Abstract 
 
 Simulation theories of empathy hypothesize that empathizing with others’ pain shares some overlapping psychological computations with the processing of one’s own pain. Support for this perspective has largely relied on functional neuroimaging evidence of an overlap between activations during the experience of physical pain and empathy for other people’s pain. Here, we extend the functional overlap perspective to the neurochemical level and test whether a common physical painkiller, acetaminophen (paracetamol), can reduce empathy for another’s pain. In two double-blind placebo-controlled experiments, participants rated perceived pain, personal distress, and empathic concern in response to reading physical or social pain scenarios, witnessing ostracism in the lab, or visualizing another study participant receiving painful noise blasts. As hypothesized, acetaminophen reduced empathy in response to others’ pain. Acetaminophen also reduced the unpleasantness of noise blasts delivered to the participant, which mediated acetaminophen's effects on empathy. Together, these findings suggest that the physical painkiller acetaminophen reduces empathy for pain and provide a new perspective on the neurochemical bases of empathy. Because empathy regulates prosocial and antisocial behavior, these drug-induced reductions in empathy raise concerns about the broader social side effects of acetaminophen, which is taken by almost a quarter of US adults each week. ||||| When you take acetaminophen, you don’t feel others’ pain as much The popular painkiller reduces empathy, study finds 
 
 
 
 Baldwin Way 
 
 COLUMBUS, Ohio – When you take acetaminophen to reduce your pain, you may also be decreasing your empathy for both the physical and social aches that other people experience, a new study suggests. 
 
 Researchers at The Ohio State University found, for example, that when participants who took acetaminophen learned about the misfortunes of others, they thought these individuals experienced less pain and suffering, when compared to those who took no 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, co-author of the study and a former Ph.D. student at Ohio State, now at the National Institutes of Health. 
 
 Dominik Mischkowski 
 
 “Acetaminophen can reduce empathy as well as serve as a painkiller.” 
 
 Mischkowski conducted the study with Baldwin Way, who is an assistant professor of psychology and member of the Ohio State Wexner Medical Center’s Institute for Behavioral Medicine Research; and Jennifer Crocker, Ohio Eminent Scholar in Social Psychology and professor of psychology at Ohio State. Their results were published online in the journal Social Cognitive and Affective Neuroscience. 
 
 Acetaminophen – the main ingredient in the painkiller Tylenol – is the most common drug ingredient in the United States, found in more than 600 medicines, according to the Consumer Healthcare Products Association, a trade group. 
 
 Each week about 23 percent of American adults (about 52 million people) use a medicine containing acetaminophen, the CHPA reports. 
 
 In an earlier study, Way and other colleagues found that acetaminophen also blunts positive emotions like joy. 
 
 Taken together, the two studies suggest there’s a lot we need to learn about one of the most popular over-the-counter drugs in the United States. 
 
 “We don’t know why acetaminophen is having these effects, but it is concerning,” said Way, the 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 researchers conducted two experiments, the first involving 80 college students. At the beginning, half the students drank a liquid containing 1,000 mg of acetaminophen, while the other half drank a placebo solution that contained no drug. The students didn’t know which group they were in. 
 
 After waiting one hour for the drug to take effect, the participants read eight short scenarios in which someone suffered some sort of pain. For example, one scenario was about a person who suffered a knife cut that went down to the bone and another was about a person experiencing the death of his father. 
 
 Participants rated the pain each person in the scenarios experienced from 1 (no pain at all) to 5 (worst possible pain). They also rated how much the protagonists in the scenarios felt hurt, wounded and pained. 
 
 Overall, the participants who took acetaminophen rated the pain of the people in the scenarios to be less severe than did those who took the placebo. 
 
 A second experiment involved 114 college students. As in the first experiment, half took acetaminophen and half took the placebo. 
 
 In one part of the experiment, the participants received four two-second blasts of white noise that ranged from 75 to 105 decibels. They then rated the noise blasts on a scale of 1 (not unpleasant at all) to 10 (extremely unpleasant). 
 
 They were then asked to imagine how much pain the same noise blasts would cause in another anonymous study participant. 
 
 Results showed that, when compared to those who took the placebo, participants who took acetaminophen rated the noise blasts as less unpleasant for themselves – and also thought they would be less unpleasant for 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 part of the experiment, participants met and socialized with each other briefly. Each participant then watched, alone, an online game that purportedly involved three of the people they just met. (The other participants weren’t actually involved). 
 
 In the “game,” two of the people the participants had met excluded the third person from the activity. 
 
 Participants were then asked to rate how much pain and hurt feelings the students in the game felt, including the one who was excluded. 
 
 Results showed that people who took acetaminophen rated the pain and hurt feelings of the excluded student as being not as severe as did the participants who took the placebo. 
 
 “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.” 
 
 While these results had not been seen before, they make sense in the light of previous research, Way said. 
 
 A 2004 study scanned the brains of people as they were experiencing pain and while they were imagining other people feeling the same pain. Those results showed that the same part of the brain was activated in both cases. 
 
 “In light of those results, it is understandable why using Tylenol to reduce your pain may also reduce your ability to feel other people’s pain as well,” he said. 
 
 The researchers are continuing to study how acetaminophen may affect people’s emotions and behavior, Way said. They are also beginning to study another common pain reliever – ibuprofen – to see if it has similar results. ||||| (CNN) The side effects of popping a pain reliever containing acetaminophen are well-known: You may get stomach pains. You might feel nauseated. 
 
 Well, add another possible one to the list: You'll feel less inclined to empathize with your fellow man. 
 
 A new study by researchers at Ohio State University found that acetaminophen -- the main ingredient in Tylenol and about 600 other medicines -- dulls you to the trials and tribulations of others. 
 
