Quote: The fact about #2 is that she doesn't know ...
Oh come on, yes she does. She isn't stupid. But, she may be afraid or avoiding what the difference looks like. The point is to get her to really think about the question FOR HERSELF, rather than dismissing it in an offhand manner by appealing to one of oft-played empty pieces of rhetoric.
"Honey, I'm not real sure what the REAL differences would be once you were passed understandable fears about trying somethijng new. What do YOU think the differences would be in terms of your life, happiness, and relationships if you coped for awhile using antidepressants versus using alcohol during that time?"
Notice, I did not say ABusing.... Tempting though it is, that is just piling on judgment.
BTW, is it really fair to your W not to let her know that in the long-term it is a dealbreaker for her not to try to work on her issues in a more productive manner than using alcohol. You are setting yourself up to be a WAS yourself -- not telling her what your boundaries are but preparing mentally in the distant future to leave if she violates them.