A new study finds only 1 in 4 residential treatment centers for U.S. teens offers a recommended treatment medicine for opioid addiction. Researchers posed as an aunt or uncle seeking help for a fictitious 16-year-old who survived a fentanyl overdose. They called rehabs and asked if they offered the treatment medication buprenorphine . It is the only medication approved for teens 16 and older with opioid use disorder. It works by reducing cravings so a patient can begin the work of recovery. The study was published Tuesday in the Journal of the American Medical Association.