The painkillers’ active ingredient, acetaminophen, seems to block our empathy and sympathy for others.
The drugs’ unexpected side effect is a great worry, say researchers, as it could be affecting the behaviour of the 52 million Americans—around 23 per cent of the nation’s adult population—who take them every week.
Researchers from Ohio State University made the discovery when they tested the drug on a group of 80 college students. Half were given 1000 mg of acetaminophen and the rest had a placebo, or sugar pill. After an hour, they were told several heart-rending stories, and were asked to rate the pain being experienced by the protagonists. The acetaminophen group all gave a lower pain score than those in the placebo group. Similar results were seen in other experiments, including hearing loud noises.
Although their own pain and reactions were deadened, the students’ feelings about the pain of others were also reduced.