Depression is linked with a considerably increased risk of developing stroke and stroke-related death as per a study.

The study is published in Journal of the American Medical Association

An Pan, Ph.D., of the Harvard School of Public Health, Boston, and colleagues carried out a systematic review and a meta-analysis of prospective cohort investigations to explain the connection between depression and risk of total and subtypes of stroke.

The new study is the latest in a long line of research linking depression to chronic disease and serious physical health problems

Depression could contribute to strokes in many ways, Pan says. People who are depressed are more likely to smoke or drink heavily, to follow an unhealthy diet, and to neglect their personal health. Most of the studies included in the analysis controlled for these and other risk factors, but the data suggests that at least some of the stroke risk in depressed people can be explained by an unhealthy lifestyle.

“We also knew that depression can occur after patients suffer a stroke. We just didn’t have strong enough evidence to know if the reverse was true, or what really comes first,” said An Pan.

Depression is still a pretty small issue when compared with conditions such as high blood pressure, but it’s a factor. “If you have depression but no other health issues, you probably don’t have to pay too much attention to stroke risk. But if you are depressed and are also obese, or have hypertension or unhealthy lifestyle factors, your risk is going to increase dramatically,” said An Pan.

Depression is associated with changes in substances in the brain that help nerve cells communicate (neurotransmitters), such as serotonin, dopamine and norepinephrine. The levels of these neurotransmitters can be influenced by, among other things, physical illnesses, genetics, hormonal changes, medications, aging, brain injuries, seasonal/light cycle changes, and social circumstances.

When a person has depression, it's more than feeling sad. Intense feelings of sadness and other symptoms, like losing interest in things you enjoy, may last for a while. Depression is a medical illness, not a sign of weakness.

Stroke is the fourth-leading cause of death and a leading cause of disability in the United States.