According to Sanberg and Portis, "Brain scientists have known for decades that opioids are complex and difficult substances to manage when it comes to addiction. The National Institute on Drug Abuse reports that more than 20 percent of the patients prescribed opioids for chronic pain misuse them, and between 8 and 12 percent of those who use prescription opioids develop a use disorder."

This article explains how opioid's affect the brain. 

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