"Alcohol Dependence To determine if topiramate is a safe and effective treatment for alcohol dependence, researchers conducted a 14-week trial of 371 men and women aged 18 to 65 years diagnosed with alcohol dependence. In this double-blind, randomized, placebo-controlled experiment, subjects were randomly given either 300 milligrams (mg) of topiramate (183 subjects) or a placebo (188 subjects) daily, along with a weekly compliance enhancement intervention. The variable used to determine the effectiveness of the treatment was self-reported percentage of heavy drinking days. Results indicated that topiramate was more effective than placebo at reducing the percentage of heavy drinking days. The researchers concluded that topiramate is a promising treatment for alcohol dependence. Source: Bankole A. Johnson, Norman Rosenthal, et al. “Topiramate for Treating Alcohol Dependence: A Randomized Controlled Trial,” Journal of the American Medical Association, 298(14):1641–1651, 2007.


What does it mean for the experiment to be placebo-controlled?"

Verified step by step guidance

1. Understand that a placebo-controlled experiment means that one group of participants receives the actual treatment (in this case, topiramate), while another group receives a placebo, which is an inactive substance designed to look like the treatment but has no therapeutic effect.
2. Recognize that the purpose of using a placebo group is to serve as a baseline to compare the effects of the actual treatment against, helping to isolate the treatment's true effect from other factors like participants' expectations or psychological effects.
3. Note that in a placebo-controlled trial, neither the participants nor the researchers know who is receiving the treatment or the placebo (this is called double-blinding), which helps prevent bias in reporting and assessing outcomes.
4. By comparing the outcomes (such as the percentage of heavy drinking days) between the treatment group and the placebo group, researchers can determine whether the treatment has a statistically significant effect beyond what might be caused by placebo effects or chance.
5. Therefore, a placebo-controlled experiment is a rigorous method to evaluate the safety and effectiveness of a treatment by controlling for psychological and other non-specific effects.

Key Concepts

Placebo-Controlled Experiment

A placebo-controlled experiment includes a group of participants who receive an inactive substance (placebo) instead of the actual treatment. This helps researchers compare the effects of the treatment against no treatment, controlling for psychological or other non-specific effects.

Randomization

Randomization is the process of assigning participants to different groups by chance, reducing bias and ensuring that groups are comparable. This helps isolate the effect of the treatment by evenly distributing confounding variables.

Double-Blind Design

In a double-blind design, neither the participants nor the researchers know who receives the treatment or placebo. This prevents bias in treatment administration and outcome assessment, increasing the reliability of the results.