Your comments about the efficacy of the drugs are understandable but if the question is the elevated overdose deaths caused by the doctor-prescribed drugs then you may wish to take a look at the Dr. Singer of Cato Institute who has convincingly shown (appearing, too, at Congressional Committee, I believe) that the the overdose deaths have continued to rise even after doctors were 'forced' to reduce its prescription, causing the often unnecessary pain to those who would have benefited from its use. As you might know even the SCOTUS sided with the two doctors who apparently used their judgement to (over)prescribe...but what's the alternative in a human-run world where even professionals sometimes may err in good faith 'overprescribing, as do other professionals in their fields. I think there is a difference between establishing whether the Overuse was due to addictive nature of the fentanyl, which DEA seems to disagree with and the Overuse that has caused the excessive increasing deaths (and still continue to do with new entries like Tranc, an animal tranquilizer, the latter one could attribute to the 'paucity of pleasure' among the users who often include housed and financially secure people, not just 'street people.' I hope it helps.
https://www.cato.org/blog/policymakers-are-stuck-state-denial-about-true-cause-overdose-crisis?utm_campaign=Cato%20Today&utm_medium=email&_hsmi=222414924&_hsenc=p2ANqtz-8SRuwhbmSlU60vHCKK9Wpn99XXdy-crHX-3ccs2hVPvY0SnooNdlGhwec-O6IwTBA35W5UiDnM06H3YhLR3N9N6koCJQ&utm_content=222414924&utm_source=hs_email