Adolescents with major depression or bipolar disease face an increased risk of early heart disease and may need early intervention to prevent it, according to a scientific statement from the American Heart Association (AHA).

"We expect that the statement itself will come as quite a surprise to most," said Dr. Benjamin I. Goldstein from Sunnybrook Health Sciences Center in Toronto, who chaired the committee that issued the report.

"This is precisely what makes the statement so important and potentially impactful; it takes a largely unrecognized and under-appreciated body of evidence, and positions it squarely on center stage," Goldstein told Reuters Health in an email.

Goldstein and his coauthors say major depression affects nearly 9 per cent of U.S. adolescents. Bipolar disorder, the fourth most disabling condition, affects about 2.6 per cent of U.S. adolescents.

The U.S. National Institute of Mental Health explains on its web site that people with major depression have persistent severe symptoms that interfere with their ability to work, sleep, study, eat, and enjoy life. In bipolar disorder, which is less common, people have mood changes that go back and forth between extreme highs (e.g., mania) to extreme lows (e.g., depression).

In developing the new scientific statement, Goldstein and his colleagues evaluated the existing data at the behest of the AHA's Council on Cardiovascular Disease in the Young.

Although research on the association between these mood disorders and heart disease is limited, what is available shows a significant increase in traditional heart disease risk factors in adolescents with major depression or bipolar disorder, the team reported in the journal Circulation.

These risk factors include obesity, high blood pressure, and unhealthy cholesterol levels.

Childhood maltreatment, sleep disorders, physical inactivity, and smoking — factors common in adolescents with depression and bipolar disorder — can also contribute to an increased heart disease risk.

Even the treatments (antidepressants and mood-stabilizing medications) can cause weight gain and other metabolic changes that increase the risk of heart disease, the statement points out.

Based on the available data, the authors say, these adolescents should be considered to be at moderate risk for early heart disease.

Don't separate mental health & physical health

Prevention efforts should focus on maintaining a healthy weight and blood pressure, healthy levels of cholesterol, and blood sugar in the normal range. The first step in achieving these targets is intensive lifestyle management that emphasizes regular physical activity, a healthy-heart diet, and, if necessary, weight loss.

"When considering cardiovascular risk among youth with mood disorders, screen more and take action earlier and at lower thresholds," Goldstein advised.

Dr. Viola Vaccarino from Rollins School of Public Health at Emory University in Atlanta, who wasn't involved in developing the statement, told Reuters Health, "It is time to end the traditional separation between mental health and physical health. Stigma from mental disorders remains widespread and results in low recognition and management of psychiatric problems outside of mental health clinics. But cardiovascular disease and depression are linked conditions; they both rank highest as causes of disability in the United States, and [are] also rapidly growing worldwide."

"Cardiovascular disease is a chronic, progressive condition that starts in youth, even if the disease becomes clinically manifest later in life," Vaccarino concluded. "This is why identification of risk conditions such as depression early in life provides an important opportunity for cardiovascular disease prevention."