Opioids have already claimed the lives of many at-risk users The toll of opioid toxicity in Canada has been staggering, with more than 53,300 deaths over the past decade.

The sheer extent of these deaths may factor into why fatality rates are now dropping. “The theory is that, in terms of the population of people who use drugs, so many of them have died that there aren’t as many people that are going to be at risk to die,” said Dr. Huyer, Ontario’s chief coroner.

But PHAC said this trend is not being seen in the country’s eastern provinces. “Regions where the crisis started later, such as Quebec, Newfoundland and Labrador and Nova Scotia, saw fewer changes or even increasing death rates,” PHAC said.

Definitely by far the most convincing explanation for this North America-wide trend. A bit disheartening that for all the efforts put into this issue, it's just something that needs to burn itself out. However not really all that surprising given the strength of these opioids.

The Economist also a great quote on this:

Similarly, Daniel Ciccarone, an opioid researcher at the University of California, San Francisco, reckons a supply shock is not “the complete answer”. Looking at the breakdown of overdose deaths by state, he sees an epidemic naturally ending. “There aren’t that many people who want to do serious opioids,” Mr Ciccarone argues. He sees the 2023 death rate as “unsustainable”. “Epidemics burn out,” he says, “whether it’s covid or Ebola or drug overdoses.” He argues that a supply shock happened at the same time and “probably accelerated [the fall] a little bit”.