Thats because the majority of people have been anxious or depressed before so they can empathize. Its harder to empathize with schizophrenia unless you have it.
I've seen people who been up for days muttering to people who ain't there....
Seen a chick who said she could hear her aborted baby crying...
Literally narrate their thoughts out loud then become paranoid that people can read their mine if someone comments on it...
I watched my a chick have sex with an invisible person at least twice...switching positions and everything...
Wouldn't wish that shyt on my worse enemy. To this they I try not to let myself get to stressed about things because I have an irrational fear I'll develop that shyt.