Its amazing how many psychiatrists are doing this as their second specialty--I don't know if there are any studies, but I doubt any other specialty has this same degree of second-residency applicants. I'm double boarded too, and I know FPs, internists, OBs, a couple of neurosurgeons, even a urologist who went on to train in psych! Some because they really wanted to do psych, but wanted "to practise real medicine" first as one internist told me. Invariably, they weren't happy in their first specialty. Interestingly, the reverse traffic from psych to boarding in other specialties is low.