Empathy might be the original gateway drug, new research suggests.

Smoke.

Image via Pixabay.

Empathy smooths your way through social situations, but it might also smooth the path to drug addictions, a new paper suggests. The research, carried out at the University of Minnesota (UoM), was carried out using mice models but may carry over to humans as well.

Blue empathy

A research group led by  Dr. Jonathan Gewirtz at the UoM set out to analyze the links between empathy, stress, and drug use. The team’s hypothesis was that empathy (the awareness of another’s feelings and emotions), while very useful in social situations, can also expose one to more stress (as revealed by previous research). This stress, the team explains, can push former drug users into relapsing.

The team started by training a group of male mice to mimic drug-seeking behavior. The animals were placed in a two-sided compartment. Mice going to one side would receive a shot of saline (water and salt) solution, while those going to the other side would get a shot of morphine. Repeated over several days, the mice started associating one side with the drug.

Next, the researchers switched things up: over two weeks, mice going into either compartment would receive only saline injections. This was meant to mimic a period of sobriety. With the mice properly sobered, the team was ready to test the role of empathy in relapse. During this step, one of the sober mice witnessed another mouse in a fearful state, the team reports. This sober mouse was then immediately placed in the dual-sided compartment, and the team tracked their fear response and preference for either compartment.

These mice consistently preferred the compartment they associated with morphine. This, the team reports, suggests they were expressing drug-seeking behavior in response to witnessing another mouse going through a traumatic event. Some mice were afterward treated with oxytocin, a hormone which has been linked with social bonding among other effects. The oxytocin heightened the mice’s fear response, the team adds.

All in all, the team concludes that mice (and people too, potentially) are negatively affected by witnessing a stressful or traumatic event. This negative emotional impact is strong enough to push them to seek drugs, even after a period of sobriety. Oxytocin treatment exacerbates this response, suggesting that social bonding (and empathy, by extension) is a driving force in this behavior.

The researchers say these findings are the first to demonstrate the direct link between empathy and drug relapse, and the first to suggest that oxytocin may play a role in enhancing this response.

The findings have been presented at the 57th Annual Meeting of the American College of Neuropsychopharmacology (ACNP), held December 9-13, 2018, in Hollywood, Florida.