Which of the following drug actions would most likely block the effectiveness of placebos?

Question

Quizplus · Accepted Answer

Placebos are believed to work through the release of endorphins, which activate the brain's reward system and have been shown to reduce pain and produce feelings of well-being. Blocking endorphin receptors would therefore prevent the placebo from having an effect. The other options (A, C, and D) would not necessarily affect the placebo response.

Which of the Following Drug Actions Would Most Likely Block