 (By the way, these are the same researchers who earlier found that the medication can suck the joy out of life for you ). 
 
 "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," said study co-author Baldwin Way, an assistant professor of psychology and member of the Ohio State Wexner Medical Center's Institute for Behavioral Medicine Research. 
 
 Reaching the conclusion 
 
 In one, they rounded up 80 college students. They gave half of them a liquid with 1,000 mg of acetaminophen. The other half was given a liquid with no drug. Obviously, the students didn't know who was drinking what. 
 
 After an hour for the drug to take effect, the participants read eight short stories with some really sad scenarios. For instance, one was about a person who suffered a knife wound that went to the bone. Another was about someone grappling with the death of his father. 
 
 The students were asked to rate the pain of the person in the scenario. 
 
 The placebo group (i.e. the ones who didn't take the acetaminophen) rated it highly. The acetaminophen group didn't think it was that big of a deal. 
 
 In another study, the participants were given two-second blasts of white noise that ranged from 75 to 105 decibels. They were asked to rate how unpleasant it was for them and how unpleasant it would be if some other poor guy were subjected to the same. 
 
 The acetaminophen group said the noise blasts weren't that unpleasant. That's understandable because the drug reduces pain. 
 
 But they also said the blasts wouldn't be that unpleasant for someone else. That's where the lack of empathy comes in again. 
 
 Figuring out the meaning 
 
 What does this mean? 
 
 "We don't know why acetaminophen is having these effects, but it is concerning," said Way, the co-author. 
 
 The findings are consistent with a 2004 study that found that the part of the brain that's activated when you're feeling pain is the same part activated when you're picturing someone else feeling the same pain. 
 
 It stands to reason that if acetaminophen dulls your pain, it'll dull that other sensation, too. 
 
 So, let's recap what the Ohio State researchers have concluded: The drug numbs pain but also pleasure and compassion. 
 
 Next up, the researchers take on that other popular OTC medicine: ibuprofen. ||||| Taking a popular painkiller may be linked to decreased ability to empathize with others' suffering, a new study suggests. 
 
 The people in the study who took acetaminophen (sold as Tylenol and various generic labels) showed lower levels of empathy toward other people who talked about feeling physical and emotional pain than those who took a placebo, the researchers found. 
 
 "Acetaminophen can reduce empathy as well as serve as a painkiller," study co-author Dominik Mischkowski, a postdoctoral fellow at the National Institutes of Health who was a Ph.D. student at The Ohio State University at the time of the research, said in a statement. [7 Bizarre Drug Side Effects] 
 
 Acetaminophen is the most common active ingredient used in drugs sold in the United States, and is found in more than 600 medicines, according to the Consumer Healthcare Products Association. Each week, about 52 million people in the United States use a medicine that contains acetaminophen, according to the association. 
 
 In one experiment in the study, 40 healthy college students drank a liquid containing 1,000 milligrams of acetaminophen (the maximum recommended dose of Tylenol for adults over the course of a 24-hour period is 3,000 milligrams, or 6 pills per day), and another 40 college students drank a placebo solution without the drug. After one hour, the students read eight short scenarios in which people suffered some sort of physical or emotional pain. For example, one scenario was about someone who had experienced a knife cut that went down to the bone, and another was about someone else mourning the recent death of his father. 
 
 Then, the people in the study rated the intensity of pain that they thought the people described in the scenarios had experienced. It turned out that the people who took acetaminophen rated the pain of the people in the scenarios to be less severe than the people who took the placebo did. [5 Surprising Facts About Pain] 
 
 In the second experiment, the researchers looked at 114 college students, who took either acetaminophen or a placebo. The students received four 2-second blasts of loud noise and rated how unpleasant the blasts were. They were also asked to rate how unpleasant the same noise blasts would be to other anonymous people. 
 
 It turned out that the people who took the acetaminophen rated the blasts as less unpleasant to both themselves and other people compared with people who took the placebo, according to the study, published in May in the journal Social Cognitive and Affective Neuroscience. 
 
 It is not clear why, exactly, the drug appears to be linked to lower levels of empathy, and more research is needed to examine the potential mechanism behind the link, the researchers said. 
 
 The study also had some caveats, the researchers said. For example, the people in the study were healthy and were not experiencing actual physical pain, said study co-author Baldwin Way, a psychology professor at The Ohio State University. 
 
 "That might be a slightly different context than someone who is taking this drug for a headache or a back ache or some sort of pain," he told Live Science. 
 
 Therefore, it is not clear if the link between taking the drug and lower empathy levels would also be present in people taking these drugs to deal with physical pain, he said. 
 
 Follow Agata Blaszczak-Boxe on Twitter. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.
– If the results of a new study hold up to further research, Tylenol may have to start coming up with a new warning label: "may cause a lack of empathy." Researchers studying acetaminophen—the active painkiller in Tylenol and about 600 other medicines—found people taking it showed less empathy toward the physical and emotional pain of others, Live Science reports. This could be a big deal as nearly a quarter of American adults take some form of acetaminophen every week, notes an Ohio State press release. "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," says the study's senior author, Baldwin Way. The study—published in Social Cognitive and Affective Neuroscience—consisted of multiple experiments involving stories of suffering, actual painful blasts of noise, and more, CNN reports. The results appear to confirm earlier studies of brain activity that showed empathy was somehow neurologically related to how a person processes their own pain. The results also "raise concerns about the broader social side effects of acetaminophen," says the study. “We don’t know why acetaminophen is having these effects, but it is concerning,” says Way. The researchers plan to test ibuprofen next. (Another recent study shows acetaminophen could reduce your ability to notice errors.)