Uhhh... no, I definitely don't see what you're seeing. I'm pretty certain that med school doesn't cause healthy people to develop personality disorders. I think that certain stressors that occur during medical school like failing an exam, criticism from an attending, etc. can exacerbate personality d/o traits, but the vast majority of people with healthy ego defenses do not all of a sudden develop an Axis II disorder due to the fact that they signed up for medical school.
Again, I think that people have to use a lot of defense mechanisms during medical training and in medicine in general to deal with the immense amount of stress (I don't think that you can even begin to understand this unless you're in med school, but maybe I'm wrong). I think that's why you see people's "true colors" come out-- aspects of narcissism, borderline traits, neuroses, etc. all of these become apparent. Some people use humor to deal with their stress, others use alcohol, exercise... we're all different.
But medical school definitely does not cause mental illness.