A 10-year French study of 7,313 older adults (65+), of whom nearly 30% of the women and 15% of the men had high levels of depressive symptoms, has found that repeated occurrences of depression produced increasing risk of heart disease or stroke. Those who had high levels of depressive symptoms on one, two, three, or four occasions during the study had 15%, 32%, 52%, and 75% greater risk, respectively, of experiencing heart disease or stroke events.
Péquignot, R., Dufouil, C., Prugger, C., Pérès, K., Artero, S., Tzourio, C., & Empana, J.-P. (2016). High Level of Depressive Symptoms at Repeated Study Visits and Risk of Coronary Heart Disease and Stroke over 10 Years in Older Adults: The Three-City Study. Journal of the American Geriatrics Society, 64(1), 118–125. http://doi.org/10.1111/jgs.13872