Teens are beset by feelings they don't understand. They feel rejection from peers, pressure from authority and doubts from within. Add triggers that might seem trivial to adults - a breakup with a girlfriend, a low test score, failing to make the team - and it's little wonder up to one in eight teens has clinical depression.

"If a child was limping for two weeks, you wouldn't think twice about having him evaluated, or if a child had headaches that wouldn't go away, you would bring him to a doctor," says Dr. Graham Emslie, chief of Psychiatry at Children's Medical Center Dallas and professor of Psychiatry at UT Southwestern. "But if kids have signs and symptoms of depression, we tend to wait much longer, thinking they'll grow out of it or it will eventually go away."

But that's a mistake. Untreated, depression can have major long-term consequences. Teens could face an increased risk for substance abuse, difficulties with school and relationships, greater likelihood of future depression, and even suicide.

According to the American Academy of Child and Adolescent Psychiatry, suicide is the third leading cause of death for 15- to 24-year-olds. While occasional periods of sadness are normal, depression tends to be more intense and pervasive, says Dr. Emslie. It lasts for several weeks, involves a change in behavior and interferes with life.

Signs and symptoms
Potential red flags include:

• Prolonged sadness, irritability or angry outbursts
• Withdrawal from favorite activities
• Dramatic changes in appetite, weight or appearance
• Sleep disturbances, excessive lethargy or restlessness
• Expressions of worthlessness or inappropriate guilt
• Inability to concentrate
• Preoccupation with death or suicide
• Physical complaints, such as stomachaches, with no evident causes
• Sudden drop in school performance
• Reckless behavior

If you suspect your child is depressed, see a qualified mental health professional at once. A diagnosis of depression often leads to treatment with a combination of psychotherapy and medication. Most people receiving treatment begin to feel better in two to four weeks.

"The good news," Dr. Emslie says, "is that depression is very treatable, particularly if we identify it early and make sure the kids get the help they need."

Lower your teen's stress level

• Provide consistency and predictability.
• Encourage open communication.
• Adopt a balanced discipline approach that includes positive feedback.
• Help teens discover and use their talents.
• Attend parent-teacher conferences and other school events.
• Make your house the one your kids' friends want to visit.
• Model problem solving and conflict resolution.