Objective-Research suggests that positive psychological well-being is associated with cardiovascular health. However, much of this research uses elderly samples and has not determined the pathways by which psychological well-being influences cardiovascular disease or whether effects are similar for men and women. This study investigates the association between two aspects of well-being (emotional vitality and optimism) and coronary heart disease (CHD) in a sample of middle age men and women, and considers potential mediating factors.Methods-Between 1991 and 1994, well-being and coronary risk factors were assessed among 7,942 individuals without a prior cardiovascular event from the Whitehall II cohort. Incident CHD (fatal CHD, first nonfatal myocardial infarction, or first definite angina) was tracked during 5 person-years of follow-up.Results-Positive psychological well-being was associated with reduced risk of CHD with an apparent threshold effect. Relative to people with the lowest levels of well-being, those with the highest levels had minimally-adjusted hazard ratios of 0.74 (95% confidence interval: 0.55-0.98) for emotional vitality and 0.73 (95% confidence interval: 0.54-0.99) for optimism. Moreover, the association was strong for both genders and was only weakly attenuated when accounting for illbeing. Neither health-related behaviors nor biological factors explained these associations.Conclusions-Positive psychological well-being was associated with a modest but consistent reduced risk of incident CHD. The relationship was comparable for men and women, and was maintained after controlling for cardiovascular risk factors and ill-being. Additional research is needed to identify underlying mechanisms and investigate whether interventions to increase wellbeing may enhance cardiovascular health.Keywords cardiovascular disease; coronary heart disease; well-being; vitality; optimism A growing body of evidence suggests that psychological health may influence physical health. Most of the research to date has focused on psychological ill-being, with less Correspondence and reprint requests to: Dr. J. Boehm, Department of Society, Human Development, and Health, Harvard School of Public Health, 401 Park Drive, Boston, MA 02215; Phone: 617-384-8777; Fax: 617-432-3123; jboehm@hsph.harvard.edu. Publisher's Disclaimer: The following manuscript is the final accepted manuscript. It has not been subjected to the final copyediting, fact-checking, and proofreading required for formal publication. It is not the definitive, publisher-authenticated version. The American Psychological Association and its Council of Editors disclaim any responsibility or liabilities for errors or omissions of this manuscript version, any version derived from this manuscript by NIH, or other third parties. The published version is available at www.apa.org/pubs/journals/hea NIH Public Access research examining whether and how positive psychological well-being influences physical health outcomes. Because psychological ill-being and well-bei...