The following article showing a link between Acetaminophen/Paracetamol usage and decline in positive empathy is highly relevant here;

The medications that change who we are - https://www.bbc.com/future/article/20200108-the-medications-...

Excerpt:

Mischkowski’s own research has uncovered a sinister side-effect of paracetamol. For a long time, scientists have known that the drug blunts physical pain by reducing activity in certain brain areas, such as the insular cortex, which plays an important role in our emotions. These areas are involved in our experience of social pain, too – and intriguingly, paracetamol can make us feel better after a rejection.

Mischkowski wondered whether painkillers might be making it harder to experience empathy

And recent research has revealed that this patch of cerebral real-estate is more crowded than anyone previously thought, because it turns out the brain’s pain centres also share their home with empathy.

For example, fMRI (functional magnetic resonance imaging) scans have shown that the same areas of our brain become active when we’re experiencing “positive empathy” –pleasure on other people’s behalf – as when we’re experiencing pain.

Given these facts, Mischkowski wondered whether painkillers might be making it harder to experience empathy. Earlier this year, together with colleagues from Ohio University and Ohio State University, he recruited some students and spilt them into two groups. One received a standard 1,000mg dose of paracetamol, while the other was given a placebo. Then he asked them to read scenarios about uplifting experiences that had happened to other people, such as the good fortune of “Alex”, who finally plucked up the courage to ask a girl on a date (she said yes).

The results revealed that paracetamol significantly reduces our ability to feel positive empathy – a result with implications for how the drug is shaping the social relationships of millions of people every day. Though the experiment didn’t look at negative empathy – where we experience and relate to other people’s pain – Mischkowski suspects that this would also be more difficult to summon after taking the drug.

Also see the previous thread; A social analgesic? Acetaminophen (paracetamol) reduces positive empathy - https://news.ycombinator.com/item?id=31263305