Comment: The study is crap and was made to produce fear mongering headings like the one on this article.  Many people will just accept the heading, or read a few lines of the article and consider it truth without even thinking.
That's the problem, and the intention of the study and the article.

Lots of profit to be lost by certain industries when cannabis is legal and many of those industries support the media.... the Pharmaceutical industry being one of the biggest.