Acetaminophen reduces negative and positive emotions, study finds

Research based on the use of acetaminophen helps to gain insight into the brain.

The paracetamol (acetaminophen) is a drug widely used for its properties against Pain and fever. As with other drugs, its use can have undesirable side effects. Until now it was known, for example, that taking it in high doses had a negative effect on the liver.

Recent research from Ohio University seems to indicate that the active ingredient in acetaminophen, which is also found in other drugs, reduces the ability to feel positive and negative emotions.

Paracetamol does not only affect pain

The study of the relationship between acetaminophen and emotions is not new; previous research 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 Scienceseems to show that this drug also affects positive emotions, not just negative ones.

The study and its results

The research, led by Geoffrey R. O. 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 suspected drug). One hour later (time needed for the acetaminophen to take effect) they were shown a series of images to elicit negative or positive emotions. These images had been selected to elicit strong emotional reactions. Subjects were asked 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 image sequence again for a second evaluation.

The results revealed that the group that had consumed paracetamol felt less intense emotional reactions to the images, i.e., those who had taken to the images, i.e., negative images were rated as less negative, and positive images were rated as less positive.

To rule out that the perception of other image qualities (such as color intensity, etc...) had not affected the emotional evaluation, a second study was conducted. 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 the two groups was not very large. The mean score of the placebo group was 6.76, while that of the group that had taken paracetamol was 5.85.

Other studies in relation to pain and emotions

We already commented 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, gave rise to the Neuromatrix Theory. This theory attributes the diffusion of pain and its transmission through the organism to a complex system. The system involves several areas (central and peripheral nervous system, autonomic nervous system and endocrine system) directly influenced by various psychological, emotional, genetic and social factors.

Another study, conducted by Naomi Eisenberger, a researcher at the University of California, Los Angeles (UCLA), seems to indicate that physical and social 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 social rejection, such as a breakup. Moreover, people "who are more sensitive to physical pain also tend to be more sensitive to social pain," concludes the author of the study.

If it is true that paracetamol affects emotions, will other analgesics, such as Aspirin or Ibuprofen? Surely there will be future research along these lines.