I see your point. There may be no statistical correlation. It would make some sociology doctoral candidate a nice thesis. I agree that anyone of normal mental health is unlikely to mortally harm themselves no matter what they’re told. But avoiding misdirection is a central part of what Jesus warned against in that whole teaching on his return. He did not want his followers being misled by panic-mongers, because irrational fear does make you do stupid things you later regret. I suspect our doctoral candidate would find that such events serve as magnets to the already unstable and tend to push them over the threshold from passive dysfunction to actively self-destructive behaviors. So perhaps no net increase in looniness, but a definite increase in harm to the already weak-minded, as Paul puts it.
Its a shame someone who's lived as long as Mr Camping doesn't realize that.
What about martyrs of normal mental health, or soldiers?