How chronic diseases can affect personality?

Schizophrenia

This serious mental illness can make you hear voices and see things that aren't there. You might believe things that have no basis in reality. At first, you just might not be as social as normal. As it gets worse, it can be tough to keep your thoughts on track, making it hard to even talk to people. And you may act in ways that are way out of character, hard to predict, and out of control.