So this guy has a book with piles of evidence from scientific studies and real data on the use and abuse of Marijuana and it's link to psychosis and violent crime. This is an article with a kind of summary:
https://imprimis.hillsdale.edu/marij...ness-violence/
And here are two very important points that he brings up:
andOver the last 30 years, psychiatrists and epidemiologists have turned speculation about marijuana’s dangers into science. Yet over the same period, a shrewd and expensive lobbying campaign has pushed public attitudes about marijuana the other way. And the effects are now becoming apparent.
Almost everything you think you know about the health effects of cannabis, almost everything advocates and the media have told you for a generation, is wrong.
You can think what you want and insult me until the cows come home. What you think you know is likely wrong, it isn't harmless and it does cause problems. While the movie Reefer Madness from back in the day has been ridiculed and discredited it seems that a lot of it's claims, while sensationalized, are proving to be accurate to one degree or another.Cannabis users today are also consuming a drug that is far more potent than ever before, as measured by the amount of THC—delta-9-tetrahydrocannabinol, the chemical in cannabis responsible for its psychoactive effects—it contains. In the 1970s, the last time this many Americans used cannabis, most marijuana contained less than two percent THC. Today, marijuana routinely contains 20 to 25 percent THC, thanks to sophisticated farming and cloning techniques—as well as to a demand by users for cannabis that produces a stronger high more quickly. In states where cannabis is legal, many users prefer extracts that are nearly pure THC. Think of the difference between near-beer and a martini, or even grain alcohol, to understand the difference.