Why do people go crazy?

You and I are so much alike. I have the biggest fear of just loosing my mind someday... and I think it's mostly because I know people who have, and I know mental issues run in my family. You CANNOT think too much, because that will drive you insane. I watched Paranormal Activity and convinced myself that I was surrounded by demons constantly, and had panic attacks over it. You're normal for being concerned, because being mentally unstable is a very scary thing! But remember, just because it runs in your family, that does not mean it HAS to happen to you! And as you said, your uncle's issues were contributed to by drugs...so if you don't use drugs, and have no major mental health concerns, you're fine! Everyone breaks down sometimes, and everyone feels a little unstable at some point in time, but this is life. Don't let these conerns consume you, because I did, and it's a terrible ordeal. If you feel you need to speak to someone, see a therapist, they work wonders! Hope I helped :o)