I know for sure drug use can cause psychosis but I will tell a small story of my drug use. I smoked weed for the first time when I was 12 yrs. After that I tried a few more times. It wasnt until I turned 14 that I started using weed daily. When I was around 16 I quit for a whole year because I wanted to get better at cross country and track. When I was around 14 I also tried synthetic weed. I have also tried xanax a few times and I was fine. When i graduated i started smoking weed again and one day i tried mushrooms and thought i could hear my friends talking from far so I tought it was a special ability but no psychosis. It wasnt until I was 20 that I went to a concert with a friend and he insisted that I should try a small piece of ecstasy. Days later or a few weeks I had my first psychosis. So I'm sure it could of been anything but sometimes I wonder if it was the ecstasy that brought out the psychosis. Later on after anonymous psychosis. I finally quit weed and thought I should be fine if I'm sober so I decided I didn't need meds but months later I had another psychosis and I've pretty much been on meds ever since. The last time I stopped meds was because I went on a small vacation and I wasnt really enjoying it because of the meds but when I came home it took a few months when I started having prodromal symptoms. I was just pacing alot so my mom noticed and told me to get back on meds which I did and I've been on meds for 11 months. I did get to switch meds so I'm doing alot better now I dont hear voices or have any delusions or hallucinations. I do want to try a different med or ween off completely but I'll save that for another post.