Adolescence can be a difficult time for both young people and their parents. The normal and often-turbulent hormonal, physical and cognitive changes that occur during this stage of development sometimes make it difficult to recognize and diagnose underlying depression in children. Depression in adolescence may also lead to behavioral problems such as irritability or moodiness, fighting, defiance, skipping school, running away, drug use, and poor grades.

One study revealed that 3 to 9 percent of teenagers meet the criteria for depression at any one time. At the end of adolescence, as many as 20 percent of teenagers report a lifetime prevalence of depression. In a recent National Institute of Mental Health (NIMH) study, 1 percent of adolescents (ages 14 to 18) were found to have met criteria for bipolar disorder or cyclothymia in their lifetimes.

Overall, it is estimated that, at any given time, 10 to 15 percent of teenagers suffer with depression, yet it is often written off as normal teenage angst. Usual care by primary care physicians fails to recognize 30-50 percent of depressed patients.

Researchers now think teens with major depression or bipolar disorder are at high risk of early heart and blood vessel disease. For the first time, experts are urging early monitoring and assertive intervention to reduce risk factors for heart and blood vessel disease among these teens.

In the 2011 "Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents," several medical conditions among adolescents were identified that predispose to accelerated atherosclerosis and early cardiovascular disease (CVD).

The declaration recommends that major depression and bipolar mood disorder be considered as independent, moderate risk factors for cardiovascular diseases — a recommendation based on a group of recent scientific studies, including heart attacks and deaths among young people.

For example, a 2011 population study of more than 7,000 U.S. young adults under age 30 revealed that a history of depression or an attempted suicide was the number one risk factor for heart disease death caused by narrowed/clogged arteries in young women and the number four risk factor in young men. Teens with major depression or bipolar disorder are more likely than other teens to have several cardiovascular disease risk factors including:

Young people with mood disorders are not yet widely recognized as a group at increased risk for excessive and early heart disease. Mood disorders are often lifelong conditions, and managing cardiovascular risk early and assertively is important to ensure the next generation of youth has better cardiovascular outcomes.

Researchers hope the guidelines will spur action from patients, families and healthcare providers to reduce the risk of cardiovascular disease.