psychosis isn't something you have, it's something you experience. every single human brain is designed to react with hallucinations, delusional thoughts, and paranoia when it reaches a certain level of stress. people who have never experienced psychosis have either never reached that level of stress, or have reacted differently to it due to the nature of their situation, but this does not make their brain inherently different from yours. if you experience psychosis regularly, you are under a great amount of stress in your daily life. every phenomenon that we categorize as mental illness is a biological reaction to some kind of stress or trauma, and psychosis is no different. and if you buy into the idea that your brain chemistry is the problem as opposed to your situation, you will have no hope of recovering; we seem to be coming around to this realization when it pertains to anxiety/depression, but for some reason, we still see psychosis as something innate to certain people, which it is not!