A new study finds a strong association between cannabis use disorder (ie: weed addiction) and schizophrenia in young men. As many as 30% cases of the mental disorder in men 21 to 30 could've been prevented by averting cannabis use disorder.

Here is the study: 2/2
https://www.cambridge.org/core/journals/psychological-medicine/article/association-between-cannabis-use-disorder-and-schizophrenia-stronger-in-young-males-than-in-females/E1F8F0E09C6541CB8529A326C3641A68

The new study, according to @NIDA, "adds to existing evidence [see the link] suggesting that the proportion of new schizophrenia cases that may be attributed to cannabis use disorder has consistently increased over the past five decades." 3/
https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2782160

Note that I should've written "might have been prevented" rather than "could've been prevented", given the uncertainty of the research. If only I could edit tweets!