"Researchers in Japan tested the effect of cannabidiol (CBD) i...

Question

"Researchers in Japan tested the effect of cannabidiol (CBD) in treating late teenagers with social anxiety disorder (SAD). Thirty-seven 18- to 19-year-old teenagers with SAD took part in the study. The patients were assigned at random to receive a daily dose of either CBD or a placebo for 4 weeks. Symptoms were measured using The Fear of Negative Evaluation Questionnaire and the Liebowitz Social Anxiety Scale at the beginning and end of the treatment. (Source: Frontiers in Psychology)
The experiment is described as a placebo-controlled, double-blind study. Explain what this means."

The experiment is described as a placebo-controlled, double-blind study. Explain what this means."

Accepted Answer

Hi everyone, glad to have you back. Our next question says. A clinical trial investigated the effectiveness of a new antihistamine in treating seasonal allergies among adults aged 20 to 25. 40 participants were randomly assigned to receive either the antihistamine or a sugar pill for 6 weeks. The study is described as a placebo-controlled double blind experiment. What does this mean? Well, we already knew from the description of the question, um, that we have a placebo controlled experiment, which would mean that you have a control group that receives no treatment during the course of the study. So in this case that was the group that received the sugar pill. And then you have a test group. That receives the treatment you're testing. So that's the meaning of the placebo controlled, and then what does it mean that it is a double blind experiment? Well, this refers to the fact that People can experience improvement in their symptoms or in their health, based on the fact that they think they're being treated with something that will help them. That's the placebo effect, which can be quite powerful. So, you want the participants in the study not to know whether or not they're receiving treatment, and that way you can tell is the improvement, the effect of actual treatment, actual medication, or just their belief that they're being treated. So, that's single blind, but this is double blind, this means that the researchers who are evaluating the results also don't know which patients are receiving the placebo. And this prevents bias because quite naturally, the researchers will have an investment in knowing whether this is going to succeed, and if they know which patients are receiving the actual treatment and which are receiving the placebo, it could affect cause bias in their evaluation. It can even affect if they're interacting with the patients, it can interact the way they they affect the way they interact and even cause that improvement based on how the patients perceive the interaction. So, double blind, referring to both participants and researchers, don't know which patients are receiving a placebo and which are receiving the treatment. And of course this is why the placebo treatment is a sugar pill and not just receiving nothing, because if the patient some patients got a pill and some patients got nothing, they would obviously know if they were getting treated. So the sugar pill means that they don't know which group they're in. So, once again, we're talking about a clinical trial of an antihistamine that's described as a placebo-controlled double blind experiment. And we've said the placebo controlled means that we have a control group that receives no treatment, and a test group that receives treatment. And double blind refers to the fact that both participants and researchers do not know. If which patients are receiving the placebo and which are pre receiving the actual treatment. See you in the next video.

Key Concepts

Placebo-Controlled Study

Double-Blind Study

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