Psychological Distress Associated with Higher Risk of Stroke
ARTICLE IN BRIEF
In a large epidemiological study, the level of psychological distress was higher in 595 people who had had a stroke and even greater in those — one in four — who subsequently died after the event.
The first hints that patients with depression were at greater risk from dying of heart attack or stroke emerged two decades ago. Then, there were hints that depression might increase the risk for vascular events and that using antidepressants could lower that risk. Now, depression has been peeled away to reveal that psychological distress might itself tip the medical scale to stroke.
And the more distress, the greater the risk. This latest bit of news, reported in the March 4 Neurology, comes from a large epidemiological study of 20,627 healthy people who were followed for up to eight years. They entered the study with no signs of stroke and filled out a lengthy questionnaire that included questions from the Mental Health Inventory (MHI-5), which asks respondents to measure how often they feel nervous; “so down in the dumps that nothing can cheer them up,” calm and peaceful; down-hearted and low; and happy.” They also included Diagnostic and Statistical Manual of Mental Disorders criteria for major depression, as well as assessed their responses to psychosocial events, anxiety; loss of behavioral or emotional control; and psychological well being.
But when psychologist Paul G. Surtees, PhD, of the University of Cambridge and his colleagues compared the responses of those who had a stroke with those who had not, what emerged was rather surprising. The level of psychological distress was higher in those 595 people who had had a stroke and even greater in those — one in four — who died.
But, Dr. Surtees said, unlike the handful of other studies that linked depression to stroke, the measure of major depression was not associated with an increased risk of stroke. His team factored out known stroke risks, including high blood pressure, obesity, previous heart attack, smoking, family history, blood cholesterol, diabetes, and cholesterol problems. They also asked about recent use of antidepressant medication.
Robert G. Robinson, MD, the Paul W. Penningroth Professor of Psychiatry at the University of Iowa, said that this epidemiological study supports what others have been saying: that even mild forms of depression — symptoms that doctors rarely ever ask about in the course of a physical — put people at risk for a stroke.
Dr. Robinson, who was not involved with the current study, said: “The message is that we need to think about and actively treat depression that is relatively mild in nature. There is a perception in medicine that if someone doesn't have a major depression than they don't have a real disorder. This is just not true.”
Dr. Surtees said that the impetus for the study emerged on the heels of an editorial in the journal Stroke calling for studies to clarify the link between depression and stroke. He wanted to know why depression might lead to an increased stroke risk. Study participants were between the ages of 41 and 80. During over eight years of follow-up almost 600 people had a first stroke. When the investigators looked back at that initial questionnaire, which included the Mental Health Inventory called MHI-5, respondents who reported most psychological distress at baseline, had a 40 percent increased risk of stroke more than those who were least psychologically distressed.
The risk was observed in men as well as women and those who died had reported the highest levels of distress up to a decade earlier
In a May 2007 paper in Stroke, the British investigators reported that the capacity to adapt more quickly to social stress is associated with a reduced incidence of stroke, that is, the number of new events per unit time per people at risk. The findings were based on evidence from the reports of over 100,000 actual stressful experiences in people's lives.
Dr. Surtees believes that the association reported in the current study in Neurology between MHI-5 score and stroke could actually be related to a person's ability to cope with stressful experiences. It is not clear from any of these studies exactly how stress or depression results in vascular changes in the body that increases the risk for stroke, he said.
The ages of those in the study, from middle to old age, may make it hard to interpret the findings for younger people. The investigators say that more work is needed to understand just how mood plays into the increased risk for stroke.
ANTIDEPRESSANTS AFTER STROKE
In an October 2003 paper in the American Journal of Psychiatry, Dr. Robinson and colleagues reported that people prescribed antidepressants after a stroke increased their chances of living longer. The study was small; only 100 patients were randomly assigned to take nortriptyline (Aventyl or Pamelor), fluoxetine (Prozac) or placebo for three months following the stroke. Nine years later, the investigators looked up the mortality records to see who had died. Those taking antidepressants not only lived longer but also were more likely to have become more independent after the stroke and had fewer cognitive problems, as measured by the Mini-Mental Status Exam and other neuropsychological tests.
In the mid-1980s, Dr. Robinson and his colleagues began studying the link between depression and stroke. They ultimately found that 40 percent of post-stroke patients had some symptoms of depression.
Depression after a heart attack or stroke is frequent, but doctors still don't know whether depressive symptoms are triggered by an underlying biological event or the result of a psychological response to the medical illness. More research is needed, they say.