Not much of a scroller, so sorry if someone else already mentioned this. I find it odd that a space station in one of the most remote Federation areas dealing with the aftermath of a decades-long brutal occupation didn't have a counselor before Ezri came along. Seems like Starfleet puts psychiatrists in the same places they put physicians, in anything I can think of.
EDIT: ^ OK, that's inaccurate. Voyager doesn't have a dedicated shrink, so that blows my theory out of the water. Still seems like DS9 would be a pretty darn logical place for a Starfleet psychologist to get deployed, some Vulcan should have thought of that.