Hello there peanut (I just had some for snack... interesting),
Anyway, I'm very interested in Behavioral Health as well. It seems as though Johns Hopkins is one of the few that focuses on Mental Health and Psychiatric Epidemiology (with the Masters degree in Mental Health), but of course it really depends on where you're interested in going. It sounds as if you're into research though.
Personally, I work at BU, so applying to BUSPH is a no brainer with the tuition remission. PLus, I'm not sure my paper states would get me into Johns Hopkins. However, you can take some classes in the summer programs there. I'm not in a program, so I can't really speak on it, but I'm in a similar boat in that I can't totally nail down where I'd like to do my research and from what angle (I have a very math focused backgroud), so I've chosen the MPH first to gain some more exposure. When I was looking into ideas, I really took the financial aspect into consideration too.
Have you been working in the field? I do think that having a more specific research interest would probably help. Unless your portfolio is awesome, then you could very well have your pick.
