The C/A‐C/A and A/A‐C/A combined genotypes of the c.803+221C>A—TPH1 and c.‐1449C>A—TPH2 (rs1800532 versus rs7963803) may lead to a development of depression, and the C/A‐C/C combined genotype of the same SNPs combination reduce the risk of developing the disease. This evidence concerns the gene TPH2 and major depressive disorder.