Tulane University Nov 3 2025 A new study from Tulane University found that, over the past decade, more states have moved to make it easier for people with opioid use disorder to get potentially life-saving medication. The study published in Health Affairs found that, as of 2023, 22 states have passed laws prohibiting private insurance plans from requiring prior authorization, a process that requires doctors to get insurer approval before prescribing certain medications for opioid use disorder.