Acetaminophen, the active ingredient in Tylenol, could have an effect on your emotions — not just your pain, according to a new study from researchers at the Ohio State University.
The study asked participants to evaluate images classified as positive and negative after taking 1,000 milligrams of either the over-the-counter drug or a placebo. That’s the equivalent of two Extra-Strength Tylenol tablets.
The images were from the International Affective Picture System, a database of “established photos that have been used for decades that reliably cause people to have positive or negative emotions,” said Geoff Durso, the lead author on the study and a doctoral student in social psychology at The Ohio State University.
On the negative side, there were photos of crying, malnourished children, a filthy toilet, an urban war zone and a dead and decaying cat. On the positive side, the photos included a smiling baby on a blanket, children in a park playing with kittens, a couple kissing in bed and a giant pile of money, Durso said.
The participants were asked to put the images in five categories: Extremely Unpleasant, Moderately Unpleasant, Neutral, Moderately Pleasant, Extremely Pleasant, said Durso.
Besides rating their feelings about the pictures, the participants were also asked to rate how emotionally stimulating the images were. Their responses were compared to a control group who hadn’t taken acetaminophen.
What they found is that the people who took acetaminophen viewed the pictures as slightly less negative and slightly less positive than people who didn’t take the drug.
“It had the strongest effects on the extremes, regardless if they are negative or positive,” Durso said. So, people who took Tylenol felt less in general about the images they saw.
Not much is known about how acetaminophen works, Durso said, but it is thought to be involved with serotonin regulation.
Scientists found in earlier research “when they give animals acetaminophen, those that aren’t able to transmit serotonin as well don’t get the same benefits of pain relief,” Durso said.
“We do know a lot more about the non-steroidal anti-inflammatory drugs, or NSAIDS,” Durso said, so a next step would be to “examine if ibuprofen has the same effect on individual psychological outcomes. We know almost precisely how ibuprofen works so that would give us a hint.”