Assuming that 3 is "meh" and 5 is "CATATONIC WITH AWFULNESS", that only really leaves 4 for what feels like quite a large continuum, if I feel at all below par. Having 4 options to fill the "below average" part of the scale, rather than 2 feels necessary to me.
I don't know if there are inventories for depression, but every time someone tells me I'm a bit talkative I take the Young Mania Ratings Scale. It's a wonderful, wonderful tool:
