Psychological distress could raise risk of stroke death

Doctors are still striving to understand how our mental health impacts our physical health, but this week they may have found another piece to the puzzle. A recent paper published in the Canadian Medical Association Journal (CMAJ) reports that psychological distress could impact our risk of suffering a deadly stroke.

The idea that psychological distress — which can include depression, anxiety and sleep disturbances — is related to cardiovascular health isn’t a new one. Previous studies have shown that these factors are linked to an increased risk for coronary heart disease and that a positive, optimistic outlook can help reduce the risk for heart disease and stroke. However, doctors noticed one area still needed further investigation: the link between psychological distress and cerebrovascular health — especially the risk of suffering a fatal stroke.

To investigate this connection, researchers from University College London examined data from a large study of 68,652 men and women who participated in the Health Survey for England. In addition to considering various factors such as smoking, high blood pressure and income, researchers employed a widely-used measure to gauge psychological distress: the General Health Questionnaire (GHQ-12). Nearly 15 per cent of participants were experiencing psychological distress. Women were more likely than men to be affected, especially if they smoked, were in a lower income group and were taking hypertension medications.

During more than eight years of follow up, there were 2367 deaths from cardiovascular disease among the study’s participants. More specifically, 1010 people died from ischemic heart disease, 562 from cerebrovascular disease and 795 from other cardiovascular-related deaths. When researchers looked at psychological distress as a possible contributing factor, they found that the risk was higher among people who experienced distress than among people who didn’t.

“Psychological distress was associated with death from cardiovascular disease, and the relation remained consistent for specific disease outcomes, including ischemic heart disease and cerebrovascular disease,” writes Dr. Mark Hamer, Department of Epidemiology and Public Health, UCL, with coauthors.

“We saw an association between psychological distress and risk of cerebrovascular disease among our participants, all of whom had been free from cardiovascular disease at baseline,” state the authors. “This association was similar in size to the association between psychological distress and ischemic heart disease in the same group.”

The study did have its limitations, of course. The average age of participants was 54.9 years, 96 per cent were Caucasian and just over half were female. Experts noted that during the course of the study, some older adults had dropped out. The study focussed on people who were living in households, not institutions (such as long-term care facilities). There’s also the possibility that some health issues were never diagnosed.

In other words, the study’s participants aren’t necessarily representative of any country’s population. What’s important is the finding that psychological distress increases the risk of death from stroke, even if we don’t have exact numbers.

How could these findings be useful? The authors note that while more investigation is needed, questionnaires could be a helpful screening tool for mental illness — and could in turn help doctors and patients better understand their risk for cardiovascular disease (including cerebrovascular disease).

“Our data suggest that questionnaires such as the GHQ-12 could be of value in systematic screening aimed at improving the recognition of common mental disorders for reducing the risk of cardiovascular disease,” conclude the authors.

What’s next? Future investigation will need to look at how reducing psychological distress affects cardiovascular disease outcomes, say the authors.

Currently, experts estimate that 15-20 per cent of the population suffers from psychological distress — and we know heart disease and stroke are top causes of death in Canada. There is still a lot that experts don’t know, but future research may find ways to change the odds.

For more information, read the full article in the CMAJ.