The Wall Street Journal is one of the last great newspapers that still reports accurately and with little bias. This bullshit article appeared in their Opinion section, and the author is not on the WSJ Editorial Board.
In fact, the author is a former New York Times reporter, which explains why he is full of shit. He also spent a lot of time reporting on the pharma industry during his tenure at the NYT, and it would appear that's where his bread is still buttered.
Personally, I think social media is responsible for increasing psychoses to a much greater extent than cannabis. And I know precisely zero violent stoners...