it seemed to be helpful - for the delusional person to experience trust in other people - so that even when the delusions were being described (and believed by that person) - the delusional person could express her concerns.
The presence of the listener. Making comfortable eye contact. Providing kindness. Because without those - perhaps this delusional and paranoid person would be feeling even more frightened.
Oh, I could go on and on - and I keep thinking about all this, and it just goes in circles.