According to US News & World Report:
"Meditation is becoming increasingly popular as a way to treat chronic illness such as the pain caused by arthritis," study author Dr. Christopher Brown, from the University of Manchester's School of Translational Medicine, said in a university news release.
"The results of the study confirm how we suspected meditation might affect the brain," explained Brown. "Meditation trains the brain to be more present-focused and therefore to spend less time anticipating future negative events. This may be why meditation is effective at reducing the recurrence of depression, which makes chronic pain considerably worse."
However, he added that "although we found that meditators anticipate pain less and find pain less unpleasant, it's not clear precisely how meditation changes brain function over time to produce these effects.