Starting around 2:22:30 of his interview with Tim Ferriss:
Maté: If you look at the United States right now, do you know what the facts are? The most common cause of death under the age of 50 is now overdose. In the US, every three weeks you have the equivalent of a 9/11. Every three weeks, a 9/11, in terms of the number of people dying.
Now where's the public outcry? Where are the resources? Where is the political will? Where is the mobilization of the media and all the public health energies, compared to what happened after 9/11? And we're having this every three weeks.
And why? Because the treatment profession, the medical profession, and politicians, and the legal profession does not understand trauma and its relationship to addiction.
The average medical student doesn't even hear the word "trauma" in four years of education... so we have this response to addiction which is just dealing with the effects, the behaviors, controlling the manifestations and not dealing with the causative factors. That's why people don't get better.
If you look at why, right now – it's cause social stress has increased, economic insecurity has increased... where the opioid overdose happens more, is in areas where there is despondency and despair.
A quick spot-check shows that Maté is slightly exaggerating the number of overdose deaths every three weeks (NIH reports 115+ people dying each day from opioid overdoses, 115 * 21 = 2,415, whereas 2,996 people died in 9/11).
His claim that overdose is now the most common cause of death under the age of 50 in the US checks out.