Psychological distress, major depressive disorder, and risk of stroke

BACKGROUND: Studies have suggested that mood status is associated with an increased risk of stroke, though mostly based on measures of depression defined by symptoms alone rather than diagnostic criteria representative of clinically important distress and impairment. We investigated this association based upon a large population-based prospective cohort study. METHODS: Baseline assessment of major depressive disorder (MDD) and of mental health well-being (defined by the Mental Health Inventory, MHI-5) was completed by 20,627 stroke-free participants, aged 41 to 80 years, in the United Kingdom European Prospective Investigation into Cancer-Norfolk study. RESULTS: During 8.5 years of follow-up, 595 incident (fatal and nonfatal) stroke endpoints were recorded. Neither past year nor lifetime MDD was associated with stroke. A one SD decrease in MHI-5 scale score (representing greater emotional distress) was associated with an 11% increased risk of stroke after adjustment for age, sex, cigarette smoking, systolic blood pressure, cholesterol, obesity, preexisting myocardial infarction, diabetes, social class, education, hypertension treatment, family history of stroke, and antidepressant medication use (hazard ratio 1.11, 95% CI 1.00 to 1.22). This association was consistent for men and for women, for fatal and nonfatal stroke, and conformed to a dose-response relationship. CONCLUSIONS: Findings from this large prospective cohort study suggest that increased psychological distress is associated with elevated stroke risk. Episodic major depressive disorder was not associated with incident stroke in this study.