Psychosis and weed:

There have been studies (like this one) that cite statistical evidence of a connection between dope and crazy.

One of the defining characteristics of smoking marijuana is getting spaced and enjoying the head trips. It's an easy way to hypothesize outcomes because it's easy to focus and hold ideas or feelings so they can be applied or not depending on the course of the trip. It usually means rationalizing how things are pretty much ok, so that if anything adverse comes up, it can be also seen in that light.

The psychosis part is a result of accepting a plausibility as fact. (the government is behind it) If a person is stoned, plausibility can be assumed to be fact for the development of hypothesis with little emotional stress. Like examining problems from behind a barrier and poking them with a selection of tools. But once an unproven concept is absorbed as fact and acted upon, the resulting behavior can be indistinguishable from psychosis.

However there's a gradient difference between clinical psychosis and weed psychosis. it stems from the motivation to overlook facts. Clinical psychosis can be initiated by some kind of emotional trauma like Batman seeing his folks getting whacked in front of some theater, as opposed to our pothead deciding orange marmalade is tastier than blackberry jam because he likes bright colors.

Psychosis is loosely defined as a break from reality. This feat can be accomplished by deciding to believe that something which is otherwise provably false, is instead true. For example "Jesus is the only begotten son of god, born of a virgin and rose from the dead after 3 days" and "The universe and everything in it was created in 6 days". There I go dumping on the Church again, I don't mean to do that, the Church fills many important social functions that government and other institutions can't begin to approach. But it's just so darn easy and psychotic behavior is one defining aspect of true believers: they gave their souls to Jesus.
People don't usually to do things like that without ulterior motives, it just feels wrong. One way to get around that feeling is through social pressure: "Hipsterism is cool", "Join the Marines", "There is no other God but Allah and Mohamed is his prophet", Join the YMCA because Jesus loves you". Subliminal belief is usually established by assuming that A must be true if B is true, then not addressing the truth of B just because it helps both make sense. That's called delusion.

There are also studies which indicate that self delusion is a common way of coping with evidence that conflicts with previous beliefs. It's simply not believed. The new evidence is doubted without confidence in the source ("since the collapse of the World Trade Center was an inside job, of course the govt would deny it"). Here the credibility of the government is questioned, with doubts supported by associated events. (corruption, questionable voting procedures, dismissive officials in charge of investigations, the Vice President in charge of air control at the time, conflicting oil interests, dust analysis showing the presence of finely ground iron oxide used in thermite explosives, the list is much longer).

Ok, so get a grip, and choose a side if you dare. If you think information is lacking: toke up, the worst that could happen is you'll decide you don't care.

Here: read this too: Pot Addicts .