Kly - Yes, it is a very horrendous disease. I've seen in the forums where people describe it as the body snatching diease. I couldn't agree more. My once sweet, caring husband turned into my worse enemy over the past four years. He actually has a medical condition which he refuses to treat - it causes these delusions..

He refuses to believe he is sick, even after a diagnosis.
He has DDJ with some persecutory mixed in. He is very paranoid. It's very sad, however, he is fully functioning (for the most part). He has a good job and is good at it. Although, he has a lot of trouble sleeping now, which has greatly increased in the past year and I can see it affecting his work attendance.
I choose to stay for now, in hopes that he will someday treat his medical condition or maybe that the condition will get worse and force him into treatment. However, if he became violent, or if the situation got worse, I would leave on my own.
My heart goes out to anyone having to deal with this horrible illness. I really never understood mental illness until my husband got sick. Even though the other person is ill, It is very trying and will drain your own soul if you do not keep yourself in check.