What I got from the article is that psychotics may act out while stoned. Or otherwise.
There are many articles showing cannabis usage linked to bipolar and schizophrenia. And showing not just linkage but cause. Long term cannabis usage damages the area of the brain, that is damaged in people with bipolar.
Pot makes you psychotic.
Speaking from personal experience, I call BS on this. I was too busy enjoying my friends, fishing, or just otherwise chilling out.
Now I just kick back in my lazy boy.