well, I'm probably the best person you have to relate to depression.
Here's my story, and be grateful I'm sharing cause I don't like to share this stuff often:
I was a top student in hs. Made the top 5 the first three years out of over 500 students in my grade when it comes to gpa. Was in a numerous amount of clubs and was in every honors class/AP. I was looking to have a full ride with school, until something happened in my life, that I'm not going to mention.
After that, I lost all interest in school and everything in life. I slept all the time (first sign) and kept thinking of why I should even continue living (sign two). I never really cried though, I sort of shut myself in (another sign).
Anyways, after dropping out of hs, I got some help from a counseler, help from family, and got back on track. I worked my a## off for a year to get my status back and am now doing great in college. I'm happy again and blah blah.
They tried to stick me on anti-depressant pills during this, but it is not for everyone. It actually had a neagative effect on me.
My suggestion, find someone to talk to that can relate to your pains and can help guide you. A counseler being best. Friends and family aren't too reliable, they tend to judge way too much.
Anyways, that's my history. There was a lot more crap that happened, but I don't think it's neccassary for me to discuss that here, I gave my opinion. I hope it helps a little.