All teens can be irritable, want to be secretive, and appear and even act alien- like. But when should a parent worry--really worry about their child? Did you know that one in 12 teens suffered at least one episode of major depression in the last year? Of those, a full 60 percent are not getting treatment.That question has caused many a sleepless night for moms and dads. The more you understand typical adolescent behavior and the signs of depression, the better you'll be at tailoring your parent