The over-the-counter (OTC) painkillers you buy at your local drug store without even thinking about them appear to do more than just kill your back pain or bring down a fever — they may actually improve your mood. A review study that looked back over previous research on pain medications like acetaminophen (Tylenol) and ibuprofen (Advil) has found that these drugs, on the shelves of most medicine cabinets, blur the boundary between physical and psychological processes.
After sifting through all the evidence, researchers report that in addition to easing headaches and sore muscles, painkillers have an effect on our emotions and our thoughts.
This reduced emotional connection to others also seemed to lower a person’s level of empathy. People taking painkillers were less distressed emotionally and less concerned about a person in a story who was experiencing either emotional or physical pain.
Another study revealed that women's memories of past betrayals became less painful after they took ibuprofen, compared to women who took a placebo. The same connection wasn’t found in men — in fact, it was the opposite for them. It’s not totally clear why this gender difference exists, but the team suggests it may be that while the medications dulled the women’s emotional pain, “men responded in the opposite manner because the drugs disrupted their default tendency to suppress emotional pain.” More work will definitely need to be done to understand this gender divide more fully.
Consumers expect an over-the-counter pain medication to relieve their physical symptoms. What they don't anticipate are painkillers' broader psychological effects.
Painkillers may even make you more generous or at least a little less grasping. When men and women took acetaminophen and were asked how much money they’d need to part with an object, they asked for less money in compensation, again compared to those who took placebo. This seems to suggest that the emotional value of an object may also be reduced when people take acetaminophen.
Taking a pill for pain may not be too helpful when it comes to performing certain tasks well, however. Compared to those who were given a placebo instead of a painkiller, people who took acetaminophen made more errors playing a game requiring them, on command, to perform or refrain from performing a task quickly.
Why would painkillers alter or reduce emotional pain in addition to physical pain? The authors point to a study that monitored what’s happening in the brain: Participants played a game in the lab that asked two players to exclude the third. The excluded participants’ brains were scanned during this time, and it turned out that one area of the brain was more active as they experienced the pain of rejection — the same area that’s active when we’re experiencing physical pain. So it may be that physical and emotional pain are in some ways one and the same, neurologically speaking.
“[T]his brain imaging work,” the University of California, Santa Barbara team writes, “provided empirical evidence that metaphors linking physical and social pain (e.g., feeling ‘stabbed in the back’ when one is betrayed by a friend) may be rooted in overlapping biological processes.”
About a week into the study, the acetaminophen group starting reporting significantly fewer hurt feelings.
It may also explain why a broken heart really feels like your heart is actually breaking.
The study is published in Policy Insights from the Behavioral and Brain Sciences.