STICKS and stones may break your bones, but words might make you more likely to get arthritis. Not as catchy as the original, but it seems social rejection could trigger diseases linked to inflammation.

Psychologist George Slavich of the University of California, Los Angeles, and colleagues asked 124 volunteers to give speeches and perform mental arithmetic in front of a panel of dismissive observers. Saliva analysis showed they exhibited elevated levels of two inflammation markers. A quarter of the volunteers then played a computer game in which other players were instructed to exclude them.

Functional MRI scans showed this triggered increased activity in two brain regions associated with rejection. Participants with the highest inflammatory responses showed the greatest increases in brain activity (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1009164107).

Understanding the role the brain plays in conditions linked to inflammation - such as asthma, arthritis, cardiovascular disease and depression - will help in the development of new treatments to combat them, says Slavich.

(Reported in New Scientist)