Common pain and fever relief drug may induce risky behavior in people by making them seem less dangerous: Study
Acetaminophen, the active ingredient in Tylenol and nearly 600 other medicines, is taken each week by an estimated 23% of the US adult population
While a common pain reliever is helping people deal with their headaches, it may also be making them more willing to take risks, according to researchers. They found that people who took the drug acetaminophen – also known as paracetamol which is used to relieve pain and reduce fever – rated activities like "bungee jumping off a tall bridge" and "walking home alone at night in an unsafe area of town" as less risky than people who took a placebo.
The finding suggests that acetaminophen could be changing perceptions of risk and make risky moves seem less dangerous. "Acetaminophen seems to make people feel less negative emotion when they consider risky activities — they just don’t feel as scared," explains co-author of the study Baldwin Way, an associate professor of psychology at The Ohio State University.
Acetaminophen, the active ingredient in Tylenol and nearly 600 other medicines, is available over-the-counter and is one of the most consumed drugs in the US. According to the team, acetaminophen is taken each week by an estimated 23% of the US adult population. "With nearly 25% of the population in the US taking acetaminophen each week, reduced risk perceptions and increased risk-taking could have important effects on society," emphasizes Way.
The current study, published in the journal Social Cognitive and Affective Neuroscience, adds to recent research that has demonstrated that acetaminophen’s effects on pain and fever reduction extend to psychological processes. Previous research by Way and his colleagues, for example, has shown that acetaminophen reduces positive and negative emotions, including hurt feelings, distress over another’s suffering and even your joy.
For the current analysis, 189 college students came to a lab in one study and took either 1,000 mg of acetaminophen (the recommended dosage for a headache) or a placebo that looked the same. After waiting for the drug to take effect, the participants rated on a scale of 1 to 7 how risky they thought various activities would be. Results showed that those under the influence of acetaminophen rated activities like bungee jumping, starting a new career in their mid-30s, and taking a skydiving class as less risky than those who took the placebo.
The effects of acetaminophen on risk-taking were also tested in three separate experimental studies. Across these studies, 545 undergraduate students took part in a task developed in 2002 that is often used by scientists to measure risk-taking behavior. Other experts have shown that taking more risk on this task predicted risky behaviors outside the laboratory, including alcohol and drug use, driving without a seatbelt, and stealing.
In the task, participants clicked a button on the computer to inflate a balloon on their computer screen. Each time they inflate it they receive virtual money. They can stop at any time and add the money to their ‘bank,’ and move on to the next balloon. But there is risk involved. “As you’re pumping the balloon, it is getting bigger and bigger on your computer screen, and you’re earning more money with each pump. But as it gets bigger you have this decision to make: Should I keep pumping and see if I can make more money, knowing that if it bursts I lose the money I had made with that balloon?” says Ways. For those who took the acetaminophen, the answer was to keep on pumping.
Results reveal that those on the drug pumped more times than those on the placebo and had more burst balloons. This suggests that the use of the drug led people to take more risks in the experiment where they could earn rewards by inflating the virtual balloon on a computer, and sometimes they went too far and the balloon popped. These results indicate that acetaminophen can increase risk-taking, which may be due to reductions in risk perceptions, particularly those that are “highly affect-laden,” say investigators. “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. 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,” writes Way.
The results have multiple real-life implications, suggest authors. “For example, acetaminophen is the recommended treatment by the CDC for initial Covid-19 symptoms. Perhaps someone with mild Covid-19 symptoms may not think it is as risky to leave their house and meet with people if they’re taking acetaminophen,” Way suggests.
Even everyday activities like driving present people with constant decisions involving risk perception and assessment that could be altered by the use of the painkiller, they caution. “Many areas of daily life require making decisions that involve the processes examined here. For example, many patients in the hospital have acetaminophen in their systems when presented with risk information and asked to make potentially life-changing risk assessments such as whether or not to do an invasive surgery. Similarly, when driving, one is regularly presented with decisions that involve risk perception and assessment. Thus, it is imperative that we understand acetaminophen’s effects on choices made and risks taken,” explain researchers. They conclude, “Risk perception and risk-taking are judgments and decisions that can affect many aspects of our lives, and this common, over-the-counter drug may influence this process, unbeknownst to the millions taking the drug.”