Paracetamol reduces negative and positive emotions

He paracetamol (acetaminophen) is a drug widely used for its properties against pain and fever. As with other medications, its use can have unwanted side effects. Until now it was known, for example, that taking it in high doses negatively affected the liver.

An investigation A recent study from Ohio University seems to indicate that the active ingredient in acetaminophen, which is also found in other medications, decreases the ability to feel positive emotions and negative.

Paracetamol does not only affect pain

The study of the relationship between paracetamol and emotions is not something new, a previous investigation found that subjects who took acetaminophen for three weeks felt less emotional pain than people who took a placebo. But the new study, published in Psychological Science, seems to show that this drug also affects positive emotions, not just negative ones.

The study and its results

The investigation, led by Geoffrey R. EITHER. Durso, Andrew Luttrell, and Baldwin M., was conducted at Ohio University. Two groups of 41 subjects each were formed. The first group received a 1000 mg dose of acetaminophen and the second group received a placebo (a putative drug). An hour later (the time required for the paracetamol to take effect) they were shown a series of images to elicit negative or positive emotions. These images had been selected to provoke strong emotional reactions. Subjects had to rate from +5 (most positive) to -5 (most negative) their positive or negative perception of the image. After looking at the images and evaluating them a first time, they were presented with the sequence of images again for a second evaluation.

The results revealed that the group that had consumed paracetamol felt less intense emotional reactions to the images, that is, negative images were evaluated as less negative, and positive images were evaluated as less positive.

To rule out that the perception of other qualities of the image (such as color intensity, etc…) had not affected the emotional evaluation, a second study was carried out. The results showed that paracetamol did not alter the visual perception of the image.

It should be mentioned that the difference in the scores of both groups was not very large. The mean of the scores of the placebo group was 6.76, while those of the group that had taken paracetamol was 5.85.

Other studies related to pain and emotions

We already discussed in the article “The Phantom Limb: Mirror Box Therapy” that the studies of Ronald Melzack, a researcher and professor of psychology at McGill University in Canada, led to the Neuromatrix Theory. This theory attributes the diffusion of pain and the transmission of this by the organism to a complex system. Various areas are involved in the system (central and peripheral nervous system, autonomic nervous system and endocrine system) directly influenced by various psychological, emotional, genetic and social.

another study, carried out by Naomi Eisenberger, a researcher at the University of California at Los Angeles (UCLA), seems to indicate that the physical pain and social pain are processed in the same brain regions. These brain regions are activated in a similar way in the face of physical pain or in the face of social rejection, such as a breakup. In addition, people "who are more sensitive to physical pain also tend to be more sensitive to social pain," concludes the author of the research.

If it is true that paracetamol affects emotions, will other pain relievers such as Aspirin or the ibuprofen? Surely there will be future research in this line.