I have had success starting pro/con lists and other serious discussions with something completely bizarre, to get DC to relax and laugh about it a little.
I agree with HK that it's important to take ALL of DC's pros/cons seriously. There have been things that have never occurred to me as being real worries that DS has raised when we've been trying to help him manage his (generalized) anxiety. It has taken practice and patience not to dismiss his concerns with, "That's nothing to worry about," but instead to understand that these things are real to him, and to help him brainstorm ways to overcome the fears, or what he might do in xx situation if he's worried about an unknown.
