by a University of Michigan Medical School team, show that the brain's natural painkiller system responds to social rejection - not just physical injury.
What's more, people who score high on a personality trait called resilience - the ability to adjust to environmental change - had the highest amount of natural painkiller activation.
The team, based at U-M's Molecular and Behavioral Neuroscience Institute, used an innovative approach to make its findings. They combined advanced brain scanning that can track chemical release in the brain with a model of social rejection based on online dating. The work was funded by the U-M Depression Center, the Michigan Institute for Clinical and Health Research, the Brain & Behavior Research Foundation, the Phil F Jenkins Foundation, and the National Institutes of Health.
They focused on the mu-opioid receptor system in the brain - the same system that the team has studied for years in relation to response to physical pain. Over more than a decade, U-M work has shown that when a person feels physical pain, their brains release chemicals called opioids into the space between neurons, dampening pain signals.
David T. Hsu, Ph.D., the lead author of the new paper, says the new research on social rejection grew out of recent studies by others, which suggests that the brain pathways that are activated during physical pain and social pain are similar.
"This is the first study to peer into the human brain to show that the opioid system is activated during social rejection," says Hsu, a research assistant professor of psychiatry. "In general, opioids have been known to be released during social distress and isolation in animals, but where this occurs in the human brain has not been shown until now."