In Reply: Drs Chellappa and Ramaraj raise the interesting hypothesis that elevated homocysteine concentrations may contribute to the excess risk of cardiovascular events associated with depressive symptoms. We measured red blood cell folic acid levels in 1012 participants in the Heart and Soul Study and found that the 198 patients with depressive symptoms (Patient Health Questionnaire score ≥10) had lower mean folic acid levels than the 814 patients without depressive symptoms (578 vs 615 ng/mL [to convert to nmol/L, multiply by 2.266]; t test P = .02). This finding is consistent with the hypothesis that lower folic acid levels (and higher homocysteine concentrations) may be partly responsible for an increased risk of cardiovascular events associated with depressive symptoms.
Whooley MA. Depression, Homocysteine Concentration, and Cardiovascular Events—Reply. JAMA. 2009;301(15):1541-1542. doi:10.1001/jama.2009.491