"The epidemic would have been avoidable if doctors as a whole had adopted a more critical and thoughtful approach"
He could be totally right about causes of that problem in that time. Currently, though, drug companies offer all kinds of financial incentives anyone that will increase drugs use in ways ranging from BS studies to incorrect info in textbooks to actual prescriptions. I've also read they give free samples.
Examples I found in quick DuckDuckGo:
https://www.bostonglobe.com/opinion/2016/04/11/medical-resea...
https://www.nytimes.com/2004/06/27/us/medical-marketing-trea...
http://content.time.com/time/health/article/0,8599,1883449,0...
This stuff could've been going on a long time. Maybe back when the push to use addictive drugs started. Or maybe that was just bad science like author says with the current push involving massive amounts of corruption. I say don't forget what's going on in any current debate about drugs, though.