Only one-quarter of people who need medication to treat opioid use disorder (OUD) receive it, according to a new study.

Researchers from Columbia University analyzed 2019 national survey data on teens and adults who could benefit from medication for OUD. They found 57% received no treatment and 15% received only services without medication. Just 28% received medication such as methadone, buprenorphine or naltrexone, HealthDay reports.

“Our nationally representative research revealed critical gaps in treatment engagement and use of medication for opioid use disorder. Increased efforts to address barriers to care are critically needed,” study lead author Pia Mauro, Ph.D., said in a news release. “Evidence supporting the effectiveness of medication for opioid use disorder such as methadone, buprenorphine, or naltrexone is unequivocal, but most people who needed OUD treatment in the US did not receive this gold standard treatment.”