I have questioned this myself. If psychosis theme is always based on facts, previous real experiences, or rational fears then is it really psychosis or delusion? I think this issue is misunderstood because of the common belief that feelings of being watched, spyed on or people coming to get or hurt you (persecution) are considered a hallmark of paranoia, delusion, and psychosis. I am truly a paranoid person, but 99% of the things I am paranoid about happening have actually happened, or could be rationally feared based on what has actually happened. Unfortunately I have been unwilling to discuss the facts behind my fears with a T, so they tend to call it delusional psychosis and a feature of mania associated with the BP1 they seem convinced I have. Interesting that no T has mentioned PTSD to me yet, but in all fairness I change the subject when they ask if anything bad ever happened to me.