If you're worried you have FFI, don't be. It's extremely rare and it runs in families. If you had it in your family, you'd know.

I just used it as an extreme example of what lack of sleep can do. It's very common for people who stay awake for several days to begin hallucinating and become paranoid and delusional. Even so-called 'normal' people.

My son says that even when he sleeps, it's seldom a deep, refreshing sleep. That's what makes me wonder if he's not getting to the deeper stages of sleep, and maybe that's why he has the mental health issues he has.

ETA: I think stages 1 and 2 describe almost everyone dx'd with sz.