Considering high prevalence of depressive disorder in ACS and usual measurement for homocysteine in cardiologic unit in practice due to importance of hyperhomocysteinemia as independent risk of ACS [20], plasma homocysteine assays with MTHFR genotyping could be utilized in the acute phase of ACS as screening to identify at-risk groups for depressive disorder at 1 year. The gene discussed is MTHFR; the disease is depressive disorder.