Explain why the double-blind procedure is often used in setting up clinical trials of therapeutic drugs?

A double-blind experiment, in which the patients don’t know what they are taking and the scientists don’t know what they are giving, is usually used to avoid the placebo effect and bias. The placebo effect is for example when you take a medicine and you think it’s going to work, but it actually doesn’t, but you still recover faster because you THINK the medicine worked. Bias is simply modifying the results so that you get the results you want.

a double blind procedure is used in clinical trials to prevent the participant AND the researchers from knowing which group (compiled of several participants) was administered the study drug and which was administered the placebo (control). This method is used in a lot of studies in order to steer away from biases and get the true result. If the participant does not know which they have taken (study drug or placebo) it prevents them from unwillingly or willingly conforming to the expected results, which can be inaccurate data.

For example… If you were going to conduct a study on a new antidepressant and the participant knew that they were given the study drug and not the placebo, they might unwillingly feel better and less depressed because they knew that this was expected in the study. Even though the drug might actually help the persons depression, you would not know for sure, it could all be in their head or the drug could actually help.

You would want the researcher blinded to the study for the same reasons. Say the researcher knew that participant A was taking the study drug and participant B was taking the placebo. When interacting with participant B she notices this participant is more quiet, reserved, but with occasion bouts of anger. The researcher may think that the reason why pariticpant B’s behavior is this way is because they are not taking the antidepressant, when in reality their behavior could be due to other contributing factors. This can cause the researcher to record false results.

If both the research and participants are blinded you are more willing to get accurate results because they are recording actual findings and not biases

I hope that helps…