A new meta-analysis of dozens of studies suggests that people with depression suffer a significantly increased risk of either suffering a stroke, or dying from one.
An Pan, Ph.D., of the Harvard School of Public Health, Boston, and colleagues conducted a systematic review and a meta-analysis of studies to describe the association between depression and risk of total and subtypes of stroke.
The researchers identified 28 studies that met criteria for inclusion in their analysis. The studies, which included 317,540 participants, reported 8,478 stroke cases during a follow-up period ranging from 2 to 29 years.
The researchers found that when the data from the studies were pooled, analysis indicated that depression was associated with a 45 percent increased risk for total stroke.
The study also found a 55 percent increased risk for fatal stroke amongst people with depression, as well as a 25 percent increased risk for ischemic stroke.
Depression was not associated with an increased of hemorrhagic stroke.
“Stroke is a leading cause of death and permanent disability, with significant economic losses due to functional impairments,” noted the researchers in the article.
“Depression is highly prevalent in the general population, and it is estimated that 5.8 percent of men and 9.5 percent of women will experience a depressive episode in a 12-month period. The lifetime incidence of depression has been estimated at more than 16 percent in the general population.”
The corresponding absolute risk difference associated with depression based on the most recent stroke statistics for the United States was estimated to be, per 100,000 individuals per year, 106 cases for total stroke, 53 cases for ischemic stroke, and 22 cases for fatal stroke.
The researchers speculate that depression may contribute to stroke through a variety of mechanisms, including having known neuroendocrine (relating to the nervous and endocrine systems) and immunological/inflammation effects, poor health behaviors (i.e., smoking, physical inactivity, poor diet, lack of medication compliance) and obesity.
Depression may contribute to stroke by having other major comorbidities, such as diabetes and hypertension, both of which are major risk factors for stroke, noted the new research.
The use of antidepressant medication use may also be one of the reasons for increased risk of stroke.
“In conclusion, this meta-analysis provides strong evidence that depression is a significant risk factor for stroke,” noted the researchers.
“Given the high prevalence and incidence of depression and stroke in the general population, the observed association between depression and stroke has clinical and public health importance. More studies are needed to explore the underlying mechanisms and elucidate the causal pathways that link depression and stroke.”
The new study appears in the September 21 issue of the Journal of the American Medical Association.