Mark Crislip has a thought-provoking post over at Science Based Medicine on whether people can die simply by willing it. He points out that while he has anecdotal evidence of the phenomenon (he’s apparently a doctor working in an acute care hospital), the study data is much less clear-cut.
It also, as he points out, shows up a contradiction of two views. One is that the mind is simply the result of the workings of the brain. He and I both share that view. But, on the other hand, if there is evidence of people who die simply because they will it, then does that not point to the "mind over matter" possibility? He’s not convinced that it does, but he remains intrigued (as do I) by that little niggle of doubt.