Since your dependent variable is dichotomous, you should do logistic regression. This is what it is designed for.
You don't say what your DV is, but let's suppose it's lived/died. If you treat this as numeric (somehow) then you are saying that there is a continuum between living and dead and also states beyond living and dead. Suppose you make living = 1 and dead = 0. Then you will get predicted values such as 0.82 or -1.23. What do they mean?
(NOTE: I know that I am making this simple; I'm trying to give a useful answer to the question, as posed, rather than a formal mathematical statement or something)