Hard to say, these days.
I was a case manager for the severely mentally ill. You would know it if you had been around someone who was in an active psychotic state. I had a client who was on Haldol shots every 30 days and at the end of the month he would pick the rats off of my shoulders and talk about the angels but within 30 minutes of getting his shot he was pretty much free from the hallucinations.
I also had one young man who wanted to see Lost in Space and thought nothing of it until he started freaking out over the aliens.
Another one went off when the Russian Army was invading his apartment.
Most of the truly schizophrenics are people who would do anything to be normal. Many are quite intelligent but their brains are broken. Not all are violent when sick.