Does Stress Cause Strokes?
There is a fairly commonly held belief that stress is a cause of strokes. In fact the evidence linking the two is far from compelling. The big problem with any attempt to associate stress with illness is the fact that so many variables have to be considered. When, for example, does stress actually begin? We all feel stress but what constitutes the tipping point when stress might trigger a cascade reaction that ultimately leads or contributes to diseases such as cancer, heart disease or stroke?
The link between stress and disease processes is frequently confounded by the fact that the route is indirect. With a broken leg the association is pretty straight forward; usually direct trauma or the action of severe muscular contraction. With stress the situation is very different and far harder to measure. A person under persistent stress may drink more alcohol, smoke, eat less well, exercise less, get less sleep, become depressed and so on. Any one or more of these events could contribute to ill health, but all stem from stress. Isolating the relationship between stress and illness is not easy but quite a lot of progress has been made. A growing body of evidence now points to psychological stress as a contributing to coronary heart disease.
A recent investigation by Katarina Jood, of the Sahlgrenska University Hospital in Sweden, and colleagues from other Institutions in Sweden, found that many patients reported prolonged periods of stress prior to suffering a stroke.
Just under 600 patients were asked to complete a questionnaire no more than 10 days following admission to hospital with a diagnosis of acute cerebral infarction (stroke). Participants were asked how often they had felt stress in the five years previous, using a six choice option from 'never' to 'permanent'. In previous studies a self report of 'permanent' but not 'periodic' stress has been found to predict myocardial infarction (heart attack).
Reporting the findings, the science website ScienceDaily.com, quotes Jood as saying:
"There appears to be a correlation between stress and stroke, but this needs to be interpreted with great caution. A new finding was that the link between stress and stroke varies between different types of cerebral infarction."
It is still not clear why or how stress plays a role in different types of stroke. The authors do however make the observation from other studies that ability to adapt to social adversity, rather than social adversity itself, seems to be associated with the incidence of stroke. Permanent stress may well induce biological responses that contribute to stroke whereas periodic stress or the ability to adapt faster to stress, do not.
There is always a danger that people who suffer from stroke interpret questions about stress as a consequence of their own experience. As the authors concede, the association between stress and stroke may be confounded by other forms of psychological distress.
Slowly but surely we are building a picture. Perhaps one of the next steps is to establish whether specific subcomponents of perceived stress are more significant than others in the link between stress and illness.
University of Gothenburg (2009, October 2). Can Severe Stress Cause Stroke?. ScienceDaily. Retrieved November 9, 2009, from http://www.sciencedaily.com/releases/2009/10/091001101502.htm
Jood, K., Redfors, P., Rosengren, A., Blomstrand, C., Jern, C. (2009) Self-Perceived Psychological Stress and Ischemic Stroke: A Case-Control Study. BMC Medicine 2009, 7:53.