While you might have not heard of paracetamol before, you will know it by the more common name, acetaminophen. Acetaminophen is a pain reliever that can be purchased over-the-counter or can be combined in opiate painkillers such as Vicodin or Percocet. Researchers at Ohio State University have actually found new side effects of taking paracetamol, which is that not only does it kill pain, but it kills your emotions too.
In the study, which was published in the journal Psychological Science, researchers concluded that the painkiller kills off emotions the same way it kills physical pain, and that the same type of brain circuits are behind both. This means that while the pain receptors are dulled, which is what acetaminophen is used for, the pleasure receptors in the brain are also being dulled, and this is something new as far as side effects are concerned. For the study, researchers took 82 students and either gave them 1,000 milligrams of acetaminophen or a placebo pill. It typically takes about an hour for the medication to start working, so then the students were asked to look at 40 different photographs. The photographs were previously selected because they would elicit an intense emotional response, such as something very violent or sad or even happy. There were pictures of children playing with cats, which should elicit a happy response, while pictures of a malnourished child should be triggering either sadness or anger. The students then had to rate the 40 different pictures based on either how negative they thought the image was or how positive the image was, all according to how the pictures made them feel internally. The pictures were rated -5 for the worst or most negative and +5 for the most positive images. The students then had to look at the pictures again and rate the pictures 0 through 10 as far as how intense the reaction was, so 10 would be an extreme emotional reaction and zero would be basically no intense feelings one way or the other.
The results of the study was that the students who took the paracetamol actually had less of an intense reaction to the images, compared to the group of students who took the placebo pill. This means that if the students saw a picture of a malnourished child, it did not elicit very intense feelings of anger or sadness, while a picture of a child playing with a cat didn’t really register to them as an extremely positive image. The students who were on the paracetamol did not have the high highs or the low lows that the group with the placebo had while going through the pictures, and almost had the same blah reaction to all of the pictures. Obviously, because of the nature of the pictures, the group who had the placebo experienced periods of intense happiness followed by intense sadness or anger.
However, while the students who took the paracetamol did not have as intense of feelings as the control group, the differences between the two groups were not that different. The students on the placebo ended up with an average emotional response to the pictures at about 6.76 out of 10, while the students who took the paracetamol averaged about a 5.85 in emotional response. While this is not a significant gap in between the two groups, it does show that the drug used to dull physical pain is also dulling the types of reactions people have emotionally. This could explain why people with a drug problem, such as to Vicodin, are often called Zombies. A lot of people addicted to drugs give the blank stares and tend to not feel as much emotionally as people who are not on painkillers, and that could also be why things become less exciting to people who are using or abusing drugs with paracetamol in them.
The researchers plan on using the same theory to test out ibuprofen and aspirin to see if the effects are the same as with paracetamol. The new side effects that the researchers at Ohio State University uncovered can better help doctors when it comes to understanding addiction as well as other diseases where paracetamol is used, such as in patients who are dealing with chronic pain. It is not known yet if more studies will be done with paracetamol or what the impact of this study will be on prescribing medication with paracetamol in it. For now, it is just another reason why taking drugs containing paracetamol might not be good for people when used for extended periods of time.
It is one thing to dull out the physical pain, but to dull out emotions and the intensity of them, is actually hindering the human experience. Humans need to feel high highs and low lows in order to connect with other people and have meaningful interpersonal relationships, so taking a medication like paracetamol that gets rid of this experience can actually be harming people in an emotional sense. There will likely be an even bigger study with paracetamol so that researchers can try to get the same results, and then maybe something will be developed that could counteract the side effect, if that is even possible considering the same brain circuits are being used.