My dad. According to my mom, he once (before I was born) came home from work in the middle of the day, having hallucinations that people were after him. He shut all the curtains and said he could see people hiding behind the trees in the front yard. He made my mom pack bags to leave town. After a couple(few?) days he gradually came back to reality. However, his personality was forever different. He became much quieter, for one thing. All of my parents' friends noticed and asked what was going on, but my mom wouldn't discuss it. My parents are very old fashioned about mental illness, so they never even saw a doctor. My mom made me promise not to tell my dad that she told me.
My dad also has a sister who has spent her entire adult life in some kind of institution or care situation. I have never been to visit her, and no one will discuss what's wrong with her.
So I put it to you, dear readers - diagnose my dad. I think it's pretty clear he had some kind of psychotic break, but does that explain the permanent personality change? I have a lot of issues with anxiety myself, and sometimes worry something like this will happen to me. And my mom has advanced dementia now, so there's no asking her for more details. So go ahead, no disclaimers necessary, and give me your opinions.