You might want to think twice before you reach for acetaminophen to reduce your pain - a new study has revealed that the common painkiller medication might also decrease empathy for the physical and social experiences of other people.
The study - conducted by Ohio State University researchers - reveals that those who took acetaminophen thought less of the pain and suffering experienced by those enduring misfortunes compared to those that did not take the painkiller.
"These findings suggest other people's pain doesn't seem as big of a deal to you when you've taken acetaminophen," said Dominik Mischkowski of The Ohio State University and co-author of the study. "Acetaminophen can reduce empathy as well as serve as a painkiller."
Acetaminophen is the main ingredient in the painkiller Tylenol and the most common drug in the U.S. Found in over 600 medicines, approximately 52 million people use a medicine containing the drug each week.
"We don't know why acetaminophen is having these effects, but it is concerning," said Baldwin Way of The Ohio State University and senior author of the study. "Empathy is important. If you are having an argument with your spouse and you just took acetaminophen, this research suggests you might be less understanding of what you did to hurt your spouse's feelings."
The first experiment outlined in the study examined 80 college students, half of whom took a liquid containing 1,000 mg of acetaminophen and the other half a placebo. After the drug took effect, participants read eight short scenarios involving someone suffering from some sort of pain and rated the pain that the people in each scenario experienced from one (no pain) to five (worst possible pain).
The results showed that participants that took acetaminophen rated the pain of the people in the scenarios as less extreme than those who took the placebo.
The second part of the experiment examined 114 college students, and as in the first experiment, half took acetaminophen and half a placebo. The participants received four two-second blasts of white noise ranging from 75 to 105 decibels and rated the blasts on a scale of one (not unpleasant) to 10 (extremely unpleasant).
The results showed that those who took acetaminophen rated the noise blasts as less unpleasant for both themselves and others.
"Acetaminophen reduced the pain they felt, but it also reduced their empathy for others who were experiencing the same noise blasts," Mischkowski said.
In another section of the second experiments, participants met and socialized with each other and then watched an online "game" alone that supposedly involved three of the people that they met; none of the other participants were actually involved. In the game, one of the three people was excluded. Afterwards, the participant was asked to rate the pain and hurt feelings of the people in the game, including the person excluded.
The data revealed that those who took acetaminophen rated the pain and hurt feelings of the excluded participant as less than those that did not take the drug.
"In this case, the participants had the chance to empathize with the suffering of someone who they thought was going through a socially painful experience," Way said. "Still, those who took acetaminophen showed a reduction in empathy. They weren't as concerned about the rejected person's hurt feelings."
The team is now moving on to ibuprofen, another common pain reliever, to determine if similar results are obtained.
The findings were published in the May 5 issue of the journal Social Cognitive and Affective Neuroscience.
