Had a really large 3 day psychosis (including blabbering on Facebook for all to see), and ended up being locked into "involuntary mental health" ward in hospital for 2 weeks, 6 months of recovery with a nurse and 6 years of putting my life back together. Started smoking when I was 18 and had the breakdown just after 21st birthday.
I feel like weed did help me get me out of my shell at the start, but looking back now, I was in a bad place and what I needed was a bigger perspective on life. Being high and browsing the internet / playing games with friends helped that perspective, but it could've came gently.
Now I've got a degree, a good job, a wife and kid :) - not many people I knew from the era still talk to me though, me going nuts was the last impression they got.
It started after a period of habitual smoking and got progressively worse anytime I smoked. Mental health ward twice (once in a country where I didn't speak the language, but that's another story). Haven't had any problems since I cleaned up my lifestyle and fully ditched weed many years ago. These days I'm also happily married with kids (three), a house and a decent career.