“That, and the possible Schizophrenia and drug use.)”
The article claims Loughner had STOPPED using marijuana—that he was absolutely clean (at least as of early 2010). Someone earlier at FR speculated that he had been self-medicating with alcohol and MJ. It’s conceivable that it actually was his decision to stop MJ, i.e., stop self-medicating, that triggered his downward spiral. It’s sort of like a depressed person going cold turkey with anti-depressants.
Loughner may well have blown up eventually no matter what, but his cessation of MJ use may partially explain the timing of the attack. Remember that he was initially provoked by Giffords in 2007, but managed to hold it together for years. Self-medicating behavior may have enabled him to keep his rage in check for an extended period etc.
But, but... but...
Isn’t Pot supposed to turn you into a murderous, white-woman-raping, maniac?????