I wouldn't worry about the depression / moody angle. We can't control a lot of things about children that play into names. As long as the "wordy" name isn't a red flag to a bull, like
Chastity, you are fine.
Allegra is a lovely name. If the allergy medication is not available where you are, then again, I wouldn't let it get in the way of a perfectly good name. All those Jewish Italian Allegras seem to be doing well, yes?
Allegra reminds me of sheet music, a nice association. Follow your motto on this: if you're all tangled up, just
Allegra on. :-)