> I also recall the show depicting meth users having all those problems - Jesse is paranoid the missionaries are bikers, there's that guy digging a hole in his front yard, Spooe and his head, etc

> Seems like the drug was fucking people up way prior to the last few years in fiction.

Meth has always, always, always been known to cause those behaviors/effects since it first became widespread. Breaking bad shows those behaviors because they're classic tweaker behaviors. The scene where Jesse distracts the guy by digging is super spot on. Brilliant scene.

So yep, the paranoia, hallucinations etc have nothing to do with "new meth", they're just what happens when someone abuses sufficient amounts of meth. And the more potent the meth, the easier it is to get to that threshold. But note that you still need to be smoking or injecting quite a bit. The people exhibiting psychosis and the like are using hundreds of milligrams per session.

I happen to be re-watching this right now, and it blew my mind to see those graphs and not see the show lagging a few years behind the reality. How is this possible? It borderline seems like the background research for the show must have actually talked to the mass manufacturers of the stuff...

The transition to super labs, and away from small time Sudafed based meth production, happened prior to the release of Breaking Bad. They based their show on what was occurring in the real world.