News Neuroscience Two distinct neural pathways may make opioids like fentanyl so addictive A study in mice identified the brain circuits behind reward and withdrawal Fentanyl and other synthetic opioids are highly addictive. Researchers have now identified two neural pathways behind this addiction. Johnrob/iStock/Getty Images Plus Share this:EmailFacebookTwitterPinterestPocketRedditPrint By Claudia López Lloreda May 22, 2024 at 11:00 am Fentanyl’s powerful pull comes from both the potent, rapid euphoria people feel while on the drug and the devastating symptoms of withdrawal. Researchers have now zeroed in on brain circuits responsible for these two forces of fentanyl addiction. The study in mice, reported May 22 in Nature, suggests two distinct brain pathways are in play.