Curling herself into the smallest possible space in the corner of the living room couch, Ella said, "I just wish I could disappear." Her voice was barely above a whisper.

Ella is the daughter of one of my best friends. She is 13-years old and a straight-A student who also plays lacrosse and basketball. She's a talented artist and loves music—or, at least, she used to love music.

Now she mostly sits in her room when she's not in school. She doesn't want to see her friends. She picks at her food. And last week, when her parents were out, she pulled out a razor and cut her wrists.

Suicide is now the third leading cause of death among teenagers. In the last ten years, the number of teenagers hospitalized for attempted suicide and suicidal thoughts has doubled. (It's not clear whether this is because more kids are attempting suicide or more are going to the hospital. But if it's the former, the trend is scary.)

Why are teenagers vulnerable? Well, no one really knows. We can speculate: the highs and lows of puberty; the stress of high expectations; the increase in cyber-bullying; the burden of school combined with the many extra-curricular activities so many kids (like Ella) have.

But whatever the cause, we—parents, friends, teachers, and caring adults—have to be more attuned to the signs of depression in teens. It's tricky because even teens who aren't depressed can be moody and irritable, sad one moment and ecstatic the next. But if you see a teen who's lost interest in things she used to like, or whose grades are slipping, or who starts napping a lot (or sleeping less), or whose appetite changes—it's time to seek professional help.

Finally, be aware of your own feelings. Anger or frustration will only push your child away; shame and denial only feed into the stigma surrounding mood disorders and may keep you from getting your child the help she needs at a critical time.

Roberta Eve Tovey