If you are a young woman with anxiety problems, watch your heart! A study has found that women under the age of 55 with potential heart problems who also have depression, re twice as likely to have a heart attack, require artery-opening procedures, or even die.
''We can't prove with this study that depression causes heart disease, but we can say that these women do worse over time,'' lead author Dr Amit Shah, from Emory University in Atlanta, said.
In general, depressed people are more likely to have heart problems than people without depression; but the exact increase in risk has varied in previous studies. The authors suspect some of that variation was because the effect of depression might differ in different groups of people.
For their study, the researchers looked at more than 3,000 people who were scheduled for cardiac catheterisation procedures to diagnose coronary artery disease or some other suspected heart problem. Coronary artery disease occurs when plaque builds up in the arteries that supply blood to the heart.
The researchers gave the patients a questionnaire to evaluate their depression symptoms before the procedure. Scoring 10 points or higher out of a possible 27 indicates at least moderate depression.
Two of the researchers examined the results of the catheterisations and noted whether the patients appeared to have coronary artery disease, and if so, how severe it was.
Over the next roughly three years, Shah's team kept tabs on the patients' health with telephone interviews and hospital admission data.
The patients were in their early 60s, on average, and a third were female. The researchers divided patients into three age groups: under 55, 56 to 64 and over 65.
Almost 30 per cent of the women 55 or younger had moderate to severe depression, according to the questionnaires, compared to 9 per cent of men 65 and older.
For the group as a whole, depression was not associated with the chance of coronary artery disease showing up on the heart exams. But when the researchers focused on particular groups of patients, there was a connection in the younger group of women.
For every one-point increase on the 27-point depression scale, their likelihood of having coronary artery disease increased by 7 per cent.
Over the following three years, depression was linked with a higher risk of death and major heart problems. The association was strongest for women age 55 and under and for men 65 and over, the authors report in the Journal of the American Heart Association.
''In that group (of older men) the nature of the relationship is probably a little different than for younger women,'' Shah said. ''The message is more consistent for younger women.''
Younger women are not at particularly high risk for coronary artery disease, he said. But those in this study who were scheduled for a catheterisation had probably had a positive stress test or chest pain, and were at higher risk than other women.
''Their stress responses may be more pathologic,'' he said. ''For example in day to day life as they're coping with their depression they may be more reactive to those depressive symptoms.''
Experiencing trauma or stress may lead to changes in the brain and in turn to changes in the body, he said.
''The young woman who is depressed is at risk for many things, and one of them may be coronary artery disease,'' said Dr Nanette Wenger. ''Probably she should ask her caregiver to check her heart symptoms.''
Wenger is a cardiologist, also at Emory University. She was not part of the new study.
Depression is common among young women, and heart problems tend to be more damaging among depressed women, she said.
''A lot of the concern is why,'' Wenger told Reuters Health. Genetics could be a factor, and so could the poor lifestyle habits that often go along with depression, like smoking and being sedentary, she said.
''There's a very strong heart-brain connection. We've seen it in older women too,'' Wenger said.
Depression should be considered along with smoking and diabetes as a risk factor for heart disease, Shah said.
''They are probably at a higher risk of heart disease from a lifetime perspective. It may not happen in the next five years, but 30 or 40 years down the line,'' he said.
As far as treatment is concerned, most things that are heart-healthy are likely mind-healthy as well, like exercise or a Mediterranean diet, Shah said. But medicines that treat depression so far haven't seemed to lower the risk of heart problems.
Read more: Depression linked to higher heart disease death risk in younger women