It is entirely possible. My grandma had dementia, so I wouldn't be surprised if my aunt was in early stages. Brought on at younger age due to poor health choices. To be clear, my aunt is not diagnosed with schizophrenia. She was only diagnosed with some kind of anxiety disorder along with a disorder associated with hoarding, but when my wife and I lived with her, we saw a lot of very concerning behavior and did some research. She has literally every single symptom of schizophrenia. I sneakily confirmed this with family by asking if they noticed these same symptoms, and got all positive responses. They didn't know I was talking about schizophrenia though. Totally not my place to offer a diagnosis, so my wife and I never talked about it with anyone else. Putting it into the context of dementia makes a lot of sense too though. I need to do some more research now.