RESUMEN
Abstract Background Major depressive disorder (MDD) is a complex disease and a significant health problem that is prevalent across the world. Angiotensin-converting enzyme (ACE) has an important role in renin-angiotensin system (RAS) and converts inactive angiotensin I to a potent vasopressor and aldosterone-stimulating peptide angiotensin II. Levels of ACE in plasma vary according to the insertion/deletion (I/D) polymorphism of ACE gene. Objective The aim of the current study was to examine the influence ACE gene I/D variations on the risk of MDD. Methods In the present case-control study, we analyzed ACE I/D polymorphism in 346 MDD patients and 210 healthy subjects using polymerase chain reaction technique. Results Comparing the two groups, no significant difference was observed with regard to either genotype distributions or allele frequencies of the I/D polymorphism of ACE gene. Discussion Our findings suggest that the ACE I/D polymorphism is not associated with MDD in Turkish case-control study. Further studies are still needed.