Depressed people find it harder to 'shake it off'

The pain of social rejection lasts longer for them, and their brain cells release less of a natural pain and stress-reducing chemical called natural opioids.

On the flip side, when someone they're interested in likes them back, depressed people do feel relatively better, but only momentarily. This might also be explained by differences in their opioid system compared to non-depressed people, according to the new results.

Further research could lead to a better understanding of how to boost the opioid response and reduce the exaggerated effect of social stress. This in turn increases the benefits of positive social interactions.

A team from the University of Michigan Medical School, Stony Brook University and the University of Illinois at Chicago worked together on a study, which builds on previous work about social rejection in non-depressed people.

The researchers focused on the mu-opioid receptor system in the brain (the same system that they have studied for years) in relation to response to physical pain. During physical pain, our brains release opioids to dampen pain signals.

The new work showed that this same system was associated with an individual's ability to withstand social stress and to positively respond to positive social interactions, said senior author Jon-Kar Zubieta, M.D., Ph.D.

The new findings have already prompted the team to plan follow-up studies to test individuals who are more sensitive to social stress and vulnerable to disorders such as social anxiety and depression, and to test ways of boosting the opioid response.

The study is published in the journal Molecular Psychiatry.