I have never experienced paranoia while I was high. I've only ever been either really relaxed, "giggly," hungry, or horny.
Now shrooms... that is a whole different story. I've only done them once, but man, those things were freakin' crazy. I did them on my college campus with my SO, and while were walking around the dorms, we saw a campus guard and I got pretty freaked out. Luckily I walked by him quickly because I definitely wanted to crawl into a corner and cry and tell him I was sorry for what I did. Then when we came back to my SO's room, I kept thinking I saw someone outside trying to get in. I had a definite feeling of paranoia go through me... started bouncing in place and rushing my SO to unlock the door... almost started crying. Interesting experience... but that's what the drug is supposed to do.