The standard explanation for the opioid epidemic blames pharmaceutical companies and doctors for overstating the benefits and understating the risks of prescription opioids. See this essay by Robert Verbruggen, the deputy managing editor of National Review.
An alternative explanation is that opioids—like many substances—are dangerous mainly when heavily restricted or outlawed. Thus, increased prescribing over the past several decades has generated overdoses by creating a group of people who find opioids beneficial but then cutting them off from legal opioids after a few weeks or months, thereby forcing them into the black market. There, they consume heroin of unknown purity that is sometimes laced with fentanyl. See my comment on Verbruggen’s essay (or this essay by Cato scholar Jeffrey Singer).
Resolving this debate is crucial: under the standard view, policy should restrict opioid prescribing further; under the alternate view, policy should liberalize prescribing or better yet allow unrestricted legal access to all opioids, prescription or otherwise.
So far policymakers have been increasing restrictions, and the opioid death rate has kept climbing. I’ll let you do the math.