I've done lots of research on depression and medication and everything related whatnot, because I want to be involved in my treatment. The best I've found is that it involves genetic vulnerability and upbringing. People are born with a genetic vulnerability for depression, and then upbringing escalates it, and then usually a situation triggers all of that, usually for a depressive episode.
So, in order to get fully better, you need to address the chemical symptoms, and the upbringing, and the situation that started it. For the genetic problem, and or chemical, you take medication that works for you. It may take awhile to find the right one that works best.
For the upbringing, which has probably given you a skewered worldview of life, you attend CBT or some kind of similiar therapy that teaches you healthier emotional responses to life, instead of the ones you grew up learning. For example, I have a very negative outlook on life. My motto is "always expect the worse, that way you won't be dissappointed, and if something better happens, its serendipitous" This is a product of my upbringing and luck, where the things I hoped for never came true, and people constantly dissapointed me in some way. I'm trying to change that.
And finally, for the situation that triggered depression, you learn stress reduction techniques, apprpriate emotional responses to stressfull situations, and you do your best to clear out some of the things that stress you out in your life, if you can.
Don't ever expect a small pill to make it all better, you're right. Medication for pretty much everyone but schizos and bipolar people, is supposed to be a short term solution for them, because you'll have to continue taking meds for the rest of your life to make you feel alright, if you don't address the stressors. Keep in mind, "short term" can mean months or years. It is just different for everyone.
And remember, the way medication works, the docs themselves aren't really sure of yet, because everybody is different. Different medications work differently for people. But the majority of anti-depressants work on increasing the serotonin, or norepinephine, or dopamine in your body, because these are the major neurotransmitters docs have discovered that have to do with depression.
Sorry to make this so long, but I hope it helps!
Megan