Widely used pain killer linked to risk taking

The most widely consumed pain reliever in the world inadvertently also reduces one's sense of fear, according to one study.

Acetaminophen, or paracetamol, makes people take to risk more willingly, suggests the paper, published in the journal Oxford Academic.

“Acetaminophen seems to make people feel less negative emotion when they consider risky activities — they just don't feel as scared,” explained Baldwin Way, co-author and associate professor of psychology at Ohio State University.

“With nearly 25 per cent of the population in the U.S. taking acetaminophen each week, reduced risk perceptions and increased risk-taking could have important effects on society,” said Way.

Though its effect could be small, the study adds to a body of research that shows the analgesic, which is a main ingredient in 600 medicines and widely sold as over-the-counter medicine under brand names Tylenol and Panadol, may have unintended effects on people's psychology. Past studies have linked the drug to dulling the pain of social rejection, reducing empathy and blunting cognitive function.

Way's findings are drawn from a series of experiments with 500 participating university students who were randomly given a 1,000 mg dose of acetaminophen (a standard extra-strength dose for adults) to judge the evaluation of risk compared to the rest, who were given placebos.

During the experiments, participants clicked a button to inflate a virtual balloon on the computer screen, with each pump earning them imaginary money. The goal was to cash out with as much money as possible without popping the balloon. They could bank the money by clicking `collect' and move on to the next balloon at any time.

The participants who took acetaminophen pumped away and burst their balloons significantly more than the control group, the study concludes.

“If you're risk-averse, you may pump a few times and then decide to cash out because you don't want the balloon to burst and lose your money,” Way said. “But for those who are on acetaminophen, as the balloon gets bigger, we believe they have less anxiety and less negative emotion about how big the balloon is getting and the possibility of it bursting.”

In the second component of the experiment, participants answered a survey rating their perception of risk in a variety of scenarios, such as betting a day's earnings on a poker game, bungee jumping off a tall bridge and driving a car without a seatbelt. The acetaminophen consumed appeared to cause a reduced perception of risk compared to the control in one survey, but the behaviour wasn't observed in a similar second survey.

When a combined average was taken, however, the authors found a significant link between taking the drug and seeking more risk.