Is it "Insane" to "Embrace" "Martyrdom"?

Ann Althouse has an interesting post (check out the comments, too) on the Abdul Rahman case, and on what appears to have been the Afghan court's solution, i.e., dismissing the case on the ground that Rahman is mentally unfit.  At the end of her post, Professor Althouse identifies as a "useful idea" the idea that "anyone who embraces martyrdom for religion is insane."  Is this idea "useful"?  I suppose a lot depends on whether "embrac[ing] martyrdom" includes "refusing to abandon one's religion, even if one knows that the refusal will result in death."  Or, do we think that this is, actually, "insane"?