Addicted to Pain?

Some brains may be wired to become addicted to pain.  In fact, researchers have been able to accurately predict people who will continue to experience back pain more than a year after their initial injuries.

A study done at Northwestern University in Illinois looked at 39 people with recent onset of back pain.  Half still had pain a year later—their original pain had converted into insidious, chronic pain.  All participants had similar pain at the start of their injuries, but the chronic pain cohort had an unusually strong connection between two regions of the brain: the nucleus accumbens and the prefrontal cortex.

The two regions seemed to work in tandem, if one was active the other also “lit up.” A stronger connection correlated with a higher likelihood of developing chronic pain.

“We’re very excited about these results,” observed study coauthor A. Vania Apkarian of Northwestern. “We think they open up a whole new way of looking at chronic pain.” The research was presented in the July 1, 2012 Nature Neuroscience online journal.

Previous studies have examined brain differences in chronic pain sufferers, but researchers had not been able to discern whether these changes were caused by the chronic pain or an effect of living with it.  This study was the first to reveal a predictive signal present in the brain before the pain becomes chronic.

Interestingly, the study may link chronic pain development to the brain’s addiction conduit since both include the nucleus accumbens.  “This is certainly part of the addiction pathway,” Apkarian noted, observing that though the idea hasn’t been tested, chronic pain may stem from the brain essentially becoming addicted to pain and warrants further study.

This article was originally published in Pathways Physician & Health Professional Bulletin - Issue 26.  To download this issue in PDF format, or past issues, visit our newsletter archives online at www.pathwayshealth.org/publications.