Taking acetaminophen – sold under the Tylenol brand – can make it harder for us to feel happy for other people, new research suggests.
The common drug belongs to a group of analgesics that relieve pain – although we are not really sure why.
Previous research confirmed that when paracetamol helps us to feel less of our own pain, it makes us less empathetic to the pain of others.
Now a follow-up study by the University of Ohio shows that the drug also makes us less empathetic to the positive, enjoyable experiences of others.
Acetaminophen – also sold as Tylenol (photo) and Paracetamol – reduces activity in parts of the brain that help us feel the pleasure of others and empathize with us, a new study finds
Painkillers are designed to address physical aches and pains.
But our pain experience is as psychological as it is physiological.
And because we can’t take a pill to immediately heal a wound or repair a broken bone, analgesics try to obstruct the way we respond to pain, versus the neurochemicals that communicate pain signals and inflammation.
But acetaminophen is special and is still poorly understood.
The latest theories suggest that the drug may be targeted at the endocannabinoid system (the one that responds to marijuana) and serotonin receptors.
No matter how it works, paracetamol does work and is the third freely available painkiller.
In recent years, scientists have made much better progress in solving the empathy mystery.
They have identified a number of areas of the brain that are important for our emotions and motivation and are therefore thought to be involved in empathy.
Previous research has shown that these areas are important not only for the experience of ‘feeling other people’s pain’, but also for positive empathy, of the empathic experience of other people’s pleasure.
These areas, some neuroimaging studies have shown, are less active after someone has taken paracetamol.
So the researchers at the University of Ohio risked a guess that paracetamol would not only reduce the empathy for others’ misfortune, but also for their happiness.
To test this theory, they gave half of their 114 placebo participants a drug and half gave 1,000 mg of acetaminophen – the equivalent of a standard dose of Tylenol Extra Strength.
They then showed the participants a series of four scenarios in which groups of men and women had a form of ‘positive experience’.
Study participants had to assess how much people in the scenarios seemed to enjoy themselves, how much pleasure they felt themselves and how empathetic they felt about the scenario cast.
The participants in paracetamol could still see that the people enjoyed the scenarios they were shown.
But they rated their own pleasure and empathy lower than the control group.
Interestingly, scientists roughly divide empathy into two categories: cognitive and affective.
Cognitive empathy allows us to see and name the emotions that others feel – such as seeing how happy people were depicted in the study scenarios.
On the other hand, affective empathy enables us to feel the emotions that others might have, and to activate those same emotions within us.
So it seems that acetaminophen left cognitive empathy intact, but had the same boring effect on people’s own emotions – which are the key to empathy as a whole – as on their experience with pain.
“I’m still surprised by the striking psychological effects of such a common painkiller as paracetamol,” said Dr. Dominik Mischkowski, professor of psychology at the University of Ohio.
However, he also conducted previous research into negative empathy and acetaminophen and said he suspected the drug would have similar effects on positive emotions.
Dr. Mischkowski added: “Given that an estimated quarter of all American-American adults use a drug containing paracetamol, this study is really important.”
It is possible that, according to this study, 81.8 million people who have taken some Tylenol from the medicine cabinet have been numbed at some point in our pain, emotions and feelings of others.