditions make placebo-controlled studies ethical.[7] 

  • The illness or disease has no effective treatment. 
  • Researchers have established that a placebo-controlled study is necessary, and those who get the placebo will not be at any imminent risk without treatment. 
  • Researchers have established that the placebo group is essential to the trial, and the resulting discovery will benefit the entire patient population. In addition, participants can receive any future approved treatments for the condition.