You may think of over-the-counter painkillers as being relatively harmless. However, intriguing new research is beginning to show that drugs, such as Ibuprofen and paracetamol, may actually be influencing our thoughts and emotions when we take them.
A new study, published in the journal Policy Insights from the Behavioural and Brain Sciences has reviewed this research, making a number of findings.
Firstly, the studies show that these pain medications can reduce our sensitivity to emotionally painful experiences or emotionally evocative objects.
One experiment, demonstrated that women who took a dose of Ibuprofen reported less hurt feelings from emotionally painful experiences – writing about a time they were betrayed, for example – compared to a control group. Men, on the other hand, reported the opposite effect - experiencing the emotional pain more intensely after taking the drug.
In addition, another experiment found that people who took a dose of paracetamol rated pleasant and unpleasant photographs less extremely than those who had taken a placebo.
Secondly, pain medications appear to have an effect on our ability to empathise with others. Research has shown that people taking paracetamol were less emotionally distressed when reading about someone's painful physical or emotional experience and also felt less regard for that person, compared to a control group.
Thirdly, the drugs may be affecting how our brains process information. People who took paracetamol made more errors in experiments involving a game where participants were asked either to perform, or not perform a task at various times.
Lastly, and perhaps most interestingly, the drugs caused discomfort when people were faced with selling their possessions.
"In many ways, the reviewed findings are alarming," write the authors of the study. "Consumers assume that when they take an over-the-counter pain medication, it will relieve their physical symptoms, but they do not anticipate broader psychological effects."
However, the authors stressed further research was necessary before policymakers consider new regulations or policies, although they do recommend that potential public health risks are considered in case the evidence is confirmed.
On a more positive note, the authors also suggest that these new medicines may have potential for helping people who are depressed or have difficulty feeling pleasure, although again, more research was needed in this area before any recommendations could be made.