Nocebo is a noun that refers to a harmless substance that causes harm because it is believed to be harmful.
You may already be familiar with the word placebo, an innocuous substance that people may believe, through the power of suggestion, has the ability to heal. A nocebo is the opposite of a placebo. It is a harmless substance that people may believe, through the power of suggestion, has the power to harm.
Placebo has its origin in the Latin words for ‘I will please.’ Nocebo’s origin is in the phrase “I will harm.”
When Tyler heard the news reports about the recalled aspirin, it turned those pills into a nocebo. Just because he believed the pills would harm him, they did.