Acetaminophen is the active ingredient in many popular over-the-counter painkillers and is widely used to treat everything from headaches to sore elbows.
But a group of researchers at the University of Toronto say their findings suggest it could also lead users to make mistakes without being aware of their errors.
It all has to do with brain function. One of the researchers, Dan Randles, says acetaminophen affects a certain area of the brain that suppresses pain. That same area happens to also to be the part of the brain that recognizes errors.
Shared neural process
"Past research tells us physical pain and social rejection share a neural process that we experience as distress, and both have been traced to the same part of the brain," Randles said in a release.
He points to previous work that demonstrates how acetaminophen inhibits pain. The researchers wondered if that same response inhibited how the brain processes information more generally.
Randles has previously conducted research that appeared to show people who have taken acetaminophen were less reactive when the situation they were in was uncertain. A series of small experiments seems to confirm the researchers' theory.
"The core idea of our study is that we don't fully understand how acetaminophen affects the brain," Randles said.
But it is very possible that taking acetaminophen makes it harder to recognize when you are making a mistake, slowing reaction time. It has significant implications for cognitive control in daily life, Randles concluded.
Prior research has been conducted that attempted to investigate acetaminophen's effect on the brain. Researchers at Ohio State conducted a series of experiments that led them to conclude that the painkiller can blunt positive emotions.
“This means that using Tylenol or similar products might have broader consequences than previously thought,” Geoffrey Durso, the study's lead author, said last year when the study was released.“Rather than just being a pain reliever, acetaminophen can be seen as an all-purpose emotion reliever.”
But the mood changes were subtle. Durso says most people taking acetaminophen probably aren't aware of any change in mood.
Acetaminophen is in a wide range of prescription medications. Doctors advise reading labels carefully to avoid overdosing. Too much of the drug can damage kidneys.