Thank you so much for posting this question.
I have been wondering myself if I should get antidepressants and reading everyone's responses is really helpful.
I'm also typically still "functioning" when I get depressed, but it tends to get worse. I first notice that I socialize less and less, then I completely isolate and only go to work/school (do what I have to), .... the problem I'm having right now is that I'm feeling so overwhelmed right now that even the things I have or should do start to be too much. College seems to be the only thing I can handle (and even that I can't really handle all that well right now) and picking up a few hrs of work here or there seems impossible right now. The other thing I noticed is that I've been having a really hard time concentrating (like I can't seem to process what I read or hear very well) and that really got me thinking that maybe it's time to do something. BUT like LifeRecovery wrote I keep going back and forth in my head on whether I am depressed or not, or if I'm depressed enough to need drugs.
I think it's similar to A's, who know they may have a problem, can see some of the consequences that result from their drinking, but still can't yet fully accept that they are A's. I remember my RAH telling me once "yes maybe I have a problem with Alcohol, but I'm not an alcoholic - I'm working, I've got an apartment, I'm not one of those people on the street thus I'm not an A and don't need treatment". I feel like I'm giving a similar response... "I may experience neg. things due to the way I feel, but it's not that bad, I'm still going to school, I'm not hospitalized, I've been worse, thus I'm not sure I'm depressed enough".
Anyways, sorry if this wasn't too helpful. I guess I just wanted to share and let you know that others out here are thinking about the same things you are thinking about.