Delusions are also a 'positive symptom' and, like hallucinations can be very disruptive to a schizophrenic person's life. A delusion is defined as "an idiosyncratic belief or impression that is firmly maintained despite being contradicted by what is generally accepted as reality or rational argument." In other words, it's believing something that isn't real, mostly due to an inability to separate real from unreal experiences.
Delusions can often go hand in hand with hallucinations. When I hear voices, I usually know that they're not real. However, when I have a hallucination that is not as common, it can often be paired with the delusion that the hallucination is real. Like when I see a nuclear bomb going off, I am likely to believe it actually is a bomb being detonated, rather than using my rationality to ignore it. I can eventually rationalize these delusions and hallucinations out of my focus, but it takes a high level of concentration.
My delusions often transform themselves into various things. I'm not sure if they manifest in certain ways based on my circumstances, or if they simply change between the levels of my mental health; for example when I'm not doing well, I'll have one certain delusion, then when I start to get better, it goes away, and then after that when I start to suffer from symptoms more frequently again, the delusions from the previous time aren't as prevalent and take shape into a different type of delusion.
I remember my first noticeable delusion being that I thought my mother was poisoning me when she made food. This, humorously enough, was very hard to rationalize in my mind, because cooking was never her strong suit. She could barely make hamburger helper (no offense, mom!), let alone concoct a poison to put in it. Not only that, but like all my family, she has been very supportive in every way imaginable, so having delusions that she wants to hurt me were so far-fetched that I would have to be incredibly ill to succumb to them, which thankfully never happened.
I already talked about my hallucinations of nuclear bombs, but I will quickly acknowledge that my delusions did play a part in making those hallucinations particularly intense. Shortly after those hallucinations and delusions subsided, I started having delusions that zombies were wandering outside of my house. I would close all the blinds to my windows in my house because I was convinced if they saw movement inside, it would provoke them into breaking in and wreaking havoc. This was probably one of the most troubling delusions I have had. Unlike the nuclear bombs where they would be 10 to 20 seconds at an alarming moment, the 'zombies' delusion was much more drawn out. I had an incredibly hard time sleeping, I would make sure the doors and windows were locked so many times you would have thought I had obsessive-compulsive disorder. That said, my doctor told me that OCD behaviors can happen in schizophrenic people sometimes.
Some of the more consistent delusions I've had, and by consistent I mean delusions that have lasted for several years is thinking that if moonlight entered my room, it would act as a beacon for aliens to abduct me. Again, like the zombies, very often I would have my blinds closed. If my room didn't have blinds at the time, I would always avoid looking out the window because I was afraid if they were outside watching me and I made eye contact, they surely would take me. Another one of the consistent delusions I have is whenever my ear gets itchy, I think it's alien bugs crawling inside my ear so they can get inside my brain and control it. Every time I felt an itch in my ear I would always push on my ear, this made me think I was crushing anything that was trying to crawl inside.