Adolescence is a challenging time that is full of changes, during which some teenagers may experience a debilitating illness known as depression. It is important for parents to be able to recognize the signs and symptoms of this condition and to know that help is available.

Signs of depression may include sleep problems, loss of interest in activities, appetite changes, energy loss, sadness or irritability, concentration problems, hopeless or guilty thoughts, body movement changes (feeling edgy or slowed down) and/or suicidal thoughts or preoccupation with death.

Dr. Graham Emslie, professor of psychiatry and pediatrics at University of Texas Southwestern Medical Center and chief of child and adolescent psychiatry at Children's Medical Center Dallas, answers questions about depression in adolescents.

Q: What is depression and can anyone have it?

A: Depression is a serious but treatable chronic condition often characterized by prolonged sadness, irritability or loss of interest in usual activities. Both adults and adolescents can suffer from depression. In fact, approximately 2 million adolescents in the U.S. ages 12 to 17 suffered a serious bout of depression in the past year. The good news is that working with a professional to develop a treatment plan can help many patients improve.

Q: My teenager sometimes acts "sad." Should I be concerned?

A: Everyone gets sad sometimes: a brief "blue mood," disappointments, grief after losing a loved one. But with depression, a person can't just "snap out of it." If the sadness, irritability or loss of interest in usual activities that a son or daughter is experiencing lasts two weeks or more, speak to a healthcare professional to determine if they have a more serious condition.

Q: What are some signs and symptoms of depression in teens that I should be on the lookout for?

A: It is important to keep in mind that symptoms of depression may differ from person to person. Keep an eye out for any signs of persistent sadness, irritability or loss of interest in usual activities in a son or daughter. For example, a teen's performance at school may suddenly decline, or he or she may lose interest in hanging out with friends.

The teenager may also visit the school nurse more often than usual, and they may get more involved in physical fights. Some other symptoms to watch for are sleep problems, appetite changes, general energy loss, concentration problems and hopeless or guilty thoughts.

Q: What can I do if I notice these signs and symptoms, and what would treatment entail?

A: More than 70 percent of children and adolescents with depressive disorder or other serious mood disorders do not receive appropriate diagnosis and treatment. Left untreated, depression in adolescents can have devastating consequences.

If a teenager is experiencing symptoms of depression, speak to a healthcare professional to determine if they have a more serious condition. For adolescents who suffer from depression, talk therapy and medication can play important roles in the management of their illness.

It is important to speak with a healthcare professional about the best approach. A healthcare professional will work with both parent and teen to develop a treatment plan and can also provide information about treatments that have been shown to be effective for depression in adolescents.

This story is provided by State Point Media.