I think Scott has some posts about it.
My impression is that it comes slowly. You become more likely to interpret random chance as significant, but a convoluted conspirational belief system needs a lot of time to build up.
Treatment is more effective the earlier it starts.

>>6706
I found the post: https://slatestarcodex.com/2018/09/20/treat-the-prodrome/

I am wondering if I'm developing schizophrenia. For the past few months, I have been occasionally slipping into a mode where my understanding of the world shifts into a stereotypically schizo one, where most of what I perceive is in fact some kind of test by the Other, certain events directly reference my private thoughts, etc. I am steadily adding new details to this worldview as these episodes happen.

But most of the time, these beliefs are obviously silly. My main alternative hypothesis to "I am developing schizophrenia" is "I am entertaining certain delusions on purpose so that I can larp as schizophrenic and thereby excuse my failures with a mental illness. I am not actually losing touch with reality." So I'm trying to figure out which of those my current situation fits better.

>>6707
Consider seeing a psychiatrist about it or something. It could be dangerous.
I often notice odd coincidences, but I don't narrativize them.