Does depression go away after a while if taking meds? Or does the person having depression need to take meds for the rest of his/her life to avoid relapsing?
Depression is usually a cycle, I'm too tired to go to class, ends up failing classes, great now I'm a useless human, fails more classes, becomes too tired to do anything I normally enjoy, can't focus on homework, becomes more depressed, socializing causes too much anxiety to make friends, etc. This was me last year.
The hope is that with the correct combination of medications you'll manage to "break" this loop. You can start to focus again, maybe complete some homework. You have enough energy to get yourself to class. Your grades improve, you don't self-loath as much, your life improves, you make supportive friends.
Once you have your life back in your control you can consider discontinuing your medication. You might go off it and be fine, now that you were able to focus on your stresses in life and how to handle them, you may find you don't have any issues without your medication. Or everything becomes worse again and you have to stay on it.
To be honest, modern psychiatry is kinda a crapshoot and nobody knows 100% for sure how antidepressants work, why some people don't respond at all to prozac but do to cymbalta, etc. There's a lot of research involving your diet, your gut bacteria's health, your immune system's effect on mood, etc. All of these will be a factor.