We found the genotype Met/Met of the Val66Met polymorphism of the brain-derived neurotrophic factor gene was significantly positively associated with depressive disorder, but there were not found any significant associations of both the depressive disorder and metabolic syndrome with the remaining polymorphisms studied (methylenetetrahydrofolate reductase 677CT, methylenetetrahydrofolate reductase 1298AC, endothelial nitric oxide synthase Glu298Asp, and tyrosine hydroxylase).