Depression is a serious mental health disorder frequently linked to adults in the popular imagination. However, mental health experts are well aware of the existence of depression in teenagers and younger children. According to the results of a study published in 2013 by researchers at the University of Pittsburgh and the Washington University School of Medicine, teens with a history of depression have much higher risks for cardiac-related health problems in later life. These health risks remain in effect even if teenagers no longer have diagnosable depression symptoms. Teen Depression Basics Roughly 11 percent of all teenagers have diagnosable cases of depression, according to findings reported in an ongoing scientific project called the National Comorbidity Survey\u2014Adolescent Supplement or NCS-A. In many respects, the signs and symptoms of teen depression resemble or closely mimic the signs and symptoms of adult depression. For instance, depressed teens and adults commonly experience such things as feelings of sadness, worthlessness or guilt; a diminished ability to think clearly, focus attention or accurately use memory; loss of interest in activities that once brought pleasure; sleeping problems; appetite changes; and a preoccupation with thoughts related to suicide or death. However, the signs and symptoms of teen depression can also differ from the signs and symptoms of adult depression in important ways. For example, depressed teens may have an unusual tendency to do such things as cause disruptions in school, lose interest in academic achievement, make frequent trips to a school nurse, fail to attend school, engage in \u201ccutting\u201d or other forms of self-harm, or make drastic changes in their clothing or general appearance. Common depression factors in teens or younger children include genetic predisposition, the adverse effects of peer pressure, exposure to bullying, the effects of ADHD or other learning disorders, the effects of eating disorders, social isolation, substance abuse, being female and having a gay, lesbian, bisexual, or transgender sexual orientation. Cardiac Health Basics Cardiac health is a general term that describes the relative fitness of any given individual\u2019s everyday heart function. Certain risk factors for poor heart health are unavoidable. Examples of these unavoidable risks include advancing age, male gender, being a post-menopausal female, having a family history of heart problems and having an African-American, Mexican-American, or Native American ethnic or racial background. Other cardiac risk factors are avoidable or controllable. Examples of these factors include smoking cigarettes, leading a sedentary (physically inactive) lifestyle, having uncontrolled high blood pressure or diabetes, having high blood levels of harmful LDL cholesterol, having low blood levels of beneficial HDL cholesterol, having poor stress or anger management skills, having high levels of tissue inflammation, and carrying excessive amounts of body weight. People with poor cardiac health have increased chances of developing serious and potentially deadly problems such as heart disease, strokes and heart attacks. Impact of Teen Depression In the first phase of the study conducted by the University of Pittsburgh and the Washington University School of Medicine, a team of researchers reviewed the findings of a previous study (published in 2004) that examined the genetic roots of depression in a group of more than 450 preteen children. Some of these children had already received a depression diagnosis, while others were the siblings of children diagnosed with depression; a third group of children in the study had no personal or family depression history. In the second phase of their new study, the multi-university research team re-examined the same group of children in 2011. After reviewing the data gathered during the second phase of their study, the researchers concluded that, when compared to teens not clinically depressed as preteens, teenagers who were clinically depressed during their preteen years have significantly increased chances of having cardiac risk factors such as sedentary lifestyles, obesity and habitual involvement in smoking. Critically, these risk factors remain in effect whether or not those children continue to experience depression symptoms during adolescence. When the researchers took steps to statistically eliminate other factors that might potentially account for obesity or involvement in smoking, the influence of depression grew stronger, not weaker. Significance The researchers concluded that any history of depression can worsen the cardiac risk factors that appear in teenagers. As a result of this finding, they also concluded that depression may actually cause an increase in cardiac risks, or alternately, may play a contributing role in combination with other unidentified factors. Interestingly, the siblings of children diagnosed with depression also have increased chances of developing the relevant cardiac risk factors, even though they don\u2019t have a personal history of depression symptoms.