Ohio State University researchers have discovered the first evidence of a brain mechanism link between opioid use disorder and chronic pain.
"Central sensitization refers to abnormal pain processing in our spinal cord and our brain. And that really leads to amplification of pain signals coming from the body or even perception of pain when we're not hurt or our injury has long since healed,” said Dr. O. Trent Hall, lead author of the study and an addiction medicine physician in Ohio State’s Department of Psychiatry and Behavioral Health.
Researchers recruited 141 participants for the study from OSU Wexner Medical Center’s addiction treatment center in Columbus. Participants answered questions about pain interference, quality of life and items regarding pain-beliefs and expectations of pain and addiction treatment.
"This study is unique in that it was conducted in a group of folks who were looking for opioid use disorder treatment,” said Hall. “They didn't come to our treatment facility looking specifically for pain management. They were actually here for help with their opioid use disorder."
Researchers measured quality of life across eight areas including general health, physical functioning, mental health, social functioning, vitality, bodily pain, role limitations due to physical health and role limitations due to emotional problems.
They found that patients with higher central sensitization more often reported pain as a major reason for why their opioid addiction started, and why they delayed addiction treatment.
“We've also found there are certain infections that can predispose people to developing central sensitization,” said Hall. “Also, childhood abuse and adult life trauma."
Hall said while treatment options are limited, there are some medications available like methadone, naltrexone, and buprenorphine. He explains some of them were originally developed for people with depression.
“Even though what we’re talking about is abnormal pain processing in the brain and spinal cord, a lot of the same chemicals that are involved in our brain and depression are actually involved in this form of pain, so these medicines can be helpful for pain as well,” said Hall.
OSU worked with researchers at the University of Michigan to create painguide.com. Hall said it includes helpful advice on human bodies and relieving pain.
