From my experience, I would liken LSD to peanuts. The vast majority of people out there can have a handful of peanuts with no problems. They may like the flavor or not but it won't cause long term harm. A small percentage are allergic and will have a reaction to peanuts ranging from mild sickness to death. LSD is similar, a small percentage of people will have problems mentally with LSD. It might last just a little while, it might cause (or trigger) life long problems. If you are unsure, take a tiny dose, maybe a 1/4 hit and see what happens. Or better yet, take a tiny dose of psilocybin mushrooms as they are the easiest to come down quickly from. Just eat a meal and you will be mostly down in about 45 minutes.

The other thing I discovered was once the paranoia starts to invade every trip consistently, you have learned all there is to learn and it's time to move on. I was annoyed with the paranoia and tried to work through it, though I was somewhat successful, LSD was just not that much fun anymore...