Ibuprofen and Acetaminophen are well-known over- the- counter (OTC) painkillers. Can ibuprofen improve your mood, too? Now a study published in the journal, Policy Insights from the Behavioral and Brain Sciences, points to evidence that OTC pain relievers may have some influence over a person’s reactions to emotionally painful experiences, ability to understand another person’s emotional responses, ability to process information and discomfort from parting with possessions.

The researchers theorise that both physical and mental pain may depend on the same behavioural and neural mechanisms that register pain-related reactions. Acetaminophen, the pain killer that takes effect through central neural mechanisms, may also reduce behavioural and neural responses to social rejection as the physical & mental pain processes overlap.

The study found that the study participants (women) who were given ibuprofen reported feeling less upset about emotionally painful experiences, such as being excluded from a game or writing about a time when they were betrayed. But men who were given ibuprofen experienced the opposite of what the women in the study felt.

In 2 experiments, participants took acetaminophen or placebo daily for 3 weeks. Acetaminophen doses resulted in decreased reports of emotional pain from daily social interactions (Experiment 1). In the 2nd experiment, the researchers used functional Magnetic Resonance Imaging (fMRI) to measure participants' brain activity. They found that acetaminophen decreased emotional responses to social rejection in brain regions previously linked to distress caused by social pain and the affective component of physical pain. These experiments demonstrated that acetaminophen lessened behavioural and neural reactions  linked to the pain of social rejection, indicating considerable overlap between social and physical pain.

Some researchers said the findings were upsetting as people who took over-the-counter painkillers may not be aware of the broader psychological results. They also highlighted need for further research as these findings may have new potential for helping people deal with hurt feelings.