Poorer lifestyle habits may go a long way in explaining why people with depression or anxiety face a higher risk of heart disease and stroke, a study published Monday suggests.

British researchers found that of nearly 6,600 adults they followed for seven years, those who were under significant psychological distress at the outset were more likely to suffer heart problems or a stroke by the study’s end.

When the researchers looked at other factors, they found that lifestyle habits seemed to account for much of the link between distress and cardiovascular disease.

“The participants with psychological distress were more likely to smoke and do little physical activity,” lead researcher Dr. Mark Hamer told Reuters Health.

The findings, he said, suggest that doctors who are treating people for depression or anxiety should also pay attention to their lifestyle habits - and, if necessary, help them with issues like smoking cessation or starting an exercise regimen.

Hamer and his colleagues at the University College London report their findings in the Journal of the American College of Cardiology.

The study included 6,576 healthy men and women who were 51 years old, on average, at the start. All completed a standard questionnaire on lifestyle habits and mental health, including any symptoms of depression or anxiety they’d had over the last month.

The researchers then followed them for an average of seven years to chart cases of heart attack, stroke, heart failure or death from cardiovascular causes.

Overall, Hamer’s team found, the risk of these complications was 54 percent higher among adults who’d been psychologically distressed at the beginning of the study, with age and sex taken into account.

When the researchers examined other factors, they found that lifestyle habits - mainly smoking and lack of exercise - accounted for about two-thirds of the relationship between distress and cardiovascular problems.

In contrast, biological factors such as higher blood pressure and markers of inflammation in the blood vessels accounted for only a small portion of the distress-heart link.

According to Hamer, it’s not clear whether the poorer lifestyle habits were a result of participants’ psychological distress. “People with depression often smoke to help cope with their symptoms,” he noted. “Depression has also been cited as both a cause and consequence of physical inactivity.”

“There is always a chicken-and-egg question of which comes first,” Hamer said.

SOURCE: Journal of the American College of Cardiology, December 16/23, 2008.