More later, but this was definitely a difficult conversation for me when I was 15. It's an embarrassing, difficult, painful thing for a kid to tell their parents, and it's made worse by the inability of most parents to understand the severity of the disorder right off the bat. I hope kids have the courage to speak up, because even if it's too awkward for them to talk to their parents about it, parents can still get them a doctor or therapist--someone the child feels comfortable being open with. It's hard to pry this confession out of kids, though. For me at least, I didn't want to let my parents down or to make them feel responsible for my pain.
Read more about telling parents you're depressed.