Scientific research has identified higher rates of depression among people with certain chronic illnesses, such as heart disease and cerebrovascular disease. There is also evidence to suggest that depression may increase your risk of heart attack, stroke, and death from such incidents. A recent study published in Stroke: Journal of the American Heart Association provides further evidence of this connection and sheds new light on how symptoms of distressed mood may affect risk of fatal stroke.

About the study

Researchers from several universities in the United Kingdom collaborated on this study of 2201 men aged 49 to 64. The study was actually phase II of the Caerphilly study, a large study of cardiovascular risk in men between the ages of 45 and 59 who were recruited from the town of Caerphilly, South Wales, between 1978 and 1983. Phase II was conducted from 1984 to 1988 when the men's ages ranged from 49 to 64.

At the start of the study, each man answered a 30-item General Health Questionnaire (GHQ) designed to classify a person's tendency toward psychological distress—a term that encompasses everything from a full-blown, persistent psychiatric disorder to passing negative moods in response to adversity. In addition, information was collected about medical history, lifestyle, smoking, height, weight, body mass index (BMI), blood pressure, and chest pain.

After 14 years of follow-up, the researchers measured how many men had strokes and compared this information with their scores on the GHQ. They also looked separately at fatal strokes, nonfatal strokes and mini-strokes, called transient ischemic attacks (TIA).

The findings

Men whose GHQ scores showed symptoms of psychological distress were more than three times more likely to die of stroke than men whose scores did not indicate psychological distress. However, distressed men were not significantly more likely than their non-distressed counterparts to suffer a nonfatal stroke or TIA.

The researchers analyzed information on smoking status, BMI, high blood pressure, heavy drinking, social class, and marital status, and found that these common risk factors for stroke did not account for the increased risk found in the distressed men. When they factored chronic disease (including heart disease, diabetes, chronic obstructive airway disease, or retirement due to ill health) into their risk analysis, they found that the risk of fatal stroke associated with psychological distress was reduced slightly from 3.36 to 2.63. This finding implies that having a chronic disease may increase a man's risk of dying of stroke, as well. However, these data still suggest that distressed men are more than 2.5 times as likely to die of stroke than non-distressed men.

There are limitations to this study that should be considered along with the results. First, the study only included men who were between 49 and 64, so the results may not apply to women or people 65 and older. Second, the researchers categorized all types and degrees of psychological distress together, so we're unable to discern what percentage of these men actually had clinical depression or generalized anxiety disorder versus temporary symptoms of distressed mood. Additionally, psychological distress levels were measured at a single point in time (at the start of the study), which does not provide information about distress levels over the 14 years of the study. Finally, psychological distress was measured via a questionnaire rather than through a clinical interview with a psychiatric professional.

How does this affect you?

The findings of this study and others like it have suggested that psychological distress, whether a formally diagnosed mood disorder or simply symptoms of distress, may increase a person's risk of having a stroke. The findings of this particular study suggest that psychological distress may increase a middle-aged or older man's risk of dying from a stroke, but not necessarily of having a nonfatal stroke or TIA. This implies some connection between the distress and the fatality of the stroke.

More studies are needed to examine more specifically how various forms and degrees of psychological distress—ranging from clinical depression or anxiety disorder to short-term distressed moods—relate to risk of fatal stroke. Such studies also should examine this relationship in women and people 65 and older.

Will treatment for depression, anxiety, other mood disorders, or symptoms of distress reduce your risk of dying of stroke? Maybe. But getting help for psychological distress of any kind is a good idea, whether or not it reduces your risk of stroke. In an editorial accompanying this article, doctors Robert Carney and Kenneth Freedland point out that treatment for depression improves physical, emotional and social functioning. They encourage treatment of mood disorders because they are health concerns in their own right and worthy of effective treatment.