When is a belief system a Mental Disorder?

...by discussingHow Do We Distinguish Faith from Delusion?orWhen Does Personal Belief Become a Public Concern?or something of that order. If the question begins by positing the notion that fundamentalists suffer from a mental disorder, even presented as a question, I think we will quickly descend into a flame war.But if we can discuss how to determine whether a personal belief crosses the Rubicon into a personal delusion/pathology and/or a public concern, maybe we can discuss general criteria before applying them to specific cases.

Having offered my input, I would prefer to defer to Moose.