Depression may increase the chances of a stroke

Depression may increase the chances of women having a stroke, research suggests.

A large six-year study found that a history of depression increased the risk of stroke in post-menopausal women by 29 per cent.

Women who used common antidepressants such as Prozac had a 39 per cent higher risk. But scientists said they did not believe the drugs were to blame and urged women not to stop taking their medication.

The 80,574 women were all participants in the Nurses’ Health Study, a major US research project focusing on factors influencing the long-term health of nurses.

All had no prior history of stroke and were aged between 54 and 79.

Researchers assessed depressive symptoms using a standard scoring system called the Mental Health Index.

Anti-depressant use was reported every two years beginning in 1996. For six years from 2000, a record was kept of the number of strokes occurring among the women.

Compared with women without a history of depression, depressed individuals were more likely to be single, smokers, and less physically active.

They were also slightly younger, heavier, and prone to more co-existing conditions such as high blood pressure, heart disease and diabetes.

A significant association between stroke and depression was seen even after adjusting for other risk factors.

The research is published today in the American Heart Association journal Stroke.

“Depression can prevent individuals from controlling other medical problems such as diabetes and hypertension (high blood pressure), from taking medications regularly or pursuing other healthy lifestyle measures such as exercise,” said study leader Kathryn Rextrode, from Brigham and Women’s Hospital in Boston, US.

“All these factors could contribute to increased risk.”

Antidepressant drugs on their own were not thought to be the primary cause of higher stroke risk.

“This study does not suggest that people should stop their medications to reduce the risk of stroke,” added Dr Rextrode.

Co-author An Pan, from Harvard Public School of Health in Boston, said depression could be linked to inflammation, which in turn might increase the risk of stroke and other conditions.

“Regardless of the mechanism, recognising that depressed individuals may be at a higher risk of stroke may help the physician focus on not only treating the depression, but treating stroke risk factors such as hypertension, diabetes and elevated cholesterol as well as addressing lifestyle behaviours such as smoking and exercise,” he said.

The scientists recognised that the study had limitations, including the fact that participants were mainly white registered nurses. Also, the study excluded women without detailed information about depression or those who had experienced stroke at a young age.