Jordan was 19 when he jumped out of his ninth-story bedroom window.
"I didn't wake up that day knowing I was going to try and take my own life," Jordan said, who, like the other teens in this story, asked that his last name not be used.
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While recovering in the hospital, he shared his story with a reporter from the Philadelphia Inquirer. Although Jordan suffered for years before deciding to jump, he said, the newspaper interview was the first time he had ever discussed his feelings with anyone.
"He [the reporter] gave me a voice," he said.
But for many others, the chance to talk about their depression never came.
Maggie was only 12 years old in 2003 when her brother, Phil, a high school senior at the time, killed himself.
"He was smart, played three sports," she said. "He was the last person anyone would've thought would take his life."
Teenage years are emotionally impulsive and awkward for many. But for 20 percent of those teetering between adolescence and independence, life on the edge is more than just a phase.
About 2 million teenagers suffer from clinical depression and about 1 in 5 young people will experience depression before they become adults, according to the U.S. Department of Health and Human Services.
Teens experience depression more intensely than adults, said Dr. Harold Koplewicz, a child and adolescent psychiatrist and president of the Child Mind Institute in New York.
"The signs of teen depression is that it lasts for more than two weeks, and there's a change in appetite, a change in sleep, a change in concentration, a change in mood and, most importantly, a change in the ability to really enjoy things," Koplewicz said.
Teens are also more likely to pick up self-injuring habits, such as cutting their skin with sharp objects.
In seventh-grade, Casey, now 19, became obsessed with cutting herself.
"My sister started noticing that I was wearing long sleeves and ... there were cuts on my arms," she said. "I ended up cutting to the point that I needed stitches."
When Emotional Pain Becomes Physical
Casey said she thought she was somehow responsible for her emotions. Cutting helped her escape her own thoughts, she said.
"I didn't want to die but I wanted to feel something other than what I was feeling, even if it was pain," she said.
Self-mutilation is used to turn emotional pain into a temporary and controllable physical pain, Koplewicz said.
"Many times, people do it because they feel the desire to feel alive," he said.
As with many teens, Casey suffered in silence. She was too ashamed to admit that she needed help, she said.
"I was totally different in how I dressed," she added. "Like, my hair was different colors. But I didn't want people to think I was different, like, in my head."
Part of the stigma stems from the belief that people can control their symptoms of depression on their own, according to ABC News' senior health and medical editor, Dr. Richard Besser.
Many teens resist medication because, for some, taking an antidepressant can be seen as cheating.
"You're not depending on it just to make you happy," Jordan said. "Your brain works differently. And, for me, it's difficult for me to do the everyday things that people take for granted like wake up on time, brush my teeth, get in the shower.
"So, that pill is making sure that I am, I can do the things that jump-start my day so I can do the things that make me happy."
Many studies show that early treatment using medication or talk therapy may prevent depressive episodes.
"Remember, depression isn't an attitude a teen is choosing," Besser said. "It's a serious and real brain disorder."
But for many teens, the symptoms of depression remain unrecognized. And unrecognized depression in some teens, including Maggie's brother, can lead to suicide.
Indeed, suicide is the third leading cause of death for people 14 to 24, according to the Centers for Disease Control and Prevention. And more than 600,000 teens make an attempt every year.
Recognizing the Warning Signs
Maggie said she believes her brother would be alive today if someone, including himself, had recognized the warning signs.
"Every single day I have to wake up and I don't have my brother," Maggie said. "And maybe things could have been different."
For more information on teen depression and how to recognize the warning signs, visit: Families for Depression Awareness at http://www.familyaware.org , aevidum at http://www.aevidum.com/aevidum/Welcome.html and the Minding Your Mind Foundation at http://mindingyourmind.org/